StackScrollAlgorithm.java revision 53ac1ef993e4bdce0d155fa00a133540f29af0ed
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 boolean isHeadsUp = (child instanceof ExpandableNotificationRow) 156 && ((ExpandableNotificationRow) child).isPinned(); 157 if (newYTranslation < previousNotificationEnd && ambientState.isShadeExpanded() 158 && !isHeadsUp) { 159 // The previous view is overlapping on top, clip! 160 float overlapAmount = previousNotificationEnd - newYTranslation; 161 state.clipTopAmount = (int) overlapAmount; 162 } else { 163 state.clipTopAmount = 0; 164 } 165 166 if (!child.isTransparent()) { 167 // Only update the previous values if we are not transparent, 168 // otherwise we would clip to a transparent view. 169 previousNotificationEnd = newNotificationEnd; 170 previousNotificationStart = newYTranslation; 171 } 172 } 173 } 174 175 public static boolean canChildBeDismissed(View v) { 176 final View veto = v.findViewById(R.id.veto); 177 return (veto != null && veto.getVisibility() != View.GONE); 178 } 179 180 /** 181 * Updates the dimmed, activated and hiding sensitive states of the children. 182 */ 183 private void updateDimmedActivatedHideSensitive(AmbientState ambientState, 184 StackScrollState resultState, StackScrollAlgorithmState algorithmState) { 185 boolean dimmed = ambientState.isDimmed(); 186 boolean dark = ambientState.isDark(); 187 boolean hideSensitive = ambientState.isHideSensitive(); 188 View activatedChild = ambientState.getActivatedChild(); 189 int childCount = algorithmState.visibleChildren.size(); 190 for (int i = 0; i < childCount; i++) { 191 View child = algorithmState.visibleChildren.get(i); 192 StackViewState childViewState = resultState.getViewStateForView(child); 193 childViewState.dimmed = dimmed; 194 childViewState.dark = dark; 195 childViewState.hideSensitive = hideSensitive; 196 boolean isActivatedChild = activatedChild == child; 197 if (dimmed && isActivatedChild) { 198 childViewState.zTranslation += 2.0f * mZDistanceBetweenElements; 199 } 200 } 201 } 202 203 /** 204 * Handle the special state when views are being dragged 205 */ 206 private void handleDraggedViews(AmbientState ambientState, StackScrollState resultState, 207 StackScrollAlgorithmState algorithmState) { 208 ArrayList<View> draggedViews = ambientState.getDraggedViews(); 209 for (View draggedView : draggedViews) { 210 int childIndex = algorithmState.visibleChildren.indexOf(draggedView); 211 if (childIndex >= 0 && childIndex < algorithmState.visibleChildren.size() - 1) { 212 View nextChild = algorithmState.visibleChildren.get(childIndex + 1); 213 if (!draggedViews.contains(nextChild)) { 214 // only if the view is not dragged itself we modify its state to be fully 215 // visible 216 StackViewState viewState = resultState.getViewStateForView( 217 nextChild); 218 // The child below the dragged one must be fully visible 219 if (ambientState.isShadeExpanded()) { 220 viewState.shadowAlpha = 1; 221 viewState.hidden = false; 222 } 223 } 224 225 // Lets set the alpha to the one it currently has, as its currently being dragged 226 StackViewState viewState = resultState.getViewStateForView(draggedView); 227 // The dragged child should keep the set alpha 228 viewState.alpha = draggedView.getAlpha(); 229 } 230 } 231 } 232 233 /** 234 * Initialize the algorithm state like updating the visible children. 235 */ 236 private void initAlgorithmState(StackScrollState resultState, StackScrollAlgorithmState state, 237 AmbientState ambientState) { 238 state.itemsInBottomStack = 0.0f; 239 state.partialInBottom = 0.0f; 240 float bottomOverScroll = ambientState.getOverScrollAmount(false /* onTop */); 241 242 int scrollY = ambientState.getScrollY(); 243 244 // Due to the overScroller, the stackscroller can have negative scroll state. This is 245 // already accounted for by the top padding and doesn't need an additional adaption 246 scrollY = Math.max(0, scrollY); 247 state.scrollY = (int) (scrollY + bottomOverScroll); 248 249 //now init the visible children and update paddings 250 ViewGroup hostView = resultState.getHostView(); 251 int childCount = hostView.getChildCount(); 252 state.visibleChildren.clear(); 253 