Oren Blasberg | f44d90b | 2015-08-31 14:15:26 -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 android.widget; |
| 18 | |
| 19 | |
| 20 | import com.android.internal.widget.AutoScrollHelper.AbsListViewAutoScroller; |
| 21 | |
| 22 | import android.animation.Animator; |
| 23 | import android.animation.AnimatorListenerAdapter; |
| 24 | import android.animation.ObjectAnimator; |
| 25 | import android.content.Context; |
| 26 | import android.graphics.drawable.Drawable; |
| 27 | import android.util.IntProperty; |
Oren Blasberg | f44d90b | 2015-08-31 14:15:26 -0700 | [diff] [blame] | 28 | import android.view.MotionEvent; |
| 29 | import android.view.View; |
Oren Blasberg | f44d90b | 2015-08-31 14:15:26 -0700 | [diff] [blame] | 30 | import android.view.animation.AccelerateDecelerateInterpolator; |
| 31 | import android.widget.TextView; |
| 32 | import android.widget.ListView; |
| 33 | |
| 34 | |
| 35 | /** |
| 36 | * Wrapper class for a ListView. This wrapper can hijack the focus to |
| 37 | * make sure the list uses the appropriate drawables and states when |
| 38 | * displayed on screen within a drop down. The focus is never actually |
| 39 | * passed to the drop down in this mode; the list only looks focused. |
| 40 | * |
| 41 | * @hide |
| 42 | */ |
| 43 | public class DropDownListView extends ListView { |
| 44 | /** Duration in milliseconds of the drag-to-open click animation. */ |
| 45 | private static final long CLICK_ANIM_DURATION = 150; |
| 46 | |
| 47 | /** Target alpha value for drag-to-open click animation. */ |
| 48 | private static final int CLICK_ANIM_ALPHA = 0x80; |
| 49 | |
| 50 | /** Wrapper around Drawable's <code>alpha</code> property. */ |
| 51 | private static final IntProperty<Drawable> DRAWABLE_ALPHA = |
| 52 | new IntProperty<Drawable>("alpha") { |
| 53 | @Override |
| 54 | public void setValue(Drawable object, int value) { |
| 55 | object.setAlpha(value); |
| 56 | } |
| 57 | |
| 58 | @Override |
| 59 | public Integer get(Drawable object) { |
| 60 | return object.getAlpha(); |
| 61 | } |
| 62 | }; |
| 63 | |
| 64 | /* |
| 65 | * WARNING: This is a workaround for a touch mode issue. |
| 66 | * |
| 67 | * Touch mode is propagated lazily to windows. This causes problems in |
| 68 | * the following scenario: |
| 69 | * - Type something in the AutoCompleteTextView and get some results |
| 70 | * - Move down with the d-pad to select an item in the list |
| 71 | * - Move up with the d-pad until the selection disappears |
| 72 | * - Type more text in the AutoCompleteTextView *using the soft keyboard* |
| 73 | * and get new results; you are now in touch mode |
| 74 | * - The selection comes back on the first item in the list, even though |
| 75 | * the list is supposed to be in touch mode |
| 76 | * |
| 77 | * Using the soft keyboard triggers the touch mode change but that change |
| 78 | * is propagated to our window only after the first list layout, therefore |
| 79 | * after the list attempts to resurrect the selection. |
| 80 | * |
| 81 | * The trick to work around this issue is to pretend the list is in touch |
| 82 | * mode when we know that the selection should not appear, that is when |
| 83 | * we know the user moved the selection away from the list. |
| 84 | * |
| 85 | * This boolean is set to true whenever we explicitly hide the list's |
| 86 | * selection and reset to false whenever we know the user moved the |
| 87 | * selection back to the list. |
| 88 | * |
| 89 | * When this boolean is true, isInTouchMode() returns true, otherwise it |
| 90 | * returns super.isInTouchMode(). |
| 91 | */ |
| 92 | private boolean mListSelectionHidden; |
| 93 | |
| 94 | /** |
