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 | |
Jorim Jaggi | d4a5744 | 2014-04-10 02:45:55 +0200 | [diff] [blame] | 26 | import java.util.ArrayList; |
| 27 | |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 28 | /** |
| 29 | * The Algorithm of the {@link com.android.systemui.statusbar.stack |
| 30 | * .NotificationStackScrollLayout} which can be queried for {@link com.android.systemui.statusbar |
| 31 | * .stack.StackScrollState} |
| 32 | */ |
| 33 | public class StackScrollAlgorithm { |
| 34 | |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 35 | private static final String LOG_TAG = "StackScrollAlgorithm"; |
| 36 | |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 37 | private static final int MAX_ITEMS_IN_BOTTOM_STACK = 3; |
| 38 | private static final int MAX_ITEMS_IN_TOP_STACK = 3; |
| 39 | |
| 40 | private int mPaddingBetweenElements; |
| 41 | private int mCollapsedSize; |
| 42 | private int mTopStackPeekSize; |
| 43 | private int mBottomStackPeekSize; |
| 44 | private int mZDistanceBetweenElements; |
| 45 | private int mZBasicHeight; |
| 46 | |
| 47 | private StackIndentationFunctor mTopStackIndentationFunctor; |
| 48 | private StackIndentationFunctor mBottomStackIndentationFunctor; |
| 49 | |
| 50 | private float mLayoutHeight; |
| 51 | private StackScrollAlgorithmState mTempAlgorithmState = new StackScrollAlgorithmState(); |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame] | 52 | private boolean mIsExpansionChanging; |
| 53 | private int mFirstChildMaxHeight; |
| 54 | private boolean mIsExpanded; |
| 55 | private View mFirstChildWhileExpanding; |
| 56 | private boolean mExpandedOnStart; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 57 | |
| 58 | public StackScrollAlgorithm(Context context) { |
| 59 | initConstants(context); |
| 60 | } |
| 61 | |
| 62 | private void initConstants(Context context) { |
| 63 | |
| 64 | // currently the padding is in the elements themself |
| 65 | mPaddingBetweenElements = 0; |
| 66 | mCollapsedSize = context.getResources() |
| 67 | .getDimensionPixelSize(R.dimen.notification_row_min_height); |
| 68 | mTopStackPeekSize = context.getResources() |
| 69 | .getDimensionPixelSize(R.dimen.top_stack_peek_amount); |
| 70 | mBottomStackPeekSize = context.getResources() |
| 71 | .getDimensionPixelSize(R.dimen.bottom_stack_peek_amount); |
| 72 | mZDistanceBetweenElements = context.getResources() |
| 73 | .getDimensionPixelSize(R.dimen.z_distance_between_notifications); |
| 74 | mZBasicHeight = (MAX_ITEMS_IN_BOTTOM_STACK + 1) * mZDistanceBetweenElements; |
| 75 | |
| 76 | mTopStackIndentationFunctor = new PiecewiseLinearIndentationFunctor( |
| 77 | MAX_ITEMS_IN_TOP_STACK, |
| 78 | mTopStackPeekSize, |
| 79 | mCollapsedSize + mPaddingBetweenElements, |
| 80 | 0.5f); |
| 81 | mBottomStackIndentationFunctor = new PiecewiseLinearIndentationFunctor( |
| 82 | MAX_ITEMS_IN_BOTTOM_STACK, |
| 83 | mBottomStackPeekSize, |
| 84 | mBottomStackPeekSize, |
| 85 | 0.5f); |
| 86 | } |
| 87 | |
| 88 | |
| 89 | public void getStackScrollState(StackScrollState resultState) { |
| 90 | // The state of the local variables are saved in an algorithmState to easily subdivide it |
| 91 | // into multiple phases. |
| 92 | StackScrollAlgorithmState algorithmState = mTempAlgorithmState; |
| 93 | |
| 94 | // First we reset the view states to their default values. |
| 95 | resultState.resetViewStates(); |
| 96 | |
Selim Cinek | b6d85eb | 2014-03-28 20:21:01 +0100 | [diff] [blame] | 97 | // 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] | 98 | algorithmState.itemsInTopStack = 1.0f; |
| 99 | algorithmState.partialInTop = 0.0f; |
| 100 | algorithmState.lastTopStackIndex = 0; |
| 101 | algorithmState.scrollY = resultState.getScrollY(); |
| 102 | algorithmState.itemsInBottomStack = 0.0f; |
