The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2006 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 android.widget; |
| 18 | |
Adam Powell | 17dfce1 | 2010-01-25 18:38:22 -0800 | [diff] [blame] | 19 | import com.android.internal.R; |
| 20 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 21 | import android.content.Context; |
| 22 | import android.content.res.TypedArray; |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 23 | import android.graphics.Canvas; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 24 | import android.graphics.Rect; |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 25 | import android.os.StrictMode; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 26 | import android.util.AttributeSet; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 27 | import android.view.FocusFinder; |
Jeff Brown | 33bbfd2 | 2011-02-24 20:55:35 -0800 | [diff] [blame] | 28 | import android.view.InputDevice; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 29 | import android.view.KeyEvent; |
| 30 | import android.view.MotionEvent; |
| 31 | import android.view.VelocityTracker; |
| 32 | import android.view.View; |
| 33 | import android.view.ViewConfiguration; |
Gilles Debunne | 2ed2eac | 2011-02-24 16:29:48 -0800 | [diff] [blame] | 34 | import android.view.ViewDebug; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 35 | import android.view.ViewGroup; |
| 36 | import android.view.ViewParent; |
Svetoslav Ganov | a015617 | 2011-06-26 17:55:44 -0700 | [diff] [blame] | 37 | import android.view.accessibility.AccessibilityEvent; |
| 38 | import android.view.accessibility.AccessibilityNodeInfo; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 39 | import android.view.animation.AnimationUtils; |
| 40 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 41 | import java.util.List; |
| 42 | |
| 43 | /** |
| 44 | * Layout container for a view hierarchy that can be scrolled by the user, |
| 45 | * allowing it to be larger than the physical display. A ScrollView |
| 46 | * is a {@link FrameLayout}, meaning you should place one child in it |
| 47 | * containing the entire contents to scroll; this child may itself be a layout |
| 48 | * manager with a complex hierarchy of objects. A child that is often used |
| 49 | * is a {@link LinearLayout} in a vertical orientation, presenting a vertical |
| 50 | * array of top-level items that the user can scroll through. |
| 51 | * |
| 52 | * <p>The {@link TextView} class also |
| 53 | * takes care of its own scrolling, so does not require a ScrollView, but |
| 54 | * using the two together is possible to achieve the effect of a text view |
| 55 | * within a larger container. |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 56 | * |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 57 | * <p>ScrollView only supports vertical scrolling. |
Romain Guy | fdbf484 | 2010-08-16 10:55:49 -0700 | [diff] [blame] | 58 | * |
| 59 | * @attr ref android.R.styleable#ScrollView_fillViewport |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 60 | */ |
| 61 | public class ScrollView extends FrameLayout { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 62 | static final int ANIMATED_SCROLL_GAP = 250; |
| 63 | |
| 64 | static final float MAX_SCROLL_FACTOR = 0.5f; |
| 65 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 66 | private long mLastScroll; |
| 67 | |
| 68 | private final Rect mTempRect = new Rect(); |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 69 | private OverScroller mScroller; |
Adam Powell | 89935e4 | 2011-08-31 14:26:12 -0700 | [diff] [blame] | 70 | private EdgeEffect mEdgeGlowTop; |
| 71 | private EdgeEffect mEdgeGlowBottom; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 72 | |
| 73 | /** |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 74 | * Position of the last motion event. |
| 75 | */ |
| 76 | private float mLastMotionY; |
| 77 | |
| 78 | /** |
| 79 | * True when the layout has changed but the traversal has not come through yet. |
| 80 | * Ideally the view hierarchy would keep track of this for us. |
| 81 | */ |
| 82 | private boolean mIsLayoutDirty = true; |
| 83 | |
| 84 | /** |
| 85 | * The child to give focus to in the event that a child has requested focus while the |
| 86 | * layout is dirty. This prevents the scroll from being wrong if the child has not been |
| 87 | * laid out before requesting focus. |
| 88 | */ |
| 89 | private View mChildToScrollTo = null; |
| 90 | |
| 91 | /** |
| 92 | * True if the user is currently dragging this ScrollView around. This is |
| 93 | * not the same as 'is being flinged', which can be checked by |
| 94 | * mScroller.isFinished() (flinging begins when the user lifts his finger). |
| 95 | */ |
| 96 | private boolean mIsBeingDragged = false; |
| 97 | |
| 98 | /** |
| 99 | * Determines speed during touch scrolling |
| 100 | */ |
| 101 | private VelocityTracker mVelocityTracker; |
| 102 | |
| 103 | /** |
| 104 | * When set to true, the scroll view measure its child to make it fill the currently |
| 105 | * visible area. |
| 106 | */ |
Romain Guy | a174d7a | 2011-01-07 13:27:39 -0800 | [diff] [blame] | 107 | @ViewDebug.ExportedProperty(category = "layout") |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 108 | private boolean mFillViewport; |
| 109 | |
| 110 | /** |
| 111 | * Whether arrow scrolling is animated. |
| 112 | */ |
| 113 | private boolean mSmoothScrollingEnabled = true; |
| 114 | |
| 115 | private int mTouchSlop; |
Romain Guy | 4296fc4 | 2009-07-06 11:48:52 -0700 | [diff] [blame] | 116 | private int mMinimumVelocity; |
| 117 | private int mMaximumVelocity; |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 118 | |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 119 | private int mOverscrollDistance; |
| 120 | private int mOverflingDistance; |
| 121 | |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 122 | /** |
| 123 | * ID of the active pointer. This is used to retain consistency during |
| 124 | * drags/flings if multiple pointers are used. |
| 125 | */ |
| 126 | private int mActivePointerId = INVALID_POINTER; |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 127 | |
| 128 | /** |
| 129 | * The StrictMode "critical time span" objects to catch animation |
| 130 | * stutters. Non-null when a time-sensitive animation is |
| 131 | * in-flight. Must call finish() on them when done animating. |
| 132 | * These are no-ops on user builds. |
| 133 | */ |
| 134 | private StrictMode.Span mScrollStrictSpan = null; // aka "drag" |
| 135 | private StrictMode.Span mFlingStrictSpan = null; |
| 136 | |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 137 | /** |
| 138 | * Sentinel value for no current active pointer. |
| 139 | * Used by {@link #mActivePointerId}. |
| 140 | */ |
| 141 | private static final int INVALID_POINTER = -1; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 142 | |
| 143 | public ScrollView(Context context) { |
| 144 | this(context, null); |
| 145 | } |
| 146 | |
| 147 | public ScrollView(Context context, AttributeSet attrs) { |
| 148 | this(context, attrs, com.android.internal.R.attr.scrollViewStyle); |
| 149 | } |
| 150 | |
| 151 | public ScrollView(Context context, AttributeSet attrs, int defStyle) { |
| 152 | super(context, attrs, defStyle); |
| 153 | initScrollView(); |
| 154 | |
| 155 | TypedArray a = |
| 156 | context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.ScrollView, defStyle, 0); |
| 157 | |
| 158 | setFillViewport(a.getBoolean(R.styleable.ScrollView_fillViewport, false)); |
| 159 | |
| 160 | a.recycle(); |
| 161 | } |
| 162 | |
| 163 | @Override |
Patrick Dubroy | e0a799a | 2011-05-04 16:19:22 -0700 | [diff] [blame] | 164 | public boolean shouldDelayChildPressedState() { |
| 165 | return true; |
| 166 | } |
| 167 | |
| 168 | @Override |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 169 | protected float getTopFadingEdgeStrength() { |
| 170 | if (getChildCount() == 0) { |
| 171 | return 0.0f; |
| 172 | } |
| 173 | |
| 174 | final int length = getVerticalFadingEdgeLength(); |
| 175 | if (mScrollY < length) { |
| 176 | return mScrollY / (float) length; |
| 177 | } |
| 178 | |
| 179 | return 1.0f; |
| 180 | } |
| 181 | |
| 182 | @Override |
| 183 | protected float getBottomFadingEdgeStrength() { |
| 184 | if (getChildCount() == 0) { |
| 185 | return 0.0f; |
| 186 | } |
| 187 | |
| 188 | final int length = getVerticalFadingEdgeLength(); |
| 189 | final int bottomEdge = getHeight() - mPaddingBottom; |
| 190 | final int span = getChildAt(0).getBottom() - mScrollY - bottomEdge; |
| 191 | if (span < length) { |
| 192 | return span / (float) length; |
| 193 | } |
| 194 | |
| 195 | return 1.0f; |
| 196 | } |
| 197 | |
| 198 | /** |
| 199 | * @return The maximum amount this scroll view will scroll in response to |
| 200 | * an arrow event. |
| 201 | */ |
| 202 | public int getMaxScrollAmount() { |
| 203 | return (int) (MAX_SCROLL_FACTOR * (mBottom - mTop)); |
| 204 | } |
| 205 | |
| 206 | |
| 207 | private void initScrollView() { |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 208 | mScroller = new OverScroller(getContext()); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 209 | setFocusable(true); |
| 210 | setDescendantFocusability(FOCUS_AFTER_DESCENDANTS); |
| 211 | setWillNotDraw(false); |
