Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2015 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.android.internal.widget; |
| 18 | |
| 19 | import android.annotation.DrawableRes; |
Alan Viverette | f6d87ec | 2016-03-11 10:09:14 -0500 | [diff] [blame] | 20 | import android.annotation.NonNull; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 21 | import android.content.Context; |
| 22 | import android.content.res.Resources; |
| 23 | import android.content.res.TypedArray; |
| 24 | import android.database.DataSetObserver; |
| 25 | import android.graphics.Canvas; |
| 26 | import android.graphics.Rect; |
| 27 | import android.graphics.drawable.Drawable; |
| 28 | import android.os.Bundle; |
| 29 | import android.os.Parcel; |
| 30 | import android.os.Parcelable; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 31 | import android.util.AttributeSet; |
| 32 | import android.util.Log; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 33 | import android.util.MathUtils; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 34 | import android.view.FocusFinder; |
| 35 | import android.view.Gravity; |
| 36 | import android.view.KeyEvent; |
| 37 | import android.view.MotionEvent; |
| 38 | import android.view.SoundEffectConstants; |
| 39 | import android.view.VelocityTracker; |
| 40 | import android.view.View; |
| 41 | import android.view.ViewConfiguration; |
| 42 | import android.view.ViewGroup; |
| 43 | import android.view.ViewParent; |
| 44 | import android.view.accessibility.AccessibilityEvent; |
| 45 | import android.view.accessibility.AccessibilityNodeInfo; |
Alan Viverette | 34457f5 | 2015-03-25 13:09:20 -0700 | [diff] [blame] | 46 | import android.view.accessibility.AccessibilityNodeInfo.AccessibilityAction; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 47 | import android.view.animation.Interpolator; |
| 48 | import android.widget.EdgeEffect; |
| 49 | import android.widget.Scroller; |
| 50 | |
Maxim Bogatov | ac6ffce | 2015-04-27 13:45:52 -0700 | [diff] [blame] | 51 | import com.android.internal.R; |
| 52 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 53 | import java.util.ArrayList; |
| 54 | import java.util.Collections; |
| 55 | import java.util.Comparator; |
| 56 | |
| 57 | /** |
Alan Viverette | 3c5a1c8 | 2016-05-31 14:00:45 -0400 | [diff] [blame] | 58 | * Framework copy of the support-v4 ViewPager class. |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 59 | */ |
| 60 | public class ViewPager extends ViewGroup { |
| 61 | private static final String TAG = "ViewPager"; |
Alan Viverette | 2ea3292 | 2015-06-26 13:31:50 -0700 | [diff] [blame] | 62 | private static final boolean DEBUG = false; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 63 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 64 | private static final int MAX_SCROLL_X = 2 << 23; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 65 | private static final boolean USE_CACHE = false; |
| 66 | |
| 67 | private static final int DEFAULT_OFFSCREEN_PAGES = 1; |
| 68 | private static final int MAX_SETTLE_DURATION = 600; // ms |
| 69 | private static final int MIN_DISTANCE_FOR_FLING = 25; // dips |
| 70 | |
| 71 | private static final int DEFAULT_GUTTER_SIZE = 16; // dips |
| 72 | |
| 73 | private static final int MIN_FLING_VELOCITY = 400; // dips |
| 74 | |
| 75 | private static final int[] LAYOUT_ATTRS = new int[] { |
| 76 | com.android.internal.R.attr.layout_gravity |
| 77 | }; |
| 78 | |
| 79 | /** |
| 80 | * Used to track what the expected number of items in the adapter should be. |
| 81 | * If the app changes this when we don't expect it, we'll throw a big obnoxious exception. |
| 82 | */ |
| 83 | private int mExpectedAdapterCount; |
| 84 | |
| 85 | static class ItemInfo { |
| 86 | Object object; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 87 | boolean scrolling; |
| 88 | float widthFactor; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 89 | |
| 90 | /** Logical position of the item within the pager adapter. */ |
| 91 | int position; |
| 92 | |
| 93 | /** Offset between the starting edges of the item and its container. */ |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 94 | float offset; |
| 95 | } |
| 96 | |
| 97 | private static final Comparator<ItemInfo> COMPARATOR = new Comparator<ItemInfo>(){ |
| 98 | @Override |
| 99 | public int compare(ItemInfo lhs, ItemInfo rhs) { |
| 100 | return lhs.position - rhs.position; |
| 101 | } |
| 102 | }; |
| 103 | |
| 104 | private static final Interpolator sInterpolator = new Interpolator() { |
| 105 | public float getInterpolation(float t) { |
| 106 | t -= 1.0f; |
| 107 | return t * t * t * t * t + 1.0f; |
| 108 | } |
| 109 | }; |
| 110 | |
| 111 | private final ArrayList<ItemInfo> mItems = new ArrayList<ItemInfo>(); |
| 112 | private final ItemInfo mTempItem = new ItemInfo(); |
| 113 | |
| 114 | private final Rect mTempRect = new Rect(); |
| 115 | |
| 116 | private PagerAdapter mAdapter; |
| 117 | private int mCurItem; // Index of currently displayed page. |
| 118 | private int mRestoredCurItem = -1; |
| 119 | private Parcelable mRestoredAdapterState = null; |
| 120 | private ClassLoader mRestoredClassLoader = null; |
Alan Viverette | 0ef59ac | 2015-03-23 13:13:25 -0700 | [diff] [blame] | 121 | private final Scroller mScroller; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 122 | private PagerObserver mObserver; |
| 123 | |
| 124 | private int mPageMargin; |
| 125 | private Drawable mMarginDrawable; |
| 126 | private int mTopPageBounds; |
| 127 | private int mBottomPageBounds; |
| 128 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 129 | /** |
| 130 | * The increment used to move in the "left" direction. Dependent on layout |
| 131 | * direction. |
| 132 | */ |
| 133 | private int mLeftIncr = -1; |
| 134 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 135 | // Offsets of the first and last items, if known. |
| 136 | // Set during population, used to determine if we are at the beginning |
| 137 | // or end of the pager data set during touch scrolling. |
| 138 | private float mFirstOffset = -Float.MAX_VALUE; |
| 139 | private float mLastOffset = Float.MAX_VALUE; |
| 140 | |
| 141 | private int mChildWidthMeasureSpec; |
| 142 | private int mChildHeightMeasureSpec; |
| 143 | private boolean mInLayout; |
| 144 | |
| 145 | private boolean mScrollingCacheEnabled; |
| 146 | |
| 147 | private boolean mPopulatePending; |
| 148 | private int mOffscreenPageLimit = DEFAULT_OFFSCREEN_PAGES; |
| 149 | |
| 150 | private boolean mIsBeingDragged; |
| 151 | private boolean mIsUnableToDrag; |
Alan Viverette | 0ef59ac | 2015-03-23 13:13:25 -0700 | [diff] [blame] | 152 | private final int mDefaultGutterSize; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 153 | private int mGutterSize; |
Alan Viverette | 0ef59ac | 2015-03-23 13:13:25 -0700 | [diff] [blame] | 154 | private final int mTouchSlop; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 155 | /** |
| 156 | * Position of the last motion event. |
| 157 | */ |
| 158 | private float mLastMotionX; |
| 159 | private float mLastMotionY; |
| 160 | private float mInitialMotionX; |
| 161 | private float mInitialMotionY; |
| 162 | /** |
| 163 | * ID of the active pointer. This is used to retain consistency during |
| 164 | * drags/flings if multiple pointers are used. |
| 165 | */ |
| 166 | private int mActivePointerId = INVALID_POINTER; |
| 167 | /** |
| 168 | * Sentinel value for no current active pointer. |
| 169 | * Used by {@link #mActivePointerId}. |
| 170 | */ |
| 171 | private static final int INVALID_POINTER = -1; |
| 172 | |
| 173 | /** |
| 174 | * Determines speed during touch scrolling |
| 175 | */ |
| 176 | private VelocityTracker mVelocityTracker; |
Alan Viverette | 0ef59ac | 2015-03-23 13:13:25 -0700 | [diff] [blame] | 177 | private final int mMinimumVelocity; |
| 178 | private final int mMaximumVelocity; |
| 179 | private final int mFlingDistance; |
| 180 | private final int mCloseEnough; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 181 | |
| 182 | // If the pager is at least this close to its final position, complete the scroll |
| 183 | // on touch down and let the user interact with the content inside instead of |
| 184 | // "catching" the flinging pager. |
| 185 | private static final int CLOSE_ENOUGH = 2; // dp |
| 186 | |
Alan Viverette | 0ef59ac | 2015-03-23 13:13:25 -0700 | [diff] [blame] | 187 | private final EdgeEffect mLeftEdge; |
| 188 | private final EdgeEffect mRightEdge; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 189 | |
| 190 | private boolean mFirstLayout = true; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 191 | private boolean mCalledSuper; |
| 192 | private int mDecorChildCount; |
| 193 | |
| 194 | private OnPageChangeListener mOnPageChangeListener; |
| 195 | private OnPageChangeListener mInternalPageChangeListener; |
| 196 | private OnAdapterChangeListener mAdapterChangeListener; |
| 197 | private PageTransformer mPageTransformer; |
| 198 | |
| 199 | private static final int DRAW_ORDER_DEFAULT = 0; |
| 200 | private static final int DRAW_ORDER_FORWARD = 1; |
| 201 | private static final int DRAW_ORDER_REVERSE = 2; |
| 202 | private int mDrawingOrder; |
| 203 | private ArrayList<View> mDrawingOrderedChildren; |
| 204 | private static final ViewPositionComparator sPositionComparator = new ViewPositionComparator(); |
| 205 | |
| 206 | /** |
| 207 | * Indicates that the pager is in an idle, settled state. The current page |
| 208 | * is fully in view and no animation is in progress. |
| 209 | */ |
| 210 | public static final int SCROLL_STATE_IDLE = 0; |
| 211 | |
| 212 | /** |
| 213 | * Indicates that the pager is currently being dragged by the user. |
| 214 | */ |
| 215 | public static final int SCROLL_STATE_DRAGGING = 1; |
| 216 | |
| 217 | /** |
| 218 | * Indicates that the pager is in the process of settling to a final position. |
| 219 | */ |
| 220 | public static final int SCROLL_STATE_SETTLING = 2; |
| 221 | |
| 222 | private final Runnable mEndScrollRunnable = new Runnable() { |
| 223 | public void run() { |
| 224 | setScrollState(SCROLL_STATE_IDLE); |
| 225 | populate(); |
| 226 | } |
| 227 | }; |
| 228 | |
| 229 | private int mScrollState = SCROLL_STATE_IDLE; |
| 230 | |
| 231 | /** |
| 232 | * Callback interface for responding to changing state of the selected page. |
| 233 | */ |
| 234 | public interface OnPageChangeListener { |
| 235 | |
| 236 | /** |
| 237 | * This method will be invoked when the current page is scrolled, either as part |
| 238 | * of a programmatically initiated smooth scroll or a user initiated touch scroll. |
| 239 | * |
| 240 | * @param position Position index of the first page currently being displayed. |
| 241 | * Page position+1 will be visible if positionOffset is nonzero. |
| 242 | * @param positionOffset Value from [0, 1) indicating the offset from the page at position. |
| 243 | * @param positionOffsetPixels Value in pixels indicating the offset from position. |
| 244 | */ |
| 245 | public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels); |
| 246 | |
| 247 | /** |
| 248 | * This method will be invoked when a new page becomes selected. Animation is not |
| 249 | * necessarily complete. |
| 250 | * |
| 251 | * @param position Position index of the new selected page. |
| 252 | */ |
| 253 | public void onPageSelected(int position); |
| 254 | |
| 255 | /** |
| 256 | * Called when the scroll state changes. Useful for discovering when the user |
| 257 | * begins dragging, when the pager is automatically settling to the current page, |
| 258 | * or when it is fully stopped/idle. |
| 259 | * |
| 260 | * @param state The new scroll state. |
| 261 | * @see com.android.internal.widget.ViewPager#SCROLL_STATE_IDLE |
| 262 | * @see com.android.internal.widget.ViewPager#SCROLL_STATE_DRAGGING |
| 263 | * @see com.android.internal.widget.ViewPager#SCROLL_STATE_SETTLING |
| 264 | */ |
| 265 | public void onPageScrollStateChanged(int state); |
| 266 | } |
| 267 | |
| 268 | /** |
| 269 | * Simple implementation of the {@link OnPageChangeListener} interface with stub |
| 270 | * implementations of each method. Extend this if you do not intend to override |
| 271 | * every method of {@link OnPageChangeListener}. |
| 272 | */ |
| 273 | public static class SimpleOnPageChangeListener implements OnPageChangeListener { |
| 274 | @Override |
| 275 | public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { |
| 276 | // This space for rent |
| 277 | } |
| 278 | |
| 279 | @Override |
| 280 | public void onPageSelected(int position) { |
| 281 | // This space for rent |
| 282 | } |
| 283 | |
| 284 | @Override |
| 285 | public void onPageScrollStateChanged(int state) { |
| 286 | // This space for rent |
| 287 | } |
| 288 | } |
| 289 | |
| 290 | /** |
| 291 | * A PageTransformer is invoked whenever a visible/attached page is scrolled. |
| 292 | * This offers an opportunity for the application to apply a custom transformation |
| 293 | * to the page views using animation properties. |
| 294 | * |
| 295 | * <p>As property animation is only supported as of Android 3.0 and forward, |
| 296 | * setting a PageTransformer on a ViewPager on earlier platform versions will |
| 297 | * be ignored.</p> |
| 298 | */ |
| 299 | public interface PageTransformer { |
| 300 | /** |
| 301 | * Apply a property transformation to the given page. |
| 302 | * |
| 303 | * @param page Apply the transformation to this page |
| 304 | * @param position Position of page relative to the current front-and-center |
| 305 | * position of the pager. 0 is front and center. 1 is one full |
| 306 | * page position to the right, and -1 is one page position to the left. |
| 307 | */ |
| 308 | public void transformPage(View page, float position); |
| 309 | } |
| 310 | |
| 311 | /** |
| 312 | * Used internally to monitor when adapters are switched. |
| 313 | */ |
| 314 | interface OnAdapterChangeListener { |
| 315 | public void onAdapterChanged(PagerAdapter oldAdapter, PagerAdapter newAdapter); |
| 316 | } |
| 317 | |
| 318 | /** |
| 319 | * Used internally to tag special types of child views that should be added as |
| 320 | * pager decorations by default. |
| 321 | */ |
| 322 | interface Decor {} |
| 323 | |
| 324 | public ViewPager(Context context) { |
Alan Viverette | 0ef59ac | 2015-03-23 13:13:25 -0700 | [diff] [blame] | 325 | this(context, null); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 326 | } |
| 327 | |
| 328 | public ViewPager(Context context, AttributeSet attrs) { |
Alan Viverette | 0ef59ac | 2015-03-23 13:13:25 -0700 | [diff] [blame] | 329 | this(context, attrs, 0); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 330 | } |
| 331 | |
Alan Viverette | 0ef59ac | 2015-03-23 13:13:25 -0700 | [diff] [blame] | 332 | public ViewPager(Context context, AttributeSet attrs, int defStyleAttr) { |
| 333 | this(context, attrs, defStyleAttr, 0); |
| 334 | } |
| 335 | |
| 336 | public ViewPager(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { |
| 337 | super(context, attrs, defStyleAttr, defStyleRes); |
| 338 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 339 | setWillNotDraw(false); |
| 340 | setDescendantFocusability(FOCUS_AFTER_DESCENDANTS); |
| 341 | setFocusable(true); |
Alan Viverette | 0ef59ac | 2015-03-23 13:13:25 -0700 | [diff] [blame] | 342 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 343 | mScroller = new Scroller(context, sInterpolator); |
| 344 | final ViewConfiguration configuration = ViewConfiguration.get(context); |
| 345 | final float density = context.getResources().getDisplayMetrics().density; |
| 346 | |
| 347 | mTouchSlop = configuration.getScaledPagingTouchSlop(); |
| 348 | mMinimumVelocity = (int) (MIN_FLING_VELOCITY * density); |
| 349 | mMaximumVelocity = configuration.getScaledMaximumFlingVelocity(); |
| 350 | mLeftEdge = new EdgeEffect(context); |
| 351 | mRightEdge = new EdgeEffect(context); |
| 352 | |
| 353 | mFlingDistance = (int) (MIN_DISTANCE_FOR_FLING * density); |
| 354 | mCloseEnough = (int) (CLOSE_ENOUGH * density); |
| 355 | mDefaultGutterSize = (int) (DEFAULT_GUTTER_SIZE * density); |
| 356 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 357 | if (getImportantForAccessibility() == IMPORTANT_FOR_ACCESSIBILITY_AUTO) { |
| 358 | setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_YES); |
| 359 | } |
| 360 | } |
| 361 | |
| 362 | @Override |
| 363 | protected void onDetachedFromWindow() { |
| 364 | removeCallbacks(mEndScrollRunnable); |
| 365 | super.onDetachedFromWindow(); |
| 366 | } |
| 367 | |
| 368 | private void setScrollState(int newState) { |
| 369 | if (mScrollState == newState) { |
| 370 | return; |
| 371 | } |
| 372 | |
| 373 | mScrollState = newState; |
| 374 | if (mPageTransformer != null) { |
| 375 | // PageTransformers can do complex things that benefit from hardware layers. |
| 376 | enableLayers(newState != SCROLL_STATE_IDLE); |
| 377 | } |
| 378 | if (mOnPageChangeListener != null) { |
| 379 | mOnPageChangeListener.onPageScrollStateChanged(newState); |
| 380 | } |
| 381 | } |
| 382 | |
| 383 | /** |
| 384 | * Set a PagerAdapter that will supply views for this pager as needed. |
| 385 | * |
| 386 | * @param adapter Adapter to use |
| 387 | */ |
| 388 | public void setAdapter(PagerAdapter adapter) { |
| 389 | if (mAdapter != null) { |
| 390 | mAdapter.unregisterDataSetObserver(mObserver); |
| 391 | mAdapter.startUpdate(this); |
| 392 | for (int i = 0; i < mItems.size(); i++) { |
| 393 | final ItemInfo ii = mItems.get(i); |
| 394 | mAdapter.destroyItem(this, ii.position, ii.object); |
| 395 | } |
| 396 | mAdapter.finishUpdate(this); |
| 397 | mItems.clear(); |
| 398 | removeNonDecorViews(); |
| 399 | mCurItem = 0; |
| 400 | scrollTo(0, 0); |
| 401 | } |
| 402 | |
| 403 | final PagerAdapter oldAdapter = mAdapter; |
| 404 | mAdapter = adapter; |
| 405 | mExpectedAdapterCount = 0; |
| 406 | |
| 407 | if (mAdapter != null) { |
| 408 | if (mObserver == null) { |
| 409 | mObserver = new PagerObserver(); |
| 410 | } |
| 411 | mAdapter.registerDataSetObserver(mObserver); |
| 412 | mPopulatePending = false; |
| 413 | final boolean wasFirstLayout = mFirstLayout; |
| 414 | mFirstLayout = true; |
| 415 | mExpectedAdapterCount = mAdapter.getCount(); |
| 416 | if (mRestoredCurItem >= 0) { |
| 417 | mAdapter.restoreState(mRestoredAdapterState, mRestoredClassLoader); |
| 418 | setCurrentItemInternal(mRestoredCurItem, false, true); |
| 419 | mRestoredCurItem = -1; |
| 420 | mRestoredAdapterState = null; |
| 421 | mRestoredClassLoader = null; |
| 422 | } else if (!wasFirstLayout) { |
| 423 | populate(); |
| 424 | } else { |
| 425 | requestLayout(); |
| 426 | } |
| 427 | } |
| 428 | |
| 429 | if (mAdapterChangeListener != null && oldAdapter != adapter) { |
| 430 | mAdapterChangeListener.onAdapterChanged(oldAdapter, adapter); |
| 431 | } |
| 432 | } |
| 433 | |
| 434 | private void removeNonDecorViews() { |
| 435 | for (int i = 0; i < getChildCount(); i++) { |
| 436 | final View child = getChildAt(i); |
| 437 | final LayoutParams lp = (LayoutParams) child.getLayoutParams(); |
| 438 | if (!lp.isDecor) { |
| 439 | removeViewAt(i); |
| 440 | i--; |
| 441 | } |
| 442 | } |
| 443 | } |
| 444 | |
| 445 | /** |
| 446 | * Retrieve the current adapter supplying pages. |
| 447 | * |
| 448 | * @return The currently registered PagerAdapter |
| 449 | */ |
| 450 | public PagerAdapter getAdapter() { |
| 451 | return mAdapter; |
| 452 | } |
| 453 | |
| 454 | void setOnAdapterChangeListener(OnAdapterChangeListener listener) { |
| 455 | mAdapterChangeListener = listener; |
| 456 | } |
| 457 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 458 | private int getPaddedWidth() { |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 459 | return getMeasuredWidth() - getPaddingLeft() - getPaddingRight(); |
| 460 | } |
| 461 | |
| 462 | /** |
| 463 | * Set the currently selected page. If the ViewPager has already been through its first |
| 464 | * layout with its current adapter there will be a smooth animated transition between |
| 465 | * the current item and the specified item. |
| 466 | * |
| 467 | * @param item Item index to select |
| 468 | */ |
| 469 | public void setCurrentItem(int item) { |
| 470 | mPopulatePending = false; |
| 471 | setCurrentItemInternal(item, !mFirstLayout, false); |
| 472 | } |
| 473 | |
| 474 | /** |
| 475 | * Set the currently selected page. |
| 476 | * |
| 477 | * @param item Item index to select |
| 478 | * @param smoothScroll True to smoothly scroll to the new item, false to transition immediately |
| 479 | */ |
| 480 | public void setCurrentItem(int item, boolean smoothScroll) { |
| 481 | mPopulatePending = false; |
| 482 | setCurrentItemInternal(item, smoothScroll, false); |
| 483 | } |
| 484 | |
| 485 | public int getCurrentItem() { |
| 486 | return mCurItem; |
| 487 | } |
| 488 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 489 | boolean setCurrentItemInternal(int item, boolean smoothScroll, boolean always) { |
| 490 | return setCurrentItemInternal(item, smoothScroll, always, 0); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 491 | } |
| 492 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 493 | boolean setCurrentItemInternal(int item, boolean smoothScroll, boolean always, int velocity) { |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 494 | if (mAdapter == null || mAdapter.getCount() <= 0) { |
| 495 | setScrollingCacheEnabled(false); |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 496 | return false; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 497 | } |
| 498 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 499 | item = MathUtils.constrain(item, 0, mAdapter.getCount() - 1); |
| 500 | if (!always && mCurItem == item && mItems.size() != 0) { |
| 501 | setScrollingCacheEnabled(false); |
| 502 | return false; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 503 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 504 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 505 | final int pageLimit = mOffscreenPageLimit; |
| 506 | if (item > (mCurItem + pageLimit) || item < (mCurItem - pageLimit)) { |
| 507 | // We are doing a jump by more than one page. To avoid |
| 508 | // glitches, we want to keep all current pages in the view |
| 509 | // until the scroll ends. |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 510 | for (int i = 0; i < mItems.size(); i++) { |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 511 | mItems.get(i).scrolling = true; |
| 512 | } |
| 513 | } |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 514 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 515 | final boolean dispatchSelected = mCurItem != item; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 516 | if (mFirstLayout) { |
| 517 | // We don't have any idea how big we are yet and shouldn't have any pages either. |
| 518 | // Just set things up and let the pending layout handle things. |
| 519 | mCurItem = item; |
| 520 | if (dispatchSelected && mOnPageChangeListener != null) { |
| 521 | mOnPageChangeListener.onPageSelected(item); |
| 522 | } |
| 523 | if (dispatchSelected && mInternalPageChangeListener != null) { |
| 524 | mInternalPageChangeListener.onPageSelected(item); |
| 525 | } |
| 526 | requestLayout(); |
| 527 | } else { |
| 528 | populate(item); |
| 529 | scrollToItem(item, smoothScroll, velocity, dispatchSelected); |
| 530 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 531 | |
| 532 | return true; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 533 | } |
| 534 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 535 | private void scrollToItem(int position, boolean smoothScroll, int velocity, |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 536 | boolean dispatchSelected) { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 537 | final int destX = getLeftEdgeForItem(position); |
| 538 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 539 | if (smoothScroll) { |
| 540 | smoothScrollTo(destX, 0, velocity); |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 541 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 542 | if (dispatchSelected && mOnPageChangeListener != null) { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 543 | mOnPageChangeListener.onPageSelected(position); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 544 | } |
| 545 | if (dispatchSelected && mInternalPageChangeListener != null) { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 546 | mInternalPageChangeListener.onPageSelected(position); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 547 | } |
| 548 | } else { |
| 549 | if (dispatchSelected && mOnPageChangeListener != null) { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 550 | mOnPageChangeListener.onPageSelected(position); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 551 | } |
| 552 | if (dispatchSelected && mInternalPageChangeListener != null) { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 553 | mInternalPageChangeListener.onPageSelected(position); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 554 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 555 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 556 | completeScroll(false); |
| 557 | scrollTo(destX, 0); |
| 558 | pageScrolled(destX); |
| 559 | } |
| 560 | } |
| 561 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 562 | private int getLeftEdgeForItem(int position) { |
| 563 | final ItemInfo info = infoForPosition(position); |
| 564 | if (info == null) { |
| 565 | return 0; |
| 566 | } |
| 567 | |
| 568 | final int width = getPaddedWidth(); |
| 569 | final int scaledOffset = (int) (width * MathUtils.constrain( |
| 570 | info.offset, mFirstOffset, mLastOffset)); |
| 571 | |
| 572 | if (isLayoutRtl()) { |
| 573 | final int itemWidth = (int) (width * info.widthFactor + 0.5f); |
| 574 | return MAX_SCROLL_X - itemWidth - scaledOffset; |
| 575 | } else { |
| 576 | return scaledOffset; |
| 577 | } |
| 578 | } |
| 579 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 580 | /** |
| 581 | * Set a listener that will be invoked whenever the page changes or is incrementally |
| 582 | * scrolled. See {@link OnPageChangeListener}. |
| 583 | * |
| 584 | * @param listener Listener to set |
| 585 | */ |
| 586 | public void setOnPageChangeListener(OnPageChangeListener listener) { |
| 587 | mOnPageChangeListener = listener; |
| 588 | } |
| 589 | |
| 590 | /** |
| 591 | * Set a {@link PageTransformer} that will be called for each attached page whenever |
| 592 | * the scroll position is changed. This allows the application to apply custom property |
| 593 | * transformations to each page, overriding the default sliding look and feel. |
| 594 | * |
| 595 | * <p><em>Note:</em> Prior to Android 3.0 the property animation APIs did not exist. |
| 596 | * As a result, setting a PageTransformer prior to Android 3.0 (API 11) will have no effect.</p> |
| 597 | * |
| 598 | * @param reverseDrawingOrder true if the supplied PageTransformer requires page views |
| 599 | * to be drawn from last to first instead of first to last. |
| 600 | * @param transformer PageTransformer that will modify each page's animation properties |
| 601 | */ |
| 602 | public void setPageTransformer(boolean reverseDrawingOrder, PageTransformer transformer) { |
| 603 | final boolean hasTransformer = transformer != null; |
| 604 | final boolean needsPopulate = hasTransformer != (mPageTransformer != null); |
| 605 | mPageTransformer = transformer; |
| 606 | setChildrenDrawingOrderEnabled(hasTransformer); |
| 607 | if (hasTransformer) { |
| 608 | mDrawingOrder = reverseDrawingOrder ? DRAW_ORDER_REVERSE : DRAW_ORDER_FORWARD; |
| 609 | } else { |
| 610 | mDrawingOrder = DRAW_ORDER_DEFAULT; |
| 611 | } |
| 612 | if (needsPopulate) populate(); |
| 613 | } |
| 614 | |
| 615 | @Override |
| 616 | protected int getChildDrawingOrder(int childCount, int i) { |
| 617 | final int index = mDrawingOrder == DRAW_ORDER_REVERSE ? childCount - 1 - i : i; |
| 618 | final int result = ((LayoutParams) mDrawingOrderedChildren.get(index).getLayoutParams()).childIndex; |
| 619 | return result; |
| 620 | } |
| 621 | |
| 622 | /** |
| 623 | * Set a separate OnPageChangeListener for internal use by the support library. |
| 624 | * |
| 625 | * @param listener Listener to set |
| 626 | * @return The old listener that was set, if any. |
| 627 | */ |
| 628 | OnPageChangeListener setInternalPageChangeListener(OnPageChangeListener listener) { |
| 629 | OnPageChangeListener oldListener = mInternalPageChangeListener; |
| 630 | mInternalPageChangeListener = listener; |
| 631 | return oldListener; |
| 632 | } |
| 633 | |
| 634 | /** |
| 635 | * Returns the number of pages that will be retained to either side of the |
| 636 | * current page in the view hierarchy in an idle state. Defaults to 1. |
| 637 | * |
| 638 | * @return How many pages will be kept offscreen on either side |
| 639 | * @see #setOffscreenPageLimit(int) |
| 640 | */ |
| 641 | public int getOffscreenPageLimit() { |
| 642 | return mOffscreenPageLimit; |
| 643 | } |
| 644 | |
| 645 | /** |
| 646 | * Set the number of pages that should be retained to either side of the |
| 647 | * current page in the view hierarchy in an idle state. Pages beyond this |
| 648 | * limit will be recreated from the adapter when needed. |
| 649 | * |
| 650 | * <p>This is offered as an optimization. If you know in advance the number |
| 651 | * of pages you will need to support or have lazy-loading mechanisms in place |
| 652 | * on your pages, tweaking this setting can have benefits in perceived smoothness |
| 653 | * of paging animations and interaction. If you have a small number of pages (3-4) |
| 654 | * that you can keep active all at once, less time will be spent in layout for |
| 655 | * newly created view subtrees as the user pages back and forth.</p> |
| 656 | * |
| 657 | * <p>You should keep this limit low, especially if your pages have complex layouts. |
| 658 | * This setting defaults to 1.</p> |
| 659 | * |
| 660 | * @param limit How many pages will be kept offscreen in an idle state. |