state.visibleChildren.ensureCapacity(childCount); 254 state.increasedPaddingMap.clear(); 255 int notGoneIndex = 0; 256 ExpandableView lastView = null; 257 for (int i = 0; i < childCount; i++) { 258 ExpandableView v = (ExpandableView) hostView.getChildAt(i); 259 if (v.getVisibility() != View.GONE) { 260 notGoneIndex = updateNotGoneIndex(resultState, state, notGoneIndex, v); 261 float increasedPadding = v.getIncreasedPaddingAmount(); 262 if (increasedPadding != 0.0f) { 263 state.increasedPaddingMap.put(v, increasedPadding); 264 if (lastView != null) { 265 Float prevValue = state.increasedPaddingMap.get(lastView); 266 float newValue = prevValue != null 267 ? Math.max(prevValue, increasedPadding) 268 : increasedPadding; 269 state.increasedPaddingMap.put(lastView, newValue); 270 } 271 } 272 if (v instanceof ExpandableNotificationRow) { 273 ExpandableNotificationRow row = (ExpandableNotificationRow) v; 274 275 // handle the notgoneIndex for the children as well 276 List<ExpandableNotificationRow> children = 277 row.getNotificationChildren(); 278 if (row.isSummaryWithChildren() && children != null) { 279 for (ExpandableNotificationRow childRow : children) { 280 if (childRow.getVisibility() != View.GONE) { 281 StackViewState childState 282 = resultState.getViewStateForView(childRow); 283 childState.notGoneIndex = notGoneIndex; 284 notGoneIndex++; 285 } 286 } 287 } 288 } 289 lastView = v; 290 } 291 } 292 } 293 294 private int updateNotGoneIndex(StackScrollState resultState, 295 StackScrollAlgorithmState state, int notGoneIndex, 296 ExpandableView v) { 297 StackViewState viewState = resultState.getViewStateForView(v); 298 viewState.notGoneIndex = notGoneIndex; 299 state.visibleChildren.add(v); 300 notGoneIndex++; 301 return notGoneIndex; 302 } 303 304 /** 305 * Determine the positions for the views. This is the main part of the algorithm. 306 * 307 * @param resultState The result state to update if a change to the properties of a child occurs 308 * @param algorithmState The state in which the current pass of the algorithm is currently in 309 * @param ambientState The current ambient state 310 */ 311 private void updatePositionsForState(StackScrollState resultState, 312 StackScrollAlgorithmState algorithmState, AmbientState ambientState) { 313 314 // The starting position of the bottom stack peek 315 float bottomPeekStart = ambientState.getInnerHeight() - mBottomStackPeekSize; 316 317 // The position where the bottom stack starts. 318 float bottomStackStart = bottomPeekStart - mBottomStackSlowDownLength; 319 320 // The y coordinate of the current child. 321 float currentYPosition = -algorithmState.scrollY; 322 323 int childCount = algorithmState.visibleChildren.size(); 324 int paddingAfterChild; 325 for (int i = 0; i < childCount; i++) { 326 ExpandableView child = algorithmState.visibleChildren.get(i); 327 StackViewState childViewState = resultState.getViewStateForView(child); 328 childViewState.location = StackViewState.LOCATION_UNKNOWN; 329 paddingAfterChild = getPaddingAfterChild(algorithmState, child); 330 int childHeight = getMaxAllowedChildHeight(child); 331 int collapsedHeight = child.getCollapsedHeight(); 332 childViewState.yTranslation = currentYPosition; 333 if (i == 0) { 334 updateFirstChildHeight(child, childViewState, childHeight, ambientState); 335 } 336 337 // The y position after this element 338 float nextYPosition = currentYPosition + childHeight + 339 paddingAfterChild; 340 if (nextYPosition >= bottomStackStart) { 341 // Case 1: 342 // We are in the bottom stack. 343 if (currentYPosition >= bottomStackStart) { 344 // According to the regular scroll view we are fully translated out of the 345 // bottom of the screen so we are fully in the bottom stack 346 updateStateForChildFullyInBottomStack(algorithmState, 347 bottomStackStart, childViewState, collapsedHeight, ambientState, child); 348 } else { 349 // According to the regular scroll view we are currently translating out of / 350 // into the bottom of the screen 351 updateStateForChildTransitioningInBottom(algorithmState, 352 bottomStackStart, child, currentYPosition, 353 childViewState, childHeight); 354 } 355 } else { 356 // Case 2: 357 // We are in the regular scroll area. 358 childViewState.location = StackViewState.LOCATION_MAIN_AREA; 359 clampPositionToBottomStackStart(childViewState, childViewState.height, childHeight, 360 ambientState); 361 } 362 363 if (i == 0 && ambientState.getScrollY() <= 0) { 364 // The first card can get into the bottom stack if it's the only one 365 // on the lockscreen which pushes it up. Let's make sure that doesn't happen and 366 // it stays at the top 367 childViewState.yTranslation = Math.max(0, childViewState.yTranslation); 368 } 369 currentYPosition = childViewState.yTranslation + childHeight + paddingAfterChild; 370 if (currentYPosition <= 0) { 371 childViewState.location = StackViewState.LOCATION_HIDDEN_TOP; 372 } 373 if (childViewState.location == StackViewState.LOCATION_UNKNOWN) { 374 Log.wtf(LOG_TAG, "Failed to assign location for child " + i); 375 } 376 377 childViewState.yTranslation += ambientState.getTopPadding() 378 + ambientState.getStackTranslation(); 379 } 380 } 381 382 private int getPaddingAfterChild(StackScrollAlgorithmState algorithmState, 383 ExpandableView child) { 384 Float paddingValue = algorithmState.increasedPaddingMap.get(child); 385 return paddingValue == null 386 ? mPaddingBetweenElements 387 : (int) NotificationUtils.interpolate(mPaddingBetweenElements, 388 mIncreasedPaddingBetweenElements, 389 paddingValue); 390 } 391 392 private void updateHeadsUpStates(StackScrollState resultState, 393 StackScrollAlgorithmState algorithmState, AmbientState ambientState) { 394 int childCount = algorithmState.visibleChildren.size(); 395 ExpandableNotificationRow topHeadsUpEntry = null; 396 for (int i = 0; i < childCount; i++) { 397 View child = algorithmState.visibleChildren.get(i); 398 if (!(child instanceof ExpandableNotificationRow)) { 399 break; 400 } 401 ExpandableNotificationRow row = (ExpandableNotificationRow) child; 402 if (!row.isHeadsUp()) { 403 break; 404 } 405 StackViewState childState = resultState.getViewStateForView(row); 406 if (topHeadsUpEntry == null) { 407 topHeadsUpEntry = row; 408 childState.location = StackViewState.LOCATION_FIRST_HUN; 409 } 410 boolean isTopEntry = topHeadsUpEntry == row; 411 float unmodifiedEndLocation = childState.yTranslation + childState.height; 412 if (mIsExpanded) { 413 // Ensure that the heads up is always visible even when scrolled off 414 clampHunToTop(ambientState, row, childState); 415 clampHunToMaxTranslation(ambientState, row, childState); 416 } 417 if (row.isPinned()) { 418 childState.yTranslation = Math.max(childState.yTranslation, 0); 419 childState.height = Math.max(row.getIntrinsicHeight(), childState.height); 420 StackViewState topState = resultState.getViewStateForView(topHeadsUpEntry); 421 if (!isTopEntry && (!mIsExpanded 422 || unmodifiedEndLocation < topState.yTranslation + topState.height)) { 423 // Ensure that a headsUp doesn't vertically extend further than the heads-up at 424 // the top most z-position 425 childState.height = row.getIntrinsicHeight(); 426 childState.yTranslation = topState.yTranslation + topState.height 427 - childState.height; 428 } 429 } 430 } 431 } 432 433 private void clampHunToTop(AmbientState ambientState, ExpandableNotificationRow row, 434 StackViewState childState) { 435 float newTranslation = Math.max(ambientState.getTopPadding() 436 + ambientState.getStackTranslation(), childState.yTranslation); 437 childState.height = (int) Math.max(childState.height - (newTranslation 438 - childState.yTranslation), row.getCollapsedHeight()); 439 childState.yTranslation = newTranslation; 440 } 441 442 private void clampHunToMaxTranslation(AmbientState ambientState, ExpandableNotificationRow row, 443 StackViewState childState) { 444 float newTranslation; 445 float bottomPosition = ambientState.getMaxHeadsUpTranslation() - row.getCollapsedHeight(); 446 newTranslation = Math.min(childState.yTranslation, bottomPosition); 447 childState.height = (int) Math.max(childState.height 448 - (childState.yTranslation - newTranslation), row.getCollapsedHeight()); 449 childState.yTranslation = newTranslation; 450 } 451 452 /** 453 * Clamp the yTranslation of the child down such that its end is at most on the beginning of 454 * the bottom stack. 