Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License |
| 15 | */ |
| 16 | |
| 17 | package com.android.systemui.statusbar.stack; |
| 18 | |
| 19 | import android.content.Context; |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 20 | import android.util.Log; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 21 | import android.view.View; |
| 22 | import android.view.ViewGroup; |
| 23 | import com.android.systemui.R; |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame^] | 24 | import com.android.systemui.statusbar.ExpandableNotificationRow; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 25 | |
| 26 | /** |
| 27 | * The Algorithm of the {@link com.android.systemui.statusbar.stack |
| 28 | * .NotificationStackScrollLayout} which can be queried for {@link com.android.systemui.statusbar |
| 29 | * .stack.StackScrollState} |
| 30 | */ |
| 31 | public class StackScrollAlgorithm { |
| 32 | |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 33 | private static final String LOG_TAG = "StackScrollAlgorithm"; |
| 34 | |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 35 | private static final int MAX_ITEMS_IN_BOTTOM_STACK = 3; |
| 36 | private static final int MAX_ITEMS_IN_TOP_STACK = 3; |
| 37 | |
| 38 | private int mPaddingBetweenElements; |
| 39 | private int mCollapsedSize; |
| 40 | private int mTopStackPeekSize; |
| 41 | private int mBottomStackPeekSize; |
| 42 | private int mZDistanceBetweenElements; |
| 43 | private int mZBasicHeight; |
| 44 | |
| 45 | private StackIndentationFunctor mTopStackIndentationFunctor; |
| 46 | private StackIndentationFunctor mBottomStackIndentationFunctor; |
| 47 | |
| 48 | private float mLayoutHeight; |
| 49 | private StackScrollAlgorithmState mTempAlgorithmState = new StackScrollAlgorithmState(); |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame^] | 50 | private boolean mIsExpansionChanging; |
| 51 | private int mFirstChildMaxHeight; |
| 52 | private boolean mIsExpanded; |
| 53 | private View mFirstChildWhileExpanding; |
| 54 | private boolean mExpandedOnStart; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 55 | |
| 56 | public StackScrollAlgorithm(Context context) { |
| 57 | initConstants(context); |
| 58 | } |
| 59 | |
| 60 | private void initConstants(Context context) { |
| 61 | |
| 62 | // currently the padding is in the elements themself |
| 63 | mPaddingBetweenElements = 0; |
| 64 | mCollapsedSize = context.getResources() |
| 65 | .getDimensionPixelSize(R.dimen.notification_row_min_height); |
| 66 | mTopStackPeekSize = context.getResources() |
| 67 | .getDimensionPixelSize(R.dimen.top_stack_peek_amount); |
| 68 | mBottomStackPeekSize = context.getResources() |
| 69 | .getDimensionPixelSize(R.dimen.bottom_stack_peek_amount); |
| 70 | mZDistanceBetweenElements = context.getResources() |
| 71 | .getDimensionPixelSize(R.dimen.z_distance_between_notifications); |
| 72 | mZBasicHeight = (MAX_ITEMS_IN_BOTTOM_STACK + 1) * mZDistanceBetweenElements; |
| 73 | |
| 74 | mTopStackIndentationFunctor = new PiecewiseLinearIndentationFunctor( |
| 75 | MAX_ITEMS_IN_TOP_STACK, |
| 76 | mTopStackPeekSize, |
| 77 | mCollapsedSize + mPaddingBetweenElements, |
| 78 | 0.5f); |
| 79 | mBottomStackIndentationFunctor = new PiecewiseLinearIndentationFunctor( |
| 80 | MAX_ITEMS_IN_BOTTOM_STACK, |
| 81 | mBottomStackPeekSize, |
| 82 | mBottomStackPeekSize, |
| 83 | 0.5f); |
| 84 | } |
| 85 | |
| 86 | |
| 87 | public void getStackScrollState(StackScrollState resultState) { |
| 88 | // The state of the local variables are saved in an algorithmState to easily subdivide it |
| 89 | // into multiple phases. |
| 90 | StackScrollAlgorithmState algorithmState = mTempAlgorithmState; |
| 91 | |
| 92 | // First we reset the view states to their default values. |
| 93 | resultState.resetViewStates(); |
| 94 | |
Selim Cinek | b6d85eb | 2014-03-28 20:21:01 +0100 | [diff] [blame] | 95 | // The first element is always in there so it's initialized with 1.0f; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 96 | algorithmState.itemsInTopStack = 1.0f; |
| 97 | algorithmState.partialInTop = 0.0f; |