Romain Guy | 4296fc4 | 2009-07-06 11:48:52 -0700 | [diff] [blame] | 212 | final ViewConfiguration configuration = ViewConfiguration.get(mContext); |
| 213 | mTouchSlop = configuration.getScaledTouchSlop(); |
| 214 | mMinimumVelocity = configuration.getScaledMinimumFlingVelocity(); |
| 215 | mMaximumVelocity = configuration.getScaledMaximumFlingVelocity(); |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 216 | mOverscrollDistance = configuration.getScaledOverscrollDistance(); |
| 217 | mOverflingDistance = configuration.getScaledOverflingDistance(); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 218 | } |
| 219 | |
| 220 | @Override |
| 221 | public void addView(View child) { |
| 222 | if (getChildCount() > 0) { |
| 223 | throw new IllegalStateException("ScrollView can host only one direct child"); |
| 224 | } |
| 225 | |
| 226 | super.addView(child); |
| 227 | } |
| 228 | |
| 229 | @Override |
| 230 | public void addView(View child, int index) { |
| 231 | if (getChildCount() > 0) { |
| 232 | throw new IllegalStateException("ScrollView can host only one direct child"); |
| 233 | } |
| 234 | |
| 235 | super.addView(child, index); |
| 236 | } |
| 237 | |
| 238 | @Override |
| 239 | public void addView(View child, ViewGroup.LayoutParams params) { |
| 240 | if (getChildCount() > 0) { |
| 241 | throw new IllegalStateException("ScrollView can host only one direct child"); |
| 242 | } |
| 243 | |
| 244 | super.addView(child, params); |
| 245 | } |
| 246 | |
| 247 | @Override |
| 248 | public void addView(View child, int index, ViewGroup.LayoutParams params) { |
| 249 | if (getChildCount() > 0) { |
| 250 | throw new IllegalStateException("ScrollView can host only one direct child"); |
| 251 | } |
| 252 | |
| 253 | super.addView(child, index, params); |
| 254 | } |
| 255 | |
| 256 | /** |
| 257 | * @return Returns true this ScrollView can be scrolled |
| 258 | */ |
| 259 | private boolean canScroll() { |
| 260 | View child = getChildAt(0); |
| 261 | if (child != null) { |
| 262 | int childHeight = child.getHeight(); |
| 263 | return getHeight() < childHeight + mPaddingTop + mPaddingBottom; |
| 264 | } |
| 265 | return false; |
| 266 | } |
| 267 | |
| 268 | /** |
| 269 | * Indicates whether this ScrollView's content is stretched to fill the viewport. |
| 270 | * |
| 271 | * @return True if the content fills the viewport, false otherwise. |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 272 | * |
Romain Guy | fdbf484 | 2010-08-16 10:55:49 -0700 | [diff] [blame] | 273 | * @attr ref android.R.styleable#ScrollView_fillViewport |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 274 | */ |
| 275 | public boolean isFillViewport() { |
| 276 | return mFillViewport; |
| 277 | } |
| 278 | |
| 279 | /** |
| 280 | * Indicates this ScrollView whether it should stretch its content height to fill |
| 281 | * the viewport or not. |
| 282 | * |
| 283 | * @param fillViewport True to stretch the content's height to the viewport's |
| 284 | * boundaries, false otherwise. |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 285 | * |
Romain Guy | fdbf484 | 2010-08-16 10:55:49 -0700 | [diff] [blame] | 286 | * @attr ref android.R.styleable#ScrollView_fillViewport |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 287 | */ |
| 288 | public void setFillViewport(boolean fillViewport) { |
| 289 | if (fillViewport != mFillViewport) { |
| 290 | mFillViewport = fillViewport; |
| 291 | requestLayout(); |
| 292 | } |
| 293 | } |
| 294 | |
| 295 | /** |
| 296 | * @return Whether arrow scrolling will animate its transition. |
| 297 | */ |
| 298 | public boolean isSmoothScrollingEnabled() { |
| 299 | return mSmoothScrollingEnabled; |
| 300 | } |
| 301 | |
| 302 | /** |
| 303 | * Set whether arrow scrolling will animate its transition. |
| 304 | * @param smoothScrollingEnabled whether arrow scrolling will animate its transition |
| 305 | */ |
| 306 | public void setSmoothScrollingEnabled(boolean smoothScrollingEnabled) { |
| 307 | mSmoothScrollingEnabled = smoothScrollingEnabled; |
| 308 | } |
| 309 | |
| 310 | @Override |
| 311 | protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { |
| 312 | super.onMeasure(widthMeasureSpec, heightMeasureSpec); |
| 313 | |
| 314 | if (!mFillViewport) { |
| 315 | return; |
| 316 | } |
| 317 | |
| 318 | final int heightMode = MeasureSpec.getMode(heightMeasureSpec); |
| 319 | if (heightMode == MeasureSpec.UNSPECIFIED) { |
| 320 | return; |
| 321 | } |
| 322 | |
Romain Guy | ef0e9ae | 2009-07-10 14:11:26 -0700 | [diff] [blame] | 323 | if (getChildCount() > 0) { |
| 324 | final View child = getChildAt(0); |
| 325 | int height = getMeasuredHeight(); |
| 326 | if (child.getMeasuredHeight() < height) { |
| 327 | final FrameLayout.LayoutParams lp = (LayoutParams) child.getLayoutParams(); |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 328 | |
Romain Guy | 9c95737 | 2011-01-04 17:39:43 -0800 | [diff] [blame] | 329 | int childWidthMeasureSpec = getChildMeasureSpec(widthMeasureSpec, |
| 330 | mPaddingLeft + mPaddingRight, lp.width); |
Romain Guy | ef0e9ae | 2009-07-10 14:11:26 -0700 | [diff] [blame] | 331 | height -= mPaddingTop; |
| 332 | height -= mPaddingBottom; |
| 333 | int childHeightMeasureSpec = |
| 334 | MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY); |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 335 | |
Romain Guy | ef0e9ae | 2009-07-10 14:11:26 -0700 | [diff] [blame] | 336 | child.measure(childWidthMeasureSpec, childHeightMeasureSpec); |
| 337 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 338 | } |
| 339 | } |
| 340 | |
| 341 | @Override |
| 342 | public boolean dispatchKeyEvent(KeyEvent event) { |
| 343 | // Let the focused view and/or our descendants get the key first |
Romain Guy | 8e618e5 | 2010-03-08 12:18:20 -0800 | [diff] [blame] | 344 | return super.dispatchKeyEvent(event) || executeKeyEvent(event); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 345 | } |
| 346 | |
| 347 | /** |
| 348 | * You can call this function yourself to have the scroll view perform |
| 349 | * scrolling from a key event, just as if the event had been dispatched to |
| 350 | * it by the view hierarchy. |
| 351 | * |
| 352 | * @param event The key event to execute. |
| 353 | * @return Return true if the event was handled, else false. |
| 354 | */ |
| 355 | public boolean executeKeyEvent(KeyEvent event) { |
| 356 | mTempRect.setEmpty(); |
| 357 | |
| 358 | if (!canScroll()) { |
Romain Guy | 2d4cff6 | 2010-04-09 15:39:00 -0700 | [diff] [blame] | 359 | if (isFocused() && event.getKeyCode() != KeyEvent.KEYCODE_BACK) { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 360 | View currentFocused = findFocus(); |
| 361 | if (currentFocused == this) currentFocused = null; |
| 362 | View nextFocused = FocusFinder.getInstance().findNextFocus(this, |
| 363 | currentFocused, View.FOCUS_DOWN); |
| 364 | return nextFocused != null |
| 365 | && nextFocused != this |
| 366 | && nextFocused.requestFocus(View.FOCUS_DOWN); |
| 367 | } |
| 368 | return false; |
| 369 | } |
| 370 | |
| 371 | boolean handled = false; |
| 372 | if (event.getAction() == KeyEvent.ACTION_DOWN) { |
| 373 | switch (event.getKeyCode()) { |
| 374 | case KeyEvent.KEYCODE_DPAD_UP: |
| 375 | if (!event.isAltPressed()) { |
| 376 | handled = arrowScroll(View.FOCUS_UP); |
| 377 | } else { |
| 378 | handled = fullScroll(View.FOCUS_UP); |
| 379 | } |
| 380 | break; |
| 381 | case KeyEvent.KEYCODE_DPAD_DOWN: |
| 382 | if (!event.isAltPressed()) { |
| 383 | handled = arrowScroll(View.FOCUS_DOWN); |
| 384 | } else { |
| 385 | handled = fullScroll(View.FOCUS_DOWN); |
| 386 | } |
| 387 | break; |
| 388 | case KeyEvent.KEYCODE_SPACE: |
| 389 | pageScroll(event.isShiftPressed() ? View.FOCUS_UP : View.FOCUS_DOWN); |
| 390 | break; |
| 391 | } |
| 392 | } |
| 393 | |
| 394 | return handled; |
| 395 | } |
| 396 | |
Joe Onorato | 9f0e8ee | 2010-02-23 19:19:22 -0800 | [diff] [blame] | 397 | private boolean inChild(int x, int y) { |
| 398 | if (getChildCount() > 0) { |
Adam Powell | 352b978 | 2010-03-24 14:23:43 -0700 | [diff] [blame] | 399 | final int scrollY = mScrollY; |
Joe Onorato | 9f0e8ee | 2010-02-23 19:19:22 -0800 | [diff] [blame] | 400 | final View child = getChildAt(0); |
Adam Powell | 352b978 | 2010-03-24 14:23:43 -0700 | [diff] [blame] | 401 | return !(y < child.getTop() - scrollY |
| 402 | || y >= child.getBottom() - scrollY |
Joe Onorato | 9f0e8ee | 2010-02-23 19:19:22 -0800 | [diff] [blame] | 403 | || x < child.getLeft() |
| 404 | || x >= child.getRight()); |
| 405 | } |
| 406 | return false; |
| 407 | } |
| 408 | |
Michael Jurka | 13451a4 | 2011-08-22 15:54:21 -0700 | [diff] [blame] | 409 | private void initOrResetVelocityTracker() { |
| 410 | if (mVelocityTracker == null) { |
| 411 | mVelocityTracker = VelocityTracker.obtain(); |
| 412 | } else { |
| 413 | mVelocityTracker.clear(); |
| 414 | } |
| 415 | } |
| 416 | |
| 417 | private void initVelocityTrackerIfNotExists() { |
| 418 | if (mVelocityTracker == null) { |
| 419 | mVelocityTracker = VelocityTracker.obtain(); |
| 420 | } |
| 421 | } |
| 422 | |
| 423 | private void recycleVelocityTracker() { |
| 424 | if (mVelocityTracker != null) { |
| 425 | mVelocityTracker.recycle(); |
| 426 | mVelocityTracker = null; |
| 427 | } |
| 428 | } |
| 429 | |
| 430 | @Override |
| 431 | public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) { |
| 432 | if (disallowIntercept) { |