| 661 | */ |
| 662 | public void setOffscreenPageLimit(int limit) { |
| 663 | if (limit < DEFAULT_OFFSCREEN_PAGES) { |
| 664 | Log.w(TAG, "Requested offscreen page limit " + limit + " too small; defaulting to " + |
| 665 | DEFAULT_OFFSCREEN_PAGES); |
| 666 | limit = DEFAULT_OFFSCREEN_PAGES; |
| 667 | } |
| 668 | if (limit != mOffscreenPageLimit) { |
| 669 | mOffscreenPageLimit = limit; |
| 670 | populate(); |
| 671 | } |
| 672 | } |
| 673 | |
| 674 | /** |
| 675 | * Set the margin between pages. |
| 676 | * |
| 677 | * @param marginPixels Distance between adjacent pages in pixels |
| 678 | * @see #getPageMargin() |
| 679 | * @see #setPageMarginDrawable(android.graphics.drawable.Drawable) |
| 680 | * @see #setPageMarginDrawable(int) |
| 681 | */ |
| 682 | public void setPageMargin(int marginPixels) { |
| 683 | final int oldMargin = mPageMargin; |
| 684 | mPageMargin = marginPixels; |
| 685 | |
| 686 | final int width = getWidth(); |
| 687 | recomputeScrollPosition(width, width, marginPixels, oldMargin); |
| 688 | |
| 689 | requestLayout(); |
| 690 | } |
| 691 | |
| 692 | /** |
| 693 | * Return the margin between pages. |
| 694 | * |
| 695 | * @return The size of the margin in pixels |
| 696 | */ |
| 697 | public int getPageMargin() { |
| 698 | return mPageMargin; |
| 699 | } |
| 700 | |
| 701 | /** |
| 702 | * Set a drawable that will be used to fill the margin between pages. |
| 703 | * |
| 704 | * @param d Drawable to display between pages |
| 705 | */ |
| 706 | public void setPageMarginDrawable(Drawable d) { |
| 707 | mMarginDrawable = d; |
| 708 | if (d != null) refreshDrawableState(); |
| 709 | setWillNotDraw(d == null); |
| 710 | invalidate(); |
| 711 | } |
| 712 | |
| 713 | /** |
| 714 | * Set a drawable that will be used to fill the margin between pages. |
| 715 | * |
| 716 | * @param resId Resource ID of a drawable to display between pages |
| 717 | */ |
| 718 | public void setPageMarginDrawable(@DrawableRes int resId) { |
| 719 | setPageMarginDrawable(getContext().getDrawable(resId)); |
| 720 | } |
| 721 | |
| 722 | @Override |
Alan Viverette | f6d87ec | 2016-03-11 10:09:14 -0500 | [diff] [blame] | 723 | protected boolean verifyDrawable(@NonNull Drawable who) { |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 724 | return super.verifyDrawable(who) || who == mMarginDrawable; |
| 725 | } |
| 726 | |
| 727 | @Override |
| 728 | protected void drawableStateChanged() { |
| 729 | super.drawableStateChanged(); |
Alan Viverette | ad0020f | 2015-09-04 10:10:42 -0400 | [diff] [blame] | 730 | final Drawable marginDrawable = mMarginDrawable; |
| 731 | if (marginDrawable != null && marginDrawable.isStateful() |
| 732 | && marginDrawable.setState(getDrawableState())) { |
| 733 | invalidateDrawable(marginDrawable); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 734 | } |
| 735 | } |
| 736 | |
| 737 | // We want the duration of the page snap animation to be influenced by the distance that |
| 738 | // the screen has to travel, however, we don't want this duration to be effected in a |
| 739 | // purely linear fashion. Instead, we use this method to moderate the effect that the distance |
| 740 | // of travel has on the overall snap duration. |
| 741 | float distanceInfluenceForSnapDuration(float f) { |
| 742 | f -= 0.5f; // center the values about 0. |
| 743 | f *= 0.3f * Math.PI / 2.0f; |
| 744 | return (float) Math.sin(f); |
| 745 | } |
| 746 | |
| 747 | /** |
| 748 | * Like {@link android.view.View#scrollBy}, but scroll smoothly instead of immediately. |
| 749 | * |
| 750 | * @param x the number of pixels to scroll by on the X axis |
| 751 | * @param y the number of pixels to scroll by on the Y axis |
| 752 | */ |
| 753 | void smoothScrollTo(int x, int y) { |
| 754 | smoothScrollTo(x, y, 0); |
| 755 | } |
| 756 | |
| 757 | /** |
| 758 | * Like {@link android.view.View#scrollBy}, but scroll smoothly instead of immediately. |
| 759 | * |
| 760 | * @param x the number of pixels to scroll by on the X axis |
| 761 | * @param y the number of pixels to scroll by on the Y axis |
| 762 | * @param velocity the velocity associated with a fling, if applicable. (0 otherwise) |
| 763 | */ |
| 764 | void smoothScrollTo(int x, int y, int velocity) { |
| 765 | if (getChildCount() == 0) { |
| 766 | // Nothing to do. |
| 767 | setScrollingCacheEnabled(false); |
| 768 | return; |
| 769 | } |
| 770 | int sx = getScrollX(); |
| 771 | int sy = getScrollY(); |
| 772 | int dx = x - sx; |
| 773 | int dy = y - sy; |
| 774 | if (dx == 0 && dy == 0) { |
| 775 | completeScroll(false); |
| 776 | populate(); |
| 777 | setScrollState(SCROLL_STATE_IDLE); |
| 778 | return; |
| 779 | } |
| 780 | |
| 781 | setScrollingCacheEnabled(true); |
| 782 | setScrollState(SCROLL_STATE_SETTLING); |
| 783 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 784 | final int width = getPaddedWidth(); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 785 | final int halfWidth = width / 2; |
| 786 | final float distanceRatio = Math.min(1f, 1.0f * Math.abs(dx) / width); |
| 787 | final float distance = halfWidth + halfWidth * |
| 788 | distanceInfluenceForSnapDuration(distanceRatio); |
| 789 | |
| 790 | int duration = 0; |
| 791 | velocity = Math.abs(velocity); |
| 792 | if (velocity > 0) { |
| 793 | duration = 4 * Math.round(1000 * Math.abs(distance / velocity)); |
| 794 | } else { |
| 795 | final float pageWidth = width * mAdapter.getPageWidth(mCurItem); |
| 796 | final float pageDelta = (float) Math.abs(dx) / (pageWidth + mPageMargin); |
| 797 | duration = (int) ((pageDelta + 1) * 100); |
| 798 | } |
| 799 | duration = Math.min(duration, MAX_SETTLE_DURATION); |
| 800 | |
| 801 | mScroller.startScroll(sx, sy, dx, dy, duration); |
| 802 | postInvalidateOnAnimation(); |
| 803 | } |
| 804 | |
| 805 | ItemInfo addNewItem(int position, int index) { |
| 806 | ItemInfo ii = new ItemInfo(); |
| 807 | ii.position = position; |
| 808 | ii.object = mAdapter.instantiateItem(this, position); |
| 809 | ii.widthFactor = mAdapter.getPageWidth(position); |
| 810 | if (index < 0 || index >= mItems.size()) { |
| 811 | mItems.add(ii); |
| 812 | } else { |
| 813 | mItems.add(index, ii); |
| 814 | } |
| 815 | return ii; |
| 816 | } |
| 817 | |
| 818 | void dataSetChanged() { |
| 819 | // This method only gets called if our observer is attached, so mAdapter is non-null. |
| 820 | |
| 821 | final int adapterCount = mAdapter.getCount(); |
| 822 | mExpectedAdapterCount = adapterCount; |
| 823 | boolean needPopulate = mItems.size() < mOffscreenPageLimit * 2 + 1 && |
| 824 | mItems.size() < adapterCount; |
| 825 | int newCurrItem = mCurItem; |
| 826 | |
| 827 | boolean isUpdating = false; |
| 828 | for (int i = 0; i < mItems.size(); i++) { |
| 829 | final ItemInfo ii = mItems.get(i); |
| 830 | final int newPos = mAdapter.getItemPosition(ii.object); |
| 831 | |
| 832 | if (newPos == PagerAdapter.POSITION_UNCHANGED) { |
| 833 | continue; |
| 834 | } |
| 835 | |
| 836 | if (newPos == PagerAdapter.POSITION_NONE) { |
| 837 | mItems.remove(i); |
| 838 | i--; |
| 839 | |
| 840 | if (!isUpdating) { |
| 841 | mAdapter.startUpdate(this); |
| 842 | isUpdating = true; |
| 843 | } |
| 844 | |
| 845 | mAdapter.destroyItem(this, ii.position, ii.object); |
| 846 | needPopulate = true; |
| 847 | |
| 848 | if (mCurItem == ii.position) { |
| 849 | // Keep the current item in the valid range |
| 850 | newCurrItem = Math.max(0, Math.min(mCurItem, adapterCount - 1)); |
| 851 | needPopulate = true; |
| 852 | } |
| 853 | continue; |
| 854 | } |
| 855 | |
| 856 | if (ii.position != newPos) { |
| 857 | if (ii.position == mCurItem) { |
| 858 | // Our current item changed position. Follow it. |
| 859 | newCurrItem = newPos; |
| 860 | } |
| 861 | |
| 862 | ii.position = newPos; |
| 863 | needPopulate = true; |
| 864 | } |
| 865 | } |
| 866 | |
| 867 | if (isUpdating) { |
| 868 | mAdapter.finishUpdate(this); |
| 869 | } |
| 870 | |
| 871 | Collections.sort(mItems, COMPARATOR); |
| 872 | |
| 873 | if (needPopulate) { |
| 874 | // Reset our known page widths; populate will recompute them. |
| 875 | final int childCount = getChildCount(); |
| 876 | for (int i = 0; i < childCount; i++) { |
| 877 | final View child = getChildAt(i); |
| 878 | final LayoutParams lp = (LayoutParams) child.getLayoutParams(); |
| 879 | if (!lp.isDecor) { |
| 880 | lp.widthFactor = 0.f; |
| 881 | } |
| 882 | } |
| 883 | |
| 884 | setCurrentItemInternal(newCurrItem, false, true); |
| 885 | requestLayout(); |
| 886 | } |
| 887 | } |
| 888 | |
Alan Viverette | 816aa14 | 2015-04-10 15:41:10 -0700 | [diff] [blame] | 889 | public void populate() { |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 890 | populate(mCurItem); |
| 891 | } |
| 892 | |
| 893 | void populate(int newCurrentItem) { |
| 894 | ItemInfo oldCurInfo = null; |
| 895 | int focusDirection = View.FOCUS_FORWARD; |
| 896 | if (mCurItem != newCurrentItem) { |
| 897 | focusDirection = mCurItem < newCurrentItem ? View.FOCUS_RIGHT : View.FOCUS_LEFT; |
| 898 | oldCurInfo = infoForPosition(mCurItem); |
| 899 | mCurItem = newCurrentItem; |
| 900 | } |
| 901 | |
| 902 | if (mAdapter == null) { |
| 903 | sortChildDrawingOrder(); |
| 904 | return; |
| 905 | } |
| 906 | |
| 907 | // Bail now if we are waiting to populate. This is to hold off |
| 908 | // on creating views from the time the user releases their finger to |
| 909 | // fling to a new position until we have finished the scroll to |
| 910 | // that position, avoiding glitches from happening at that point. |
| 911 | if (mPopulatePending) { |
| 912 | if (DEBUG) Log.i(TAG, "populate is pending, skipping for now..."); |
| 913 | sortChildDrawingOrder(); |
| 914 | return; |
| 915 | } |
| 916 | |
| 917 | // Also, don't populate until we are attached to a window. This is to |
| 918 | // avoid trying to populate before we have restored our view hierarchy |
| 919 | // state and conflicting with what is restored. |
| 920 | if (getWindowToken() == null) { |
| 921 | return; |
| 922 | } |
| 923 | |
| 924 | mAdapter.startUpdate(this); |
| 925 | |
| 926 | final int pageLimit = mOffscreenPageLimit; |
| 927 | final int startPos = Math.max(0, mCurItem - pageLimit); |
| 928 | final int N = mAdapter.getCount(); |
| 929 | final int endPos = Math.min(N-1, mCurItem + pageLimit); |
| 930 | |
| 931 | if (N != mExpectedAdapterCount) { |
| 932 | String resName; |
| 933 | try { |
| 934 | resName = getResources().getResourceName(getId()); |
| 935 | } catch (Resources.NotFoundException e) { |
| 936 | resName = Integer.toHexString(getId()); |
| 937 | } |
| 938 | throw new IllegalStateException("The application's PagerAdapter changed the adapter's" + |
| 939 | " contents without calling PagerAdapter#notifyDataSetChanged!" + |
| 940 | " Expected adapter item count: " + mExpectedAdapterCount + ", found: " + N + |
| 941 | " Pager id: " + resName + |
| 942 | " Pager class: " + getClass() + |
| 943 | " Problematic adapter: " + mAdapter.getClass()); |
| 944 | } |
| 945 | |
| 946 | // Locate the currently focused item or add it if needed. |
| 947 | int curIndex = -1; |
| 948 | ItemInfo curItem = null; |
| 949 | for (curIndex = 0; curIndex < mItems.size(); curIndex++) { |
| 950 | final ItemInfo ii = mItems.get(curIndex); |
| 951 | if (ii.position >= mCurItem) { |
| 952 | if (ii.position == mCurItem) curItem = ii; |
| 953 | break; |
| 954 | } |
| 955 | } |
| 956 | |
| 957 | if (curItem == null && N > 0) { |
| 958 | curItem = addNewItem(mCurItem, curIndex); |
| 959 | } |
| 960 | |
| 961 | // Fill 3x the available width or up to the number of offscreen |
| 962 | // pages requested to either side, whichever is larger. |
| 963 | // If we have no current item we have no work to do. |
| 964 | if (curItem != null) { |
| 965 | float extraWidthLeft = 0.f; |
| 966 | int itemIndex = curIndex - 1; |
| 967 | ItemInfo ii = itemIndex >= 0 ? mItems.get(itemIndex) : null; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 968 | final int clientWidth = getPaddedWidth(); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 969 | final float leftWidthNeeded = clientWidth <= 0 ? 0 : |
| 970 | 2.f - curItem.widthFactor + (float) getPaddingLeft() / (float) clientWidth; |
| 971 | for (int pos = mCurItem - 1; pos >= 0; pos--) { |
| 972 | if (extraWidthLeft >= leftWidthNeeded && pos < startPos) { |
| 973 | if (ii == null) { |
| 974 | break; |
| 975 | } |
| 976 | if (pos == ii.position && !ii.scrolling) { |
| 977 | mItems.remove(itemIndex); |
| 978 | mAdapter.destroyItem(this, pos, ii.object); |
| 979 | if (DEBUG) { |
| 980 | Log.i(TAG, "populate() - destroyItem() with pos: " + pos + |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 981 | " view: " + ii.object); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 982 | } |
| 983 | itemIndex--; |
| 984 | curIndex--; |
| 985 | ii = itemIndex >= 0 ? mItems.get(itemIndex) : null; |
| 986 | } |
| 987 | } else if (ii != null && pos == ii.position) { |
| 988 | extraWidthLeft += ii.widthFactor; |
| 989 | itemIndex--; |
| 990 | ii = itemIndex >= 0 ? mItems.get(itemIndex) : null; |
| 991 | } else { |
| 992 | ii = addNewItem(pos, itemIndex + 1); |
| 993 | extraWidthLeft += ii.widthFactor; |
| 994 | curIndex++; |
| 995 | ii = itemIndex >= 0 ? mItems.get(itemIndex) : null; |
| 996 | } |
| 997 | } |
| 998 | |
| 999 | float extraWidthRight = curItem.widthFactor; |
| 1000 | itemIndex = curIndex + 1; |
| 1001 | if (extraWidthRight < 2.f) { |
| 1002 | ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null; |
| 1003 | final float rightWidthNeeded = clientWidth <= 0 ? 0 : |
| 1004 | (float) getPaddingRight() / (float) clientWidth + 2.f; |
| 1005 | for (int pos = mCurItem + 1; pos < N; pos++) { |
| 1006 | if (extraWidthRight >= rightWidthNeeded && pos > endPos) { |
| 1007 | if (ii == null) { |
| 1008 | break; |
| 1009 | } |
| 1010 | if (pos == ii.position && !ii.scrolling) { |
| 1011 | mItems.remove(itemIndex); |
| 1012 | mAdapter.destroyItem(this, pos, ii.object); |
| 1013 | if (DEBUG) { |
| 1014 | Log.i(TAG, "populate() - destroyItem() with pos: " + pos + |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1015 | " view: " + ii.object); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1016 | } |
| 1017 | ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null; |
| 1018 | } |
| 1019 | } else if (ii != null && pos == ii.position) { |
| 1020 | extraWidthRight += ii.widthFactor; |
| 1021 | itemIndex++; |
| 1022 | ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null; |
| 1023 | } else { |
| 1024 | ii = addNewItem(pos, itemIndex); |
| 1025 | itemIndex++; |
| 1026 | extraWidthRight += ii.widthFactor; |
| 1027 | ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null; |
| 1028 | } |
| 1029 | } |
| 1030 | } |
| 1031 | |
| 1032 | calculatePageOffsets(curItem, curIndex, oldCurInfo); |
| 1033 | } |
| 1034 | |
| 1035 | if (DEBUG) { |
| 1036 | Log.i(TAG, "Current page list:"); |
| 1037 | for (int i=0; i<mItems.size(); i++) { |
| 1038 | Log.i(TAG, "#" + i + ": page " + mItems.get(i).position); |
| 1039 | } |
| 1040 | } |
| 1041 | |
