StackScrollAlgorithm.java revision 9b1d30ee900ae49ad717b1ef7eb685b96393402d
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 17package com.android.systemui.statusbar.stack; 18 19import android.content.Context; 20import android.util.Log; 21import android.view.View; 22import android.view.ViewGroup; 23 24import com.android.systemui.R; 25import com.android.systemui.statusbar.ExpandableNotificationRow; 26import com.android.systemui.statusbar.ExpandableView; 27import com.android.systemui.statusbar.notification.FakeShadowView; 28import com.android.systemui.statusbar.notification.NotificationUtils; 29 30import java.util.ArrayList; 31import java.util.HashMap; 32import java.util.List; 33 34/** 35 * The Algorithm of the {@link com.android.systemui.statusbar.stack 36 * .NotificationStackScrollLayout} which can be queried for {@link com.android.systemui.statusbar 37 * .stack.StackScrollState} 38 */ 39public class StackScrollAlgorithm { 40 41 private static final String LOG_TAG = "StackScrollAlgorithm"; 42 43 private static final int MAX_ITEMS_IN_BOTTOM_STACK = 3; 44 45 private int mPaddingBetweenElements; 46 private int mIncreasedPaddingBetweenElements; 47 private int mCollapsedSize; 48 private int mBottomStackPeekSize; 49 private int mZDistanceBetweenElements; 50 private int mZBasicHeight; 51 52 private StackIndentationFunctor mBottomStackIndentationFunctor; 53 54 private StackScrollAlgorithmState mTempAlgorithmState = new StackScrollAlgorithmState(); 55 private boolean mIsExpanded; 56 private int mBottomStackSlowDownLength; 57 58 public StackScrollAlgorithm(Context context) { 59 initView(context); 60 } 61 62 public void initView(Context context) { 63 initConstants(context); 64 } 65 66 public int getBottomStackSlowDownLength() { 67 return mBottomStackSlowDownLength + mPaddingBetweenElements; 68 } 69 70 private void initConstants(Context context) { 71 mPaddingBetweenElements = Math.max(1, context.getResources() 72 .getDimensionPixelSize(R.dimen.notification_divider_height)); 73 mIncreasedPaddingBetweenElements = context.getResources() 74 .getDimensionPixelSize(R.dimen.notification_divider_height_increased); 75 mCollapsedSize = context.getResources() 76 .getDimensionPixelSize(R.dimen.notification_min_height); 77 mBottomStackPeekSize = context.getResources() 78 .getDimensionPixelSize(R.dimen.bottom_stack_peek_amount); 79 mZDistanceBetweenElements = Math.max(1, context.getResources() 80 .getDimensionPixelSize(R.dimen.z_distance_between_notifications)); 81 mZBasicHeight = (MAX_ITEMS_IN_BOTTOM_STACK + 1) * mZDistanceBetweenElements; 82 mBottomStackSlowDownLength = context.getResources() 83 .getDimensionPixelSize(R.dimen.bottom_stack_slow_down_length); 84 mBottomStackIndentationFunctor = new PiecewiseLinearIndentationFunctor( 85 MAX_ITEMS_IN_BOTTOM_STACK, 86 mBottomStackPeekSize, 87 getBottomStackSlowDownLength(), 88 0.5f); 89 } 90 91 public void getStackScrollState(AmbientState ambientState, StackScrollState resultState) { 92 // The state of the local variables are saved in an algorithmState to easily subdivide it 93 // into multiple phases. 94 StackScrollAlgorithmState algorithmState = mTempAlgorithmState; 95 96 // First we reset the view states to their default values. 97 resultState.resetViewStates(); 98 99 initAlgorithmState(resultState, algorithmState, ambientState); 100 101 updatePositionsForState(resultState, algorithmState, ambientState); 102 103 updateZValuesForState(resultState, algorithmState, ambientState); 104 105 updateHeadsUpStates(resultState, algorithmState, ambientState); 106 107 handleDraggedViews(ambientState, resultState, algorithmState); 108 updateDimmedActivatedHideSensitive(ambientState, resultState, algorithmState); 109 updateClipping(resultState, algorithmState, ambientState); 110 updateSpeedBumpState(resultState, algorithmState, ambientState.getSpeedBumpIndex()); 111 getNotificationChildrenStates(resultState, algorithmState); 