| 433 | recycleVelocityTracker(); |
| 434 | } |
| 435 | super.requestDisallowInterceptTouchEvent(disallowIntercept); |
| 436 | } |
| 437 | |
| 438 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 439 | @Override |
| 440 | public boolean onInterceptTouchEvent(MotionEvent ev) { |
| 441 | /* |
| 442 | * This method JUST determines whether we want to intercept the motion. |
| 443 | * If we return true, onMotionEvent will be called and we do the actual |
| 444 | * scrolling there. |
| 445 | */ |
| 446 | |
| 447 | /* |
| 448 | * Shortcut the most recurring case: the user is in the dragging |
| 449 | * state and he is moving his finger. We want to intercept this |
| 450 | * motion. |
| 451 | */ |
| 452 | final int action = ev.getAction(); |
| 453 | if ((action == MotionEvent.ACTION_MOVE) && (mIsBeingDragged)) { |
| 454 | return true; |
| 455 | } |
| 456 | |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 457 | switch (action & MotionEvent.ACTION_MASK) { |
| 458 | case MotionEvent.ACTION_MOVE: { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 459 | /* |
| 460 | * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check |
| 461 | * whether the user has moved far enough from his original down touch. |
| 462 | */ |
| 463 | |
| 464 | /* |
| 465 | * Locally do absolute value. mLastMotionY is set to the y value |
| 466 | * of the down event. |
| 467 | */ |
Adam Powell | 9d0335b | 2010-03-24 13:42:51 -0700 | [diff] [blame] | 468 | final int activePointerId = mActivePointerId; |
| 469 | if (activePointerId == INVALID_POINTER) { |
| 470 | // If we don't have a valid id, the touch down wasn't on content. |
| 471 | break; |
| 472 | } |
| 473 | |
| 474 | final int pointerIndex = ev.findPointerIndex(activePointerId); |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 475 | final float y = ev.getY(pointerIndex); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 476 | final int yDiff = (int) Math.abs(y - mLastMotionY); |
| 477 | if (yDiff > mTouchSlop) { |
| 478 | mIsBeingDragged = true; |
Romain Guy | f7b4acc | 2009-12-01 16:24:45 -0800 | [diff] [blame] | 479 | mLastMotionY = y; |
Michael Jurka | 13451a4 | 2011-08-22 15:54:21 -0700 | [diff] [blame] | 480 | initVelocityTrackerIfNotExists(); |
| 481 | mVelocityTracker.addMovement(ev); |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 482 | if (mScrollStrictSpan == null) { |
| 483 | mScrollStrictSpan = StrictMode.enterCriticalSpan("ScrollView-scroll"); |
| 484 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 485 | } |
| 486 | break; |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 487 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 488 | |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 489 | case MotionEvent.ACTION_DOWN: { |
| 490 | final float y = ev.getY(); |
Adam Powell | 4cd4770 | 2010-02-25 11:21:14 -0800 | [diff] [blame] | 491 | if (!inChild((int) ev.getX(), (int) y)) { |
Joe Onorato | 9f0e8ee | 2010-02-23 19:19:22 -0800 | [diff] [blame] | 492 | mIsBeingDragged = false; |
Michael Jurka | 13451a4 | 2011-08-22 15:54:21 -0700 | [diff] [blame] | 493 | recycleVelocityTracker(); |
Joe Onorato | 9f0e8ee | 2010-02-23 19:19:22 -0800 | [diff] [blame] | 494 | break; |
| 495 | } |
| 496 | |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 497 | /* |
| 498 | * Remember location of down touch. |
| 499 | * ACTION_DOWN always refers to pointer index 0. |
| 500 | */ |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 501 | mLastMotionY = y; |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 502 | mActivePointerId = ev.getPointerId(0); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 503 | |
Michael Jurka | 13451a4 | 2011-08-22 15:54:21 -0700 | [diff] [blame] | 504 | initOrResetVelocityTracker(); |
| 505 | mVelocityTracker.addMovement(ev); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 506 | /* |
| 507 | * If being flinged and user touches the screen, initiate drag; |
| 508 | * otherwise don't. mScroller.isFinished should be false when |
| 509 | * being flinged. |
| 510 | */ |
| 511 | mIsBeingDragged = !mScroller.isFinished(); |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 512 | if (mIsBeingDragged && mScrollStrictSpan == null) { |
| 513 | mScrollStrictSpan = StrictMode.enterCriticalSpan("ScrollView-scroll"); |
| 514 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 515 | break; |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 516 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 517 | |
| 518 | case MotionEvent.ACTION_CANCEL: |
| 519 | case MotionEvent.ACTION_UP: |
| 520 | /* Release the drag */ |
| 521 | mIsBeingDragged = false; |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 522 | mActivePointerId = INVALID_POINTER; |
Michael Jurka | 13451a4 | 2011-08-22 15:54:21 -0700 | [diff] [blame] | 523 | recycleVelocityTracker(); |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 524 | if (mScroller.springBack(mScrollX, mScrollY, 0, 0, 0, getScrollRange())) { |
| 525 | invalidate(); |
| 526 | } |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 527 | break; |
| 528 | case MotionEvent.ACTION_POINTER_UP: |
| 529 | onSecondaryPointerUp(ev); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 530 | break; |
| 531 | } |
| 532 | |
| 533 | /* |
| 534 | * The only time we want to intercept motion events is if we are in the |
| 535 | * drag mode. |
| 536 | */ |
| 537 | return mIsBeingDragged; |
| 538 | } |
| 539 | |
| 540 | @Override |
| 541 | public boolean onTouchEvent(MotionEvent ev) { |
Michael Jurka | 13451a4 | 2011-08-22 15:54:21 -0700 | [diff] [blame] | 542 | initVelocityTrackerIfNotExists(); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 543 | mVelocityTracker.addMovement(ev); |
| 544 | |
| 545 | final int action = ev.getAction(); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 546 | |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 547 | switch (action & MotionEvent.ACTION_MASK) { |
| 548 | case MotionEvent.ACTION_DOWN: { |
Jeff Brown | fb75738 | 2011-01-18 18:42:33 -0800 | [diff] [blame] | 549 | mIsBeingDragged = getChildCount() != 0; |
| 550 | if (!mIsBeingDragged) { |
| 551 | return false; |
| 552 | } |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 553 | |
Adam Powell | 352b978 | 2010-03-24 14:23:43 -0700 | [diff] [blame] | 554 | /* |
| 555 | * If being flinged and user touches, stop the fling. isFinished |
| 556 | * will be false if being flinged. |
| 557 | */ |
| 558 | if (!mScroller.isFinished()) { |
| 559 | mScroller.abortAnimation(); |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 560 | if (mFlingStrictSpan != null) { |
| 561 | mFlingStrictSpan.finish(); |
| 562 | mFlingStrictSpan = null; |
| 563 | } |
Adam Powell | 352b978 | 2010-03-24 14:23:43 -0700 | [diff] [blame] | 564 | } |
| 565 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 566 | // Remember where the motion event started |
Jeff Brown | fb75738 | 2011-01-18 18:42:33 -0800 | [diff] [blame] | 567 | mLastMotionY = ev.getY(); |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 568 | mActivePointerId = ev.getPointerId(0); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 569 | break; |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 570 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 571 | case MotionEvent.ACTION_MOVE: |
Joe Onorato | 9f0e8ee | 2010-02-23 19:19:22 -0800 | [diff] [blame] | 572 | if (mIsBeingDragged) { |
| 573 | // Scroll to follow the motion event |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 574 | final int activePointerIndex = ev.findPointerIndex(mActivePointerId); |
| 575 | final float y = ev.getY(activePointerIndex); |
Joe Onorato | 9f0e8ee | 2010-02-23 19:19:22 -0800 | [diff] [blame] | 576 | final int deltaY = (int) (mLastMotionY - y); |
| 577 | mLastMotionY = y; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 578 | |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 579 | final int oldX = mScrollX; |
| 580 | final int oldY = mScrollY; |
| 581 | final int range = getScrollRange(); |
Fabrice Di Meglio | e9dbef8 | 2011-09-12 16:36:46 -0700 | [diff] [blame] | 582 | final int overscrollMode = getOverScrollMode(); |
| 583 | final boolean canOverscroll = overscrollMode == OVER_SCROLL_ALWAYS || |
| 584 | (overscrollMode == OVER_SCROLL_IF_CONTENT_SCROLLS && range > 0); |
| 585 | |
Adam Powell | f6a6c97 | 2011-09-28 23:30:20 -0700 | [diff] [blame] | 586 | if (overScrollBy(0, deltaY, 0, mScrollY, |
Fabrice Di Meglio | e9dbef8 | 2011-09-12 16:36:46 -0700 | [diff] [blame] | 587 | 0, range, 0, mOverscrollDistance, true)) { |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 588 | // Break our velocity if we hit a scroll barrier. |
| 589 | mVelocityTracker.clear(); |
| 590 | } |
| 591 | onScrollChanged(mScrollX, mScrollY, oldX, oldY); |
| 592 | |
Fabrice Di Meglio | e9dbef8 | 2011-09-12 16:36:46 -0700 | [diff] [blame] | 593 | if (canOverscroll) { |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 594 | final int pulledToY = oldY + deltaY; |
| 595 | if (pulledToY < 0) { |
| 596 | mEdgeGlowTop.onPull((float) deltaY / getHeight()); |
| 597 | if (!mEdgeGlowBottom.isFinished()) { |
| 598 | mEdgeGlowBottom.onRelease(); |
| 599 | } |
| 600 | } else if (pulledToY > range) { |
| 601 | mEdgeGlowBottom.onPull((float) deltaY / getHeight()); |
| 602 | if (!mEdgeGlowTop.isFinished()) { |
| 603 | mEdgeGlowTop.onRelease(); |