| 1042 | mAdapter.setPrimaryItem(this, mCurItem, curItem != null ? curItem.object : null); |
| 1043 | |
| 1044 | mAdapter.finishUpdate(this); |
| 1045 | |
| 1046 | // Check width measurement of current pages and drawing sort order. |
| 1047 | // Update LayoutParams as needed. |
| 1048 | final int childCount = getChildCount(); |
| 1049 | for (int i = 0; i < childCount; i++) { |
| 1050 | final View child = getChildAt(i); |
| 1051 | final LayoutParams lp = (LayoutParams) child.getLayoutParams(); |
| 1052 | lp.childIndex = i; |
| 1053 | if (!lp.isDecor && lp.widthFactor == 0.f) { |
| 1054 | // 0 means requery the adapter for this, it doesn't have a valid width. |
| 1055 | final ItemInfo ii = infoForChild(child); |
| 1056 | if (ii != null) { |
| 1057 | lp.widthFactor = ii.widthFactor; |
| 1058 | lp.position = ii.position; |
| 1059 | } |
| 1060 | } |
| 1061 | } |
| 1062 | sortChildDrawingOrder(); |
| 1063 | |
| 1064 | if (hasFocus()) { |
| 1065 | View currentFocused = findFocus(); |
| 1066 | ItemInfo ii = currentFocused != null ? infoForAnyChild(currentFocused) : null; |
| 1067 | if (ii == null || ii.position != mCurItem) { |
| 1068 | for (int i=0; i<getChildCount(); i++) { |
| 1069 | View child = getChildAt(i); |
| 1070 | ii = infoForChild(child); |
| 1071 | if (ii != null && ii.position == mCurItem) { |
George Mount | e998c3f | 2015-10-27 08:46:44 -0700 | [diff] [blame] | 1072 | final Rect focusRect; |
| 1073 | if (currentFocused == null) { |
| 1074 | focusRect = null; |
| 1075 | } else { |
| 1076 | focusRect = mTempRect; |
| 1077 | currentFocused.getFocusedRect(mTempRect); |
| 1078 | offsetDescendantRectToMyCoords(currentFocused, mTempRect); |
| 1079 | offsetRectIntoDescendantCoords(child, mTempRect); |
| 1080 | } |
| 1081 | if (child.requestFocus(focusDirection, focusRect)) { |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1082 | break; |
| 1083 | } |
| 1084 | } |
| 1085 | } |
| 1086 | } |
| 1087 | } |
| 1088 | } |
| 1089 | |
| 1090 | private void sortChildDrawingOrder() { |
| 1091 | if (mDrawingOrder != DRAW_ORDER_DEFAULT) { |
| 1092 | if (mDrawingOrderedChildren == null) { |
| 1093 | mDrawingOrderedChildren = new ArrayList<View>(); |
| 1094 | } else { |
| 1095 | mDrawingOrderedChildren.clear(); |
| 1096 | } |
| 1097 | final int childCount = getChildCount(); |
| 1098 | for (int i = 0; i < childCount; i++) { |
| 1099 | final View child = getChildAt(i); |
| 1100 | mDrawingOrderedChildren.add(child); |
| 1101 | } |
| 1102 | Collections.sort(mDrawingOrderedChildren, sPositionComparator); |
| 1103 | } |
| 1104 | } |
| 1105 | |
| 1106 | private void calculatePageOffsets(ItemInfo curItem, int curIndex, ItemInfo oldCurInfo) { |
| 1107 | final int N = mAdapter.getCount(); |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1108 | final int width = getPaddedWidth(); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1109 | final float marginOffset = width > 0 ? (float) mPageMargin / width : 0; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1110 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1111 | // Fix up offsets for later layout. |
| 1112 | if (oldCurInfo != null) { |
| 1113 | final int oldCurPosition = oldCurInfo.position; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1114 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1115 | // Base offsets off of oldCurInfo. |
| 1116 | if (oldCurPosition < curItem.position) { |
| 1117 | int itemIndex = 0; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1118 | float offset = oldCurInfo.offset + oldCurInfo.widthFactor + marginOffset; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1119 | for (int pos = oldCurPosition + 1; pos <= curItem.position && itemIndex < mItems.size(); pos++) { |
| 1120 | ItemInfo ii = mItems.get(itemIndex); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1121 | while (pos > ii.position && itemIndex < mItems.size() - 1) { |
| 1122 | itemIndex++; |
| 1123 | ii = mItems.get(itemIndex); |
| 1124 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1125 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1126 | while (pos < ii.position) { |
| 1127 | // We don't have an item populated for this, |
| 1128 | // ask the adapter for an offset. |
| 1129 | offset += mAdapter.getPageWidth(pos) + marginOffset; |
| 1130 | pos++; |
| 1131 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1132 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1133 | ii.offset = offset; |
| 1134 | offset += ii.widthFactor + marginOffset; |
| 1135 | } |
| 1136 | } else if (oldCurPosition > curItem.position) { |
| 1137 | int itemIndex = mItems.size() - 1; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1138 | float offset = oldCurInfo.offset; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1139 | for (int pos = oldCurPosition - 1; pos >= curItem.position && itemIndex >= 0; pos--) { |
| 1140 | ItemInfo ii = mItems.get(itemIndex); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1141 | while (pos < ii.position && itemIndex > 0) { |
| 1142 | itemIndex--; |
| 1143 | ii = mItems.get(itemIndex); |
| 1144 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1145 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1146 | while (pos > ii.position) { |
| 1147 | // We don't have an item populated for this, |
| 1148 | // ask the adapter for an offset. |
| 1149 | offset -= mAdapter.getPageWidth(pos) + marginOffset; |
| 1150 | pos--; |
| 1151 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1152 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1153 | offset -= ii.widthFactor + marginOffset; |
| 1154 | ii.offset = offset; |
| 1155 | } |
| 1156 | } |
| 1157 | } |
| 1158 | |
| 1159 | // Base all offsets off of curItem. |
| 1160 | final int itemCount = mItems.size(); |
| 1161 | float offset = curItem.offset; |
| 1162 | int pos = curItem.position - 1; |
| 1163 | mFirstOffset = curItem.position == 0 ? curItem.offset : -Float.MAX_VALUE; |
| 1164 | mLastOffset = curItem.position == N - 1 ? |
| 1165 | curItem.offset + curItem.widthFactor - 1 : Float.MAX_VALUE; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1166 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1167 | // Previous pages |
| 1168 | for (int i = curIndex - 1; i >= 0; i--, pos--) { |
| 1169 | final ItemInfo ii = mItems.get(i); |
| 1170 | while (pos > ii.position) { |
| 1171 | offset -= mAdapter.getPageWidth(pos--) + marginOffset; |
| 1172 | } |
| 1173 | offset -= ii.widthFactor + marginOffset; |
| 1174 | ii.offset = offset; |
| 1175 | if (ii.position == 0) mFirstOffset = offset; |
| 1176 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1177 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1178 | offset = curItem.offset + curItem.widthFactor + marginOffset; |
| 1179 | pos = curItem.position + 1; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1180 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1181 | // Next pages |
| 1182 | for (int i = curIndex + 1; i < itemCount; i++, pos++) { |
| 1183 | final ItemInfo ii = mItems.get(i); |
| 1184 | while (pos < ii.position) { |
| 1185 | offset += mAdapter.getPageWidth(pos++) + marginOffset; |
| 1186 | } |
| 1187 | if (ii.position == N - 1) { |
| 1188 | mLastOffset = offset + ii.widthFactor - 1; |
| 1189 | } |
| 1190 | ii.offset = offset; |
| 1191 | offset += ii.widthFactor + marginOffset; |
| 1192 | } |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1193 | } |
| 1194 | |
| 1195 | /** |
| 1196 | * This is the persistent state that is saved by ViewPager. Only needed |
| 1197 | * if you are creating a sublass of ViewPager that must save its own |
| 1198 | * state, in which case it should implement a subclass of this which |
| 1199 | * contains that state. |
| 1200 | */ |
| 1201 | public static class SavedState extends BaseSavedState { |
| 1202 | int position; |
| 1203 | Parcelable adapterState; |
| 1204 | ClassLoader loader; |
| 1205 | |
| 1206 | public SavedState(Parcel source) { |
| 1207 | super(source); |
| 1208 | } |
| 1209 | |
| 1210 | public SavedState(Parcelable superState) { |
| 1211 | super(superState); |
| 1212 | } |
| 1213 | |
| 1214 | @Override |
| 1215 | public void writeToParcel(Parcel out, int flags) { |
| 1216 | super.writeToParcel(out, flags); |
| 1217 | out.writeInt(position); |
| 1218 | out.writeParcelable(adapterState, flags); |
| 1219 | } |
| 1220 | |
| 1221 | @Override |
| 1222 | public String toString() { |
| 1223 | return "FragmentPager.SavedState{" |
| 1224 | + Integer.toHexString(System.identityHashCode(this)) |
| 1225 | + " position=" + position + "}"; |
| 1226 | } |
| 1227 | |
| 1228 | public static final Creator<SavedState> CREATOR = new Creator<SavedState>() { |
| 1229 | @Override |
| 1230 | public SavedState createFromParcel(Parcel in) { |
| 1231 | return new SavedState(in); |
| 1232 | } |
| 1233 | @Override |
| 1234 | public SavedState[] newArray(int size) { |
| 1235 | return new SavedState[size]; |
| 1236 | } |
| 1237 | }; |
| 1238 | |
| 1239 | SavedState(Parcel in, ClassLoader loader) { |
| 1240 | super(in); |
| 1241 | if (loader == null) { |
| 1242 | loader = getClass().getClassLoader(); |
| 1243 | } |
| 1244 | position = in.readInt(); |
| 1245 | adapterState = in.readParcelable(loader); |
| 1246 | this.loader = loader; |
| 1247 | } |
| 1248 | } |
| 1249 | |
| 1250 | @Override |
| 1251 | public Parcelable onSaveInstanceState() { |
| 1252 | Parcelable superState = super.onSaveInstanceState(); |
| 1253 | SavedState ss = new SavedState(superState); |
| 1254 | ss.position = mCurItem; |
| 1255 | if (mAdapter != null) { |
| 1256 | ss.adapterState = mAdapter.saveState(); |
| 1257 | } |
| 1258 | return ss; |
| 1259 | } |
| 1260 | |
| 1261 | @Override |
| 1262 | public void onRestoreInstanceState(Parcelable state) { |
| 1263 | if (!(state instanceof SavedState)) { |
| 1264 | super.onRestoreInstanceState(state); |
| 1265 | return; |
| 1266 | } |
| 1267 | |
| 1268 | SavedState ss = (SavedState)state; |
| 1269 | super.onRestoreInstanceState(ss.getSuperState()); |
| 1270 | |
| 1271 | if (mAdapter != null) { |
| 1272 | mAdapter.restoreState(ss.adapterState, ss.loader); |
| 1273 | setCurrentItemInternal(ss.position, false, true); |
| 1274 | } else { |
| 1275 | mRestoredCurItem = ss.position; |
| 1276 | mRestoredAdapterState = ss.adapterState; |
| 1277 | mRestoredClassLoader = ss.loader; |
| 1278 | } |
| 1279 | } |
| 1280 | |
| 1281 | @Override |
| 1282 | public void addView(View child, int index, ViewGroup.LayoutParams params) { |
| 1283 | if (!checkLayoutParams(params)) { |
| 1284 | params = generateLayoutParams(params); |
| 1285 | } |
| 1286 | final LayoutParams lp = (LayoutParams) params; |
| 1287 | lp.isDecor |= child instanceof Decor; |
| 1288 | if (mInLayout) { |
| 1289 | if (lp != null && lp.isDecor) { |
| 1290 | throw new IllegalStateException("Cannot add pager decor view during layout"); |
| 1291 | } |
| 1292 | lp.needsMeasure = true; |
| 1293 | addViewInLayout(child, index, params); |
| 1294 | } else { |
| 1295 | super.addView(child, index, params); |
| 1296 | } |
| 1297 | |
| 1298 | if (USE_CACHE) { |
| 1299 | if (child.getVisibility() != GONE) { |
| 1300 | child.setDrawingCacheEnabled(mScrollingCacheEnabled); |
| 1301 | } else { |
| 1302 | child.setDrawingCacheEnabled(false); |
| 1303 | } |
| 1304 | } |
| 1305 | } |
| 1306 | |
George Mount | e998c3f | 2015-10-27 08:46:44 -0700 | [diff] [blame] | 1307 | public Object getCurrent() { |
| 1308 | final ItemInfo itemInfo = infoForPosition(getCurrentItem()); |
| 1309 | return itemInfo == null ? null : itemInfo.object; |
| 1310 | } |
| 1311 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1312 | @Override |
| 1313 | public void removeView(View view) { |
| 1314 | if (mInLayout) { |
| 1315 | removeViewInLayout(view); |
| 1316 | } else { |
| 1317 | super.removeView(view); |
| 1318 | } |
| 1319 | } |
| 1320 | |
| 1321 | ItemInfo infoForChild(View child) { |
| 1322 | for (int i=0; i<mItems.size(); i++) { |
| 1323 | ItemInfo ii = mItems.get(i); |
| 1324 | if (mAdapter.isViewFromObject(child, ii.object)) { |
| 1325 | return ii; |
| 1326 | } |
| 1327 | } |
| 1328 | return null; |
| 1329 | } |
| 1330 | |
| 1331 | ItemInfo infoForAnyChild(View child) { |
| 1332 | ViewParent parent; |
| 1333 | while ((parent=child.getParent()) != this) { |
| 1334 | if (parent == null || !(parent instanceof View)) { |
| 1335 | return null; |
| 1336 | } |
| 1337 | child = (View)parent; |
| 1338 | } |
| 1339 | return infoForChild(child); |
| 1340 | } |
| 1341 | |
| 1342 | ItemInfo infoForPosition(int position) { |
| 1343 | for (int i = 0; i < mItems.size(); i++) { |
| 1344 | ItemInfo ii = mItems.get(i); |
| 1345 | if (ii.position == position) { |
| 1346 | return ii; |
| 1347 | } |
| 1348 | } |
| 1349 | return null; |
| 1350 | } |
| 1351 | |
| 1352 | @Override |
| 1353 | protected void onAttachedToWindow() { |
| 1354 | super.onAttachedToWindow(); |
| 1355 | mFirstLayout = true; |
| 1356 | } |
| 1357 | |
| 1358 | @Override |
| 1359 | protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { |
| 1360 | // For simple implementation, our internal size is always 0. |
| 1361 | // We depend on the container to specify the layout size of |
| 1362 | // our view. We can't really know what it is since we will be |
| 1363 | // adding and removing different arbitrary views and do not |
| 1364 | // want the layout to change as this happens. |
| 1365 | setMeasuredDimension(getDefaultSize(0, widthMeasureSpec), |
| 1366 | getDefaultSize(0, heightMeasureSpec)); |
| 1367 | |
| 1368 | final int measuredWidth = getMeasuredWidth(); |
| 1369 | final int maxGutterSize = measuredWidth / 10; |
| 1370 | mGutterSize = Math.min(maxGutterSize, mDefaultGutterSize); |
| 1371 | |
| 1372 | // Children are just made to fill our space. |
| 1373 | int childWidthSize = measuredWidth - getPaddingLeft() - getPaddingRight(); |
| 1374 | int childHeightSize = getMeasuredHeight() - getPaddingTop() - getPaddingBottom(); |
| 1375 | |
| 1376 | /* |
| 1377 | * Make sure all children have been properly measured. Decor views first. |
| 1378 | * Right now we cheat and make this less complicated by assuming decor |
| 1379 | * views won't intersect. We will pin to edges based on gravity. |
| 1380 | */ |
| 1381 | int size = getChildCount(); |
| 1382 | for (int i = 0; i < size; ++i) { |
| 1383 | final View child = getChildAt(i); |
| 1384 | if (child.getVisibility() != GONE) { |
| 1385 | final LayoutParams lp = (LayoutParams) child.getLayoutParams(); |
| 1386 | if (lp != null && lp.isDecor) { |
| 1387 | final int hgrav = lp.gravity & Gravity.HORIZONTAL_GRAVITY_MASK; |
| 1388 | final int vgrav = lp.gravity & Gravity.VERTICAL_GRAVITY_MASK; |
| 1389 | int widthMode = MeasureSpec.AT_MOST; |
| 1390 | int heightMode = MeasureSpec.AT_MOST; |
| 1391 | boolean consumeVertical = vgrav == Gravity.TOP || vgrav == Gravity.BOTTOM; |
| 1392 | boolean consumeHorizontal = hgrav == Gravity.LEFT || hgrav == Gravity.RIGHT; |
| 1393 | |
| 1394 | if (consumeVertical) { |
| 1395 | widthMode = MeasureSpec.EXACTLY; |
| 1396 | } else if (consumeHorizontal) { |
| 1397 | heightMode = MeasureSpec.EXACTLY; |