Jorim Jaggi | d4a5744 | 2014-04-10 02:45:55 +0200 | [diff] [blame] | 103 | updateVisibleChildren(resultState, algorithmState); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 104 | |
| 105 | // Phase 1: |
| 106 | findNumberOfItemsInTopStackAndUpdateState(resultState, algorithmState); |
| 107 | |
| 108 | // Phase 2: |
| 109 | updatePositionsForState(resultState, algorithmState); |
| 110 | |
| 111 | // Phase 3: |
| 112 | updateZValuesForState(resultState, algorithmState); |
| 113 | |
Selim Cinek | b6d85eb | 2014-03-28 20:21:01 +0100 | [diff] [blame] | 114 | // write the algorithm state to the result |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 115 | resultState.setScrollY(algorithmState.scrollY); |
| 116 | } |
| 117 | |
| 118 | /** |
Jorim Jaggi | d4a5744 | 2014-04-10 02:45:55 +0200 | [diff] [blame] | 119 | * Update the visible children on the state. |
| 120 | */ |
| 121 | private void updateVisibleChildren(StackScrollState resultState, |
| 122 | StackScrollAlgorithmState state) { |
| 123 | ViewGroup hostView = resultState.getHostView(); |
| 124 | int childCount = hostView.getChildCount(); |
| 125 | state.visibleChildren.clear(); |
| 126 | state.visibleChildren.ensureCapacity(childCount); |
| 127 | for (int i = 0; i < childCount; i++) { |
| 128 | View v = hostView.getChildAt(i); |
| 129 | if (v.getVisibility() != View.GONE) { |
| 130 | state.visibleChildren.add(v); |
| 131 | } |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | /** |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 136 | * Determine the positions for the views. This is the main part of the algorithm. |
| 137 | * |
| 138 | * @param resultState The result state to update if a change to the properties of a child occurs |
| 139 | * @param algorithmState The state in which the current pass of the algorithm is currently in |
| 140 | * and which will be updated |
| 141 | */ |
| 142 | private void updatePositionsForState(StackScrollState resultState, |
| 143 | StackScrollAlgorithmState algorithmState) { |
| 144 | float stackHeight = getLayoutHeight(); |
| 145 | |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame] | 146 | // The starting position of the bottom stack peek |
| 147 | float bottomPeekStart = stackHeight - mBottomStackPeekSize; |
| 148 | |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 149 | // The position where the bottom stack starts. |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame] | 150 | float transitioningPositionStart = bottomPeekStart - mCollapsedSize; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 151 | |
| 152 | // The y coordinate of the current child. |
| 153 | float currentYPosition = 0.0f; |
| 154 | |
| 155 | // How far in is the element currently transitioning into the bottom stack. |
| 156 | float yPositionInScrollView = 0.0f; |
| 157 | |
Jorim Jaggi | d4a5744 | 2014-04-10 02:45:55 +0200 | [diff] [blame] | 158 | int childCount = algorithmState.visibleChildren.size(); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 159 | int numberOfElementsCompletelyIn = (int) algorithmState.itemsInTopStack; |
| 160 | for (int i = 0; i < childCount; i++) { |
Jorim Jaggi | d4a5744 | 2014-04-10 02:45:55 +0200 | [diff] [blame] | 161 | View child = algorithmState.visibleChildren.get(i); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 162 | StackScrollState.ViewState childViewState = resultState.getViewStateForView(child); |
| 163 | childViewState.yTranslation = currentYPosition; |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 164 | childViewState.location = StackScrollState.ViewState.LOCATION_UNKNOWN; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 165 | int childHeight = child.getHeight(); |
| 166 | // The y position after this element |
| 167 | float nextYPosition = currentYPosition + childHeight + mPaddingBetweenElements; |