| 604 | } |
| 605 | } |
| 606 | if (mEdgeGlowTop != null |
| 607 | && (!mEdgeGlowTop.isFinished() || !mEdgeGlowBottom.isFinished())) { |
| 608 | invalidate(); |
| 609 | } |
| 610 | } |
Joe Onorato | 9f0e8ee | 2010-02-23 19:19:22 -0800 | [diff] [blame] | 611 | } |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 612 | break; |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 613 | case MotionEvent.ACTION_UP: |
Joe Onorato | 9f0e8ee | 2010-02-23 19:19:22 -0800 | [diff] [blame] | 614 | if (mIsBeingDragged) { |
| 615 | final VelocityTracker velocityTracker = mVelocityTracker; |
| 616 | velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity); |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 617 | int initialVelocity = (int) velocityTracker.getYVelocity(mActivePointerId); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 618 | |
Adam Powell | f6a6c97 | 2011-09-28 23:30:20 -0700 | [diff] [blame] | 619 | if (getChildCount() > 0) { |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 620 | if ((Math.abs(initialVelocity) > mMinimumVelocity)) { |
| 621 | fling(-initialVelocity); |
| 622 | } else { |
Adam Powell | f6a6c97 | 2011-09-28 23:30:20 -0700 | [diff] [blame] | 623 | if (mScroller.springBack(mScrollX, mScrollY, 0, 0, 0, |
| 624 | getScrollRange())) { |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 625 | invalidate(); |
| 626 | } |
| 627 | } |
Adam Powell | 17dfce1 | 2010-01-25 18:38:22 -0800 | [diff] [blame] | 628 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 629 | |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 630 | mActivePointerId = INVALID_POINTER; |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 631 | endDrag(); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 632 | } |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 633 | break; |
Adam Powell | 352b978 | 2010-03-24 14:23:43 -0700 | [diff] [blame] | 634 | case MotionEvent.ACTION_CANCEL: |
| 635 | if (mIsBeingDragged && getChildCount() > 0) { |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 636 | if (mScroller.springBack(mScrollX, mScrollY, 0, 0, 0, getScrollRange())) { |
| 637 | invalidate(); |
| 638 | } |
Adam Powell | 352b978 | 2010-03-24 14:23:43 -0700 | [diff] [blame] | 639 | mActivePointerId = INVALID_POINTER; |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 640 | endDrag(); |
Adam Powell | 352b978 | 2010-03-24 14:23:43 -0700 | [diff] [blame] | 641 | } |
| 642 | break; |
Adam Powell | 9bc30d3 | 2011-02-28 10:27:49 -0800 | [diff] [blame] | 643 | case MotionEvent.ACTION_POINTER_DOWN: { |
| 644 | final int index = ev.getActionIndex(); |
| 645 | final float y = ev.getY(index); |
| 646 | mLastMotionY = y; |
| 647 | mActivePointerId = ev.getPointerId(index); |
| 648 | break; |
| 649 | } |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 650 | case MotionEvent.ACTION_POINTER_UP: |
| 651 | onSecondaryPointerUp(ev); |
Adam Powell | 9bc30d3 | 2011-02-28 10:27:49 -0800 | [diff] [blame] | 652 | mLastMotionY = ev.getY(ev.findPointerIndex(mActivePointerId)); |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 653 | break; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 654 | } |
| 655 | return true; |
| 656 | } |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 657 | |
Adam Powell | bc4e753 | 2010-02-23 14:49:01 -0800 | [diff] [blame] | 658 | private void onSecondaryPointerUp(MotionEvent ev) { |
| 659 | final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> |
| 660 | MotionEvent.ACTION_POINTER_INDEX_SHIFT; |
| 661 | final int pointerId = ev.getPointerId(pointerIndex); |
| 662 | if (pointerId == mActivePointerId) { |
| 663 | // This was our active pointer going up. Choose a new |
| 664 | // active pointer and adjust accordingly. |
| 665 | // TODO: Make this decision more intelligent. |
| 666 | final int newPointerIndex = pointerIndex == 0 ? 1 : 0; |
| 667 | mLastMotionY = ev.getY(newPointerIndex); |
| 668 | mActivePointerId = ev.getPointerId(newPointerIndex); |
| 669 | if (mVelocityTracker != null) { |
| 670 | mVelocityTracker.clear(); |
| 671 | } |
| 672 | } |
| 673 | } |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 674 | |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 675 | @Override |
Jeff Brown | 33bbfd2 | 2011-02-24 20:55:35 -0800 | [diff] [blame] | 676 | public boolean onGenericMotionEvent(MotionEvent event) { |
| 677 | if ((event.getSource() & InputDevice.SOURCE_CLASS_POINTER) != 0) { |
| 678 | switch (event.getAction()) { |
| 679 | case MotionEvent.ACTION_SCROLL: { |
| 680 | if (!mIsBeingDragged) { |
| 681 | final float vscroll = event.getAxisValue(MotionEvent.AXIS_VSCROLL); |
| 682 | if (vscroll != 0) { |
| 683 | final int delta = (int) (vscroll * getVerticalScrollFactor()); |
| 684 | final int range = getScrollRange(); |
| 685 | int oldScrollY = mScrollY; |
| 686 | int newScrollY = oldScrollY - delta; |
| 687 | if (newScrollY < 0) { |
| 688 | newScrollY = 0; |
| 689 | } else if (newScrollY > range) { |
| 690 | newScrollY = range; |
| 691 | } |
| 692 | if (newScrollY != oldScrollY) { |
| 693 | super.scrollTo(mScrollX, newScrollY); |
| 694 | return true; |
| 695 | } |
| 696 | } |
| 697 | } |
| 698 | } |
| 699 | } |
| 700 | } |
| 701 | return super.onGenericMotionEvent(event); |
| 702 | } |
| 703 | |
| 704 | @Override |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 705 | protected void onOverScrolled(int scrollX, int scrollY, |
| 706 | boolean clampedX, boolean clampedY) { |
| 707 | // Treat animating scrolls differently; see #computeScroll() for why. |
| 708 | if (!mScroller.isFinished()) { |
| 709 | mScrollX = scrollX; |
| 710 | mScrollY = scrollY; |
Romain Guy | 0fd89bf | 2011-01-26 15:41:30 -0800 | [diff] [blame] | 711 | invalidateParentIfNeeded(); |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 712 | if (clampedY) { |
| 713 | mScroller.springBack(mScrollX, mScrollY, 0, 0, 0, getScrollRange()); |
| 714 | } |
| 715 | } else { |
| 716 | super.scrollTo(scrollX, scrollY); |
| 717 | } |
| 718 | awakenScrollBars(); |
| 719 | } |
| 720 | |
Svetoslav Ganov | a015617 | 2011-06-26 17:55:44 -0700 | [diff] [blame] | 721 | @Override |
| 722 | public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) { |
| 723 | super.onInitializeAccessibilityNodeInfo(info); |
Svetoslav Ganov | 8a78fd4 | 2012-01-17 14:36:46 -0800 | [diff] [blame] | 724 | info.setClassName(ScrollView.class.getName()); |
Svetoslav Ganov | d9ee72f | 2011-10-05 22:26:05 -0700 | [diff] [blame] | 725 | info.setScrollable(getScrollRange() > 0); |
Svetoslav Ganov | a015617 | 2011-06-26 17:55:44 -0700 | [diff] [blame] | 726 | } |
| 727 | |
| 728 | @Override |
| 729 | public void onInitializeAccessibilityEvent(AccessibilityEvent event) { |
| 730 | super.onInitializeAccessibilityEvent(event); |
Svetoslav Ganov | 8a78fd4 | 2012-01-17 14:36:46 -0800 | [diff] [blame] | 731 | event.setClassName(ScrollView.class.getName()); |
Svetoslav Ganov | d9ee72f | 2011-10-05 22:26:05 -0700 | [diff] [blame] | 732 | final boolean scrollable = getScrollRange() > 0; |
| 733 | event.setScrollable(scrollable); |
| 734 | event.setScrollX(mScrollX); |
| 735 | event.setScrollY(mScrollY); |
| 736 | event.setMaxScrollX(mScrollX); |
| 737 | event.setMaxScrollY(getScrollRange()); |
Svetoslav Ganov | a015617 | 2011-06-26 17:55:44 -0700 | [diff] [blame] | 738 | } |
| 739 | |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 740 | private int getScrollRange() { |
| 741 | int scrollRange = 0; |
| 742 | if (getChildCount() > 0) { |
| 743 | View child = getChildAt(0); |
| 744 | scrollRange = Math.max(0, |
| 745 | child.getHeight() - (getHeight() - mPaddingBottom - mPaddingTop)); |
| 746 | } |
| 747 | return scrollRange; |
| 748 | } |
| 749 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 750 | /** |
| 751 | * <p> |
| 752 | * Finds the next focusable component that fits in this View's bounds |
| 753 | * (excluding fading edges) pretending that this View's top is located at |
| 754 | * the parameter top. |
| 755 | * </p> |
| 756 | * |
Gilles Debunne | 2ed2eac | 2011-02-24 16:29:48 -0800 | [diff] [blame] | 757 | * @param topFocus look for a candidate at the top of the bounds if topFocus is true, |
| 758 | * or at the bottom of the bounds if topFocus is false |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 759 | * @param top the top offset of the bounds in which a focusable must be |
| 760 | * found (the fading edge is assumed to start at this position) |
| 761 | * @param preferredFocusable the View that has highest priority and will be |
| 762 | * returned if it is within my bounds (null is valid) |
Gilles Debunne | 2ed2eac | 2011-02-24 16:29:48 -0800 | [diff] [blame] | 763 | * @return the next focusable component in the bounds or null if none can be found |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 764 | */ |
| 765 | private View findFocusableViewInMyBounds(final boolean topFocus, |
| 766 | final int top, View preferredFocusable) { |
| 767 | /* |
| 768 | * The fading edge's transparent side should be considered for focus |
| 769 | * since it's mostly visible, so we divide the actual fading edge length |
| 770 | * by 2. |
| 771 | */ |
| 772 | final int fadingEdgeLength = getVerticalFadingEdgeLength() / 2; |
| 773 | final int topWithoutFadingEdge = top + fadingEdgeLength; |
| 774 | final int bottomWithoutFadingEdge = top + getHeight() - fadingEdgeLength; |
| 775 | |