| 95 | * True if this wrapper should fake focus. |
| 96 | */ |
| 97 | private boolean mHijackFocus; |
| 98 | |
| 99 | /** Whether to force drawing of the pressed state selector. */ |
| 100 | private boolean mDrawsInPressedState; |
| 101 | |
| 102 | /** Current drag-to-open click animation, if any. */ |
| 103 | private Animator mClickAnimation; |
| 104 | |
| 105 | /** Helper for drag-to-open auto scrolling. */ |
| 106 | private AbsListViewAutoScroller mScrollHelper; |
| 107 | |
| 108 | /** |
| 109 | * Creates a new list view wrapper. |
| 110 | * |
| 111 | * @param context this view's context |
| 112 | */ |
| 113 | public DropDownListView(Context context, boolean hijackFocus) { |
| 114 | this(context, hijackFocus, com.android.internal.R.attr.dropDownListViewStyle); |
| 115 | } |
| 116 | |
| 117 | /** |
| 118 | * Creates a new list view wrapper. |
| 119 | * |
| 120 | * @param context this view's context |
| 121 | */ |
| 122 | public DropDownListView(Context context, boolean hijackFocus, int defStyleAttr) { |
| 123 | super(context, null, defStyleAttr); |
| 124 | mHijackFocus = hijackFocus; |
| 125 | // TODO: Add an API to control this |
| 126 | setCacheColorHint(0); // Transparent, since the background drawable could be anything. |
| 127 | } |
| 128 | |
Oren Blasberg | 8e12f8d | 2015-09-02 14:25:56 -0700 | [diff] [blame] | 129 | @Override |
Alan Viverette | 00aa510 | 2015-11-03 13:03:15 -0500 | [diff] [blame] | 130 | boolean shouldShowSelector() { |
| 131 | return isHovered() || super.shouldShowSelector(); |
Oren Blasberg | 8e12f8d | 2015-09-02 14:25:56 -0700 | [diff] [blame] | 132 | } |
| 133 | |
Oren Blasberg | 8e12f8d | 2015-09-02 14:25:56 -0700 | [diff] [blame] | 134 | @Override |
| 135 | public boolean onHoverEvent(MotionEvent ev) { |
Alan Viverette | 00aa510 | 2015-11-03 13:03:15 -0500 | [diff] [blame] | 136 | // Allow the super class to handle hover state management first. |
| 137 | final boolean handled = super.onHoverEvent(ev); |
| 138 | |
Oren Blasberg | 8e12f8d | 2015-09-02 14:25:56 -0700 | [diff] [blame] | 139 | final int action = ev.getActionMasked(); |
| 140 | if (action == MotionEvent.ACTION_HOVER_ENTER |
| 141 | || action == MotionEvent.ACTION_HOVER_MOVE) { |
| 142 | final int position = pointToPosition((int) ev.getX(), (int) ev.getY()); |
| 143 | if (position != INVALID_POSITION && position != mSelectedPosition) { |
| 144 | final View hoveredItem = getChildAt(position - getFirstVisiblePosition()); |
| 145 | if (hoveredItem.isEnabled()) { |
| 146 | // Force a focus so that the proper selector state gets used when we update. |
| 147 | requestFocus(); |
| 148 | |
| 149 | positionSelector(position, hoveredItem); |
| 150 | setSelectedPositionInt(position); |
| 151 | setNextSelectedPositionInt(position); |
| 152 | } |
| 153 | updateSelectorState(); |
| 154 | } |
| 155 | } else { |
| 156 | // Do not cancel the selected position if the selection is visible by other reasons. |
| 157 | if (!super.shouldShowSelector()) { |
| 158 | setSelectedPositionInt(INVALID_POSITION); |
Alan Viverette | 00aa510 | 2015-11-03 13:03:15 -0500 | [diff] [blame] | 159 | setNextSelectedPositionInt(INVALID_POSITION); |
Oren Blasberg | 8e12f8d | 2015-09-02 14:25:56 -0700 | [diff] [blame] | 160 | } |
| 161 | } |
Oren Blasberg | 8e12f8d | 2015-09-02 14:25:56 -0700 | [diff] [blame] | 162 | |
Alan Viverette | 00aa510 | 2015-11-03 13:03:15 -0500 | [diff] [blame] | 163 | return handled; |
Alan Viverette | 2ac975d | 2015-10-08 19:54:16 +0000 | [diff] [blame] | 164 | } |
| 165 | |
Oren Blasberg | f44d90b | 2015-08-31 14:15:26 -0700 | [diff] [blame] | 166 | /** |
| 167 | * Handles forwarded events. |
| 168 | * |
| 169 | * @param activePointerId id of the pointer that activated forwarding |