| 168 | float yPositionInScrollViewAfterElement = yPositionInScrollView |
| 169 | + childHeight |
| 170 | + mPaddingBetweenElements; |
| 171 | float scrollOffset = yPositionInScrollViewAfterElement - algorithmState.scrollY; |
| 172 | if (i < algorithmState.lastTopStackIndex) { |
| 173 | // Case 1: |
| 174 | // We are in the top Stack |
| 175 | nextYPosition = updateStateForTopStackChild(algorithmState, |
| 176 | numberOfElementsCompletelyIn, |
| 177 | i, childViewState); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 178 | } else if (i == algorithmState.lastTopStackIndex) { |
| 179 | // Case 2: |
| 180 | // First element of regular scrollview comes next, so the position is just the |
| 181 | // scrolling position |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame] | 182 | nextYPosition = updateStateForFirstScrollingChild(transitioningPositionStart, |
| 183 | childViewState, scrollOffset); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 184 | } else if (nextYPosition >= transitioningPositionStart) { |
| 185 | if (currentYPosition >= transitioningPositionStart) { |
| 186 | // Case 3: |
| 187 | // According to the regular scroll view we are fully translated out of the |
| 188 | // bottom of the screen so we are fully in the bottom stack |
| 189 | nextYPosition = updateStateForChildFullyInBottomStack(algorithmState, |
| 190 | transitioningPositionStart, childViewState, childHeight); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 191 | } else { |
| 192 | // Case 4: |
| 193 | // According to the regular scroll view we are currently translating out of / |
| 194 | // into the bottom of the screen |
| 195 | nextYPosition = updateStateForChildTransitioningInBottom( |
| 196 | algorithmState, stackHeight, transitioningPositionStart, |
| 197 | currentYPosition, childViewState, |
| 198 | childHeight, nextYPosition); |
| 199 | } |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 200 | } else { |
| 201 | childViewState.location = StackScrollState.ViewState.LOCATION_MAIN_AREA; |
| 202 | } |
| 203 | // The first card is always rendered. |
| 204 | if (i == 0) { |
| 205 | childViewState.alpha = 1.0f; |
| 206 | childViewState.location = StackScrollState.ViewState.LOCATION_FIRST_CARD; |
| 207 | } |
| 208 | if (childViewState.location == StackScrollState.ViewState.LOCATION_UNKNOWN) { |
| 209 | Log.wtf(LOG_TAG, "Failed to assign location for child " + i); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 210 | } |
Selim Cinek | b6d85eb | 2014-03-28 20:21:01 +0100 | [diff] [blame] | 211 | nextYPosition = Math.max(0, nextYPosition); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 212 | currentYPosition = nextYPosition; |
| 213 | yPositionInScrollView = yPositionInScrollViewAfterElement; |
| 214 | } |
| 215 | } |
| 216 | |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame] | 217 | /** |
| 218 | * Update the state for the first child which is in the regular scrolling area. |
| 219 | * |
| 220 | * @param transitioningPositionStart the transition starting position of the bottom stack |
| 221 | * @param childViewState the view state of the child |
| 222 | * @param scrollOffset the position in the regular scroll view after this child |
| 223 | * @return the next child position |
| 224 | */ |
| 225 | private float updateStateForFirstScrollingChild(float transitioningPositionStart, |
| 226 | StackScrollState.ViewState childViewState, float scrollOffset) { |
| 227 | childViewState.location = StackScrollState.ViewState.LOCATION_TOP_STACK_PEEKING; |
| 228 | if (scrollOffset < transitioningPositionStart) { |
| 229 | return scrollOffset; |
| 230 | } else { |
| 231 | return transitioningPositionStart; |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | private int getMaxAllowedChildHeight(View child) { |
| 236 | if (child instanceof ExpandableNotificationRow) { |