| 98 | algorithmState.lastTopStackIndex = 0; |
| 99 | algorithmState.scrollY = resultState.getScrollY(); |
| 100 | algorithmState.itemsInBottomStack = 0.0f; |
| 101 | |
| 102 | // Phase 1: |
| 103 | findNumberOfItemsInTopStackAndUpdateState(resultState, algorithmState); |
| 104 | |
| 105 | // Phase 2: |
| 106 | updatePositionsForState(resultState, algorithmState); |
| 107 | |
| 108 | // Phase 3: |
| 109 | updateZValuesForState(resultState, algorithmState); |
| 110 | |
Selim Cinek | b6d85eb | 2014-03-28 20:21:01 +0100 | [diff] [blame] | 111 | // write the algorithm state to the result |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 112 | resultState.setScrollY(algorithmState.scrollY); |
| 113 | } |
| 114 | |
| 115 | /** |
| 116 | * Determine the positions for the views. This is the main part of the algorithm. |
| 117 | * |
| 118 | * @param resultState The result state to update if a change to the properties of a child occurs |
| 119 | * @param algorithmState The state in which the current pass of the algorithm is currently in |
| 120 | * and which will be updated |
| 121 | */ |
| 122 | private void updatePositionsForState(StackScrollState resultState, |
| 123 | StackScrollAlgorithmState algorithmState) { |
| 124 | float stackHeight = getLayoutHeight(); |
| 125 | |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame^] | 126 | // The starting position of the bottom stack peek |
| 127 | float bottomPeekStart = stackHeight - mBottomStackPeekSize; |
| 128 | |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 129 | // The position where the bottom stack starts. |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame^] | 130 | float transitioningPositionStart = bottomPeekStart - mCollapsedSize; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 131 | |
| 132 | // The y coordinate of the current child. |
| 133 | float currentYPosition = 0.0f; |
| 134 | |
| 135 | // How far in is the element currently transitioning into the bottom stack. |
| 136 | float yPositionInScrollView = 0.0f; |
| 137 | |
| 138 | ViewGroup hostView = resultState.getHostView(); |
| 139 | int childCount = hostView.getChildCount(); |
| 140 | int numberOfElementsCompletelyIn = (int) algorithmState.itemsInTopStack; |
| 141 | for (int i = 0; i < childCount; i++) { |
| 142 | View child = hostView.getChildAt(i); |
| 143 | StackScrollState.ViewState childViewState = resultState.getViewStateForView(child); |
| 144 | childViewState.yTranslation = currentYPosition; |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 145 | childViewState.location = StackScrollState.ViewState.LOCATION_UNKNOWN; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 146 | int childHeight = child.getHeight(); |
| 147 | // The y position after this element |
| 148 | float nextYPosition = currentYPosition + childHeight + mPaddingBetweenElements; |
| 149 | float yPositionInScrollViewAfterElement = yPositionInScrollView |
| 150 | + childHeight |
| 151 | + mPaddingBetweenElements; |
| 152 | float scrollOffset = yPositionInScrollViewAfterElement - algorithmState.scrollY; |
| 153 | if (i < algorithmState.lastTopStackIndex) { |
| 154 | // Case 1: |
| 155 | // We are in the top Stack |
| 156 | nextYPosition = updateStateForTopStackChild(algorithmState, |
| 157 | numberOfElementsCompletelyIn, |
| 158 | i, childViewState); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 159 | } else if (i == algorithmState.lastTopStackIndex) { |
| 160 | // Case 2: |
| 161 | // First element of regular scrollview comes next, so the position is just the |
| 162 | // scrolling position |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame^] | 163 | nextYPosition = updateStateForFirstScrollingChild(transitioningPositionStart, |
| 164 | childViewState, scrollOffset); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 165 | } else if (nextYPosition >= transitioningPositionStart) { |
| 166 | if (currentYPosition >= transitioningPositionStart) { |
| 167 | // Case 3: |
| 168 | // According to the regular scroll view we are fully translated out of the |
| 169 | // bottom of the screen so we are fully in the bottom stack |