| 1398 | } |
| 1399 | |
| 1400 | int widthSize = childWidthSize; |
| 1401 | int heightSize = childHeightSize; |
| 1402 | if (lp.width != LayoutParams.WRAP_CONTENT) { |
| 1403 | widthMode = MeasureSpec.EXACTLY; |
| 1404 | if (lp.width != LayoutParams.FILL_PARENT) { |
| 1405 | widthSize = lp.width; |
| 1406 | } |
| 1407 | } |
| 1408 | if (lp.height != LayoutParams.WRAP_CONTENT) { |
| 1409 | heightMode = MeasureSpec.EXACTLY; |
| 1410 | if (lp.height != LayoutParams.FILL_PARENT) { |
| 1411 | heightSize = lp.height; |
| 1412 | } |
| 1413 | } |
| 1414 | final int widthSpec = MeasureSpec.makeMeasureSpec(widthSize, widthMode); |
| 1415 | final int heightSpec = MeasureSpec.makeMeasureSpec(heightSize, heightMode); |
| 1416 | child.measure(widthSpec, heightSpec); |
| 1417 | |
| 1418 | if (consumeVertical) { |
| 1419 | childHeightSize -= child.getMeasuredHeight(); |
| 1420 | } else if (consumeHorizontal) { |
| 1421 | childWidthSize -= child.getMeasuredWidth(); |
| 1422 | } |
| 1423 | } |
| 1424 | } |
| 1425 | } |
| 1426 | |
| 1427 | mChildWidthMeasureSpec = MeasureSpec.makeMeasureSpec(childWidthSize, MeasureSpec.EXACTLY); |
| 1428 | mChildHeightMeasureSpec = MeasureSpec.makeMeasureSpec(childHeightSize, MeasureSpec.EXACTLY); |
| 1429 | |
| 1430 | // Make sure we have created all fragments that we need to have shown. |
| 1431 | mInLayout = true; |
| 1432 | populate(); |
| 1433 | mInLayout = false; |
| 1434 | |
| 1435 | // Page views next. |
| 1436 | size = getChildCount(); |
| 1437 | for (int i = 0; i < size; ++i) { |
| 1438 | final View child = getChildAt(i); |
| 1439 | if (child.getVisibility() != GONE) { |
| 1440 | if (DEBUG) Log.v(TAG, "Measuring #" + i + " " + child |
| 1441 | + ": " + mChildWidthMeasureSpec); |
| 1442 | |
| 1443 | final LayoutParams lp = (LayoutParams) child.getLayoutParams(); |
| 1444 | if (lp == null || !lp.isDecor) { |
| 1445 | final int widthSpec = MeasureSpec.makeMeasureSpec( |
| 1446 | (int) (childWidthSize * lp.widthFactor), MeasureSpec.EXACTLY); |
| 1447 | child.measure(widthSpec, mChildHeightMeasureSpec); |
| 1448 | } |
| 1449 | } |
| 1450 | } |
| 1451 | } |
| 1452 | |
| 1453 | @Override |
| 1454 | protected void onSizeChanged(int w, int h, int oldw, int oldh) { |
| 1455 | super.onSizeChanged(w, h, oldw, oldh); |
| 1456 | |
| 1457 | // Make sure scroll position is set correctly. |
| 1458 | if (w != oldw) { |
| 1459 | recomputeScrollPosition(w, oldw, mPageMargin, mPageMargin); |
| 1460 | } |
| 1461 | } |
| 1462 | |
| 1463 | private void recomputeScrollPosition(int width, int oldWidth, int margin, int oldMargin) { |
| 1464 | if (oldWidth > 0 && !mItems.isEmpty()) { |
| 1465 | final int widthWithMargin = width - getPaddingLeft() - getPaddingRight() + margin; |
| 1466 | final int oldWidthWithMargin = oldWidth - getPaddingLeft() - getPaddingRight() |
| 1467 | + oldMargin; |
| 1468 | final int xpos = getScrollX(); |
| 1469 | final float pageOffset = (float) xpos / oldWidthWithMargin; |
| 1470 | final int newOffsetPixels = (int) (pageOffset * widthWithMargin); |
| 1471 | |
| 1472 | scrollTo(newOffsetPixels, getScrollY()); |
| 1473 | if (!mScroller.isFinished()) { |
| 1474 | // We now return to your regularly scheduled scroll, already in progress. |
| 1475 | final int newDuration = mScroller.getDuration() - mScroller.timePassed(); |
| 1476 | ItemInfo targetInfo = infoForPosition(mCurItem); |
| 1477 | mScroller.startScroll(newOffsetPixels, 0, |
| 1478 | (int) (targetInfo.offset * width), 0, newDuration); |
| 1479 | } |
| 1480 | } else { |
| 1481 | final ItemInfo ii = infoForPosition(mCurItem); |
| 1482 | final float scrollOffset = ii != null ? Math.min(ii.offset, mLastOffset) : 0; |
| 1483 | final int scrollPos = (int) (scrollOffset * |
| 1484 | (width - getPaddingLeft() - getPaddingRight())); |
| 1485 | if (scrollPos != getScrollX()) { |
| 1486 | completeScroll(false); |
| 1487 | scrollTo(scrollPos, getScrollY()); |
| 1488 | } |
| 1489 | } |
| 1490 | } |
| 1491 | |
| 1492 | @Override |
| 1493 | protected void onLayout(boolean changed, int l, int t, int r, int b) { |
| 1494 | final int count = getChildCount(); |
| 1495 | int width = r - l; |
| 1496 | int height = b - t; |
| 1497 | int paddingLeft = getPaddingLeft(); |
| 1498 | int paddingTop = getPaddingTop(); |
| 1499 | int paddingRight = getPaddingRight(); |
| 1500 | int paddingBottom = getPaddingBottom(); |
| 1501 | final int scrollX = getScrollX(); |
| 1502 | |
| 1503 | int decorCount = 0; |
| 1504 | |
| 1505 | // First pass - decor views. We need to do this in two passes so that |
| 1506 | // we have the proper offsets for non-decor views later. |
| 1507 | for (int i = 0; i < count; i++) { |
| 1508 | final View child = getChildAt(i); |
| 1509 | if (child.getVisibility() != GONE) { |
| 1510 | final LayoutParams lp = (LayoutParams) child.getLayoutParams(); |
| 1511 | int childLeft = 0; |
| 1512 | int childTop = 0; |
| 1513 | if (lp.isDecor) { |
| 1514 | final int hgrav = lp.gravity & Gravity.HORIZONTAL_GRAVITY_MASK; |
| 1515 | final int vgrav = lp.gravity & Gravity.VERTICAL_GRAVITY_MASK; |
| 1516 | switch (hgrav) { |
| 1517 | default: |
| 1518 | childLeft = paddingLeft; |
| 1519 | break; |
| 1520 | case Gravity.LEFT: |
| 1521 | childLeft = paddingLeft; |
| 1522 | paddingLeft += child.getMeasuredWidth(); |
| 1523 | break; |
| 1524 | case Gravity.CENTER_HORIZONTAL: |
| 1525 | childLeft = Math.max((width - child.getMeasuredWidth()) / 2, |
| 1526 | paddingLeft); |
| 1527 | break; |
| 1528 | case Gravity.RIGHT: |
| 1529 | childLeft = width - paddingRight - child.getMeasuredWidth(); |
| 1530 | paddingRight += child.getMeasuredWidth(); |
| 1531 | break; |
| 1532 | } |
| 1533 | switch (vgrav) { |
| 1534 | default: |
| 1535 | childTop = paddingTop; |
| 1536 | break; |
| 1537 | case Gravity.TOP: |
| 1538 | childTop = paddingTop; |
| 1539 | paddingTop += child.getMeasuredHeight(); |
| 1540 | break; |
| 1541 | case Gravity.CENTER_VERTICAL: |
| 1542 | childTop = Math.max((height - child.getMeasuredHeight()) / 2, |
| 1543 | paddingTop); |
| 1544 | break; |
| 1545 | case Gravity.BOTTOM: |
| 1546 | childTop = height - paddingBottom - child.getMeasuredHeight(); |
| 1547 | paddingBottom += child.getMeasuredHeight(); |
| 1548 | break; |
| 1549 | } |
| 1550 | childLeft += scrollX; |
| 1551 | child.layout(childLeft, childTop, |
| 1552 | childLeft + child.getMeasuredWidth(), |
| 1553 | childTop + child.getMeasuredHeight()); |
| 1554 | decorCount++; |
| 1555 | } |
| 1556 | } |
| 1557 | } |
| 1558 | |
| 1559 | final int childWidth = width - paddingLeft - paddingRight; |
| 1560 | // Page views. Do this once we have the right padding offsets from above. |
| 1561 | for (int i = 0; i < count; i++) { |
| 1562 | final View child = getChildAt(i); |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1563 | if (child.getVisibility() == GONE) { |
| 1564 | continue; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1565 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1566 | |
| 1567 | final LayoutParams lp = (LayoutParams) child.getLayoutParams(); |
| 1568 | if (lp.isDecor) { |
| 1569 | continue; |
| 1570 | } |
| 1571 | |
| 1572 | final ItemInfo ii = infoForChild(child); |
| 1573 | if (ii == null) { |
| 1574 | continue; |
| 1575 | } |
| 1576 | |
| 1577 | if (lp.needsMeasure) { |
| 1578 | // This was added during layout and needs measurement. |
| 1579 | // Do it now that we know what we're working with. |
| 1580 | lp.needsMeasure = false; |
| 1581 | final int widthSpec = MeasureSpec.makeMeasureSpec( |
| 1582 | (int) (childWidth * lp.widthFactor), |
| 1583 | MeasureSpec.EXACTLY); |
| 1584 | final int heightSpec = MeasureSpec.makeMeasureSpec( |
| 1585 | (int) (height - paddingTop - paddingBottom), |
| 1586 | MeasureSpec.EXACTLY); |
| 1587 | child.measure(widthSpec, heightSpec); |
| 1588 | } |
| 1589 | |
| 1590 | final int childMeasuredWidth = child.getMeasuredWidth(); |
| 1591 | final int startOffset = (int) (childWidth * ii.offset); |
| 1592 | final int childLeft; |
| 1593 | if (isLayoutRtl()) { |
| 1594 | childLeft = MAX_SCROLL_X - paddingRight - startOffset - childMeasuredWidth; |
| 1595 | } else { |
| 1596 | childLeft = paddingLeft + startOffset; |
| 1597 | } |
| 1598 | |
| 1599 | final int childTop = paddingTop; |
| 1600 | child.layout(childLeft, childTop, childLeft + childMeasuredWidth, |
| 1601 | childTop + child.getMeasuredHeight()); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1602 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1603 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1604 | mTopPageBounds = paddingTop; |
| 1605 | mBottomPageBounds = height - paddingBottom; |
| 1606 | mDecorChildCount = decorCount; |
| 1607 | |
| 1608 | if (mFirstLayout) { |
| 1609 | scrollToItem(mCurItem, false, 0, false); |
| 1610 | } |
| 1611 | mFirstLayout = false; |
| 1612 | } |
| 1613 | |
| 1614 | @Override |
| 1615 | public void computeScroll() { |
| 1616 | if (!mScroller.isFinished() && mScroller.computeScrollOffset()) { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1617 | final int oldX = getScrollX(); |
| 1618 | final int oldY = getScrollY(); |
| 1619 | final int x = mScroller.getCurrX(); |
| 1620 | final int y = mScroller.getCurrY(); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1621 | |
| 1622 | if (oldX != x || oldY != y) { |
| 1623 | scrollTo(x, y); |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1624 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1625 | if (!pageScrolled(x)) { |
| 1626 | mScroller.abortAnimation(); |
| 1627 | scrollTo(0, y); |
| 1628 | } |
| 1629 | } |
| 1630 | |
| 1631 | // Keep on drawing until the animation has finished. |
| 1632 | postInvalidateOnAnimation(); |
| 1633 | return; |
| 1634 | } |
| 1635 | |
| 1636 | // Done with scroll, clean up state. |
| 1637 | completeScroll(true); |
| 1638 | } |
| 1639 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1640 | private boolean pageScrolled(int scrollX) { |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1641 | if (mItems.size() == 0) { |
| 1642 | mCalledSuper = false; |
| 1643 | onPageScrolled(0, 0, 0); |
| 1644 | if (!mCalledSuper) { |
| 1645 | throw new IllegalStateException( |
| 1646 | "onPageScrolled did not call superclass implementation"); |
| 1647 | } |
| 1648 | return false; |
| 1649 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1650 | |
| 1651 | // Translate to scrollX to scrollStart for RTL. |
| 1652 | final int scrollStart; |
| 1653 | if (isLayoutRtl()) { |
| 1654 | scrollStart = MAX_SCROLL_X - scrollX; |
| 1655 | } else { |
| 1656 | scrollStart = scrollX; |
| 1657 | } |
| 1658 | |
| 1659 | final ItemInfo ii = infoForFirstVisiblePage(); |
| 1660 | final int width = getPaddedWidth(); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1661 | final int widthWithMargin = width + mPageMargin; |
| 1662 | final float marginOffset = (float) mPageMargin / width; |
| 1663 | final int currentPage = ii.position; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1664 | final float pageOffset = (((float) scrollStart / width) - ii.offset) / |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1665 | (ii.widthFactor + marginOffset); |
| 1666 | final int offsetPixels = (int) (pageOffset * widthWithMargin); |
| 1667 | |
| 1668 | mCalledSuper = false; |
| 1669 | onPageScrolled(currentPage, pageOffset, offsetPixels); |
| 1670 | if (!mCalledSuper) { |
| 1671 | throw new IllegalStateException( |
| 1672 | "onPageScrolled did not call superclass implementation"); |
| 1673 | } |
| 1674 | return true; |
| 1675 | } |
| 1676 | |
| 1677 | /** |
| 1678 | * This method will be invoked when the current page is scrolled, either as part |
| 1679 | * of a programmatically initiated smooth scroll or a user initiated touch scroll. |
| 1680 | * If you override this method you must call through to the superclass implementation |
| 1681 | * (e.g. super.onPageScrolled(position, offset, offsetPixels)) before onPageScrolled |
| 1682 | * returns. |
| 1683 | * |
| 1684 | * @param position Position index of the first page currently being displayed. |
| 1685 | * Page position+1 will be visible if positionOffset is nonzero. |
| 1686 | * @param offset Value from [0, 1) indicating the offset from the page at position. |
| 1687 | * @param offsetPixels Value in pixels indicating the offset from position. |
| 1688 | */ |
| 1689 | protected void onPageScrolled(int position, float offset, int offsetPixels) { |
| 1690 | // Offset any decor views if needed - keep them on-screen at all times. |
| 1691 | if (mDecorChildCount > 0) { |
| 1692 | final int scrollX = getScrollX(); |
| 1693 | int paddingLeft = getPaddingLeft(); |
| 1694 | int paddingRight = getPaddingRight(); |
| 1695 | final int width = getWidth(); |
| 1696 | final int childCount = getChildCount(); |
| 1697 | for (int i = 0; i < childCount; i++) { |
| 1698 | final View child = getChildAt(i); |
| 1699 | final LayoutParams lp = (LayoutParams) child.getLayoutParams(); |
| 1700 | if (!lp.isDecor) continue; |
| 1701 | |
| 1702 | final int hgrav = lp.gravity & Gravity.HORIZONTAL_GRAVITY_MASK; |
| 1703 | int childLeft = 0; |
| 1704 | switch (hgrav) { |
| 1705 | default: |
| 1706 | childLeft = paddingLeft; |
| 1707 | break; |
| 1708 | case Gravity.LEFT: |
| 1709 | childLeft = paddingLeft; |
| 1710 | paddingLeft += child.getWidth(); |
| 1711 | break; |
| 1712 | case Gravity.CENTER_HORIZONTAL: |
| 1713 | childLeft = Math.max((width - child.getMeasuredWidth()) / 2, |
| 1714 | paddingLeft); |
| 1715 | break; |
| 1716 | case Gravity.RIGHT: |
| 1717 | childLeft = width - paddingRight - child.getMeasuredWidth(); |
| 1718 | paddingRight += child.getMeasuredWidth(); |
| 1719 | break; |
| 1720 | } |
| 1721 | childLeft += scrollX; |
| 1722 | |
| 1723 | final int childOffset = childLeft - child.getLeft(); |
| 1724 | if (childOffset != 0) { |
| 1725 | child.offsetLeftAndRight(childOffset); |
| 1726 | } |
| 1727 | } |
| 1728 | } |
| 1729 | |
| 1730 | if (mOnPageChangeListener != null) { |
| 1731 | mOnPageChangeListener.onPageScrolled(position, offset, offsetPixels); |
| 1732 | } |
| 1733 | if (mInternalPageChangeListener != null) { |
| 1734 | mInternalPageChangeListener.onPageScrolled(position, offset, offsetPixels); |
| 1735 | } |
| 1736 | |
| 1737 | if (mPageTransformer != null) { |
| 1738 | final int scrollX = getScrollX(); |
| 1739 | final int childCount = getChildCount(); |
| 1740 | for (int i = 0; i < childCount; i++) { |
| 1741 | final View child = getChildAt(i); |
| 1742 | final LayoutParams lp = (LayoutParams) child.getLayoutParams(); |
| 1743 | |
| 1744 | if (lp.isDecor) continue; |
| 1745 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1746 | final float transformPos = (float) (child.getLeft() - scrollX) / getPaddedWidth(); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1747 | mPageTransformer.transformPage(child, transformPos); |
| 1748 | } |
| 1749 | } |
| 1750 | |
| 1751 | mCalledSuper = true; |
| 1752 | } |
| 1753 | |
| 1754 | private void completeScroll(boolean postEvents) { |
| 1755 | boolean needPopulate = mScrollState == SCROLL_STATE_SETTLING; |