455 * 456 * @param childViewState the view state of the child 457 * @param childHeight the height of this child 458 * @param minHeight the minumum Height of the View 459 */ 460 private void clampPositionToBottomStackStart(StackViewState childViewState, 461 int childHeight, int minHeight, AmbientState ambientState) { 462 463 int bottomStackStart = ambientState.getInnerHeight() 464 - mBottomStackPeekSize - mBottomStackSlowDownLength; 465 int childStart = bottomStackStart - childHeight; 466 if (childStart < childViewState.yTranslation) { 467 float newHeight = bottomStackStart - childViewState.yTranslation; 468 if (newHeight < minHeight) { 469 newHeight = minHeight; 470 childViewState.yTranslation = bottomStackStart - minHeight; 471 } 472 childViewState.height = (int) newHeight; 473 } 474 } 475 476 private int getMaxAllowedChildHeight(View child) { 477 if (child instanceof ExpandableView) { 478 ExpandableView expandableView = (ExpandableView) child; 479 return expandableView.getIntrinsicHeight(); 480 } 481 return child == null? mCollapsedSize : child.getHeight(); 482 } 483 484 private void updateStateForChildTransitioningInBottom(StackScrollAlgorithmState algorithmState, 485 float transitioningPositionStart, ExpandableView child, float currentYPosition, 486 StackViewState childViewState, int childHeight) { 487 488 // This is the transitioning element on top of bottom stack, calculate how far we are in. 489 algorithmState.partialInBottom = 1.0f - ( 490 (transitioningPositionStart - currentYPosition) / (childHeight + 491 getPaddingAfterChild(algorithmState, child))); 492 493 // the offset starting at the transitionPosition of the bottom stack 494 float offset = mBottomStackIndentationFunctor.getValue(algorithmState.partialInBottom); 495 algorithmState.itemsInBottomStack += algorithmState.partialInBottom; 496 int newHeight = childHeight; 497 if (childHeight > child.getCollapsedHeight()) { 498 newHeight = (int) Math.max(Math.min(transitioningPositionStart + offset - 499 getPaddingAfterChild(algorithmState, child) - currentYPosition, childHeight), 500 child.getCollapsedHeight()); 501 childViewState.height = newHeight; 502 } 503 childViewState.yTranslation = transitioningPositionStart + offset - newHeight 504 - getPaddingAfterChild(algorithmState, child); 505 childViewState.location = StackViewState.LOCATION_MAIN_AREA; 506 } 507 508 private void updateStateForChildFullyInBottomStack(StackScrollAlgorithmState algorithmState, 509 float transitioningPositionStart, StackViewState childViewState, 510 int collapsedHeight, AmbientState ambientState, ExpandableView child) { 511 float currentYPosition; 512 algorithmState.itemsInBottomStack += 1.0f; 513 if (algorithmState.itemsInBottomStack < MAX_ITEMS_IN_BOTTOM_STACK) { 514 // We are visually entering the bottom stack 515 currentYPosition = transitioningPositionStart 516 + mBottomStackIndentationFunctor.getValue(algorithmState.itemsInBottomStack) 517 - getPaddingAfterChild(algorithmState, child); 518 childViewState.location = StackViewState.LOCATION_BOTTOM_STACK_PEEKING; 519 } else { 520 // we are fully inside the stack 521 if (algorithmState.itemsInBottomStack > MAX_ITEMS_IN_BOTTOM_STACK + 2) { 522 childViewState.hidden = true; 523 childViewState.shadowAlpha = 0.0f; 524 } else if (algorithmState.itemsInBottomStack 525 > MAX_ITEMS_IN_BOTTOM_STACK + 1) { 526 childViewState.shadowAlpha = 1.0f - algorithmState.partialInBottom; 527 } 528 childViewState.location = StackViewState.LOCATION_BOTTOM_STACK_HIDDEN; 529 currentYPosition = ambientState.getInnerHeight(); 530 } 531 childViewState.height = collapsedHeight; 532 childViewState.yTranslation = currentYPosition - collapsedHeight; 533 } 534 535 536 /** 537 * Update the height of the first child i.e clamp it to the bottom stack 538 * 539 * @param child the child to update 540 * @param childViewState the viewstate of the child 541 * @param childHeight the height of the child 542 * @param ambientState The ambient state of the algorithm 543 */ 544 private void updateFirstChildHeight(ExpandableView child, StackViewState childViewState, 545 int childHeight, AmbientState ambientState) { 546 