| 237 | ExpandableNotificationRow row = (ExpandableNotificationRow) child; |
| 238 | return row.getMaximumAllowedExpandHeight(); |
| 239 | } |
| 240 | return child.getHeight(); |
| 241 | } |
| 242 | |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 243 | private float updateStateForChildTransitioningInBottom(StackScrollAlgorithmState algorithmState, |
| 244 | float stackHeight, float transitioningPositionStart, float currentYPosition, |
| 245 | StackScrollState.ViewState childViewState, int childHeight, float nextYPosition) { |
| 246 | float newSize = transitioningPositionStart + mCollapsedSize - currentYPosition; |
| 247 | newSize = Math.min(childHeight, newSize); |
| 248 | // Transitioning element on top of bottom stack: |
| 249 | algorithmState.partialInBottom = 1.0f - ( |
| 250 | (stackHeight - mBottomStackPeekSize - nextYPosition) / mCollapsedSize); |
| 251 | // Our element can be expanded, so we might even have to scroll further than |
| 252 | // mCollapsedSize |
| 253 | algorithmState.partialInBottom = Math.min(1.0f, algorithmState.partialInBottom); |
| 254 | float offset = mBottomStackIndentationFunctor.getValue( |
| 255 | algorithmState.partialInBottom); |
| 256 | nextYPosition = transitioningPositionStart + offset; |
| 257 | algorithmState.itemsInBottomStack += algorithmState.partialInBottom; |
| 258 | // TODO: only temporarily collapse |
| 259 | if (childHeight != (int) newSize) { |
| 260 | childViewState.height = (int) newSize; |
| 261 | } |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 262 | childViewState.location = StackScrollState.ViewState.LOCATION_MAIN_AREA; |
| 263 | |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 264 | return nextYPosition; |
| 265 | } |
| 266 | |
| 267 | private float updateStateForChildFullyInBottomStack(StackScrollAlgorithmState algorithmState, |
| 268 | float transitioningPositionStart, StackScrollState.ViewState childViewState, |
| 269 | int childHeight) { |
| 270 | |
| 271 | float nextYPosition; |
| 272 | algorithmState.itemsInBottomStack += 1.0f; |
| 273 | if (algorithmState.itemsInBottomStack < MAX_ITEMS_IN_BOTTOM_STACK) { |
| 274 | // We are visually entering the bottom stack |
| 275 | nextYPosition = transitioningPositionStart |
| 276 | + mBottomStackIndentationFunctor.getValue( |
| 277 | algorithmState.itemsInBottomStack); |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 278 | childViewState.location = StackScrollState.ViewState.LOCATION_BOTTOM_STACK_PEEKING; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 279 | } else { |
| 280 | // we are fully inside the stack |
| 281 | if (algorithmState.itemsInBottomStack > MAX_ITEMS_IN_BOTTOM_STACK + 2) { |
| 282 | childViewState.alpha = 0.0f; |
| 283 | } else if (algorithmState.itemsInBottomStack |
| 284 | > MAX_ITEMS_IN_BOTTOM_STACK + 1) { |
| 285 | childViewState.alpha = 1.0f - algorithmState.partialInBottom; |
| 286 | } |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 287 | childViewState.location = StackScrollState.ViewState.LOCATION_BOTTOM_STACK_HIDDEN; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 288 | nextYPosition = transitioningPositionStart + mBottomStackPeekSize; |
| 289 | } |
| 290 | // TODO: only temporarily collapse |
| 291 | if (childHeight != mCollapsedSize) { |
| 292 | childViewState.height = mCollapsedSize; |
| 293 | } |
| 294 | return nextYPosition; |
| 295 | } |
| 296 | |
| 297 | private float updateStateForTopStackChild(StackScrollAlgorithmState algorithmState, |
| 298 | int numberOfElementsCompletelyIn, int i, StackScrollState.ViewState childViewState) { |
| 299 | |
| 300 | float nextYPosition = 0; |
| 301 | |
| 302 | // First we calculate the index relative to the current stack window of size at most |
| 303 | // {@link #MAX_ITEMS_IN_TOP_STACK} |
| 304 | int paddedIndex = i |
| 305 | - Math.max(numberOfElementsCompletelyIn - MAX_ITEMS_IN_TOP_STACK, 0); |