| 170 | nextYPosition = updateStateForChildFullyInBottomStack(algorithmState, |
| 171 | transitioningPositionStart, childViewState, childHeight); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 172 | } else { |
| 173 | // Case 4: |
| 174 | // According to the regular scroll view we are currently translating out of / |
| 175 | // into the bottom of the screen |
| 176 | nextYPosition = updateStateForChildTransitioningInBottom( |
| 177 | algorithmState, stackHeight, transitioningPositionStart, |
| 178 | currentYPosition, childViewState, |
| 179 | childHeight, nextYPosition); |
| 180 | } |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 181 | } else { |
| 182 | childViewState.location = StackScrollState.ViewState.LOCATION_MAIN_AREA; |
| 183 | } |
| 184 | // The first card is always rendered. |
| 185 | if (i == 0) { |
| 186 | childViewState.alpha = 1.0f; |
| 187 | childViewState.location = StackScrollState.ViewState.LOCATION_FIRST_CARD; |
| 188 | } |
| 189 | if (childViewState.location == StackScrollState.ViewState.LOCATION_UNKNOWN) { |
| 190 | Log.wtf(LOG_TAG, "Failed to assign location for child " + i); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 191 | } |
Selim Cinek | b6d85eb | 2014-03-28 20:21:01 +0100 | [diff] [blame] | 192 | nextYPosition = Math.max(0, nextYPosition); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 193 | currentYPosition = nextYPosition; |
| 194 | yPositionInScrollView = yPositionInScrollViewAfterElement; |
| 195 | } |
| 196 | } |
| 197 | |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame^] | 198 | /** |
| 199 | * Update the state for the first child which is in the regular scrolling area. |
| 200 | * |
| 201 | * @param transitioningPositionStart the transition starting position of the bottom stack |
| 202 | * @param childViewState the view state of the child |
| 203 | * @param scrollOffset the position in the regular scroll view after this child |
| 204 | * @return the next child position |
| 205 | */ |
| 206 | private float updateStateForFirstScrollingChild(float transitioningPositionStart, |
| 207 | StackScrollState.ViewState childViewState, float scrollOffset) { |
| 208 | childViewState.location = StackScrollState.ViewState.LOCATION_TOP_STACK_PEEKING; |
| 209 | if (scrollOffset < transitioningPositionStart) { |
| 210 | return scrollOffset; |
| 211 | } else { |
| 212 | return transitioningPositionStart; |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | private int getMaxAllowedChildHeight(View child) { |
| 217 | if (child instanceof ExpandableNotificationRow) { |
| 218 | ExpandableNotificationRow row = (ExpandableNotificationRow) child; |
| 219 | return row.getMaximumAllowedExpandHeight(); |
| 220 | } |
| 221 | return child.getHeight(); |
| 222 | } |
| 223 | |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 224 | private float updateStateForChildTransitioningInBottom(StackScrollAlgorithmState algorithmState, |
| 225 | float stackHeight, float transitioningPositionStart, float currentYPosition, |
| 226 | StackScrollState.ViewState childViewState, int childHeight, float nextYPosition) { |
| 227 | float newSize = transitioningPositionStart + mCollapsedSize - currentYPosition; |
| 228 | newSize = Math.min(childHeight, newSize); |
| 229 | // Transitioning element on top of bottom stack: |
| 230 | algorithmState.partialInBottom = 1.0f - ( |
| 231 | (stackHeight - mBottomStackPeekSize - nextYPosition) / mCollapsedSize); |
| 232 | // Our element can be expanded, so we might even have to scroll further than |
| 233 | // mCollapsedSize |
| 234 | algorithmState.partialInBottom = Math.min(1.0f, algorithmState.partialInBottom); |
| 235 | float offset = mBottomStackIndentationFunctor.getValue( |
| 236 | algorithmState.partialInBottom); |
| 237 | nextYPosition = transitioningPositionStart + offset; |
| 238 | algorithmState.itemsInBottomStack += algorithmState.partialInBottom; |
| 239 | // TODO: only temporarily collapse |
| 240 | if (childHeight != (int) newSize) { |
| 241 | childViewState.height = (int) newSize; |
| 242 | } |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 243 | childViewState.location = StackScrollState.ViewState.LOCATION_MAIN_AREA; |