| 776 | if ((preferredFocusable != null) |
| 777 | && (preferredFocusable.getTop() < bottomWithoutFadingEdge) |
| 778 | && (preferredFocusable.getBottom() > topWithoutFadingEdge)) { |
| 779 | return preferredFocusable; |
| 780 | } |
| 781 | |
| 782 | return findFocusableViewInBounds(topFocus, topWithoutFadingEdge, |
| 783 | bottomWithoutFadingEdge); |
| 784 | } |
| 785 | |
| 786 | /** |
| 787 | * <p> |
| 788 | * Finds the next focusable component that fits in the specified bounds. |
| 789 | * </p> |
| 790 | * |
| 791 | * @param topFocus look for a candidate is the one at the top of the bounds |
| 792 | * if topFocus is true, or at the bottom of the bounds if topFocus is |
| 793 | * false |
| 794 | * @param top the top offset of the bounds in which a focusable must be |
| 795 | * found |
| 796 | * @param bottom the bottom offset of the bounds in which a focusable must |
| 797 | * be found |
| 798 | * @return the next focusable component in the bounds or null if none can |
| 799 | * be found |
| 800 | */ |
| 801 | private View findFocusableViewInBounds(boolean topFocus, int top, int bottom) { |
| 802 | |
| 803 | List<View> focusables = getFocusables(View.FOCUS_FORWARD); |
| 804 | View focusCandidate = null; |
| 805 | |
| 806 | /* |
| 807 | * A fully contained focusable is one where its top is below the bound's |
| 808 | * top, and its bottom is above the bound's bottom. A partially |
| 809 | * contained focusable is one where some part of it is within the |
| 810 | * bounds, but it also has some part that is not within bounds. A fully contained |
| 811 | * focusable is preferred to a partially contained focusable. |
| 812 | */ |
| 813 | boolean foundFullyContainedFocusable = false; |
| 814 | |
| 815 | int count = focusables.size(); |
| 816 | for (int i = 0; i < count; i++) { |
| 817 | View view = focusables.get(i); |
| 818 | int viewTop = view.getTop(); |
| 819 | int viewBottom = view.getBottom(); |
| 820 | |
| 821 | if (top < viewBottom && viewTop < bottom) { |
| 822 | /* |
| 823 | * the focusable is in the target area, it is a candidate for |
| 824 | * focusing |
| 825 | */ |
| 826 | |
| 827 | final boolean viewIsFullyContained = (top < viewTop) && |
| 828 | (viewBottom < bottom); |
| 829 | |
| 830 | if (focusCandidate == null) { |
| 831 | /* No candidate, take this one */ |
| 832 | focusCandidate = view; |
| 833 | foundFullyContainedFocusable = viewIsFullyContained; |
| 834 | } else { |
| 835 | final boolean viewIsCloserToBoundary = |
| 836 | (topFocus && viewTop < focusCandidate.getTop()) || |
| 837 | (!topFocus && viewBottom > focusCandidate |
| 838 | .getBottom()); |
| 839 | |
| 840 | if (foundFullyContainedFocusable) { |
| 841 | if (viewIsFullyContained && viewIsCloserToBoundary) { |
| 842 | /* |
| 843 | * We're dealing with only fully contained views, so |
| 844 | * it has to be closer to the boundary to beat our |
| 845 | * candidate |
| 846 | */ |
| 847 | focusCandidate = view; |
| 848 | } |
| 849 | } else { |
| 850 | if (viewIsFullyContained) { |
| 851 | /* Any fully contained view beats a partially contained view */ |
| 852 | focusCandidate = view; |
| 853 | foundFullyContainedFocusable = true; |
| 854 | } else if (viewIsCloserToBoundary) { |
| 855 | /* |
| 856 | * Partially contained view beats another partially |
| 857 | * contained view if it's closer |
| 858 | */ |
| 859 | focusCandidate = view; |
| 860 | } |
| 861 | } |
| 862 | } |
| 863 | } |
| 864 | } |
| 865 | |
| 866 | return focusCandidate; |
| 867 | } |
| 868 | |
| 869 | /** |
| 870 | * <p>Handles scrolling in response to a "page up/down" shortcut press. This |
| 871 | * method will scroll the view by one page up or down and give the focus |
| 872 | * to the topmost/bottommost component in the new visible area. If no |
| 873 | * component is a good candidate for focus, this scrollview reclaims the |
| 874 | * focus.</p> |
| 875 | * |
| 876 | * @param direction the scroll direction: {@link android.view.View#FOCUS_UP} |
| 877 | * to go one page up or |
| 878 | * {@link android.view.View#FOCUS_DOWN} to go one page down |
| 879 | * @return true if the key event is consumed by this method, false otherwise |
| 880 | */ |
| 881 | public boolean pageScroll(int direction) { |
| 882 | boolean down = direction == View.FOCUS_DOWN; |
| 883 | int height = getHeight(); |
| 884 | |
| 885 | if (down) { |
| 886 | mTempRect.top = getScrollY() + height; |
| 887 | int count = getChildCount(); |
| 888 | if (count > 0) { |
| 889 | View view = getChildAt(count - 1); |
| 890 | if (mTempRect.top + height > view.getBottom()) { |
| 891 | mTempRect.top = view.getBottom() - height; |
| 892 | } |
| 893 | } |
| 894 | } else { |
| 895 | mTempRect.top = getScrollY() - height; |
| 896 | if (mTempRect.top < 0) { |
| 897 | mTempRect.top = 0; |
| 898 | } |
| 899 | } |
| 900 | mTempRect.bottom = mTempRect.top + height; |
| 901 | |
| 902 | return scrollAndFocus(direction, mTempRect.top, mTempRect.bottom); |
| 903 | } |
| 904 | |
| 905 | /** |
| 906 | * <p>Handles scrolling in response to a "home/end" shortcut press. This |
| 907 | * method will scroll the view to the top or bottom and give the focus |
| 908 | * to the topmost/bottommost component in the new visible area. If no |
| 909 | * component is a good candidate for focus, this scrollview reclaims the |
| 910 | * focus.</p> |
| 911 | * |
| 912 | * @param direction the scroll direction: {@link android.view.View#FOCUS_UP} |
| 913 | * to go the top of the view or |
| 914 | * {@link android.view.View#FOCUS_DOWN} to go the bottom |
| 915 | * @return true if the key event is consumed by this method, false otherwise |
| 916 | */ |
| 917 | public boolean fullScroll(int direction) { |
| 918 | boolean down = direction == View.FOCUS_DOWN; |
| 919 | int height = getHeight(); |
| 920 | |
| 921 | mTempRect.top = 0; |
| 922 | mTempRect.bottom = height; |
| 923 | |
| 924 | if (down) { |
| 925 | int count = getChildCount(); |
| 926 | if (count > 0) { |
| 927 | View view = getChildAt(count - 1); |
Mattias Petersson | 5435a06 | 2011-04-07 15:46:56 +0200 | [diff] [blame] | 928 | mTempRect.bottom = view.getBottom() + mPaddingBottom; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 929 | mTempRect.top = mTempRect.bottom - height; |
| 930 | } |
| 931 | } |
| 932 | |
| 933 | return scrollAndFocus(direction, mTempRect.top, mTempRect.bottom); |
| 934 | } |
| 935 | |
| 936 | /** |
| 937 | * <p>Scrolls the view to make the area defined by <code>top</code> and |
| 938 | * <code>bottom</code> visible. This method attempts to give the focus |
| 939 | * to a component visible in this area. If no component can be focused in |
Gilles Debunne | 2ed2eac | 2011-02-24 16:29:48 -0800 | [diff] [blame] | 940 | * the new visible area, the focus is reclaimed by this ScrollView.</p> |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 941 | * |
| 942 | * @param direction the scroll direction: {@link android.view.View#FOCUS_UP} |
Gilles Debunne | 2ed2eac | 2011-02-24 16:29:48 -0800 | [diff] [blame] | 943 | * to go upward, {@link android.view.View#FOCUS_DOWN} to downward |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 944 | * @param top the top offset of the new area to be made visible |
| 945 | * @param bottom the bottom offset of the new area to be made visible |
| 946 | * @return true if the key event is consumed by this method, false otherwise |
| 947 | */ |
| 948 | private boolean scrollAndFocus(int direction, int top, int bottom) { |
| 949 | boolean handled = true; |
| 950 | |
| 951 | int height = getHeight(); |
| 952 | int containerTop = getScrollY(); |
| 953 | int containerBottom = containerTop + height; |
| 954 | boolean up = direction == View.FOCUS_UP; |
| 955 | |
| 956 | View newFocused = findFocusableViewInBounds(up, top, bottom); |
| 957 | if (newFocused == null) { |
| 958 | newFocused = this; |
| 959 | } |
| 960 | |
| 961 | if (top >= containerTop && bottom <= containerBottom) { |
| 962 | handled = false; |
| 963 | } else { |
| 964 | int delta = up ? (top - containerTop) : (bottom - containerBottom); |
| 965 | doScrollY(delta); |
| 966 | } |
| 967 | |
Gilles Debunne | 2ed2eac | 2011-02-24 16:29:48 -0800 | [diff] [blame] | 968 | if (newFocused != findFocus()) newFocused.requestFocus(direction); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 969 | |
| 970 | return handled; |
| 971 | } |
| 972 | |
| 973 | /** |
| 974 | * Handle scrolling in response to an up or down arrow click. |
| 975 | * |
| 976 | * @param direction The direction corresponding to the arrow key that was |
| 977 | * pressed |
| 978 | * @return True if we consumed the event, false otherwise |
| 979 | */ |
| 980 | public boolean arrowScroll(int direction) { |
| 981 | |
| 982 | View currentFocused = findFocus(); |
| 983 | if (currentFocused == this) currentFocused = null; |
| 984 | |
| 985 | View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction); |
| 986 | |
| 987 | final int maxJump = getMaxScrollAmount(); |
| 988 | |
Jack Veenstra | 7d4200d | 2009-09-21 19:45:14 -0700 | [diff] [blame] | 989 | if (nextFocused != null && isWithinDeltaOfScreen(nextFocused, maxJump, getHeight())) { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 990 | nextFocused.getDrawingRect(mTempRect); |
| 991 | offsetDescendantRectToMyCoords(nextFocused, mTempRect); |
| 992 | int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect); |