112 } 113 114 private void getNotificationChildrenStates(StackScrollState resultState, 115 StackScrollAlgorithmState algorithmState) { 116 int childCount = algorithmState.visibleChildren.size(); 117 for (int i = 0; i < childCount; i++) { 118 ExpandableView v = algorithmState.visibleChildren.get(i); 119 if (v instanceof ExpandableNotificationRow) { 120 ExpandableNotificationRow row = (ExpandableNotificationRow) v; 121 row.getChildrenStates(resultState); 122 } 123 } 124 } 125 126 private void updateSpeedBumpState(StackScrollState resultState, 127 StackScrollAlgorithmState algorithmState, int speedBumpIndex) { 128 int childCount = algorithmState.visibleChildren.size(); 129 for (int i = 0; i < childCount; i++) { 130 View child = algorithmState.visibleChildren.get(i); 131 StackViewState childViewState = resultState.getViewStateForView(child); 132 133 // The speed bump can also be gone, so equality needs to be taken when comparing 134 // indices. 135 childViewState.belowSpeedBump = speedBumpIndex != -1 && i >= speedBumpIndex; 136 } 137 } 138 139 private void updateClipping(StackScrollState resultState, 140 StackScrollAlgorithmState algorithmState, AmbientState ambientState) { 141 float drawStart = ambientState.getTopPadding() + ambientState.getStackTranslation(); 142 float previousNotificationEnd = 0; 143 float previousNotificationStart = 0; 144 int childCount = algorithmState.visibleChildren.size(); 145 for (int i = 0; i < childCount; i++) { 146 ExpandableView child = algorithmState.visibleChildren.get(i); 147 StackViewState state = resultState.getViewStateForView(child); 148 if (!child.mustStayOnScreen()) { 149 previousNotificationEnd = Math.max(drawStart, previousNotificationEnd); 150 previousNotificationStart = Math.max(drawStart, previousNotificationStart); 151 } 152 float newYTranslation = state.yTranslation; 153 float newHeight = state.height; 154 float newNotificationEnd = newYTranslation + newHeight; 155 156 if (newYTranslation < previousNotificationEnd) { 157 // The previous view is overlapping on top, clip! 158 float overlapAmount = previousNotificationEnd - newYTranslation; 159 state.clipTopAmount = (int) overlapAmount; 160 } else { 161 state.clipTopAmount = 0; 162 } 163 164 if (!child.isTransparent()) { 165 // Only update the previous values if we are not transparent, 166 // otherwise we would clip to a transparent view. 167 previousNotificationEnd = newNotificationEnd; 168 previousNotificationStart = newYTranslation; 169 } 170 } 171 } 172 173 public static boolean canChildBeDismissed(View v) { 174 if (v instanceof ExpandableNotificationRow) { 175 ExpandableNotificationRow row = (ExpandableNotificationRow) v; 176 if (row.areGutsExposed()) { 177 return false; 178 } 179 } 180 final View veto = v.findViewById(R.id.veto); 181 return (veto != null && veto.getVisibility() != View.GONE); 182 } 183 184 /** 185 * Updates the dimmed, activated and hiding sensitive states of the children. 186 */ 187 private void updateDimmedActivatedHideSensitive(AmbientState ambientState, 188 StackScrollState resultState, StackScrollAlgorithmState algorithmState) { 189 boolean dimmed = ambientState.isDimmed(); 190 boolean dark = ambientState.isDark(); 191 boolean hideSensitive = ambientState.isHideSensitive(); 192 View activatedChild = ambientState.getActivatedChild(); 193 int childCount = algorithmState.visibleChildren.size(); 194 for (int i = 0; i < childCount; i++) { 195 View child = algorithmState.visibleChildren.get(i); 196 StackViewState childViewState = resultState.getViewStateForView(child); 197 childViewState.dimmed = dimmed; 198 childViewState.dark = dark; 199 childViewState.hideSensitive = hideSensitive; 200 boolean isActivatedChild = activatedChild == child; 201 if (dimmed && isActivatedChild) { 202 childViewState.zTranslation += 2.0f * mZDistanceBetweenElements; 203 } 204 } 205 } 206 207 /** 208 * Handle the special state when views are being dragged 209 */ 210 private void handleDraggedViews(AmbientState ambientState, StackScrollState resultState, 211 StackScrollAlgorithmState algorithmState) { 212 ArrayList<View> draggedViews = ambientState.getDraggedViews(); 213 for (View draggedView : draggedViews) { 214 int childIndex = algorithmState.visibleChildren.indexOf(draggedView); 215 if (childIndex >= 0 && childIndex < algorithmState.visibleChildren.size() - 1) { 216 View nextChild = algorithmState.visibleChildren.get(childIndex + 1); 217 if (!draggedViews.contains(nextChild)) { 218 // only if the view is not dragged itself we modify its state to be fully 219 // visible 220 StackViewState viewState = resultState.getViewStateForView( 221 nextChild); 222 // The child below the dragged one must be fully visible 223 if (ambientState.isShadeExpanded()) { 224 viewState.shadowAlpha = 1; 225 viewState.hidden = false; 226 } 227 } 228 229 // Lets set the alpha to the one it currently has, as its currently being dragged 230 StackViewState viewState = resultState.getViewStateForView(draggedView); 231 // The dragged child should keep the set alpha 232 viewState.alpha = draggedView.getAlpha(); 233 } 234 } 235 } 236 237 /** 238 * Initialize the algorithm state like updating the visible children. 239 */ 240 private void initAlgorithmState(StackScrollState resultState, StackScrollAlgorithmState state, 241 AmbientState ambientState) { 242 state.itemsInBottomStack = 0.0f; 243 state.partialInBottom = 0.0f; 244 float bottomOverScroll = ambientState.getOverScrollAmount(false /* onTop */); 245 246 int scrollY = ambientState.getScrollY(); 247 248 // Due to the overScroller, the stackscroller can have negative scroll state. This is 249 // already accounted for by the top padding and doesn't need an additional adaption 250 scrollY = Math.max(0, scrollY); 251 state.scrollY = (int) (scrollY + bottomOverScroll); 252 253 //now init the visible children and update paddings 254 ViewGroup hostView = resultState.getHostView(); 255 int childCount = hostView.getChildCount(); 256 state.visibleChildren.clear(); 257 state.visibleChildren.ensureCapacity(childCount); 258 state.increasedPaddingMap.clear(); 259 int notGoneIndex = 0; 260 ExpandableView lastView = null; 261 for (int i = 0; i < childCount; i++) { 262 ExpandableView v = (ExpandableView) hostView.getChildAt(i); 263 if (v.getVisibility() != View.GONE) { 264 notGoneIndex = updateNotGoneIndex(resultState, state, notGoneIndex, v); 265 float increasedPadding = v.getIncreasedPaddingAmount(); 266 if (increasedPadding != 0.0f) { 267 state.increasedPaddingMap.put(v, increasedPadding); 268 if (lastView != null) { 269 Float prevValue = state.increasedPaddingMap.get(lastView); 270 float newValue = prevValue != null 271 ? Math.max(prevValue, increasedPadding) 272 : increasedPadding; 273 state.increasedPaddingMap.put(lastView, newValue); 274 } 275 } 276 if (v instanceof ExpandableNotificationRow) { 277 ExpandableNotificationRow row = (ExpandableNotificationRow) v; 278 279 // handle the notgoneIndex for the children as well 280 List<ExpandableNotificationRow> children = 281 row.getNotificationChildren(); 282 if (row.isSummaryWithChildren() && children != null) { 283 for (ExpandableNotificationRow childRow : children) { 284 if (childRow.getVisibility() != View.GONE) { 285 StackViewState childState 286 = resultState.getViewStateForView(childRow); 287 childState.notGoneIndex = notGoneIndex; 288 notGoneIndex++; 289 } 290 } 291 } 292 } 293 lastView = v; 294 } 295 } 296 } 297 298 private int updateNotGoneIndex(StackScrollState resultState, 299 StackScrollAlgorithmState state, int notGoneIndex, 300 ExpandableView v) { 301 StackViewState viewState = resultState.getViewStateForView(v); 302 viewState.notGoneIndex = notGoneIndex; 303 state.visibleChildren.add(v); 304 notGoneIndex++; 305 return notGoneIndex; 306 } 307 308 /** 309 * Determine the positions for the views. This is the main part of the algorithm. 