| 306 | if (paddedIndex >= 0) { |
| 307 | // We are currently visually entering the top stack |
| 308 | nextYPosition = mCollapsedSize + mPaddingBetweenElements - |
| 309 | mTopStackIndentationFunctor.getValue( |
| 310 | algorithmState.itemsInTopStack - i - 1); |
Selim Cinek | b6d85eb | 2014-03-28 20:21:01 +0100 | [diff] [blame] | 311 | nextYPosition = Math.min(nextYPosition, mLayoutHeight - mCollapsedSize |
| 312 | - mBottomStackPeekSize); |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 313 | if (paddedIndex == 0) { |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 314 | childViewState.alpha = 1.0f - algorithmState.partialInTop; |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 315 | childViewState.location = StackScrollState.ViewState.LOCATION_TOP_STACK_HIDDEN; |
| 316 | } else { |
| 317 | childViewState.location = StackScrollState.ViewState.LOCATION_TOP_STACK_PEEKING; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 318 | } |
| 319 | } else { |
Christoph Studer | 6e3eceb | 2014-04-01 18:40:27 +0200 | [diff] [blame] | 320 | // We are hidden behind the top card and faded out, so we can hide ourselves. |
| 321 | childViewState.alpha = 0.0f; |
| 322 | childViewState.location = StackScrollState.ViewState.LOCATION_TOP_STACK_HIDDEN; |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 323 | } |
| 324 | return nextYPosition; |
| 325 | } |
| 326 | |
| 327 | /** |
| 328 | * Find the number of items in the top stack and update the result state if needed. |
| 329 | * |
| 330 | * @param resultState The result state to update if a height change of an child occurs |
| 331 | * @param algorithmState The state in which the current pass of the algorithm is currently in |
| 332 | * and which will be updated |
| 333 | */ |
| 334 | private void findNumberOfItemsInTopStackAndUpdateState(StackScrollState resultState, |
| 335 | StackScrollAlgorithmState algorithmState) { |
| 336 | |
| 337 | // The y Position if the element would be in a regular scrollView |
| 338 | float yPositionInScrollView = 0.0f; |
Jorim Jaggi | d4a5744 | 2014-04-10 02:45:55 +0200 | [diff] [blame] | 339 | int childCount = algorithmState.visibleChildren.size(); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 340 | |
| 341 | // find the number of elements in the top stack. |
| 342 | for (int i = 0; i < childCount; i++) { |
Jorim Jaggi | d4a5744 | 2014-04-10 02:45:55 +0200 | [diff] [blame] | 343 | View child = algorithmState.visibleChildren.get(i); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 344 | StackScrollState.ViewState childViewState = resultState.getViewStateForView(child); |
| 345 | int childHeight = child.getHeight(); |
| 346 | float yPositionInScrollViewAfterElement = yPositionInScrollView |
| 347 | + childHeight |
| 348 | + mPaddingBetweenElements; |
| 349 | if (yPositionInScrollView < algorithmState.scrollY) { |
| 350 | if (yPositionInScrollViewAfterElement <= algorithmState.scrollY) { |
| 351 | // According to the regular scroll view we are fully off screen |
| 352 | algorithmState.itemsInTopStack += 1.0f; |
| 353 | if (childHeight != mCollapsedSize) { |
| 354 | childViewState.height = mCollapsedSize; |
| 355 | } |
| 356 | } else { |
| 357 | // According to the regular scroll view we are partially off screen |
| 358 | // If it is expanded we have to collapse it to a new size |
| 359 | float newSize = yPositionInScrollViewAfterElement |
| 360 | - mPaddingBetweenElements |
| 361 | - algorithmState.scrollY; |
| 362 | |
| 363 | // How much did we scroll into this child |
| 364 | algorithmState.partialInTop = (mCollapsedSize - newSize) / (mCollapsedSize |
| 365 | + mPaddingBetweenElements); |
| 366 | |
| 367 | // Our element can be expanded, so this can get negative |
| 368 | algorithmState.partialInTop = Math.max(0.0f, algorithmState.partialInTop); |