| 993 | doScrollY(scrollDelta); |
| 994 | nextFocused.requestFocus(direction); |
| 995 | } else { |
| 996 | // no new focus |
| 997 | int scrollDelta = maxJump; |
| 998 | |
| 999 | if (direction == View.FOCUS_UP && getScrollY() < scrollDelta) { |
| 1000 | scrollDelta = getScrollY(); |
| 1001 | } else if (direction == View.FOCUS_DOWN) { |
Romain Guy | ef0e9ae | 2009-07-10 14:11:26 -0700 | [diff] [blame] | 1002 | if (getChildCount() > 0) { |
| 1003 | int daBottom = getChildAt(0).getBottom(); |
Mattias Petersson | 5435a06 | 2011-04-07 15:46:56 +0200 | [diff] [blame] | 1004 | int screenBottom = getScrollY() + getHeight() - mPaddingBottom; |
Romain Guy | ef0e9ae | 2009-07-10 14:11:26 -0700 | [diff] [blame] | 1005 | if (daBottom - screenBottom < maxJump) { |
| 1006 | scrollDelta = daBottom - screenBottom; |
| 1007 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1008 | } |
| 1009 | } |
| 1010 | if (scrollDelta == 0) { |
| 1011 | return false; |
| 1012 | } |
| 1013 | doScrollY(direction == View.FOCUS_DOWN ? scrollDelta : -scrollDelta); |
| 1014 | } |
| 1015 | |
| 1016 | if (currentFocused != null && currentFocused.isFocused() |
| 1017 | && isOffScreen(currentFocused)) { |
| 1018 | // previously focused item still has focus and is off screen, give |
| 1019 | // it up (take it back to ourselves) |
| 1020 | // (also, need to temporarily force FOCUS_BEFORE_DESCENDANTS so we are |
| 1021 | // sure to |
| 1022 | // get it) |
| 1023 | final int descendantFocusability = getDescendantFocusability(); // save |
| 1024 | setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS); |
| 1025 | requestFocus(); |
| 1026 | setDescendantFocusability(descendantFocusability); // restore |
| 1027 | } |
| 1028 | return true; |
| 1029 | } |
| 1030 | |
| 1031 | /** |
| 1032 | * @return whether the descendant of this scroll view is scrolled off |
| 1033 | * screen. |
| 1034 | */ |
| 1035 | private boolean isOffScreen(View descendant) { |
Jack Veenstra | 7d4200d | 2009-09-21 19:45:14 -0700 | [diff] [blame] | 1036 | return !isWithinDeltaOfScreen(descendant, 0, getHeight()); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1037 | } |
| 1038 | |
| 1039 | /** |
| 1040 | * @return whether the descendant of this scroll view is within delta |
| 1041 | * pixels of being on the screen. |
| 1042 | */ |
Jack Veenstra | 7d4200d | 2009-09-21 19:45:14 -0700 | [diff] [blame] | 1043 | private boolean isWithinDeltaOfScreen(View descendant, int delta, int height) { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1044 | descendant.getDrawingRect(mTempRect); |
| 1045 | offsetDescendantRectToMyCoords(descendant, mTempRect); |
| 1046 | |
| 1047 | return (mTempRect.bottom + delta) >= getScrollY() |
Jack Veenstra | 7d4200d | 2009-09-21 19:45:14 -0700 | [diff] [blame] | 1048 | && (mTempRect.top - delta) <= (getScrollY() + height); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1049 | } |
| 1050 | |
| 1051 | /** |
| 1052 | * Smooth scroll by a Y delta |
| 1053 | * |
| 1054 | * @param delta the number of pixels to scroll by on the Y axis |
| 1055 | */ |
| 1056 | private void doScrollY(int delta) { |
| 1057 | if (delta != 0) { |
| 1058 | if (mSmoothScrollingEnabled) { |
| 1059 | smoothScrollBy(0, delta); |
| 1060 | } else { |
| 1061 | scrollBy(0, delta); |
| 1062 | } |
| 1063 | } |
| 1064 | } |
| 1065 | |
| 1066 | /** |
| 1067 | * Like {@link View#scrollBy}, but scroll smoothly instead of immediately. |
| 1068 | * |
| 1069 | * @param dx the number of pixels to scroll by on the X axis |
| 1070 | * @param dy the number of pixels to scroll by on the Y axis |
| 1071 | */ |
| 1072 | public final void smoothScrollBy(int dx, int dy) { |
Adam Powell | 3fc3737 | 2010-01-28 13:52:24 -0800 | [diff] [blame] | 1073 | if (getChildCount() == 0) { |
| 1074 | // Nothing to do. |
| 1075 | return; |
| 1076 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1077 | long duration = AnimationUtils.currentAnimationTimeMillis() - mLastScroll; |
| 1078 | if (duration > ANIMATED_SCROLL_GAP) { |
Adam Powell | f544605 | 2010-01-28 17:24:56 -0800 | [diff] [blame] | 1079 | final int height = getHeight() - mPaddingBottom - mPaddingTop; |
| 1080 | final int bottom = getChildAt(0).getHeight(); |
| 1081 | final int maxY = Math.max(0, bottom - height); |
| 1082 | final int scrollY = mScrollY; |
| 1083 | dy = Math.max(0, Math.min(scrollY + dy, maxY)) - scrollY; |
| 1084 | |
| 1085 | mScroller.startScroll(mScrollX, scrollY, 0, dy); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1086 | invalidate(); |
| 1087 | } else { |
| 1088 | if (!mScroller.isFinished()) { |
| 1089 | mScroller.abortAnimation(); |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 1090 | if (mFlingStrictSpan != null) { |
| 1091 | mFlingStrictSpan.finish(); |
| 1092 | mFlingStrictSpan = null; |
| 1093 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1094 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1095 | scrollBy(dx, dy); |
| 1096 | } |
| 1097 | mLastScroll = AnimationUtils.currentAnimationTimeMillis(); |
| 1098 | } |
| 1099 | |
| 1100 | /** |
| 1101 | * Like {@link #scrollTo}, but scroll smoothly instead of immediately. |
| 1102 | * |
| 1103 | * @param x the position where to scroll on the X axis |
| 1104 | * @param y the position where to scroll on the Y axis |
| 1105 | */ |
| 1106 | public final void smoothScrollTo(int x, int y) { |
| 1107 | smoothScrollBy(x - mScrollX, y - mScrollY); |
| 1108 | } |
| 1109 | |
| 1110 | /** |
| 1111 | * <p>The scroll range of a scroll view is the overall height of all of its |
| 1112 | * children.</p> |
| 1113 | */ |
| 1114 | @Override |
| 1115 | protected int computeVerticalScrollRange() { |
Adam Powell | a2f9101 | 2010-02-16 12:26:33 -0800 | [diff] [blame] | 1116 | final int count = getChildCount(); |
| 1117 | final int contentHeight = getHeight() - mPaddingBottom - mPaddingTop; |
Adam Powell | 0b8bb42 | 2010-02-08 14:30:45 -0800 | [diff] [blame] | 1118 | if (count == 0) { |
Adam Powell | a2f9101 | 2010-02-16 12:26:33 -0800 | [diff] [blame] | 1119 | return contentHeight; |
Adam Powell | 0b8bb42 | 2010-02-08 14:30:45 -0800 | [diff] [blame] | 1120 | } |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 1121 | |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 1122 | int scrollRange = getChildAt(0).getBottom(); |
| 1123 | final int scrollY = mScrollY; |
| 1124 | final int overscrollBottom = Math.max(0, scrollRange - contentHeight); |
| 1125 | if (scrollY < 0) { |
| 1126 | scrollRange -= scrollY; |
| 1127 | } else if (scrollY > overscrollBottom) { |
| 1128 | scrollRange += scrollY - overscrollBottom; |
| 1129 | } |
| 1130 | |
| 1131 | return scrollRange; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1132 | } |
| 1133 | |
Adam Powell | 0b8bb42 | 2010-02-08 14:30:45 -0800 | [diff] [blame] | 1134 | @Override |
| 1135 | protected int computeVerticalScrollOffset() { |
| 1136 | return Math.max(0, super.computeVerticalScrollOffset()); |
| 1137 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1138 | |
| 1139 | @Override |
| 1140 | protected void measureChild(View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec) { |
| 1141 | ViewGroup.LayoutParams lp = child.getLayoutParams(); |
| 1142 | |
| 1143 | int childWidthMeasureSpec; |
| 1144 | int childHeightMeasureSpec; |
| 1145 | |
| 1146 | childWidthMeasureSpec = getChildMeasureSpec(parentWidthMeasureSpec, mPaddingLeft |
| 1147 | + mPaddingRight, lp.width); |
| 1148 | |
| 1149 | childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); |
| 1150 | |
| 1151 | child.measure(childWidthMeasureSpec, childHeightMeasureSpec); |
| 1152 | } |
| 1153 | |
| 1154 | @Override |
| 1155 | protected void measureChildWithMargins(View child, int parentWidthMeasureSpec, int widthUsed, |
| 1156 | int parentHeightMeasureSpec, int heightUsed) { |
| 1157 | final MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams(); |
| 1158 | |
| 1159 | final int childWidthMeasureSpec = getChildMeasureSpec(parentWidthMeasureSpec, |
| 1160 | mPaddingLeft + mPaddingRight + lp.leftMargin + lp.rightMargin |
| 1161 | + widthUsed, lp.width); |
| 1162 | final int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec( |
| 1163 | lp.topMargin + lp.bottomMargin, MeasureSpec.UNSPECIFIED); |
| 1164 | |
| 1165 | child.measure(childWidthMeasureSpec, childHeightMeasureSpec); |
| 1166 | } |
| 1167 | |
| 1168 | @Override |
| 1169 | public void computeScroll() { |
| 1170 | if (mScroller.computeScrollOffset()) { |
| 1171 | // This is called at drawing time by ViewGroup. We don't want to |
| 1172 | // re-show the scrollbars at this point, which scrollTo will do, |
| 1173 | // so we replicate most of scrollTo here. |
| 1174 | // |
| 1175 | // It's a little odd to call onScrollChanged from inside the drawing. |
| 1176 | // |
| 1177 | // It is, except when you remember that computeScroll() is used to |
| 1178 | // animate scrolling. So unless we want to defer the onScrollChanged() |
| 1179 | // until the end of the animated scrolling, we don't really have a |
| 1180 | // choice here. |
| 1181 | // |
| 1182 | // I agree. The alternative, which I think would be worse, is to post |
| 1183 | // something and tell the subclasses later. This is bad because there |
| 1184 | // will be a window where mScrollX/Y is different from what the app |
| 1185 | // thinks it is. |
| 1186 | // |
| 1187 | int oldX = mScrollX; |
| 1188 | int oldY = mScrollY; |