| 1756 | if (needPopulate) { |
| 1757 | // Done with scroll, no longer want to cache view drawing. |
| 1758 | setScrollingCacheEnabled(false); |
| 1759 | mScroller.abortAnimation(); |
| 1760 | int oldX = getScrollX(); |
| 1761 | int oldY = getScrollY(); |
| 1762 | int x = mScroller.getCurrX(); |
| 1763 | int y = mScroller.getCurrY(); |
| 1764 | if (oldX != x || oldY != y) { |
| 1765 | scrollTo(x, y); |
| 1766 | } |
| 1767 | } |
| 1768 | mPopulatePending = false; |
| 1769 | for (int i=0; i<mItems.size(); i++) { |
| 1770 | ItemInfo ii = mItems.get(i); |
| 1771 | if (ii.scrolling) { |
| 1772 | needPopulate = true; |
| 1773 | ii.scrolling = false; |
| 1774 | } |
| 1775 | } |
| 1776 | if (needPopulate) { |
| 1777 | if (postEvents) { |
| 1778 | postOnAnimation(mEndScrollRunnable); |
| 1779 | } else { |
| 1780 | mEndScrollRunnable.run(); |
| 1781 | } |
| 1782 | } |
| 1783 | } |
| 1784 | |
| 1785 | private boolean isGutterDrag(float x, float dx) { |
| 1786 | return (x < mGutterSize && dx > 0) || (x > getWidth() - mGutterSize && dx < 0); |
| 1787 | } |
| 1788 | |
| 1789 | private void enableLayers(boolean enable) { |
| 1790 | final int childCount = getChildCount(); |
| 1791 | for (int i = 0; i < childCount; i++) { |
| 1792 | final int layerType = enable ? LAYER_TYPE_HARDWARE : LAYER_TYPE_NONE; |
| 1793 | getChildAt(i).setLayerType(layerType, null); |
| 1794 | } |
| 1795 | } |
| 1796 | |
| 1797 | @Override |
| 1798 | public boolean onInterceptTouchEvent(MotionEvent ev) { |
| 1799 | /* |
| 1800 | * This method JUST determines whether we want to intercept the motion. |
| 1801 | * If we return true, onMotionEvent will be called and we do the actual |
| 1802 | * scrolling there. |
| 1803 | */ |
| 1804 | |
| 1805 | final int action = ev.getAction() & MotionEvent.ACTION_MASK; |
| 1806 | |
| 1807 | // Always take care of the touch gesture being complete. |
| 1808 | if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) { |
| 1809 | // Release the drag. |
| 1810 | if (DEBUG) Log.v(TAG, "Intercept done!"); |
| 1811 | mIsBeingDragged = false; |
| 1812 | mIsUnableToDrag = false; |
| 1813 | mActivePointerId = INVALID_POINTER; |
| 1814 | if (mVelocityTracker != null) { |
| 1815 | mVelocityTracker.recycle(); |
| 1816 | mVelocityTracker = null; |
| 1817 | } |
| 1818 | return false; |
| 1819 | } |
| 1820 | |
| 1821 | // Nothing more to do here if we have decided whether or not we |
| 1822 | // are dragging. |
| 1823 | if (action != MotionEvent.ACTION_DOWN) { |
| 1824 | if (mIsBeingDragged) { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1825 | if (DEBUG) Log.v(TAG, "Being dragged, intercept returning true!"); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1826 | return true; |
| 1827 | } |
| 1828 | if (mIsUnableToDrag) { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 1829 | if (DEBUG) Log.v(TAG, "Unable to drag, intercept returning false!"); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1830 | return false; |
| 1831 | } |
| 1832 | } |
| 1833 | |
| 1834 | switch (action) { |
| 1835 | case MotionEvent.ACTION_MOVE: { |
| 1836 | /* |
| 1837 | * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check |
| 1838 | * whether the user has moved far enough from his original down touch. |
| 1839 | */ |
| 1840 | |
| 1841 | /* |
| 1842 | * Locally do absolute value. mLastMotionY is set to the y value |
| 1843 | * of the down event. |
| 1844 | */ |
| 1845 | final int activePointerId = mActivePointerId; |
| 1846 | if (activePointerId == INVALID_POINTER) { |
| 1847 | // If we don't have a valid id, the touch down wasn't on content. |
| 1848 | break; |
| 1849 | } |
| 1850 | |
| 1851 | final int pointerIndex = ev.findPointerIndex(activePointerId); |
| 1852 | final float x = ev.getX(pointerIndex); |
| 1853 | final float dx = x - mLastMotionX; |
| 1854 | final float xDiff = Math.abs(dx); |
| 1855 | final float y = ev.getY(pointerIndex); |
| 1856 | final float yDiff = Math.abs(y - mInitialMotionY); |
| 1857 | if (DEBUG) Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff); |
| 1858 | |
| 1859 | if (dx != 0 && !isGutterDrag(mLastMotionX, dx) && |
| 1860 | canScroll(this, false, (int) dx, (int) x, (int) y)) { |
| 1861 | // Nested view has scrollable area under this point. Let it be handled there. |
| 1862 | mLastMotionX = x; |
| 1863 | mLastMotionY = y; |
| 1864 | mIsUnableToDrag = true; |
| 1865 | return false; |
| 1866 | } |
| 1867 | if (xDiff > mTouchSlop && xDiff * 0.5f > yDiff) { |
| 1868 | if (DEBUG) Log.v(TAG, "Starting drag!"); |
| 1869 | mIsBeingDragged = true; |
| 1870 | requestParentDisallowInterceptTouchEvent(true); |
| 1871 | setScrollState(SCROLL_STATE_DRAGGING); |
| 1872 | mLastMotionX = dx > 0 ? mInitialMotionX + mTouchSlop : |
| 1873 | mInitialMotionX - mTouchSlop; |
| 1874 | mLastMotionY = y; |
| 1875 | setScrollingCacheEnabled(true); |
| 1876 | } else if (yDiff > mTouchSlop) { |
| 1877 | // The finger has moved enough in the vertical |
| 1878 | // direction to be counted as a drag... abort |
| 1879 | // any attempt to drag horizontally, to work correctly |
| 1880 | // with children that have scrolling containers. |
| 1881 | if (DEBUG) Log.v(TAG, "Starting unable to drag!"); |
| 1882 | mIsUnableToDrag = true; |
| 1883 | } |
| 1884 | if (mIsBeingDragged) { |
| 1885 | // Scroll to follow the motion event |
| 1886 | if (performDrag(x)) { |
| 1887 | postInvalidateOnAnimation(); |
| 1888 | } |
| 1889 | } |
| 1890 | break; |
| 1891 | } |
| 1892 | |
| 1893 | case MotionEvent.ACTION_DOWN: { |
| 1894 | /* |
| 1895 | * Remember location of down touch. |
| 1896 | * ACTION_DOWN always refers to pointer index 0. |
| 1897 | */ |
| 1898 | mLastMotionX = mInitialMotionX = ev.getX(); |
| 1899 | mLastMotionY = mInitialMotionY = ev.getY(); |
| 1900 | mActivePointerId = ev.getPointerId(0); |
| 1901 | mIsUnableToDrag = false; |
| 1902 | |
| 1903 | mScroller.computeScrollOffset(); |
| 1904 | if (mScrollState == SCROLL_STATE_SETTLING && |
| 1905 | Math.abs(mScroller.getFinalX() - mScroller.getCurrX()) > mCloseEnough) { |
| 1906 | // Let the user 'catch' the pager as it animates. |
| 1907 | mScroller.abortAnimation(); |
| 1908 | mPopulatePending = false; |
| 1909 | populate(); |
| 1910 | mIsBeingDragged = true; |
| 1911 | requestParentDisallowInterceptTouchEvent(true); |
| 1912 | setScrollState(SCROLL_STATE_DRAGGING); |
| 1913 | } else { |
| 1914 | completeScroll(false); |
| 1915 | mIsBeingDragged = false; |
| 1916 | } |
| 1917 | |
| 1918 | if (DEBUG) Log.v(TAG, "Down at " + mLastMotionX + "," + mLastMotionY |
| 1919 | + " mIsBeingDragged=" + mIsBeingDragged |
| 1920 | + "mIsUnableToDrag=" + mIsUnableToDrag); |
| 1921 | break; |
| 1922 | } |
| 1923 | |
| 1924 | case MotionEvent.ACTION_POINTER_UP: |
| 1925 | onSecondaryPointerUp(ev); |
| 1926 | break; |
| 1927 | } |
| 1928 | |
| 1929 | if (mVelocityTracker == null) { |
| 1930 | mVelocityTracker = VelocityTracker.obtain(); |
| 1931 | } |
| 1932 | mVelocityTracker.addMovement(ev); |
| 1933 | |
| 1934 | /* |
| 1935 | * The only time we want to intercept motion events is if we are in the |
| 1936 | * drag mode. |
| 1937 | */ |
| 1938 | return mIsBeingDragged; |
| 1939 | } |
| 1940 | |
| 1941 | @Override |
| 1942 | public boolean onTouchEvent(MotionEvent ev) { |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 1943 | if (ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) { |
| 1944 | // Don't handle edge touches immediately -- they may actually belong to one of our |
| 1945 | // descendants. |
| 1946 | return false; |
| 1947 | } |
| 1948 | |
| 1949 | if (mAdapter == null || mAdapter.getCount() == 0) { |
| 1950 | // Nothing to present or scroll; nothing to touch. |
| 1951 | return false; |
| 1952 | } |
| 1953 | |
| 1954 | if (mVelocityTracker == null) { |
| 1955 | mVelocityTracker = VelocityTracker.obtain(); |
| 1956 | } |
| 1957 | mVelocityTracker.addMovement(ev); |
| 1958 | |
| 1959 | final int action = ev.getAction(); |
| 1960 | boolean needsInvalidate = false; |
| 1961 | |
| 1962 | switch (action & MotionEvent.ACTION_MASK) { |
| 1963 | case MotionEvent.ACTION_DOWN: { |
| 1964 | mScroller.abortAnimation(); |
| 1965 | mPopulatePending = false; |
| 1966 | populate(); |
| 1967 | |
| 1968 | // Remember where the motion event started |
| 1969 | mLastMotionX = mInitialMotionX = ev.getX(); |
| 1970 | mLastMotionY = mInitialMotionY = ev.getY(); |
| 1971 | mActivePointerId = ev.getPointerId(0); |
| 1972 | break; |
| 1973 | } |
| 1974 | case MotionEvent.ACTION_MOVE: |
| 1975 | if (!mIsBeingDragged) { |
| 1976 | final int pointerIndex = ev.findPointerIndex(mActivePointerId); |
| 1977 | final float x = ev.getX(pointerIndex); |
| 1978 | final float xDiff = Math.abs(x - mLastMotionX); |
| 1979 | final float y = ev.getY(pointerIndex); |
| 1980 | final float yDiff = Math.abs(y - mLastMotionY); |
| 1981 | if (DEBUG) Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff); |
| 1982 | if (xDiff > mTouchSlop && xDiff > yDiff) { |
| 1983 | if (DEBUG) Log.v(TAG, "Starting drag!"); |
| 1984 | mIsBeingDragged = true; |
| 1985 | requestParentDisallowInterceptTouchEvent(true); |
| 1986 | mLastMotionX = x - mInitialMotionX > 0 ? mInitialMotionX + mTouchSlop : |
| 1987 | mInitialMotionX - mTouchSlop; |
| 1988 | mLastMotionY = y; |
| 1989 | setScrollState(SCROLL_STATE_DRAGGING); |
| 1990 | setScrollingCacheEnabled(true); |
| 1991 | |
| 1992 | // Disallow Parent Intercept, just in case |
| 1993 | ViewParent parent = getParent(); |
| 1994 | if (parent != null) { |
| 1995 | parent.requestDisallowInterceptTouchEvent(true); |
| 1996 | } |
| 1997 | } |
| 1998 | } |
| 1999 | // Not else! Note that mIsBeingDragged can be set above. |
| 2000 | if (mIsBeingDragged) { |
| 2001 | // Scroll to follow the motion event |
| 2002 | final int activePointerIndex = ev.findPointerIndex(mActivePointerId); |
| 2003 | final float x = ev.getX(activePointerIndex); |
| 2004 | needsInvalidate |= performDrag(x); |
| 2005 | } |
| 2006 | break; |
| 2007 | case MotionEvent.ACTION_UP: |
| 2008 | if (mIsBeingDragged) { |
| 2009 | final VelocityTracker velocityTracker = mVelocityTracker; |
| 2010 | velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity); |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2011 | final int initialVelocity = (int) velocityTracker.getXVelocity(mActivePointerId); |
| 2012 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2013 | mPopulatePending = true; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2014 | |
| 2015 | final float scrollStart = getScrollStart(); |
| 2016 | final float scrolledPages = scrollStart / getPaddedWidth(); |
| 2017 | final ItemInfo ii = infoForFirstVisiblePage(); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2018 | final int currentPage = ii.position; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2019 | final float nextPageOffset; |
| 2020 | if (isLayoutRtl()) { |
| 2021 | nextPageOffset = (ii.offset - scrolledPages) / ii.widthFactor; |
| 2022 | } else { |
| 2023 | nextPageOffset = (scrolledPages - ii.offset) / ii.widthFactor; |
| 2024 | } |
| 2025 | |
| 2026 | final int activePointerIndex = ev.findPointerIndex(mActivePointerId); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2027 | final float x = ev.getX(activePointerIndex); |
| 2028 | final int totalDelta = (int) (x - mInitialMotionX); |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2029 | final int nextPage = determineTargetPage( |
| 2030 | currentPage, nextPageOffset, initialVelocity, totalDelta); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2031 | setCurrentItemInternal(nextPage, true, true, initialVelocity); |
| 2032 | |
| 2033 | mActivePointerId = INVALID_POINTER; |
| 2034 | endDrag(); |
| 2035 | mLeftEdge.onRelease(); |
| 2036 | mRightEdge.onRelease(); |
| 2037 | needsInvalidate = true; |
| 2038 | } |
| 2039 | break; |
| 2040 | case MotionEvent.ACTION_CANCEL: |
| 2041 | if (mIsBeingDragged) { |
| 2042 | scrollToItem(mCurItem, true, 0, false); |
| 2043 | mActivePointerId = INVALID_POINTER; |
| 2044 | endDrag(); |
| 2045 | mLeftEdge.onRelease(); |
| 2046 | mRightEdge.onRelease(); |
| 2047 | needsInvalidate = true; |
| 2048 | } |
| 2049 | break; |
| 2050 | case MotionEvent.ACTION_POINTER_DOWN: { |
| 2051 | final int index = ev.getActionIndex(); |
| 2052 | final float x = ev.getX(index); |
| 2053 | mLastMotionX = x; |
| 2054 | mActivePointerId = ev.getPointerId(index); |
| 2055 | break; |
| 2056 | } |
| 2057 | case MotionEvent.ACTION_POINTER_UP: |
| 2058 | onSecondaryPointerUp(ev); |
| 2059 | mLastMotionX = ev.getX(ev.findPointerIndex(mActivePointerId)); |
| 2060 | break; |
| 2061 | } |
| 2062 | if (needsInvalidate) { |
| 2063 | postInvalidateOnAnimation(); |
| 2064 | } |
| 2065 | return true; |
| 2066 | } |
| 2067 | |
| 2068 | private void requestParentDisallowInterceptTouchEvent(boolean disallowIntercept) { |
| 2069 | final ViewParent parent = getParent(); |
| 2070 | if (parent != null) { |
| 2071 | parent.requestDisallowInterceptTouchEvent(disallowIntercept); |
| 2072 | } |
| 2073 | } |
| 2074 | |
| 2075 | private boolean performDrag(float x) { |
| 2076 | boolean needsInvalidate = false; |
| 2077 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2078 | final int width = getPaddedWidth(); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2079 | final float deltaX = mLastMotionX - x; |
| 2080 | mLastMotionX = x; |
| 2081 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2082 | final EdgeEffect startEdge; |
| 2083 | final EdgeEffect endEdge; |
| 2084 | if (isLayoutRtl()) { |
| 2085 | startEdge = mRightEdge; |
| 2086 | endEdge = mLeftEdge; |
| 2087 | } else { |
| 2088 | startEdge = mLeftEdge; |
| 2089 | endEdge = mRightEdge; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2090 | } |
| 2091 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2092 | // Translate scroll to relative coordinates. |
| 2093 | final float nextScrollX = getScrollX() + deltaX; |
| 2094 | final float scrollStart; |
| 2095 | if (isLayoutRtl()) { |
| 2096 | scrollStart = MAX_SCROLL_X - nextScrollX; |
| 2097 | } else { |
| 2098 | scrollStart = nextScrollX; |
| 2099 | } |
| 2100 | |
| 2101 | final float startBound; |
| 2102 | final ItemInfo startItem = mItems.get(0); |
| 2103 | final boolean startAbsolute = startItem.position == 0; |
| 2104 | if (startAbsolute) { |
| 2105 | startBound = startItem.offset * width; |
| 2106 | } else { |
| 2107 | startBound = width * mFirstOffset; |
| 2108 | } |
| 2109 | |
| 2110 | final float endBound; |
| 2111 | final ItemInfo endItem = mItems.get(mItems.size() - 1); |
| 2112 | final boolean endAbsolute = endItem.position == mAdapter.getCount() - 1; |
| 2113 | if (endAbsolute) { |
| 2114 | endBound = endItem.offset * width; |
| 2115 | } else { |
| 2116 | endBound = width * mLastOffset; |
| 2117 | } |
| 2118 | |
| 2119 | final float clampedScrollStart; |
| 2120 | if (scrollStart < startBound) { |
| 2121 | if (startAbsolute) { |
| 2122 | final float over = startBound - scrollStart; |
| 2123 | startEdge.onPull(Math.abs(over) / width); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2124 | needsInvalidate = true; |