| 170 | * @return whether the event was handled |
| 171 | */ |
| 172 | public boolean onForwardedEvent(MotionEvent event, int activePointerId) { |
| 173 | boolean handledEvent = true; |
| 174 | boolean clearPressedItem = false; |
| 175 | |
| 176 | final int actionMasked = event.getActionMasked(); |
| 177 | switch (actionMasked) { |
| 178 | case MotionEvent.ACTION_CANCEL: |
| 179 | handledEvent = false; |
| 180 | break; |
| 181 | case MotionEvent.ACTION_UP: |
| 182 | handledEvent = false; |
| 183 | // $FALL-THROUGH$ |
| 184 | case MotionEvent.ACTION_MOVE: |
| 185 | final int activeIndex = event.findPointerIndex(activePointerId); |
| 186 | if (activeIndex < 0) { |
| 187 | handledEvent = false; |
| 188 | break; |
| 189 | } |
| 190 | |
| 191 | final int x = (int) event.getX(activeIndex); |
| 192 | final int y = (int) event.getY(activeIndex); |
| 193 | final int position = pointToPosition(x, y); |
| 194 | if (position == INVALID_POSITION) { |
| 195 | clearPressedItem = true; |
| 196 | break; |
| 197 | } |
| 198 | |
| 199 | final View child = getChildAt(position - getFirstVisiblePosition()); |
| 200 | setPressedItem(child, position, x, y); |
| 201 | handledEvent = true; |
| 202 | |
| 203 | if (actionMasked == MotionEvent.ACTION_UP) { |
| 204 | clickPressedItem(child, position); |
| 205 | } |
| 206 | break; |
| 207 | } |
| 208 | |
| 209 | // Failure to handle the event cancels forwarding. |
| 210 | if (!handledEvent || clearPressedItem) { |
| 211 | clearPressedItem(); |
| 212 | } |
| 213 | |
| 214 | // Manage automatic scrolling. |
| 215 | if (handledEvent) { |
| 216 | if (mScrollHelper == null) { |
| 217 | mScrollHelper = new AbsListViewAutoScroller(this); |
| 218 | } |
| 219 | mScrollHelper.setEnabled(true); |
| 220 | mScrollHelper.onTouch(this, event); |
| 221 | } else if (mScrollHelper != null) { |
| 222 | mScrollHelper.setEnabled(false); |
| 223 | } |
| 224 | |
| 225 | return handledEvent; |
| 226 | } |
| 227 | |
| 228 | /** |
| 229 | * Sets whether the list selection is hidden, as part of a workaround for a touch mode issue |
| 230 | * (see the declaration for mListSelectionHidden). |
| 231 | * @param listSelectionHidden |
| 232 | */ |
| 233 | public void setListSelectionHidden(boolean listSelectionHidden) { |
| 234 | this.mListSelectionHidden = listSelectionHidden; |
| 235 | } |
| 236 | |
| 237 | /** |
| 238 | * Starts an alpha animation on the selector. When the animation ends, |
| 239 | * the list performs a click on the item. |
| 240 | */ |
| 241 | private void clickPressedItem(final View child, final int position) { |
| 242 | final long id = getItemIdAtPosition(position); |
| 243 | final Animator anim = ObjectAnimator.ofInt( |
| 244 | mSelector, DRAWABLE_ALPHA, 0xFF, CLICK_ANIM_ALPHA, 0xFF); |
| 245 | anim.setDuration(CLICK_ANIM_DURATION); |
| 246 | anim.setInterpolator(new AccelerateDecelerateInterpolator()); |
| 247 | anim.addListener(new AnimatorListenerAdapter() { |
| 248 | @Override |
| 249 | public void onAnimationEnd(Animator animation) { |
| 250 | performItemClick(child, position, id); |
| 251 | } |
| 252 | }); |
| 253 | anim.start(); |
| 254 | |
| 255 | if (mClickAnimation != null) { |
| 256 | mClickAnimation.cancel(); |
| 257 | } |
| 258 | mClickAnimation = anim; |
| 259 | } |
| 260 | |
| 261 | private void clearPressedItem() { |
| 262 | mDrawsInPressedState = false; |
| 263 | setPressed(false); |
| 264 | updateSelectorState(); |
| 265 | |
| 266 | final View motionView = getChildAt(mMotionPosition - mFirstPosition); |
| 267 | if (motionView != null) { |
| 268 | motionView.setPressed(false); |
| 269 | } |
| 270 | |
| 271 | if (mClickAnimation != null) { |
