Animate scrolling grid into place when there is a gap between last tasks
and clear all.

- Stagger animation starts
- Adds a grid translation property to TaskView for animating these
translations.

Also fixes an issue where the gap between clear all and focused task is
greater than spacing between grid tasks and clear all.

Test: manual
Fix: 188793333
Change-Id: Ib2ba8b1b84dc63c4ba186bd0b9b4962d3c66ce5a
diff --git a/quickstep/src/com/android/quickstep/views/ClearAllButton.java b/quickstep/src/com/android/quickstep/views/ClearAllButton.java
index b9a9006..22c87b0 100644
--- a/quickstep/src/com/android/quickstep/views/ClearAllButton.java
+++ b/quickstep/src/com/android/quickstep/views/ClearAllButton.java
@@ -39,10 +39,24 @@
                 }
             };
 
+    public static final FloatProperty<ClearAllButton> DISMISS_ALPHA =
+            new FloatProperty<ClearAllButton>("dismissAlpha") {
+                @Override
+                public Float get(ClearAllButton view) {
+                    return view.mDismissAlpha;
+                }
+
+                @Override
+                public void setValue(ClearAllButton view, float v) {
+                    view.setDismissAlpha(v);
+                }
+            };
+
     private final StatefulActivity mActivity;
     private float mScrollAlpha = 1;
     private float mContentAlpha = 1;
     private float mVisibilityAlpha = 1;
+    private float mDismissAlpha = 1;
     private float mFullscreenProgress = 1;
     private float mGridProgress = 1;
 
@@ -97,6 +111,13 @@
         }
     }
 
+    public void setDismissAlpha(float alpha) {
+        if (mDismissAlpha != alpha) {
+            mDismissAlpha = alpha;
+            updateAlpha();
+        }
+    }
+
     public void onRecentsViewScroll(int scroll, boolean gridEnabled) {
         RecentsView recentsView = getRecentsView();
         if (recentsView == null) {
@@ -123,7 +144,7 @@
     }
 
     private void updateAlpha() {
-        final float alpha = mScrollAlpha * mContentAlpha * mVisibilityAlpha;
+        final float alpha = mScrollAlpha * mContentAlpha * mVisibilityAlpha * mDismissAlpha;
         setAlpha(alpha);
         setClickable(Math.min(alpha, 1) == 1);
     }
diff --git a/quickstep/src/com/android/quickstep/views/RecentsView.java b/quickstep/src/com/android/quickstep/views/RecentsView.java
index aeb10aa..dff82cc 100644
--- a/quickstep/src/com/android/quickstep/views/RecentsView.java
+++ b/quickstep/src/com/android/quickstep/views/RecentsView.java
@@ -29,6 +29,7 @@
 import static com.android.launcher3.LauncherState.BACKGROUND_APP;
 import static com.android.launcher3.QuickstepTransitionManager.RECENTS_LAUNCH_DURATION;
 import static com.android.launcher3.Utilities.EDGE_NAV_BAR;
+import static com.android.launcher3.Utilities.boundToRange;
 import static com.android.launcher3.Utilities.mapToRange;
 import static com.android.launcher3.Utilities.squaredHypot;
 import static com.android.launcher3.Utilities.squaredTouchSlop;
@@ -49,6 +50,7 @@
 import static com.android.launcher3.util.Executors.UI_HELPER_EXECUTOR;
 import static com.android.launcher3.util.SystemUiController.UI_STATE_FULLSCREEN_TASK;
 import static com.android.quickstep.TaskUtils.checkCurrentOrManagedUserId;
+import static com.android.quickstep.views.ClearAllButton.DISMISS_ALPHA;
 import static com.android.quickstep.views.OverviewActionsView.HIDDEN_NON_ZERO_ROTATION;
 import static com.android.quickstep.views.OverviewActionsView.HIDDEN_NO_RECENTS;
 import static com.android.quickstep.views.OverviewActionsView.HIDDEN_NO_TASKS;
@@ -359,6 +361,7 @@
     private static final float INITIAL_DISMISS_TRANSLATION_INTERPOLATION_OFFSET = 0.55f;
     private static final float ADDITIONAL_DISMISS_TRANSLATION_INTERPOLATION_OFFSET = 0.05f;
     private static final float ANIMATION_DISMISS_PROGRESS_MIDPOINT = 0.5f;
+    private static final float END_DISMISS_TRANSLATION_INTERPOLATION_OFFSET = 0.75f;
 
     private static final float SIGNIFICANT_MOVE_THRESHOLD_TABLET = 0.15f;
 