310 * 311 * @param resultState The result state to update if a change to the properties of a child occurs 312 * @param algorithmState The state in which the current pass of the algorithm is currently in 313 * @param ambientState The current ambient state 314 */ 315 private void updatePositionsForState(StackScrollState resultState, 316 StackScrollAlgorithmState algorithmState, AmbientState ambientState) { 317 318 // The starting position of the bottom stack peek 319 float bottomPeekStart = ambientState.getInnerHeight() - mBottomStackPeekSize; 320 321 // The position where the bottom stack starts. 322 float bottomStackStart = bottomPeekStart - mBottomStackSlowDownLength; 323 324 // The y coordinate of the current child. 325 float currentYPosition = -algorithmState.scrollY; 326 int childCount = algorithmState.visibleChildren.size(); 327 for (int i = 0; i < childCount; i++) { 328 currentYPosition = updateChild(i, resultState, algorithmState, ambientState, 329 currentYPosition, bottomStackStart); 330 } 331 } 332 333 protected float updateChild(int i, StackScrollState resultState, 334 StackScrollAlgorithmState algorithmState, AmbientState ambientState, 335 float currentYPosition, float bottomStackStart) { 336 ExpandableView child = algorithmState.visibleChildren.get(i); 337 StackViewState childViewState = resultState.getViewStateForView(child); 338 childViewState.location = StackViewState.LOCATION_UNKNOWN; 339 int paddingAfterChild = getPaddingAfterChild(algorithmState, child); 340 int childHeight = getMaxAllowedChildHeight(child); 341 int collapsedHeight = child.getCollapsedHeight(); 342 childViewState.yTranslation = currentYPosition; 343 if (i == 0) { 344 updateFirstChildHeight(child, childViewState, childHeight, ambientState); 345 } 346 347 // The y position after this element 348 float nextYPosition = currentYPosition + childHeight + 349 paddingAfterChild; 350 if (nextYPosition >= bottomStackStart) { 351 // Case 1: 352 // We are in the bottom stack. 353 if (currentYPosition >= bottomStackStart) { 354 // According to the regular scroll view we are fully translated out of the 355 // bottom of the screen so we are fully in the bottom stack 356 updateStateForChildFullyInBottomStack(algorithmState, 357 bottomStackStart, childViewState, collapsedHeight, ambientState, child); 358 } else { 359 // According to the regular scroll view we are currently translating out of / 360 // into the bottom of the screen 361 updateStateForChildTransitioningInBottom(algorithmState, 362 bottomStackStart, child, currentYPosition, 363 childViewState, childHeight); 364 } 365 } else { 366 // Case 2: 367 // We are in the regular scroll area. 368 childViewState.location = StackViewState.LOCATION_MAIN_AREA; 369 clampPositionToBottomStackStart(childViewState, childViewState.height, childHeight, 370 ambientState); 371 } 372 373 if (i == 0 && ambientState.getScrollY() <= 0) { 374 // The first card can get into the bottom stack if it's the only one 375 // on the lockscreen which pushes it up. Let's make sure that doesn't happen and 376 // it stays at the top 377 childViewState.yTranslation = Math.max(0, childViewState.yTranslation); 378 } 379 currentYPosition = childViewState.yTranslation + childHeight + paddingAfterChild; 380 if (currentYPosition <= 0) { 381 childViewState.location = StackViewState.LOCATION_HIDDEN_TOP; 382 } 383 if (childViewState.location == StackViewState.LOCATION_UNKNOWN) { 384 Log.wtf(LOG_TAG, "Failed to assign location for child " + i); 385 } 386 387 childViewState.yTranslation += ambientState.getTopPadding() 388 + ambientState.getStackTranslation(); 389 return currentYPosition; 390 } 391 392 protected int getPaddingAfterChild(StackScrollAlgorithmState algorithmState, 393 ExpandableView child) { 394 Float paddingValue = algorithmState.increasedPaddingMap.get(child); 