| 244 | |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 245 | return nextYPosition; |
| 246 | } |
| 247 | |
| 248 | private float updateStateForChildFullyInBottomStack(StackScrollAlgorithmState algorithmState, |
| 249 | float transitioningPositionStart, StackScrollState.ViewState childViewState, |
| 250 | int childHeight) { |
| 251 | |
| 252 | float nextYPosition; |
| 253 | algorithmState.itemsInBottomStack += 1.0f; |
| 254 | if (algorithmState.itemsInBottomStack < MAX_ITEMS_IN_BOTTOM_STACK) { |
| 255 | // We are visually entering the bottom stack |
| 256 | nextYPosition = transitioningPositionStart |
| 257 | + mBottomStackIndentationFunctor.getValue( |
| 258 | algorithmState.itemsInBottomStack); |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 259 | childViewState.location = StackScrollState.ViewState.LOCATION_BOTTOM_STACK_PEEKING; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 260 | } else { |
| 261 | // we are fully inside the stack |
| 262 | if (algorithmState.itemsInBottomStack > MAX_ITEMS_IN_BOTTOM_STACK + 2) { |
| 263 | childViewState.alpha = 0.0f; |
| 264 | } else if (algorithmState.itemsInBottomStack |
| 265 | > MAX_ITEMS_IN_BOTTOM_STACK + 1) { |
| 266 | childViewState.alpha = 1.0f - algorithmState.partialInBottom; |
| 267 | } |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 268 | childViewState.location = StackScrollState.ViewState.LOCATION_BOTTOM_STACK_HIDDEN; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 269 | nextYPosition = transitioningPositionStart + mBottomStackPeekSize; |
| 270 | } |
| 271 | // TODO: only temporarily collapse |
| 272 | if (childHeight != mCollapsedSize) { |
| 273 | childViewState.height = mCollapsedSize; |
| 274 | } |
| 275 | return nextYPosition; |
| 276 | } |
| 277 | |
| 278 | private float updateStateForTopStackChild(StackScrollAlgorithmState algorithmState, |
| 279 | int numberOfElementsCompletelyIn, int i, StackScrollState.ViewState childViewState) { |
| 280 | |
| 281 | float nextYPosition = 0; |
| 282 | |
| 283 | // First we calculate the index relative to the current stack window of size at most |
| 284 | // {@link #MAX_ITEMS_IN_TOP_STACK} |
| 285 | int paddedIndex = i |
| 286 | - Math.max(numberOfElementsCompletelyIn - MAX_ITEMS_IN_TOP_STACK, 0); |
| 287 | if (paddedIndex >= 0) { |
| 288 | // We are currently visually entering the top stack |
| 289 | nextYPosition = mCollapsedSize + mPaddingBetweenElements - |
| 290 | mTopStackIndentationFunctor.getValue( |
| 291 | algorithmState.itemsInTopStack - i - 1); |
Selim Cinek | b6d85eb | 2014-03-28 20:21:01 +0100 | [diff] [blame] | 292 | nextYPosition = Math.min(nextYPosition, mLayoutHeight - mCollapsedSize |
| 293 | - mBottomStackPeekSize); |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 294 | if (paddedIndex == 0) { |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 295 | childViewState.alpha = 1.0f - algorithmState.partialInTop; |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 296 | childViewState.location = StackScrollState.ViewState.LOCATION_TOP_STACK_HIDDEN; |
| 297 | } else { |
| 298 | childViewState.location = StackScrollState.ViewState.LOCATION_TOP_STACK_PEEKING; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 299 | } |
| 300 | } else { |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 301 | // We are hidden behind the top card and faded out, so we can hide ourselves. |
| 302 | childViewState.alpha = 0.0f; |
| 303 | childViewState.location = StackScrollState.ViewState.LOCATION_TOP_STACK_HIDDEN; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 304 | } |
| 305 | return nextYPosition; |
| 306 | } |
| 307 | |
| 308 | /** |
| 309 | * Find the number of items in the top stack and update the result state if needed. |
| 310 | * |
| 311 | * @param resultState The result state to update if a height change of an child occurs |
| 312 | * @param algorithmState The state in which the current pass of the algorithm is currently in |
| 313 | * and which will be updated |
| 314 | */ |
| 315 | private void findNumberOfItemsInTopStackAndUpdateState(StackScrollState resultState, |