| 369 | algorithmState.itemsInTopStack += algorithmState.partialInTop; |
| 370 | // TODO: handle overlapping sizes with end stack |
| 371 | newSize = Math.max(mCollapsedSize, newSize); |
| 372 | // TODO: only temporarily collapse |
| 373 | if (newSize != childHeight) { |
| 374 | childViewState.height = (int) newSize; |
| 375 | |
| 376 | // We decrease scrollY by the same amount we made this child smaller. |
| 377 | // The new scroll position is therefore the start of the element |
| 378 | algorithmState.scrollY = (int) yPositionInScrollView; |
| 379 | resultState.setScrollY(algorithmState.scrollY); |
| 380 | } |
| 381 | if (childHeight > mCollapsedSize) { |
| 382 | // If we are just resizing this child, this element is not treated to be |
| 383 | // transitioning into the stack and therefore it is the last element in |
| 384 | // the stack. |
| 385 | algorithmState.lastTopStackIndex = i; |
| 386 | break; |
| 387 | } |
| 388 | } |
| 389 | } else { |
| 390 | algorithmState.lastTopStackIndex = i; |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame] | 391 | if (i == 0) { |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 392 | |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame] | 393 | // The starting position of the bottom stack peek |
| 394 | float bottomPeekStart = getLayoutHeight() - mBottomStackPeekSize; |
| 395 | // Collapse and expand the first child while the shade is being expanded |
| 396 | float maxHeight = mIsExpansionChanging && child == mFirstChildWhileExpanding |
| 397 | ? mFirstChildMaxHeight |
| 398 | : childHeight; |
| 399 | childViewState.height = (int) Math.max(Math.min(bottomPeekStart, maxHeight), |
| 400 | mCollapsedSize); |
| 401 | } |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 402 | // We are already past the stack so we can end the loop |
| 403 | break; |
| 404 | } |
| 405 | yPositionInScrollView = yPositionInScrollViewAfterElement; |
| 406 | } |
| 407 | } |
| 408 | |
| 409 | /** |
| 410 | * Calculate the Z positions for all children based on the number of items in both stacks and |
| 411 | * save it in the resultState |
| 412 | * |
| 413 | * @param resultState The result state to update the zTranslation values |
| 414 | * @param algorithmState The state in which the current pass of the algorithm is currently in |
| 415 | */ |
| 416 | private void updateZValuesForState(StackScrollState resultState, |
| 417 | StackScrollAlgorithmState algorithmState) { |
Jorim Jaggi | d4a5744 | 2014-04-10 02:45:55 +0200 | [diff] [blame] | 418 | int childCount = algorithmState.visibleChildren.size(); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 419 | for (int i = 0; i < childCount; i++) { |
Jorim Jaggi | d4a5744 | 2014-04-10 02:45:55 +0200 | [diff] [blame] | 420 | View child = algorithmState.visibleChildren.get(i); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 421 | StackScrollState.ViewState childViewState = resultState.getViewStateForView(child); |
| 422 | if (i < algorithmState.itemsInTopStack) { |
| 423 | float stackIndex = algorithmState.itemsInTopStack - i; |
| 424 | stackIndex = Math.min(stackIndex, MAX_ITEMS_IN_TOP_STACK + 2); |
| 425 | childViewState.zTranslation = mZBasicHeight |
| 426 | + stackIndex * mZDistanceBetweenElements; |
| 427 | } else if (i > (childCount - 1 - algorithmState.itemsInBottomStack)) { |
| 428 | float numItemsAbove = i - (childCount - 1 - algorithmState.itemsInBottomStack); |
| 429 | float translationZ = mZBasicHeight |
| 430 | - numItemsAbove * mZDistanceBetweenElements; |
| 431 | childViewState.zTranslation = translationZ; |
| 432 | } else { |
| 433 | childViewState.zTranslation = mZBasicHeight; |
| 434 | } |
| 435 | } |
| 436 | } |
| 437 | |
| 438 | public float getLayoutHeight() { |
| 439 | return mLayoutHeight; |
| 440 | } |
| 441 | |
| 442 | public void setLayoutHeight(float layoutHeight) { |