| 272 | mClickAnimation.cancel(); |
| 273 | mClickAnimation = null; |
| 274 | } |
| 275 | } |
| 276 | |
| 277 | private void setPressedItem(View child, int position, float x, float y) { |
| 278 | mDrawsInPressedState = true; |
| 279 | |
| 280 | // Ordering is essential. First, update the container's pressed state. |
| 281 | drawableHotspotChanged(x, y); |
| 282 | if (!isPressed()) { |
| 283 | setPressed(true); |
| 284 | } |
| 285 | |
| 286 | // Next, run layout if we need to stabilize child positions. |
| 287 | if (mDataChanged) { |
| 288 | layoutChildren(); |
| 289 | } |
| 290 | |
| 291 | // Manage the pressed view based on motion position. This allows us to |
| 292 | // play nicely with actual touch and scroll events. |
| 293 | final View motionView = getChildAt(mMotionPosition - mFirstPosition); |
| 294 | if (motionView != null && motionView != child && motionView.isPressed()) { |
| 295 | motionView.setPressed(false); |
| 296 | } |
| 297 | mMotionPosition = position; |
| 298 | |
| 299 | // Offset for child coordinates. |
| 300 | final float childX = x - child.getLeft(); |
| 301 | final float childY = y - child.getTop(); |
| 302 | child.drawableHotspotChanged(childX, childY); |
| 303 | if (!child.isPressed()) { |
| 304 | child.setPressed(true); |
| 305 | } |
| 306 | |
| 307 | // Ensure that keyboard focus starts from the last touched position. |
| 308 | setSelectedPositionInt(position); |
| 309 | positionSelectorLikeTouch(position, child, x, y); |
| 310 | |
| 311 | // Refresh the drawable state to reflect the new pressed state, |
| 312 | // which will also update the selector state. |
| 313 | refreshDrawableState(); |
| 314 | |
| 315 | if (mClickAnimation != null) { |
| 316 | mClickAnimation.cancel(); |
| 317 | mClickAnimation = null; |
| 318 | } |
| 319 | } |
| 320 | |
| 321 | @Override |
| 322 | boolean touchModeDrawsInPressedState() { |
| 323 | return mDrawsInPressedState || super.touchModeDrawsInPressedState(); |
| 324 | } |
| 325 | |
| 326 | /** |
| 327 | * Avoids jarring scrolling effect by ensuring that list elements |
| 328 | * made of a text view fit on a single line. |
| 329 | * |
| 330 | * @param position the item index in the list to get a view for |
| 331 | * @return the view for the specified item |
| 332 | */ |
| 333 | @Override |
| 334 | View obtainView(int position, boolean[] isScrap) { |
| 335 | View view = super.obtainView(position, isScrap); |
| 336 | |
| 337 | if (view instanceof TextView) { |
| 338 | ((TextView) view).setHorizontallyScrolling(true); |
| 339 | } |
| 340 | |
| 341 | return view; |
| 342 | } |
| 343 | |
| 344 | @Override |
| 345 | public boolean isInTouchMode() { |
| 346 | // WARNING: Please read the comment where mListSelectionHidden is declared |
| 347 | return (mHijackFocus && mListSelectionHidden) || super.isInTouchMode(); |
| 348 | } |
| 349 | |
| 350 | /** |
| 351 | * Returns the focus state in the drop down. |
| 352 | * |
| 353 | * @return true always if hijacking focus |
| 354 | */ |
| 355 | @Override |
| 356 | public boolean hasWindowFocus() { |
| 357 | return mHijackFocus || super.hasWindowFocus(); |
| 358 | } |
| 359 | |
| 360 | /** |
| 361 | * Returns the focus state in the drop down. |
| 362 | * |
| 363 | * @return true always if hijacking focus |
| 364 | */ |
| 365 | @Override |
| 366 | public boolean isFocused() { |
| 367 | return mHijackFocus || super.isFocused(); |
| 368 | } |
| 369 | |
| 370 | /** |
| 371 | * Returns the focus state in the drop down. |
| 372 | * |
| 373 | * @return true always if hijacking focus |
| 374 | */ |
| 375 | @Override |
| 376 | public boolean hasFocus() { |
| 377 | return mHijackFocus || super.hasFocus(); |
| 378 | } |
| 379 | } |