| 316 | StackScrollAlgorithmState algorithmState) { |
| 317 | |
| 318 | // The y Position if the element would be in a regular scrollView |
| 319 | float yPositionInScrollView = 0.0f; |
| 320 | ViewGroup hostView = resultState.getHostView(); |
| 321 | int childCount = hostView.getChildCount(); |
| 322 | |
| 323 | // find the number of elements in the top stack. |
| 324 | for (int i = 0; i < childCount; i++) { |
| 325 | View child = hostView.getChildAt(i); |
| 326 | StackScrollState.ViewState childViewState = resultState.getViewStateForView(child); |
| 327 | int childHeight = child.getHeight(); |
| 328 | float yPositionInScrollViewAfterElement = yPositionInScrollView |
| 329 | + childHeight |
| 330 | + mPaddingBetweenElements; |
| 331 | if (yPositionInScrollView < algorithmState.scrollY) { |
| 332 | if (yPositionInScrollViewAfterElement <= algorithmState.scrollY) { |
| 333 | // According to the regular scroll view we are fully off screen |
| 334 | algorithmState.itemsInTopStack += 1.0f; |
| 335 | if (childHeight != mCollapsedSize) { |
| 336 | childViewState.height = mCollapsedSize; |
| 337 | } |
| 338 | } else { |
| 339 | // According to the regular scroll view we are partially off screen |
| 340 | // If it is expanded we have to collapse it to a new size |
| 341 | float newSize = yPositionInScrollViewAfterElement |
| 342 | - mPaddingBetweenElements |
| 343 | - algorithmState.scrollY; |
| 344 | |
| 345 | // How much did we scroll into this child |
| 346 | algorithmState.partialInTop = (mCollapsedSize - newSize) / (mCollapsedSize |
| 347 | + mPaddingBetweenElements); |
| 348 | |
| 349 | // Our element can be expanded, so this can get negative |
| 350 | algorithmState.partialInTop = Math.max(0.0f, algorithmState.partialInTop); |
| 351 | algorithmState.itemsInTopStack += algorithmState.partialInTop; |
| 352 | // TODO: handle overlapping sizes with end stack |
| 353 | newSize = Math.max(mCollapsedSize, newSize); |
| 354 | // TODO: only temporarily collapse |
| 355 | if (newSize != childHeight) { |
| 356 | childViewState.height = (int) newSize; |
| 357 | |
| 358 | // We decrease scrollY by the same amount we made this child smaller. |
| 359 | // The new scroll position is therefore the start of the element |
| 360 | algorithmState.scrollY = (int) yPositionInScrollView; |
| 361 | resultState.setScrollY(algorithmState.scrollY); |
| 362 | } |
| 363 | if (childHeight > mCollapsedSize) { |
| 364 | // If we are just resizing this child, this element is not treated to be |
| 365 | // transitioning into the stack and therefore it is the last element in |
| 366 | // the stack. |
| 367 | algorithmState.lastTopStackIndex = i; |
| 368 | break; |
| 369 | } |
| 370 | } |
| 371 | } else { |
| 372 | algorithmState.lastTopStackIndex = i; |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame^] | 373 | if (i == 0) { |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 374 | |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame^] | 375 | // The starting position of the bottom stack peek |
| 376 | float bottomPeekStart = getLayoutHeight() - mBottomStackPeekSize; |
| 377 | // Collapse and expand the first child while the shade is being expanded |
| 378 | float maxHeight = mIsExpansionChanging && child == mFirstChildWhileExpanding |
| 379 | ? mFirstChildMaxHeight |
| 380 | : childHeight; |
| 381 | childViewState.height = (int) Math.max(Math.min(bottomPeekStart, maxHeight), |
| 382 | mCollapsedSize); |
| 383 | } |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 384 | // We are already past the stack so we can end the loop |
| 385 | break; |
| 386 | } |
| 387 | yPositionInScrollView = yPositionInScrollViewAfterElement; |
| 388 | } |
| 389 | } |
| 390 | |
| 391 | /** |
| 392 | * Calculate the Z positions for all children based on the number of items in both stacks and |
| 393 | * save it in the resultState |
| 394 | * |
| 395 | * @param resultState The result state to update the zTranslation values |
| 396 | * @param algorithmState The state in which the current pass of the algorithm is currently in |
| 397 | */ |
| 398 | private void updateZValuesForState(StackScrollState resultState, |