395 return paddingValue == null 396 ? mPaddingBetweenElements 397 : (int) NotificationUtils.interpolate(mPaddingBetweenElements, 398 mIncreasedPaddingBetweenElements, 399 paddingValue); 400 } 401 402 private void updateHeadsUpStates(StackScrollState resultState, 403 StackScrollAlgorithmState algorithmState, AmbientState ambientState) { 404 int childCount = algorithmState.visibleChildren.size(); 405 ExpandableNotificationRow topHeadsUpEntry = null; 406 for (int i = 0; i < childCount; i++) { 407 View child = algorithmState.visibleChildren.get(i); 408 if (!(child instanceof ExpandableNotificationRow)) { 409 break; 410 } 411 ExpandableNotificationRow row = (ExpandableNotificationRow) child; 412 if (!row.isHeadsUp()) { 413 break; 414 } 415 StackViewState childState = resultState.getViewStateForView(row); 416 if (topHeadsUpEntry == null) { 417 topHeadsUpEntry = row; 418 childState.location = StackViewState.LOCATION_FIRST_HUN; 419 } 420 boolean isTopEntry = topHeadsUpEntry == row; 421 float unmodifiedEndLocation = childState.yTranslation + childState.height; 422 if (mIsExpanded) { 423 // Ensure that the heads up is always visible even when scrolled off 424 clampHunToTop(ambientState, row, childState); 425 clampHunToMaxTranslation(ambientState, row, childState); 426 } 427 if (row.isPinned()) { 428 childState.yTranslation = Math.max(childState.yTranslation, 0); 429 childState.height = Math.max(row.getIntrinsicHeight(), childState.height); 430 StackViewState topState = resultState.getViewStateForView(topHeadsUpEntry); 431 if (!isTopEntry && (!mIsExpanded 432 || unmodifiedEndLocation < topState.yTranslation + topState.height)) { 433 // Ensure that a headsUp doesn't vertically extend further than the heads-up at 434 // the top most z-position 435 childState.height = row.getIntrinsicHeight(); 436 childState.yTranslation = topState.yTranslation + topState.height 437 - childState.height; 438 } 439 } 440 } 441 } 442 443 private void clampHunToTop(AmbientState ambientState, ExpandableNotificationRow row, 444 StackViewState childState) { 445 float newTranslation = Math.max(ambientState.getTopPadding() 446 + ambientState.getStackTranslation(), childState.yTranslation); 447 childState.height = (int) Math.max(childState.height - (newTranslation 448 - childState.yTranslation), row.getCollapsedHeight()); 449 childState.yTranslation = newTranslation; 450 } 451 452 private void clampHunToMaxTranslation(AmbientState ambientState, ExpandableNotificationRow row, 453 StackViewState childState) { 454 float newTranslation; 455 float bottomPosition = ambientState.getMaxHeadsUpTranslation() - row.getCollapsedHeight(); 456 newTranslation = Math.min(childState.yTranslation, bottomPosition); 457 childState.height = (int) Math.max(childState.height 458 - (childState.yTranslation - newTranslation), row.getCollapsedHeight()); 459 childState.yTranslation = newTranslation; 460 } 461 462 /** 463 * Clamp the yTranslation of the child down such that its end is at most on the beginning of 464 * the bottom stack. 465 * 466 * @param childViewState the view state of the child 467 * @param childHeight the height of this child 468 * @param minHeight the minumum Height of the View 469 */ 470 private void clampPositionToBottomStackStart(StackViewState childViewState, 471 int childHeight, int minHeight, AmbientState ambientState) { 472 473 int bottomStackStart = ambientState.getInnerHeight() 474 - mBottomStackPeekSize - mBottomStackSlowDownLength; 475 int childStart = bottomStackStart - childHeight; 476 if (childStart < childViewState.yTranslation) { 477 float newHeight = bottomStackStart - childViewState.yTranslation; 478 if (newHeight < minHeight) { 479 newHeight = minHeight; 480 childViewState.yTranslation = bottomStackStart - minHeight; 481 } 482 childViewState.height = (int) newHeight; 483 } 484 } 485 486 protected int getMaxAllowedChildHeight(View