| 2125 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2126 | clampedScrollStart = startBound; |
| 2127 | } else if (scrollStart > endBound) { |
| 2128 | if (endAbsolute) { |
| 2129 | final float over = scrollStart - endBound; |
| 2130 | endEdge.onPull(Math.abs(over) / width); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2131 | needsInvalidate = true; |
| 2132 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2133 | clampedScrollStart = endBound; |
| 2134 | } else { |
| 2135 | clampedScrollStart = scrollStart; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2136 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2137 | |
| 2138 | // Translate back to absolute coordinates. |
| 2139 | final float targetScrollX; |
| 2140 | if (isLayoutRtl()) { |
| 2141 | targetScrollX = MAX_SCROLL_X - clampedScrollStart; |
| 2142 | } else { |
| 2143 | targetScrollX = clampedScrollStart; |
| 2144 | } |
| 2145 | |
| 2146 | // Don't lose the rounded component. |
| 2147 | mLastMotionX += targetScrollX - (int) targetScrollX; |
| 2148 | |
| 2149 | scrollTo((int) targetScrollX, getScrollY()); |
| 2150 | pageScrolled((int) targetScrollX); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2151 | |
| 2152 | return needsInvalidate; |
| 2153 | } |
| 2154 | |
| 2155 | /** |
| 2156 | * @return Info about the page at the current scroll position. |
| 2157 | * This can be synthetic for a missing middle page; the 'object' field can be null. |
| 2158 | */ |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2159 | private ItemInfo infoForFirstVisiblePage() { |
| 2160 | final int startOffset = getScrollStart(); |
| 2161 | final int width = getPaddedWidth(); |
| 2162 | final float scrollOffset = width > 0 ? (float) startOffset / width : 0; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2163 | final float marginOffset = width > 0 ? (float) mPageMargin / width : 0; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2164 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2165 | int lastPos = -1; |
| 2166 | float lastOffset = 0.f; |
| 2167 | float lastWidth = 0.f; |
| 2168 | boolean first = true; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2169 | ItemInfo lastItem = null; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2170 | |
| 2171 | final int N = mItems.size(); |
| 2172 | for (int i = 0; i < N; i++) { |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2173 | ItemInfo ii = mItems.get(i); |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2174 | |
| 2175 | // Seek to position. |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2176 | if (!first && ii.position != lastPos + 1) { |
| 2177 | // Create a synthetic item for a missing page. |
| 2178 | ii = mTempItem; |
| 2179 | ii.offset = lastOffset + lastWidth + marginOffset; |
| 2180 | ii.position = lastPos + 1; |
| 2181 | ii.widthFactor = mAdapter.getPageWidth(ii.position); |
| 2182 | i--; |
| 2183 | } |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2184 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2185 | final float offset = ii.offset; |
| 2186 | final float startBound = offset; |
| 2187 | if (first || scrollOffset >= startBound) { |
| 2188 | final float endBound = offset + ii.widthFactor + marginOffset; |
| 2189 | if (scrollOffset < endBound || i == mItems.size() - 1) { |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2190 | return ii; |
| 2191 | } |
| 2192 | } else { |
| 2193 | return lastItem; |
| 2194 | } |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2195 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2196 | first = false; |
| 2197 | lastPos = ii.position; |
| 2198 | lastOffset = offset; |
| 2199 | lastWidth = ii.widthFactor; |
| 2200 | lastItem = ii; |
| 2201 | } |
| 2202 | |
| 2203 | return lastItem; |
| 2204 | } |
| 2205 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2206 | private int getScrollStart() { |
| 2207 | if (isLayoutRtl()) { |
| 2208 | return MAX_SCROLL_X - getScrollX(); |
| 2209 | } else { |
| 2210 | return getScrollX(); |
| 2211 | } |
| 2212 | } |
| 2213 | |
| 2214 | /** |
| 2215 | * @param currentPage the position of the page with the first visible starting edge |
| 2216 | * @param pageOffset the fraction of the right-hand page that's visible |
| 2217 | * @param velocity the velocity of the touch event stream |
| 2218 | * @param deltaX the distance of the touch event stream |
| 2219 | * @return the position of the target page |
| 2220 | */ |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2221 | private int determineTargetPage(int currentPage, float pageOffset, int velocity, int deltaX) { |
| 2222 | int targetPage; |
| 2223 | if (Math.abs(deltaX) > mFlingDistance && Math.abs(velocity) > mMinimumVelocity) { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2224 | targetPage = currentPage - (velocity < 0 ? mLeftIncr : 0); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2225 | } else { |
| 2226 | final float truncator = currentPage >= mCurItem ? 0.4f : 0.6f; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2227 | targetPage = (int) (currentPage - mLeftIncr * (pageOffset + truncator)); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2228 | } |
| 2229 | |
| 2230 | if (mItems.size() > 0) { |
| 2231 | final ItemInfo firstItem = mItems.get(0); |
| 2232 | final ItemInfo lastItem = mItems.get(mItems.size() - 1); |
| 2233 | |
| 2234 | // Only let the user target pages we have items for |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2235 | targetPage = MathUtils.constrain(targetPage, firstItem.position, lastItem.position); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2236 | } |
| 2237 | |
| 2238 | return targetPage; |
| 2239 | } |
| 2240 | |
| 2241 | @Override |
| 2242 | public void draw(Canvas canvas) { |
| 2243 | super.draw(canvas); |
| 2244 | boolean needsInvalidate = false; |
| 2245 | |
| 2246 | final int overScrollMode = getOverScrollMode(); |
| 2247 | if (overScrollMode == View.OVER_SCROLL_ALWAYS || |
| 2248 | (overScrollMode == View.OVER_SCROLL_IF_CONTENT_SCROLLS && |
| 2249 | mAdapter != null && mAdapter.getCount() > 1)) { |
| 2250 | if (!mLeftEdge.isFinished()) { |
| 2251 | final int restoreCount = canvas.save(); |
| 2252 | final int height = getHeight() - getPaddingTop() - getPaddingBottom(); |
| 2253 | final int width = getWidth(); |
| 2254 | |
| 2255 | canvas.rotate(270); |
| 2256 | canvas.translate(-height + getPaddingTop(), mFirstOffset * width); |
| 2257 | mLeftEdge.setSize(height, width); |
| 2258 | needsInvalidate |= mLeftEdge.draw(canvas); |
| 2259 | canvas.restoreToCount(restoreCount); |
| 2260 | } |
| 2261 | if (!mRightEdge.isFinished()) { |
| 2262 | final int restoreCount = canvas.save(); |
| 2263 | final int width = getWidth(); |
| 2264 | final int height = getHeight() - getPaddingTop() - getPaddingBottom(); |
| 2265 | |
| 2266 | canvas.rotate(90); |
| 2267 | canvas.translate(-getPaddingTop(), -(mLastOffset + 1) * width); |
| 2268 | mRightEdge.setSize(height, width); |
| 2269 | needsInvalidate |= mRightEdge.draw(canvas); |
| 2270 | canvas.restoreToCount(restoreCount); |
| 2271 | } |
| 2272 | } else { |
| 2273 | mLeftEdge.finish(); |
| 2274 | mRightEdge.finish(); |
| 2275 | } |
| 2276 | |
| 2277 | if (needsInvalidate) { |
| 2278 | // Keep animating |
| 2279 | postInvalidateOnAnimation(); |
| 2280 | } |
| 2281 | } |
| 2282 | |
| 2283 | @Override |
| 2284 | protected void onDraw(Canvas canvas) { |
| 2285 | super.onDraw(canvas); |
| 2286 | |
| 2287 | // Draw the margin drawable between pages if needed. |
| 2288 | if (mPageMargin > 0 && mMarginDrawable != null && mItems.size() > 0 && mAdapter != null) { |
| 2289 | final int scrollX = getScrollX(); |
| 2290 | final int width = getWidth(); |
| 2291 | |
| 2292 | final float marginOffset = (float) mPageMargin / width; |
| 2293 | int itemIndex = 0; |
| 2294 | ItemInfo ii = mItems.get(0); |
| 2295 | float offset = ii.offset; |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2296 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2297 | final int itemCount = mItems.size(); |
| 2298 | final int firstPos = ii.position; |
| 2299 | final int lastPos = mItems.get(itemCount - 1).position; |
| 2300 | for (int pos = firstPos; pos < lastPos; pos++) { |
| 2301 | while (pos > ii.position && itemIndex < itemCount) { |
| 2302 | ii = mItems.get(++itemIndex); |
| 2303 | } |
| 2304 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2305 | final float itemOffset; |
| 2306 | final float widthFactor; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2307 | if (pos == ii.position) { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2308 | itemOffset = ii.offset; |
| 2309 | widthFactor = ii.widthFactor; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2310 | } else { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2311 | itemOffset = offset; |
| 2312 | widthFactor = mAdapter.getPageWidth(pos); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2313 | } |
| 2314 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2315 | final float left; |
| 2316 | final float scaledOffset = itemOffset * width; |
| 2317 | if (isLayoutRtl()) { |
| 2318 | left = MAX_SCROLL_X - scaledOffset; |
| 2319 | } else { |
| 2320 | left = scaledOffset + widthFactor * width; |
| 2321 | } |
| 2322 | |
| 2323 | offset = itemOffset + widthFactor + marginOffset; |
| 2324 | |
| 2325 | if (left + mPageMargin > scrollX) { |
| 2326 | mMarginDrawable.setBounds((int) left, mTopPageBounds, |
| 2327 | (int) (left + mPageMargin + 0.5f), mBottomPageBounds); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2328 | mMarginDrawable.draw(canvas); |
| 2329 | } |
| 2330 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2331 | if (left > scrollX + width) { |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2332 | break; // No more visible, no sense in continuing |
| 2333 | } |
| 2334 | } |
| 2335 | } |
| 2336 | } |
| 2337 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2338 | private void onSecondaryPointerUp(MotionEvent ev) { |
| 2339 | final int pointerIndex = ev.getActionIndex(); |
| 2340 | final int pointerId = ev.getPointerId(pointerIndex); |
| 2341 | if (pointerId == mActivePointerId) { |
| 2342 | // This was our active pointer going up. Choose a new |
| 2343 | // active pointer and adjust accordingly. |
| 2344 | final int newPointerIndex = pointerIndex == 0 ? 1 : 0; |
| 2345 | mLastMotionX = ev.getX(newPointerIndex); |
| 2346 | mActivePointerId = ev.getPointerId(newPointerIndex); |
| 2347 | if (mVelocityTracker != null) { |
| 2348 | mVelocityTracker.clear(); |
| 2349 | } |
| 2350 | } |
| 2351 | } |
| 2352 | |
| 2353 | private void endDrag() { |
| 2354 | mIsBeingDragged = false; |
| 2355 | mIsUnableToDrag = false; |
| 2356 | |
| 2357 | if (mVelocityTracker != null) { |
| 2358 | mVelocityTracker.recycle(); |
| 2359 | mVelocityTracker = null; |
| 2360 | } |
| 2361 | } |
| 2362 | |
| 2363 | private void setScrollingCacheEnabled(boolean enabled) { |
| 2364 | if (mScrollingCacheEnabled != enabled) { |
| 2365 | mScrollingCacheEnabled = enabled; |
| 2366 | if (USE_CACHE) { |
| 2367 | final int size = getChildCount(); |
| 2368 | for (int i = 0; i < size; ++i) { |
| 2369 | final View child = getChildAt(i); |
| 2370 | if (child.getVisibility() != GONE) { |
| 2371 | child.setDrawingCacheEnabled(enabled); |
| 2372 | } |
| 2373 | } |
| 2374 | } |
| 2375 | } |
| 2376 | } |
| 2377 | |
| 2378 | public boolean canScrollHorizontally(int direction) { |
| 2379 | if (mAdapter == null) { |
| 2380 | return false; |
| 2381 | } |
| 2382 | |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2383 | final int width = getPaddedWidth(); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2384 | final int scrollX = getScrollX(); |
| 2385 | if (direction < 0) { |
| 2386 | return (scrollX > (int) (width * mFirstOffset)); |
| 2387 | } else if (direction > 0) { |
| 2388 | return (scrollX < (int) (width * mLastOffset)); |
| 2389 | } else { |
| 2390 | return false; |
| 2391 | } |
| 2392 | } |
| 2393 | |
| 2394 | /** |
| 2395 | * Tests scrollability within child views of v given a delta of dx. |
| 2396 | * |
| 2397 | * @param v View to test for horizontal scrollability |
| 2398 | * @param checkV Whether the view v passed should itself be checked for scrollability (true), |
| 2399 | * or just its children (false). |
| 2400 | * @param dx Delta scrolled in pixels |
| 2401 | * @param x X coordinate of the active touch point |
| 2402 | * @param y Y coordinate of the active touch point |
| 2403 | * @return true if child views of v can be scrolled by delta of dx. |
| 2404 | */ |
| 2405 | protected boolean canScroll(View v, boolean checkV, int dx, int x, int y) { |
| 2406 | if (v instanceof ViewGroup) { |
| 2407 | final ViewGroup group = (ViewGroup) v; |
| 2408 | final int scrollX = v.getScrollX(); |
| 2409 | final int scrollY = v.getScrollY(); |
| 2410 | final int count = group.getChildCount(); |
| 2411 | // Count backwards - let topmost views consume scroll distance first. |
| 2412 | for (int i = count - 1; i >= 0; i--) { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2413 | // TODO: Add support for transformed views. |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2414 | final View child = group.getChildAt(i); |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2415 | if (x + scrollX >= child.getLeft() && x + scrollX < child.getRight() |
| 2416 | && y + scrollY >= child.getTop() && y + scrollY < child.getBottom() |
| 2417 | && canScroll(child, true, dx, x + scrollX - child.getLeft(), |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2418 | y + scrollY - child.getTop())) { |
| 2419 | return true; |
| 2420 | } |
| 2421 | } |
| 2422 | } |
| 2423 | |
| 2424 | return checkV && v.canScrollHorizontally(-dx); |
| 2425 | } |
| 2426 | |
| 2427 | @Override |
| 2428 | public boolean dispatchKeyEvent(KeyEvent event) { |
| 2429 | // Let the focused view and/or our descendants get the key first |
| 2430 | return super.dispatchKeyEvent(event) || executeKeyEvent(event); |
| 2431 | } |
| 2432 | |
| 2433 | /** |
| 2434 | * You can call this function yourself to have the scroll view perform |
| 2435 | * scrolling from a key event, just as if the event had been dispatched to |
| 2436 | * it by the view hierarchy. |
| 2437 | * |
| 2438 | * @param event The key event to execute. |
| 2439 | * @return Return true if the event was handled, else false. |
| 2440 | */ |
| 2441 | public boolean executeKeyEvent(KeyEvent event) { |
| 2442 | boolean handled = false; |
| 2443 | if (event.getAction() == KeyEvent.ACTION_DOWN) { |
| 2444 | switch (event.getKeyCode()) { |
| 2445 | case KeyEvent.KEYCODE_DPAD_LEFT: |
| 2446 | handled = arrowScroll(FOCUS_LEFT); |
| 2447 | break; |
| 2448 | case KeyEvent.KEYCODE_DPAD_RIGHT: |
| 2449 | handled = arrowScroll(FOCUS_RIGHT); |
| 2450 | break; |
| 2451 | case KeyEvent.KEYCODE_TAB: |
| 2452 | if (event.hasNoModifiers()) { |
| 2453 | handled = arrowScroll(FOCUS_FORWARD); |
| 2454 | } else if (event.hasModifiers(KeyEvent.META_SHIFT_ON)) { |
| 2455 | handled = arrowScroll(FOCUS_BACKWARD); |
| 2456 | } |
| 2457 | break; |