| 399 | StackScrollAlgorithmState algorithmState) { |
| 400 | ViewGroup hostView = resultState.getHostView(); |
| 401 | int childCount = hostView.getChildCount(); |
| 402 | for (int i = 0; i < childCount; i++) { |
| 403 | View child = hostView.getChildAt(i); |
| 404 | StackScrollState.ViewState childViewState = resultState.getViewStateForView(child); |
| 405 | if (i < algorithmState.itemsInTopStack) { |
| 406 | float stackIndex = algorithmState.itemsInTopStack - i; |
| 407 | stackIndex = Math.min(stackIndex, MAX_ITEMS_IN_TOP_STACK + 2); |
| 408 | childViewState.zTranslation = mZBasicHeight |
| 409 | + stackIndex * mZDistanceBetweenElements; |
| 410 | } else if (i > (childCount - 1 - algorithmState.itemsInBottomStack)) { |
| 411 | float numItemsAbove = i - (childCount - 1 - algorithmState.itemsInBottomStack); |
| 412 | float translationZ = mZBasicHeight |
| 413 | - numItemsAbove * mZDistanceBetweenElements; |
| 414 | childViewState.zTranslation = translationZ; |
| 415 | } else { |
| 416 | childViewState.zTranslation = mZBasicHeight; |
| 417 | } |
| 418 | } |
| 419 | } |
| 420 | |
| 421 | public float getLayoutHeight() { |
| 422 | return mLayoutHeight; |
| 423 | } |
| 424 | |
| 425 | public void setLayoutHeight(float layoutHeight) { |
| 426 | this.mLayoutHeight = layoutHeight; |
| 427 | } |
| 428 | |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame^] | 429 | public void onExpansionStarted(StackScrollState currentState) { |
| 430 | mIsExpansionChanging = true; |
| 431 | mExpandedOnStart = mIsExpanded; |
| 432 | ViewGroup hostView = currentState.getHostView(); |
| 433 | updateFirstChildHeightWhileExpanding(hostView); |
| 434 | } |
| 435 | |
| 436 | private void updateFirstChildHeightWhileExpanding(ViewGroup hostView) { |
| 437 | if (hostView.getChildCount() > 0) { |
| 438 | mFirstChildWhileExpanding = hostView.getChildAt(0); |
| 439 | if (mExpandedOnStart) { |
| 440 | |
| 441 | // We are collapsing the shade, so the first child can get as most as high as the |
| 442 | // current height. |
| 443 | mFirstChildMaxHeight = mFirstChildWhileExpanding.getHeight(); |
| 444 | } else { |
| 445 | |
| 446 | // We are expanding the shade, expand it to its full height. |
| 447 | mFirstChildMaxHeight = getMaxAllowedChildHeight(mFirstChildWhileExpanding); |
| 448 | } |
| 449 | } else { |
| 450 | mFirstChildWhileExpanding = null; |
| 451 | mFirstChildMaxHeight = 0; |
| 452 | } |
| 453 | } |
| 454 | |
| 455 | public void onExpansionStopped() { |
| 456 | mIsExpansionChanging = false; |
| 457 | mFirstChildWhileExpanding = null; |
| 458 | } |
| 459 | |
| 460 | public void setIsExpanded(boolean isExpanded) { |
| 461 | this.mIsExpanded = isExpanded; |
| 462 | } |
| 463 | |
| 464 | public void notifyChildrenChanged(ViewGroup hostView) { |
| 465 | if (mIsExpansionChanging) { |
| 466 | updateFirstChildHeightWhileExpanding(hostView); |
| 467 | } |
| 468 | } |
| 469 | |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 470 | class StackScrollAlgorithmState { |
| 471 | |
| 472 | /** |
| 473 | * The scroll position of the algorithm |
| 474 | */ |
| 475 | public int scrollY; |
| 476 | |
| 477 | /** |
| 478 | * The quantity of items which are in the top stack. |
| 479 | */ |
| 480 | public float itemsInTopStack; |
| 481 | |
| 482 | /** |
| 483 | * how far in is the element currently transitioning into the top stack |
| 484 | */ |
| 485 | public float partialInTop; |
| 486 | |
| 487 | /** |
| 488 | * The last item index which is in the top stack. |
| 489 | * NOTE: In the top stack the item after the transitioning element is also in the stack! |
| 490 | * This is needed to ensure a smooth transition between the y position in the regular |
| 491 | * scrollview and the one in the stack. |
| 492 | */ |
| 493 | public int lastTopStackIndex; |
| 494 | |
| 495 | /** |
| 496 | * The quantity of items which are in the bottom stack. |
| 497 | */ |
| 498 | public float itemsInBottomStack; |
| 499 | |
| 500 | /** |
| 501 | * how far in is the element currently transitioning into the bottom stack |
| 502 | */ |
| 503 | public float partialInBottom; |
| 504 | } |
| 505 | |
| 506 | } |