| 1189 | int x = mScroller.getCurrX(); |
| 1190 | int y = mScroller.getCurrY(); |
Adam Powell | 17dfce1 | 2010-01-25 18:38:22 -0800 | [diff] [blame] | 1191 | |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 1192 | if (oldX != x || oldY != y) { |
Fabrice Di Meglio | e9dbef8 | 2011-09-12 16:36:46 -0700 | [diff] [blame] | 1193 | final int range = getScrollRange(); |
| 1194 | final int overscrollMode = getOverScrollMode(); |
| 1195 | final boolean canOverscroll = overscrollMode == OVER_SCROLL_ALWAYS || |
| 1196 | (overscrollMode == OVER_SCROLL_IF_CONTENT_SCROLLS && range > 0); |
| 1197 | |
| 1198 | overScrollBy(x - oldX, y - oldY, oldX, oldY, 0, range, |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 1199 | 0, mOverflingDistance, false); |
| 1200 | onScrollChanged(mScrollX, mScrollY, oldX, oldY); |
| 1201 | |
Fabrice Di Meglio | e9dbef8 | 2011-09-12 16:36:46 -0700 | [diff] [blame] | 1202 | if (canOverscroll) { |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 1203 | if (y < 0 && oldY >= 0) { |
| 1204 | mEdgeGlowTop.onAbsorb((int) mScroller.getCurrVelocity()); |
| 1205 | } else if (y > range && oldY <= range) { |
| 1206 | mEdgeGlowBottom.onAbsorb((int) mScroller.getCurrVelocity()); |
| 1207 | } |
Adam Powell | 9d32d24 | 2010-03-29 16:02:07 -0700 | [diff] [blame] | 1208 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1209 | } |
Fabrice Di Meglio | e9dbef8 | 2011-09-12 16:36:46 -0700 | [diff] [blame] | 1210 | |
Adam Powell | a0d645cb | 2010-03-31 17:27:49 -0700 | [diff] [blame] | 1211 | awakenScrollBars(); |
Adam Powell | 9d32d24 | 2010-03-29 16:02:07 -0700 | [diff] [blame] | 1212 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1213 | // Keep on drawing until the animation has finished. |
| 1214 | postInvalidate(); |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 1215 | } else { |
| 1216 | if (mFlingStrictSpan != null) { |
| 1217 | mFlingStrictSpan.finish(); |
| 1218 | mFlingStrictSpan = null; |
| 1219 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1220 | } |
| 1221 | } |
| 1222 | |
| 1223 | /** |
| 1224 | * Scrolls the view to the given child. |
| 1225 | * |
| 1226 | * @param child the View to scroll to |
| 1227 | */ |
| 1228 | private void scrollToChild(View child) { |
| 1229 | child.getDrawingRect(mTempRect); |
| 1230 | |
| 1231 | /* Offset from child's local coordinates to ScrollView coordinates */ |
| 1232 | offsetDescendantRectToMyCoords(child, mTempRect); |
| 1233 | |
| 1234 | int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect); |
| 1235 | |
| 1236 | if (scrollDelta != 0) { |
| 1237 | scrollBy(0, scrollDelta); |
| 1238 | } |
| 1239 | } |
| 1240 | |
| 1241 | /** |
| 1242 | * If rect is off screen, scroll just enough to get it (or at least the |
| 1243 | * first screen size chunk of it) on screen. |
| 1244 | * |
| 1245 | * @param rect The rectangle. |
| 1246 | * @param immediate True to scroll immediately without animation |
| 1247 | * @return true if scrolling was performed |
| 1248 | */ |
| 1249 | private boolean scrollToChildRect(Rect rect, boolean immediate) { |
| 1250 | final int delta = computeScrollDeltaToGetChildRectOnScreen(rect); |
| 1251 | final boolean scroll = delta != 0; |
| 1252 | if (scroll) { |
| 1253 | if (immediate) { |
| 1254 | scrollBy(0, delta); |
| 1255 | } else { |
| 1256 | smoothScrollBy(0, delta); |
| 1257 | } |
| 1258 | } |
| 1259 | return scroll; |
| 1260 | } |
| 1261 | |
| 1262 | /** |
| 1263 | * Compute the amount to scroll in the Y direction in order to get |
| 1264 | * a rectangle completely on the screen (or, if taller than the screen, |
| 1265 | * at least the first screen size chunk of it). |
| 1266 | * |
| 1267 | * @param rect The rect. |
| 1268 | * @return The scroll delta. |
| 1269 | */ |
| 1270 | protected int computeScrollDeltaToGetChildRectOnScreen(Rect rect) { |
Romain Guy | ef0e9ae | 2009-07-10 14:11:26 -0700 | [diff] [blame] | 1271 | if (getChildCount() == 0) return 0; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1272 | |
| 1273 | int height = getHeight(); |
| 1274 | int screenTop = getScrollY(); |
| 1275 | int screenBottom = screenTop + height; |
| 1276 | |
| 1277 | int fadingEdge = getVerticalFadingEdgeLength(); |
| 1278 | |
| 1279 | // leave room for top fading edge as long as rect isn't at very top |
| 1280 | if (rect.top > 0) { |
| 1281 | screenTop += fadingEdge; |
| 1282 | } |
| 1283 | |
| 1284 | // leave room for bottom fading edge as long as rect isn't at very bottom |
| 1285 | if (rect.bottom < getChildAt(0).getHeight()) { |
| 1286 | screenBottom -= fadingEdge; |
| 1287 | } |
| 1288 | |
| 1289 | int scrollYDelta = 0; |
| 1290 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1291 | if (rect.bottom > screenBottom && rect.top > screenTop) { |
| 1292 | // need to move down to get it in view: move down just enough so |
| 1293 | // that the entire rectangle is in view (or at least the first |
| 1294 | // screen size chunk). |
| 1295 | |
| 1296 | if (rect.height() > height) { |
| 1297 | // just enough to get screen size chunk on |
| 1298 | scrollYDelta += (rect.top - screenTop); |
| 1299 | } else { |
| 1300 | // get entire rect at bottom of screen |
| 1301 | scrollYDelta += (rect.bottom - screenBottom); |
| 1302 | } |
| 1303 | |
| 1304 | // make sure we aren't scrolling beyond the end of our content |
Romain Guy | ef0e9ae | 2009-07-10 14:11:26 -0700 | [diff] [blame] | 1305 | int bottom = getChildAt(0).getBottom(); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1306 | int distanceToBottom = bottom - screenBottom; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1307 | scrollYDelta = Math.min(scrollYDelta, distanceToBottom); |
| 1308 | |
| 1309 | } else if (rect.top < screenTop && rect.bottom < screenBottom) { |
| 1310 | // need to move up to get it in view: move up just enough so that |
| 1311 | // entire rectangle is in view (or at least the first screen |
| 1312 | // size chunk of it). |
| 1313 | |
| 1314 | if (rect.height() > height) { |
| 1315 | // screen size chunk |
| 1316 | scrollYDelta -= (screenBottom - rect.bottom); |
| 1317 | } else { |
| 1318 | // entire rect at top |
| 1319 | scrollYDelta -= (screenTop - rect.top); |
| 1320 | } |
| 1321 | |
| 1322 | // make sure we aren't scrolling any further than the top our content |
| 1323 | scrollYDelta = Math.max(scrollYDelta, -getScrollY()); |
| 1324 | } |
| 1325 | return scrollYDelta; |
| 1326 | } |
| 1327 | |
| 1328 | @Override |
| 1329 | public void requestChildFocus(View child, View focused) { |
Gilles Debunne | 2ed2eac | 2011-02-24 16:29:48 -0800 | [diff] [blame] | 1330 | if (!mIsLayoutDirty) { |
| 1331 | scrollToChild(focused); |
| 1332 | } else { |
| 1333 | // The child may not be laid out yet, we can't compute the scroll yet |
| 1334 | mChildToScrollTo = focused; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1335 | } |
| 1336 | super.requestChildFocus(child, focused); |
| 1337 | } |
| 1338 | |
| 1339 | |
| 1340 | /** |
| 1341 | * When looking for focus in children of a scroll view, need to be a little |
| 1342 | * more careful not to give focus to something that is scrolled off screen. |
| 1343 | * |
| 1344 | * This is more expensive than the default {@link android.view.ViewGroup} |
| 1345 | * implementation, otherwise this behavior might have been made the default. |
| 1346 | */ |
| 1347 | @Override |
| 1348 | protected boolean onRequestFocusInDescendants(int direction, |
| 1349 | Rect previouslyFocusedRect) { |
| 1350 | |
| 1351 | // convert from forward / backward notation to up / down / left / right |
| 1352 | // (ugh). |
| 1353 | if (direction == View.FOCUS_FORWARD) { |
| 1354 | direction = View.FOCUS_DOWN; |
| 1355 | } else if (direction == View.FOCUS_BACKWARD) { |
| 1356 | direction = View.FOCUS_UP; |
| 1357 | } |
| 1358 | |
| 1359 | final View nextFocus = previouslyFocusedRect == null ? |
| 1360 | FocusFinder.getInstance().findNextFocus(this, null, direction) : |
| 1361 | FocusFinder.getInstance().findNextFocusFromRect(this, |
| 1362 | previouslyFocusedRect, direction); |
| 1363 | |
| 1364 | if (nextFocus == null) { |
| 1365 | return false; |
| 1366 | } |
| 1367 | |
| 1368 | if (isOffScreen(nextFocus)) { |
| 1369 | return false; |
| 1370 | } |
| 1371 | |
| 1372 | return nextFocus.requestFocus(direction, previouslyFocusedRect); |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 1373 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1374 | |
| 1375 | @Override |
| 1376 | public boolean requestChildRectangleOnScreen(View child, Rect rectangle, |
| 1377 | boolean immediate) { |
| 1378 | // offset into coordinate space of this scroll view |
| 1379 | rectangle.offset(child.getLeft() - child.getScrollX(), |
| 1380 | child.getTop() - child.getScrollY()); |
| 1381 | |
| 1382 | return scrollToChildRect(rectangle, immediate); |
| 1383 | } |
| 1384 | |
| 1385 | @Override |
| 1386 | public void requestLayout() { |
| 1387 | mIsLayoutDirty = true; |
| 1388 | super.requestLayout(); |
| 1389 | } |
| 1390 | |
| 1391 | @Override |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 1392 | protected void onDetachedFromWindow() { |
| 1393 | super.onDetachedFromWindow(); |
| 1394 | |
| 1395 | if (mScrollStrictSpan != null) { |
| 1396 | mScrollStrictSpan.finish(); |
| 1397 | mScrollStrictSpan = null; |
| 1398 | } |
| 1399 | if (mFlingStrictSpan != null) { |
| 1400 | mFlingStrictSpan.finish(); |