| 2458 | } |
| 2459 | } |
| 2460 | return handled; |
| 2461 | } |
| 2462 | |
| 2463 | public boolean arrowScroll(int direction) { |
| 2464 | View currentFocused = findFocus(); |
| 2465 | if (currentFocused == this) { |
| 2466 | currentFocused = null; |
| 2467 | } else if (currentFocused != null) { |
| 2468 | boolean isChild = false; |
| 2469 | for (ViewParent parent = currentFocused.getParent(); parent instanceof ViewGroup; |
| 2470 | parent = parent.getParent()) { |
| 2471 | if (parent == this) { |
| 2472 | isChild = true; |
| 2473 | break; |
| 2474 | } |
| 2475 | } |
| 2476 | if (!isChild) { |
| 2477 | // This would cause the focus search down below to fail in fun ways. |
| 2478 | final StringBuilder sb = new StringBuilder(); |
| 2479 | sb.append(currentFocused.getClass().getSimpleName()); |
| 2480 | for (ViewParent parent = currentFocused.getParent(); parent instanceof ViewGroup; |
| 2481 | parent = parent.getParent()) { |
| 2482 | sb.append(" => ").append(parent.getClass().getSimpleName()); |
| 2483 | } |
| 2484 | Log.e(TAG, "arrowScroll tried to find focus based on non-child " + |
| 2485 | "current focused view " + sb.toString()); |
| 2486 | currentFocused = null; |
| 2487 | } |
| 2488 | } |
| 2489 | |
| 2490 | boolean handled = false; |
| 2491 | |
| 2492 | View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, |
| 2493 | direction); |
| 2494 | if (nextFocused != null && nextFocused != currentFocused) { |
| 2495 | if (direction == View.FOCUS_LEFT) { |
| 2496 | // If there is nothing to the left, or this is causing us to |
| 2497 | // jump to the right, then what we really want to do is page left. |
| 2498 | final int nextLeft = getChildRectInPagerCoordinates(mTempRect, nextFocused).left; |
| 2499 | final int currLeft = getChildRectInPagerCoordinates(mTempRect, currentFocused).left; |
| 2500 | if (currentFocused != null && nextLeft >= currLeft) { |
| 2501 | handled = pageLeft(); |
| 2502 | } else { |
| 2503 | handled = nextFocused.requestFocus(); |
| 2504 | } |
| 2505 | } else if (direction == View.FOCUS_RIGHT) { |
| 2506 | // If there is nothing to the right, or this is causing us to |
| 2507 | // jump to the left, then what we really want to do is page right. |
| 2508 | final int nextLeft = getChildRectInPagerCoordinates(mTempRect, nextFocused).left; |
| 2509 | final int currLeft = getChildRectInPagerCoordinates(mTempRect, currentFocused).left; |
| 2510 | if (currentFocused != null && nextLeft <= currLeft) { |
| 2511 | handled = pageRight(); |
| 2512 | } else { |
| 2513 | handled = nextFocused.requestFocus(); |
| 2514 | } |
| 2515 | } |
| 2516 | } else if (direction == FOCUS_LEFT || direction == FOCUS_BACKWARD) { |
| 2517 | // Trying to move left and nothing there; try to page. |
| 2518 | handled = pageLeft(); |
| 2519 | } else if (direction == FOCUS_RIGHT || direction == FOCUS_FORWARD) { |
| 2520 | // Trying to move right and nothing there; try to page. |
| 2521 | handled = pageRight(); |
| 2522 | } |
| 2523 | if (handled) { |
| 2524 | playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction)); |
| 2525 | } |
| 2526 | return handled; |
| 2527 | } |
| 2528 | |
| 2529 | private Rect getChildRectInPagerCoordinates(Rect outRect, View child) { |
| 2530 | if (outRect == null) { |
| 2531 | outRect = new Rect(); |
| 2532 | } |
| 2533 | if (child == null) { |
| 2534 | outRect.set(0, 0, 0, 0); |
| 2535 | return outRect; |
| 2536 | } |
| 2537 | outRect.left = child.getLeft(); |
| 2538 | outRect.right = child.getRight(); |
| 2539 | outRect.top = child.getTop(); |
| 2540 | outRect.bottom = child.getBottom(); |
| 2541 | |
| 2542 | ViewParent parent = child.getParent(); |
| 2543 | while (parent instanceof ViewGroup && parent != this) { |
| 2544 | final ViewGroup group = (ViewGroup) parent; |
| 2545 | outRect.left += group.getLeft(); |
| 2546 | outRect.right += group.getRight(); |
| 2547 | outRect.top += group.getTop(); |
| 2548 | outRect.bottom += group.getBottom(); |
| 2549 | |
| 2550 | parent = group.getParent(); |
| 2551 | } |
| 2552 | return outRect; |
| 2553 | } |
| 2554 | |
| 2555 | boolean pageLeft() { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2556 | return setCurrentItemInternal(mCurItem + mLeftIncr, true, false); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2557 | } |
| 2558 | |
| 2559 | boolean pageRight() { |
Alan Viverette | ddf655c | 2015-04-22 13:43:31 -0700 | [diff] [blame] | 2560 | return setCurrentItemInternal(mCurItem - mLeftIncr, true, false); |
| 2561 | } |
| 2562 | |
| 2563 | @Override |
| 2564 | public void onRtlPropertiesChanged(@ResolvedLayoutDir int layoutDirection) { |
| 2565 | super.onRtlPropertiesChanged(layoutDirection); |
| 2566 | |
| 2567 | if (layoutDirection == LAYOUT_DIRECTION_LTR) { |
| 2568 | mLeftIncr = -1; |
| 2569 | } else { |
| 2570 | mLeftIncr = 1; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2571 | } |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2572 | } |
| 2573 | |
| 2574 | /** |
| 2575 | * We only want the current page that is being shown to be focusable. |
| 2576 | */ |
| 2577 | @Override |
| 2578 | public void addFocusables(ArrayList<View> views, int direction, int focusableMode) { |
| 2579 | final int focusableCount = views.size(); |
| 2580 | |
| 2581 | final int descendantFocusability = getDescendantFocusability(); |
| 2582 | |
| 2583 | if (descendantFocusability != FOCUS_BLOCK_DESCENDANTS) { |
| 2584 | for (int i = 0; i < getChildCount(); i++) { |
| 2585 | final View child = getChildAt(i); |
| 2586 | if (child.getVisibility() == VISIBLE) { |
| 2587 | ItemInfo ii = infoForChild(child); |
| 2588 | if (ii != null && ii.position == mCurItem) { |
| 2589 | child.addFocusables(views, direction, focusableMode); |
| 2590 | } |
| 2591 | } |
| 2592 | } |
| 2593 | } |
| 2594 | |
| 2595 | // we add ourselves (if focusable) in all cases except for when we are |
| 2596 | // FOCUS_AFTER_DESCENDANTS and there are some descendants focusable. this is |
| 2597 | // to avoid the focus search finding layouts when a more precise search |
| 2598 | // among the focusable children would be more interesting. |
| 2599 | if ( |
| 2600 | descendantFocusability != FOCUS_AFTER_DESCENDANTS || |
| 2601 | // No focusable descendants |
| 2602 | (focusableCount == views.size())) { |
| 2603 | // Note that we can't call the superclass here, because it will |
| 2604 | // add all views in. So we need to do the same thing View does. |
| 2605 | if (!isFocusable()) { |
| 2606 | return; |
| 2607 | } |
| 2608 | if ((focusableMode & FOCUSABLES_TOUCH_MODE) == FOCUSABLES_TOUCH_MODE && |
| 2609 | isInTouchMode() && !isFocusableInTouchMode()) { |
| 2610 | return; |
| 2611 | } |
| 2612 | if (views != null) { |
| 2613 | views.add(this); |
| 2614 | } |
| 2615 | } |
| 2616 | } |
| 2617 | |
| 2618 | /** |
| 2619 | * We only want the current page that is being shown to be touchable. |
| 2620 | */ |
| 2621 | @Override |
| 2622 | public void addTouchables(ArrayList<View> views) { |
| 2623 | // Note that we don't call super.addTouchables(), which means that |
| 2624 | // we don't call View.addTouchables(). This is okay because a ViewPager |
| 2625 | // is itself not touchable. |
| 2626 | for (int i = 0; i < getChildCount(); i++) { |
| 2627 | final View child = getChildAt(i); |
| 2628 | if (child.getVisibility() == VISIBLE) { |
| 2629 | ItemInfo ii = infoForChild(child); |
| 2630 | if (ii != null && ii.position == mCurItem) { |
| 2631 | child.addTouchables(views); |
| 2632 | } |
| 2633 | } |
| 2634 | } |
| 2635 | } |
| 2636 | |
| 2637 | /** |
| 2638 | * We only want the current page that is being shown to be focusable. |
| 2639 | */ |
| 2640 | @Override |
| 2641 | protected boolean onRequestFocusInDescendants(int direction, |
| 2642 | Rect previouslyFocusedRect) { |
| 2643 | int index; |
| 2644 | int increment; |
| 2645 | int end; |
| 2646 | int count = getChildCount(); |
| 2647 | if ((direction & FOCUS_FORWARD) != 0) { |
| 2648 | index = 0; |
| 2649 | increment = 1; |
| 2650 | end = count; |
| 2651 | } else { |
| 2652 | index = count - 1; |
| 2653 | increment = -1; |
| 2654 | end = -1; |
| 2655 | } |
| 2656 | for (int i = index; i != end; i += increment) { |
| 2657 | View child = getChildAt(i); |
| 2658 | if (child.getVisibility() == VISIBLE) { |
| 2659 | ItemInfo ii = infoForChild(child); |
| 2660 | if (ii != null && ii.position == mCurItem) { |
| 2661 | if (child.requestFocus(direction, previouslyFocusedRect)) { |
| 2662 | return true; |
| 2663 | } |
| 2664 | } |
| 2665 | } |
| 2666 | } |
| 2667 | return false; |
| 2668 | } |
| 2669 | |
| 2670 | @Override |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2671 | protected ViewGroup.LayoutParams generateDefaultLayoutParams() { |
| 2672 | return new LayoutParams(); |
| 2673 | } |
| 2674 | |
| 2675 | @Override |
| 2676 | protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) { |
| 2677 | return generateDefaultLayoutParams(); |
| 2678 | } |
| 2679 | |
| 2680 | @Override |
| 2681 | protected boolean checkLayoutParams(ViewGroup.LayoutParams p) { |
| 2682 | return p instanceof LayoutParams && super.checkLayoutParams(p); |
| 2683 | } |
| 2684 | |
| 2685 | @Override |
| 2686 | public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) { |
| 2687 | return new LayoutParams(getContext(), attrs); |
| 2688 | } |
| 2689 | |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2690 | |
Alan Viverette | 34457f5 | 2015-03-25 13:09:20 -0700 | [diff] [blame] | 2691 | @Override |
| 2692 | public void onInitializeAccessibilityEvent(AccessibilityEvent event) { |
| 2693 | super.onInitializeAccessibilityEvent(event); |
| 2694 | |
| 2695 | event.setClassName(ViewPager.class.getName()); |
| 2696 | event.setScrollable(canScroll()); |
| 2697 | |
| 2698 | if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_SCROLLED && mAdapter != null) { |
| 2699 | event.setItemCount(mAdapter.getCount()); |
| 2700 | event.setFromIndex(mCurItem); |
| 2701 | event.setToIndex(mCurItem); |
| 2702 | } |
| 2703 | } |
| 2704 | |
| 2705 | @Override |
| 2706 | public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) { |
| 2707 | super.onInitializeAccessibilityNodeInfo(info); |
| 2708 | |
| 2709 | info.setClassName(ViewPager.class.getName()); |
| 2710 | info.setScrollable(canScroll()); |
| 2711 | |
| 2712 | if (canScrollHorizontally(1)) { |
| 2713 | info.addAction(AccessibilityAction.ACTION_SCROLL_FORWARD); |
Maxim Bogatov | ac6ffce | 2015-04-27 13:45:52 -0700 | [diff] [blame] | 2714 | info.addAction(AccessibilityAction.ACTION_SCROLL_RIGHT); |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2715 | } |
| 2716 | |
Alan Viverette | 34457f5 | 2015-03-25 13:09:20 -0700 | [diff] [blame] | 2717 | if (canScrollHorizontally(-1)) { |
| 2718 | info.addAction(AccessibilityAction.ACTION_SCROLL_BACKWARD); |
Maxim Bogatov | ac6ffce | 2015-04-27 13:45:52 -0700 | [diff] [blame] | 2719 | info.addAction(AccessibilityAction.ACTION_SCROLL_LEFT); |
Alan Viverette | 34457f5 | 2015-03-25 13:09:20 -0700 | [diff] [blame] | 2720 | } |
| 2721 | } |
| 2722 | |
| 2723 | @Override |
| 2724 | public boolean performAccessibilityAction(int action, Bundle args) { |
| 2725 | if (super.performAccessibilityAction(action, args)) { |
| 2726 | return true; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2727 | } |
| 2728 | |
Alan Viverette | 34457f5 | 2015-03-25 13:09:20 -0700 | [diff] [blame] | 2729 | switch (action) { |
| 2730 | case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD: |
Maxim Bogatov | ac6ffce | 2015-04-27 13:45:52 -0700 | [diff] [blame] | 2731 | case R.id.accessibilityActionScrollRight: |
Alan Viverette | 34457f5 | 2015-03-25 13:09:20 -0700 | [diff] [blame] | 2732 | if (canScrollHorizontally(1)) { |
| 2733 | setCurrentItem(mCurItem + 1); |
| 2734 | return true; |
| 2735 | } |
| 2736 | return false; |
| 2737 | case AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD: |
Maxim Bogatov | ac6ffce | 2015-04-27 13:45:52 -0700 | [diff] [blame] | 2738 | case R.id.accessibilityActionScrollLeft: |
Alan Viverette | 34457f5 | 2015-03-25 13:09:20 -0700 | [diff] [blame] | 2739 | if (canScrollHorizontally(-1)) { |
| 2740 | setCurrentItem(mCurItem - 1); |
| 2741 | return true; |
| 2742 | } |
| 2743 | return false; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2744 | } |
| 2745 | |
Alan Viverette | 34457f5 | 2015-03-25 13:09:20 -0700 | [diff] [blame] | 2746 | return false; |
| 2747 | } |
| 2748 | |
| 2749 | private boolean canScroll() { |
| 2750 | return mAdapter != null && mAdapter.getCount() > 1; |
Alan Viverette | 75fd8f9 | 2015-03-09 15:51:10 -0700 | [diff] [blame] | 2751 | } |
| 2752 | |
| 2753 | private class PagerObserver extends DataSetObserver { |
| 2754 | @Override |
| 2755 | public void onChanged() { |
| 2756 | dataSetChanged(); |
| 2757 | } |
| 2758 | @Override |
| 2759 | public void onInvalidated() { |
| 2760 | dataSetChanged(); |
| 2761 | } |
| 2762 | } |
| 2763 | |
| 2764 | /** |
| 2765 | * Layout parameters that should be supplied for views added to a |
| 2766 | * ViewPager. |
| 2767 | */ |
| 2768 | public static class LayoutParams extends ViewGroup.LayoutParams { |
| 2769 | /** |
| 2770 | * true if this view is a decoration on the pager itself and not |
| 2771 | * a view supplied by the adapter. |
| 2772 | */ |
| 2773 | public boolean isDecor; |
| 2774 | |
| 2775 | /** |
| 2776 | * Gravity setting for use on decor views only: |
| 2777 | * Where to position the view page within the overall ViewPager |
| 2778 | * container; constants are defined in {@link android.view.Gravity}. |
| 2779 | */ |
| 2780 | public int gravity; |
| 2781 | |
| 2782 | /** |
| 2783 | * Width as a 0-1 multiplier of the measured pager width |
| 2784 | */ |
| 2785 | float widthFactor = 0.f; |
| 2786 | |
| 2787 | /** |
| 2788 | * true if this view was added during layout and needs to be measured |
| 2789 | * before being positioned. |
| 2790 | */ |
| 2791 | boolean needsMeasure; |
| 2792 | |
| 2793 | /** |
| 2794 | * Adapter position this view is for if !isDecor |
| 2795 | */ |
| 2796 | int position; |
| 2797 | |
| 2798 | /** |
| 2799 | * Current child index within the ViewPager that this view occupies |
| 2800 | */ |
| 2801 | int childIndex; |
| 2802 | |
| 2803 | public LayoutParams() { |
| 2804 | super(FILL_PARENT, FILL_PARENT); |
| 2805 | } |
| 2806 | |
| 2807 | public LayoutParams(Context context, AttributeSet attrs) { |
| 2808 | super(context, attrs); |
| 2809 | |
| 2810 | final TypedArray a = context.obtainStyledAttributes(attrs, LAYOUT_ATTRS); |
| 2811 | gravity = a.getInteger(0, Gravity.TOP); |
| 2812 | a.recycle(); |
| 2813 | } |
| 2814 | } |
| 2815 | |
| 2816 | static class ViewPositionComparator implements Comparator<View> { |
| 2817 | @Override |
| 2818 | public int compare(View lhs, View rhs) { |
| 2819 | final LayoutParams llp = (LayoutParams) lhs.getLayoutParams(); |
| 2820 | final LayoutParams rlp = (LayoutParams) rhs.getLayoutParams(); |
| 2821 | if (llp.isDecor != rlp.isDecor) { |
| 2822 | return llp.isDecor ? 1 : -1; |
| 2823 | } |
| 2824 | return llp.position - rlp.position; |
| 2825 | } |
| 2826 | } |
| 2827 | } |