| 443 | this.mLayoutHeight = layoutHeight; |
| 444 | } |
| 445 | |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame] | 446 | public void onExpansionStarted(StackScrollState currentState) { |
| 447 | mIsExpansionChanging = true; |
| 448 | mExpandedOnStart = mIsExpanded; |
| 449 | ViewGroup hostView = currentState.getHostView(); |
| 450 | updateFirstChildHeightWhileExpanding(hostView); |
| 451 | } |
| 452 | |
| 453 | private void updateFirstChildHeightWhileExpanding(ViewGroup hostView) { |
Jorim Jaggi | 9f347ae | 2014-04-11 00:47:18 +0200 | [diff] [blame^] | 454 | mFirstChildWhileExpanding = findFirstVisibleChild(hostView); |
| 455 | if (mFirstChildWhileExpanding != null) { |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame] | 456 | if (mExpandedOnStart) { |
| 457 | |
| 458 | // We are collapsing the shade, so the first child can get as most as high as the |
| 459 | // current height. |
| 460 | mFirstChildMaxHeight = mFirstChildWhileExpanding.getHeight(); |
| 461 | } else { |
| 462 | |
| 463 | // We are expanding the shade, expand it to its full height. |
| 464 | mFirstChildMaxHeight = getMaxAllowedChildHeight(mFirstChildWhileExpanding); |
| 465 | } |
| 466 | } else { |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame] | 467 | mFirstChildMaxHeight = 0; |
| 468 | } |
| 469 | } |
| 470 | |
Jorim Jaggi | 9f347ae | 2014-04-11 00:47:18 +0200 | [diff] [blame^] | 471 | private View findFirstVisibleChild(ViewGroup container) { |
| 472 | int childCount = container.getChildCount(); |
| 473 | for (int i = 0; i < childCount; i++) { |
| 474 | View child = container.getChildAt(i); |
| 475 | if (child.getVisibility() != View.GONE) { |
| 476 | return child; |
| 477 | } |
| 478 | } |
| 479 | return null; |
| 480 | } |
| 481 | |
Selim Cinek | 1685e63 | 2014-04-08 02:27:49 +0200 | [diff] [blame] | 482 | public void onExpansionStopped() { |
| 483 | mIsExpansionChanging = false; |
| 484 | mFirstChildWhileExpanding = null; |
| 485 | } |
| 486 | |
| 487 | public void setIsExpanded(boolean isExpanded) { |
| 488 | this.mIsExpanded = isExpanded; |
| 489 | } |
| 490 | |
| 491 | public void notifyChildrenChanged(ViewGroup hostView) { |
| 492 | if (mIsExpansionChanging) { |
| 493 | updateFirstChildHeightWhileExpanding(hostView); |
| 494 | } |
| 495 | } |
| 496 | |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 497 | class StackScrollAlgorithmState { |
| 498 | |
| 499 | /** |
| 500 | * The scroll position of the algorithm |
| 501 | */ |
| 502 | public int scrollY; |
| 503 | |
| 504 | /** |
| 505 | * The quantity of items which are in the top stack. |
| 506 | */ |
| 507 | public float itemsInTopStack; |
| 508 | |
| 509 | /** |
| 510 | * how far in is the element currently transitioning into the top stack |
| 511 | */ |
| 512 | public float partialInTop; |
| 513 | |
| 514 | /** |
| 515 | * The last item index which is in the top stack. |
| 516 | * NOTE: In the top stack the item after the transitioning element is also in the stack! |
| 517 | * This is needed to ensure a smooth transition between the y position in the regular |
| 518 | * scrollview and the one in the stack. |
| 519 | */ |
| 520 | public int lastTopStackIndex; |
| 521 | |
| 522 | /** |
| 523 | * The quantity of items which are in the bottom stack. |
| 524 | */ |
| 525 | public float itemsInBottomStack; |
| 526 | |
| 527 | /** |
| 528 | * how far in is the element currently transitioning into the bottom stack |
| 529 | */ |
| 530 | public float partialInBottom; |
Jorim Jaggi | d4a5744 | 2014-04-10 02:45:55 +0200 | [diff] [blame] | 531 | |
| 532 | /** |
| 533 | * The children from the host view which are not gone. |
| 534 | */ |
| 535 | public final ArrayList<View> visibleChildren = new ArrayList<View>(); |
Selim Cinek | 67b2260 | 2014-03-10 15:40:16 +0100 | [diff] [blame] | 536 | } |
| 537 | |
| 538 | } |