child) { 487 if (child instanceof ExpandableView) { 488 ExpandableView expandableView = (ExpandableView) child; 489 return expandableView.getIntrinsicHeight(); 490 } 491 return child == null? mCollapsedSize : child.getHeight(); 492 } 493 494 private void updateStateForChildTransitioningInBottom(StackScrollAlgorithmState algorithmState, 495 float transitioningPositionStart, ExpandableView child, float currentYPosition, 496 StackViewState childViewState, int childHeight) { 497 498 // This is the transitioning element on top of bottom stack, calculate how far we are in. 499 algorithmState.partialInBottom = 1.0f - ( 500 (transitioningPositionStart - currentYPosition) / (childHeight + 501 getPaddingAfterChild(algorithmState, child))); 502 503 // the offset starting at the transitionPosition of the bottom stack 504 float offset = mBottomStackIndentationFunctor.getValue(algorithmState.partialInBottom); 505 algorithmState.itemsInBottomStack += algorithmState.partialInBottom; 506 int newHeight = childHeight; 507 if (childHeight > child.getCollapsedHeight()) { 508 newHeight = (int) Math.max(Math.min(transitioningPositionStart + offset - 509 getPaddingAfterChild(algorithmState, child) - currentYPosition, childHeight), 510 child.getCollapsedHeight()); 511 childViewState.height = newHeight; 512 } 513 childViewState.yTranslation = transitioningPositionStart + offset - newHeight 514 - getPaddingAfterChild(algorithmState, child); 515 childViewState.location = StackViewState.LOCATION_MAIN_AREA; 516 } 517 518 private void updateStateForChildFullyInBottomStack(StackScrollAlgorithmState algorithmState, 519 float transitioningPositionStart, StackViewState childViewState, 520 int collapsedHeight, AmbientState ambientState, ExpandableView child) { 521 float currentYPosition; 522 algorithmState.itemsInBottomStack += 1.0f; 523 if (algorithmState.itemsInBottomStack < MAX_ITEMS_IN_BOTTOM_STACK) { 524 // We are visually entering the bottom stack 525 currentYPosition = transitioningPositionStart 526 + mBottomStackIndentationFunctor.getValue(algorithmState.itemsInBottomStack) 527 - getPaddingAfterChild(algorithmState, child); 528 childViewState.location = StackViewState.LOCATION_BOTTOM_STACK_PEEKING; 529 } else { 530 // we are fully inside the stack 531 if (algorithmState.itemsInBottomStack > MAX_ITEMS_IN_BOTTOM_STACK + 2) { 532 childViewState.hidden = true; 533 childViewState.shadowAlpha = 0.0f; 534 } else if (algorithmState.itemsInBottomStack 535 > MAX_ITEMS_IN_BOTTOM_STACK + 1) { 536 childViewState.shadowAlpha = 1.0f - algorithmState.partialInBottom; 537 } 538 childViewState.location = StackViewState.LOCATION_BOTTOM_STACK_HIDDEN; 539 currentYPosition = ambientState.getInnerHeight(); 540 } 541 childViewState.height = collapsedHeight; 542 childViewState.yTranslation = currentYPosition - collapsedHeight; 543 } 544 545 546 /** 547 * Update the height of the first child i.e clamp it to the bottom stack 548 * 549 * @param child the child to update 550 * @param childViewState the viewstate of the child 551 * @param childHeight the height of the child 552 * @param ambientState The ambient state of the algorithm 553 */ 554 protected void updateFirstChildHeight(ExpandableView child, StackViewState childViewState, 555 int childHeight, AmbientState ambientState) { 556 557 // The starting position of the bottom stack peek 558 int bottomPeekStart = ambientState.getInnerHeight() - mBottomStackPeekSize - 559 mBottomStackSlowDownLength + ambientState.getScrollY(); 560 // Collapse and expand the first child while the shade is being expanded 561 childViewState.height = (int) Math.max(Math.min(bottomPeekStart, (float) childHeight), 562 child.getCollapsedHeight()); 563 } 564 565 /** 566 * Calculate the Z positions for all children based on the number of items in both stacks and 567 * save it in the resultState 568 * @param resultState The result state to