| 1401 | mFlingStrictSpan = null; |
| 1402 | } |
| 1403 | } |
| 1404 | |
| 1405 | @Override |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1406 | protected void onLayout(boolean changed, int l, int t, int r, int b) { |
| 1407 | super.onLayout(changed, l, t, r, b); |
| 1408 | mIsLayoutDirty = false; |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 1409 | // Give a child focus if it needs it |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1410 | if (mChildToScrollTo != null && isViewDescendantOf(mChildToScrollTo, this)) { |
Romain Guy | 9c95737 | 2011-01-04 17:39:43 -0800 | [diff] [blame] | 1411 | scrollToChild(mChildToScrollTo); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1412 | } |
| 1413 | mChildToScrollTo = null; |
| 1414 | |
Ken Wakasa | f76a50c | 2012-03-09 19:56:35 +0900 | [diff] [blame^] | 1415 | // Calling this with the present values causes it to re-claim them |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1416 | scrollTo(mScrollX, mScrollY); |
| 1417 | } |
| 1418 | |
| 1419 | @Override |
| 1420 | protected void onSizeChanged(int w, int h, int oldw, int oldh) { |
| 1421 | super.onSizeChanged(w, h, oldw, oldh); |
| 1422 | |
| 1423 | View currentFocused = findFocus(); |
| 1424 | if (null == currentFocused || this == currentFocused) |
| 1425 | return; |
| 1426 | |
Jack Veenstra | 7d4200d | 2009-09-21 19:45:14 -0700 | [diff] [blame] | 1427 | // If the currently-focused view was visible on the screen when the |
| 1428 | // screen was at the old height, then scroll the screen to make that |
| 1429 | // view visible with the new screen height. |
| 1430 | if (isWithinDeltaOfScreen(currentFocused, 0, oldh)) { |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1431 | currentFocused.getDrawingRect(mTempRect); |
| 1432 | offsetDescendantRectToMyCoords(currentFocused, mTempRect); |
| 1433 | int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect); |
| 1434 | doScrollY(scrollDelta); |
| 1435 | } |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 1436 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1437 | |
| 1438 | /** |
Ken Wakasa | f76a50c | 2012-03-09 19:56:35 +0900 | [diff] [blame^] | 1439 | * Return true if child is a descendant of parent, (or equal to the parent). |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1440 | */ |
| 1441 | private boolean isViewDescendantOf(View child, View parent) { |
| 1442 | if (child == parent) { |
| 1443 | return true; |
| 1444 | } |
| 1445 | |
| 1446 | final ViewParent theParent = child.getParent(); |
| 1447 | return (theParent instanceof ViewGroup) && isViewDescendantOf((View) theParent, parent); |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 1448 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1449 | |
| 1450 | /** |
| 1451 | * Fling the scroll view |
| 1452 | * |
| 1453 | * @param velocityY The initial velocity in the Y direction. Positive |
Gilles Debunne | 5296424 | 2010-02-24 11:05:19 -0800 | [diff] [blame] | 1454 | * numbers mean that the finger/cursor is moving down the screen, |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1455 | * which means we want to scroll towards the top. |
| 1456 | */ |
| 1457 | public void fling(int velocityY) { |
Romain Guy | ef0e9ae | 2009-07-10 14:11:26 -0700 | [diff] [blame] | 1458 | if (getChildCount() > 0) { |
| 1459 | int height = getHeight() - mPaddingBottom - mPaddingTop; |
| 1460 | int bottom = getChildAt(0).getHeight(); |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 1461 | |
| 1462 | mScroller.fling(mScrollX, mScrollY, 0, velocityY, 0, 0, 0, |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 1463 | Math.max(0, bottom - height), 0, height/2); |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 1464 | |
Romain Guy | ef0e9ae | 2009-07-10 14:11:26 -0700 | [diff] [blame] | 1465 | final boolean movingDown = velocityY > 0; |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 1466 | |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 1467 | if (mFlingStrictSpan == null) { |
| 1468 | mFlingStrictSpan = StrictMode.enterCriticalSpan("ScrollView-fling"); |
| 1469 | } |
| 1470 | |
Romain Guy | ef0e9ae | 2009-07-10 14:11:26 -0700 | [diff] [blame] | 1471 | invalidate(); |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1472 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1473 | } |
| 1474 | |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 1475 | private void endDrag() { |
| 1476 | mIsBeingDragged = false; |
| 1477 | |
Michael Jurka | 13451a4 | 2011-08-22 15:54:21 -0700 | [diff] [blame] | 1478 | recycleVelocityTracker(); |
Brad Fitzpatrick | ce81f3a | 2010-11-21 18:46:08 -0800 | [diff] [blame] | 1479 | |
| 1480 | if (mEdgeGlowTop != null) { |
| 1481 | mEdgeGlowTop.onRelease(); |
| 1482 | mEdgeGlowBottom.onRelease(); |
| 1483 | } |
| 1484 | |
| 1485 | if (mScrollStrictSpan != null) { |
| 1486 | mScrollStrictSpan.finish(); |
| 1487 | mScrollStrictSpan = null; |
| 1488 | } |
| 1489 | } |
| 1490 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1491 | /** |
| 1492 | * {@inheritDoc} |
| 1493 | * |
| 1494 | * <p>This version also clamps the scrolling to the bounds of our child. |
| 1495 | */ |
Gilles Debunne | 5296424 | 2010-02-24 11:05:19 -0800 | [diff] [blame] | 1496 | @Override |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1497 | public void scrollTo(int x, int y) { |
| 1498 | // we rely on the fact the View.scrollBy calls scrollTo. |
| 1499 | if (getChildCount() > 0) { |
| 1500 | View child = getChildAt(0); |
| 1501 | x = clamp(x, getWidth() - mPaddingRight - mPaddingLeft, child.getWidth()); |
| 1502 | y = clamp(y, getHeight() - mPaddingBottom - mPaddingTop, child.getHeight()); |
| 1503 | if (x != mScrollX || y != mScrollY) { |
| 1504 | super.scrollTo(x, y); |
| 1505 | } |
| 1506 | } |
| 1507 | } |
| 1508 | |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 1509 | @Override |
| 1510 | public void setOverScrollMode(int mode) { |
| 1511 | if (mode != OVER_SCROLL_NEVER) { |
| 1512 | if (mEdgeGlowTop == null) { |
Mindy Pereira | 4e30d89 | 2010-11-24 15:32:39 -0800 | [diff] [blame] | 1513 | Context context = getContext(); |
Adam Powell | 89935e4 | 2011-08-31 14:26:12 -0700 | [diff] [blame] | 1514 | mEdgeGlowTop = new EdgeEffect(context); |
| 1515 | mEdgeGlowBottom = new EdgeEffect(context); |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 1516 | } |
| 1517 | } else { |
| 1518 | mEdgeGlowTop = null; |
| 1519 | mEdgeGlowBottom = null; |
| 1520 | } |
| 1521 | super.setOverScrollMode(mode); |
| 1522 | } |
| 1523 | |
| 1524 | @Override |
| 1525 | public void draw(Canvas canvas) { |
| 1526 | super.draw(canvas); |
| 1527 | if (mEdgeGlowTop != null) { |
| 1528 | final int scrollY = mScrollY; |
| 1529 | if (!mEdgeGlowTop.isFinished()) { |
| 1530 | final int restoreCount = canvas.save(); |
Adam Powell | 7d86378 | 2011-02-15 15:05:03 -0800 | [diff] [blame] | 1531 | final int width = getWidth() - mPaddingLeft - mPaddingRight; |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 1532 | |
Adam Powell | 7d86378 | 2011-02-15 15:05:03 -0800 | [diff] [blame] | 1533 | canvas.translate(mPaddingLeft, Math.min(0, scrollY)); |
Mindy Pereira | b1297f7 | 2010-12-07 15:06:47 -0800 | [diff] [blame] | 1534 | mEdgeGlowTop.setSize(width, getHeight()); |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 1535 | if (mEdgeGlowTop.draw(canvas)) { |
| 1536 | invalidate(); |
| 1537 | } |
| 1538 | canvas.restoreToCount(restoreCount); |
| 1539 | } |
| 1540 | if (!mEdgeGlowBottom.isFinished()) { |
| 1541 | final int restoreCount = canvas.save(); |
Adam Powell | 7d86378 | 2011-02-15 15:05:03 -0800 | [diff] [blame] | 1542 | final int width = getWidth() - mPaddingLeft - mPaddingRight; |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 1543 | final int height = getHeight(); |
| 1544 | |
Adam Powell | 7d86378 | 2011-02-15 15:05:03 -0800 | [diff] [blame] | 1545 | canvas.translate(-width + mPaddingLeft, |
| 1546 | Math.max(getScrollRange(), scrollY) + height); |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 1547 | canvas.rotate(180, width, 0); |
Mindy Pereira | b1297f7 | 2010-12-07 15:06:47 -0800 | [diff] [blame] | 1548 | mEdgeGlowBottom.setSize(width, height); |
Adam Powell | 637d337 | 2010-08-25 14:37:03 -0700 | [diff] [blame] | 1549 | if (mEdgeGlowBottom.draw(canvas)) { |
| 1550 | invalidate(); |
| 1551 | } |
| 1552 | canvas.restoreToCount(restoreCount); |
| 1553 | } |
| 1554 | } |
| 1555 | } |
| 1556 | |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1557 | private int clamp(int n, int my, int child) { |
| 1558 | if (my >= child || n < 0) { |
| 1559 | /* my >= child is this case: |
| 1560 | * |--------------- me ---------------| |
| 1561 | * |------ child ------| |
| 1562 | * or |
| 1563 | * |--------------- me ---------------| |
| 1564 | * |------ child ------| |
| 1565 | * or |
| 1566 | * |--------------- me ---------------| |
| 1567 | * |------ child ------| |
| 1568 | * |
| 1569 | * n < 0 is this case: |
| 1570 | * |------ me ------| |
| 1571 | * |-------- child --------| |
| 1572 | * |-- mScrollX --| |
| 1573 | */ |
| 1574 | return 0; |
| 1575 | } |
| 1576 | if ((my+n) > child) { |
| 1577 | /* this case: |
| 1578 | * |------ me ------| |
| 1579 | * |------ child ------| |
| 1580 | * |-- mScrollX --| |
| 1581 | */ |
| 1582 | return child-my; |
| 1583 | } |
| 1584 | return n; |
| 1585 | } |
| 1586 | } |