547 // The starting position of the bottom stack peek 548 int bottomPeekStart = ambientState.getInnerHeight() - mBottomStackPeekSize - 549 mBottomStackSlowDownLength + ambientState.getScrollY(); 550 // Collapse and expand the first child while the shade is being expanded 551 childViewState.height = (int) Math.max(Math.min(bottomPeekStart, (float) childHeight), 552 child.getCollapsedHeight()); 553 } 554 555 /** 556 * Calculate the Z positions for all children based on the number of items in both stacks and 557 * save it in the resultState 558 * @param resultState The result state to update the zTranslation values 559 * @param algorithmState The state in which the current pass of the algorithm is currently in 560 * @param ambientState The ambient state of the algorithm 561 */ 562 private void updateZValuesForState(StackScrollState resultState, 563 StackScrollAlgorithmState algorithmState, AmbientState ambientState) { 564 int childCount = algorithmState.visibleChildren.size(); 565 float childrenOnTop = 0.0f; 566 for (int i = childCount - 1; i >= 0; i--) { 567 ExpandableView child = algorithmState.visibleChildren.get(i); 568 StackViewState childViewState = resultState.getViewStateForView(child); 569 if (i > (childCount - 1 - algorithmState.itemsInBottomStack)) { 570 // We are in the bottom stack 571 float numItemsAbove = i - (childCount - 1 - algorithmState.itemsInBottomStack); 572 float zSubtraction; 573 if (numItemsAbove <= 1.0f) { 574 float factor = 0.2f; 575 // Lets fade in slower to the threshold to make the shadow fade in look nicer 576 if (numItemsAbove <= factor) { 577 zSubtraction = FakeShadowView.SHADOW_SIBLING_TRESHOLD 578 * numItemsAbove * (1.0f / factor); 579 } else { 580 zSubtraction = FakeShadowView.SHADOW_SIBLING_TRESHOLD 581 + (numItemsAbove - factor) * (1.0f / (1.0f - factor)) 582 * (mZDistanceBetweenElements 583 - FakeShadowView.SHADOW_SIBLING_TRESHOLD); 584 } 585 } else { 586 zSubtraction = numItemsAbove * mZDistanceBetweenElements; 587 } 588 childViewState.zTranslation = mZBasicHeight - zSubtraction; 589 } else if (child.mustStayOnScreen() 590 && childViewState.yTranslation < ambientState.getTopPadding() 591 + ambientState.getStackTranslation()) { 592 if (childrenOnTop != 0.0f) { 593 childrenOnTop++; 594 } else { 595 float overlap = ambientState.getTopPadding() 596 + ambientState.getStackTranslation() - childViewState.yTranslation; 597 childrenOnTop += Math.min(1.0f, overlap / childViewState.height); 598 } 599 childViewState.zTranslation = mZBasicHeight 600 + childrenOnTop * mZDistanceBetweenElements; 601 } else { 602 childViewState.zTranslation = mZBasicHeight; 603 } 604 } 605 } 606 607 private boolean isMaxSizeInitialized(ExpandableView child) { 608 if (child instanceof ExpandableNotificationRow) { 609 ExpandableNotificationRow row = (ExpandableNotificationRow) child; 610 return row.isMaxExpandHeightInitialized(); 611 } 612 return child == null || child.getWidth() != 0; 613 } 614 615 private View findFirstVisibleChild(ViewGroup container) { 616 int childCount = container.getChildCount(); 617 for (int i = 0; i < childCount; i++) { 618 View child = container.getChildAt(i); 619 if (child.getVisibility() != View.GONE) { 620 return child; 621 } 622 } 623 return null; 624 } 625 626 public void setIsExpanded(boolean isExpanded) { 627 this.mIsExpanded = isExpanded; 628 } 629 630 class StackScrollAlgorithmState { 631 632 /** 633 * The scroll position of the algorithm 634 */ 635 public int scrollY; 636 637 /** 638 * The quantity of items which are in the bottom stack. 639 */ 640 public float itemsInBottomStack; 641 642 /** 643 * how far in is the element currently transitioning into the bottom stack 644 */ 645 public float partialInBottom; 646 647 /** 648 * The children from the host view which are not gone. 649 */ 650 public final ArrayList<ExpandableView> visibleChildren = new ArrayList<ExpandableView>(); 651 652 /** 653 * The children from the host that need an increased padding after them. A value of 0 means 654 * no increased padding, a value of 1 means full padding. 655 */ 656 public final HashMap<ExpandableView, Float> increasedPaddingMap = new HashMap<>(); 657 } 658 659} 660