update the zTranslation values 569 * @param algorithmState The state in which the current pass of the algorithm is currently in 570 * @param ambientState The ambient state of the algorithm 571 */ 572 private void updateZValuesForState(StackScrollState resultState, 573 StackScrollAlgorithmState algorithmState, AmbientState ambientState) { 574 int childCount = algorithmState.visibleChildren.size(); 575 float childrenOnTop = 0.0f; 576 for (int i = childCount - 1; i >= 0; i--) { 577 updateChildZValue(i, childCount, childrenOnTop, 578 resultState, algorithmState, ambientState); 579 } 580 } 581 582 protected void updateChildZValue(int i, int childCount, float childrenOnTop, 583 StackScrollState resultState, StackScrollAlgorithmState algorithmState, 584 AmbientState ambientState) { 585 ExpandableView child = algorithmState.visibleChildren.get(i); 586 StackViewState childViewState = resultState.getViewStateForView(child); 587 if (i > (childCount - 1 - algorithmState.itemsInBottomStack)) { 588 // We are in the bottom stack 589 float numItemsAbove = i - (childCount - 1 - algorithmState.itemsInBottomStack); 590 float zSubtraction; 591 if (numItemsAbove <= 1.0f) { 592 float factor = 0.2f; 593 // Lets fade in slower to the threshold to make the shadow fade in look nicer 594 if (numItemsAbove <= factor) { 595 zSubtraction = FakeShadowView.SHADOW_SIBLING_TRESHOLD 596 * numItemsAbove * (1.0f / factor); 597 } else { 598 zSubtraction = FakeShadowView.SHADOW_SIBLING_TRESHOLD 599 + (numItemsAbove - factor) * (1.0f / (1.0f - factor)) 600 * (mZDistanceBetweenElements 601 - FakeShadowView.SHADOW_SIBLING_TRESHOLD); 602 } 603 } else { 604 zSubtraction = numItemsAbove * mZDistanceBetweenElements; 605 } 606 childViewState.zTranslation = mZBasicHeight - zSubtraction; 607 } else if (child.mustStayOnScreen() 608 && childViewState.yTranslation < ambientState.getTopPadding() 609 + ambientState.getStackTranslation()) { 610 if (childrenOnTop != 0.0f) { 611 childrenOnTop++; 612 } else { 613 float overlap = ambientState.getTopPadding() 614 + ambientState.getStackTranslation() - childViewState.yTranslation; 615 childrenOnTop += Math.min(1.0f, overlap / childViewState.height); 616 } 617 childViewState.zTranslation = mZBasicHeight 618 + childrenOnTop * mZDistanceBetweenElements; 619 } else { 620 childViewState.zTranslation = mZBasicHeight; 621 } 622 } 623 624 private boolean isMaxSizeInitialized(ExpandableView child) { 625 if (child instanceof ExpandableNotificationRow) { 626 ExpandableNotificationRow row = (ExpandableNotificationRow) child; 627 return row.isMaxExpandHeightInitialized(); 628 } 629 return child == null || child.getWidth() != 0; 630 } 631 632 private View findFirstVisibleChild(ViewGroup container) { 633 int childCount = container.getChildCount(); 634 for (int i = 0; i < childCount; i++) { 635 View child = container.getChildAt(i); 636 if (child.getVisibility() != View.GONE) { 637 return child; 638 } 639 } 640 return null; 641 } 642 643 public void setIsExpanded(boolean isExpanded) { 644 this.mIsExpanded = isExpanded; 645 } 646 647 protected class StackScrollAlgorithmState { 648 649 /** 650 * The scroll position of the algorithm 651 */ 652 public int scrollY; 653 654 /** 655 * The quantity of items which are in the bottom stack. 656 */ 657 public float itemsInBottomStack; 658 659 /** 660 * how far in is the element currently transitioning into the bottom stack 661 */ 662 public float partialInBottom; 663 664 /** 665 * The children from the host view which are not gone. 666 */ 667 public final ArrayList<ExpandableView> visibleChildren = new ArrayList<ExpandableView>(); 668 669 /** 670 * The children from the host that need an increased padding after them. A value of 0 means 671 * no increased padding, a value of 1 means full padding. 672 */ 673 public final HashMap<ExpandableView, Float> increasedPaddingMap = new HashMap<>(); 674 } 675 676} 677