@@ -1004,6 +1007,43 @@
         }
     }
 
+    private boolean isLastGridTaskVisible() {
+        TaskView lastTaskView = getLastGridTaskView();
+        return lastTaskView != null && lastTaskView.isVisibleToUser();
+    }
+
+    private TaskView getLastGridTaskView() {
+        IntArray topRowIdArray = getTopRowIdArray();
+        IntArray bottomRowIdArray = getBottomRowIdArray();
+        if (topRowIdArray.isEmpty() && bottomRowIdArray.isEmpty()) {
+            return null;
+        }
+        int lastTaskViewId = topRowIdArray.size() >= bottomRowIdArray.size() ? topRowIdArray.get(
+                topRowIdArray.size() - 1) : bottomRowIdArray.get(bottomRowIdArray.size() - 1);
+        return getTaskViewFromTaskViewId(lastTaskViewId);
+    }
+
+    private int getSnapToLastTaskScrollDiff() {
+        // Snap to a position where ClearAll is just invisible.
+        int screenStart = mOrientationHandler.getPrimaryScroll(this);
+        int clearAllWidth = mOrientationHandler.getPrimarySize(mClearAllButton);
+        int clearAllScroll = getScrollForPage(indexOfChild(mClearAllButton));
+        int targetScroll = clearAllScroll + (mIsRtl ? clearAllWidth : -clearAllWidth);
+        return screenStart - targetScroll;
+    }
+
+    private int getSnapToFocusedTaskScrollDiff(boolean isClearAllHidden) {
+        int screenStart = mOrientationHandler.getPrimaryScroll(this);
+        int targetScroll = getScrollForPage(indexOfChild(getFocusedTaskView()));
+        if (!isClearAllHidden) {
+            int clearAllWidth = mOrientationHandler.getPrimarySize(mClearAllButton);
+            int taskGridHorizontalDiff = mLastComputedTaskSize.right - mLastComputedGridSize.right;
+            int clearAllFocusScrollDiff =  taskGridHorizontalDiff - clearAllWidth;
+            targetScroll += mIsRtl ? clearAllFocusScrollDiff : -clearAllFocusScrollDiff;
+        }
+        return screenStart - targetScroll;
+    }
+
     private boolean isTaskViewWithinBounds(TaskView tv, int start, int end) {
         int taskStart = mOrientationHandler.getChildStart(tv) + (int) tv.getOffsetAdjustment(
                 showAsFullscreen(), showAsGrid());
@@ -1083,7 +1123,6 @@
         super.onPageEndTransition();
         if (isClearAllHidden()) {
             mActionsView.updateDisabledFlags(OverviewActionsView.DISABLED_SCROLLING, false);
-        } else {
         }
         if (getNextPage() > 0) {
             setSwipeDownShouldLaunchApp(true);
@@ -2676,6 +2715,94 @@
             }
         }
 
+        float dismissTranslationInterpolationEnd = 1;
+        boolean closeGapBetweenClearAll = false;
+        boolean isClearAllHidden = isClearAllHidden();
+        if (showAsGrid && isLastGridTaskVisible()) {
+            // After dismissal, animate translation of the remaining tasks to fill any gap left
+            // between the end of the grid and the clear all button. Only animate if the clear
+            // all button is visible or would become visible after dismissal.
+            float longGridRowWidthDiff = 0;
+
+            int topGridRowSize = mTopRowIdSet.size();
+            int bottomGridRowSize = taskCount - mTopRowIdSet.size() - 1;
+            boolean topRowLonger = topGridRowSize > bottomGridRowSize;
+            boolean bottomRowLonger = bottomGridRowSize > topGridRowSize;
+            boolean dismissedTaskFromTop = mTopRowIdSet.contains(dismissedTaskViewId);
+            boolean dismissedTaskFromBottom = !dismissedTaskFromTop && !isFocusedTaskDismissed;
+            float gapWidth = 0;
+            if ((topRowLonger && dismissedTaskFromTop)
+                    || (bottomRowLonger && dismissedTaskFromBottom)) {
+                gapWidth = dismissedTaskWidth;
+            } else if ((topRowLonger && nextFocusedTaskFromTop)
+                    || (bottomRowLonger && !nextFocusedTaskFromTop)) {
+                gapWidth = nextFocusedTaskWidth;
+            }
+            if (gapWidth > 0) {
+                if (taskCount > 2) {
+                    // Compensate the removed gap.
+                    longGridRowWidthDiff += mIsRtl ? -gapWidth : gapWidth;
+                    if (isClearAllHidden) {
+                        // If ClearAllButton isn't fully shown, snap to the last task.
+                        longGridRowWidthDiff += getSnapToLastTaskScrollDiff();
+                    }
+                } else {
+                    // If only focused task will be left, snap to focused task instead.
+                    longGridRowWidthDiff += getSnapToFocusedTaskScrollDiff(isClearAllHidden);
+                }
+            }
+
+            // If we need to animate the grid to compensate the clear all gap, we split the second
+            // half of the dismiss pending animation (in which the non-dismissed tasks slide into
+            // place) in half again, making the first quarter the existing non-dismissal sliding
+            // and the second quarter this new animation of gap filling. This is due to the fact
+            // that PendingAnimation is a single animation, not a sequence of animations, so we
+            // fake it using interpolation.
+            if (longGridRowWidthDiff != 0) {
+                closeGapBetweenClearAll = true;
+                // Stagger the offsets of each additional task for a delayed animation. We use
+                // half here as this animation is half of half of an animation (1/4th).
+                float halfAdditionalDismissTranslationOffset =
+                        (0.5f * ADDITIONAL_DISMISS_TRANSLATION_INTERPOLATION_OFFSET);
+                dismissTranslationInterpolationEnd = Utilities.boundToRange(
+                        END_DISMISS_TRANSLATION_INTERPOLATION_OFFSET
+                                + (taskCount - 1) * halfAdditionalDismissTranslationOffset,
+                        END_DISMISS_TRANSLATION_INTERPOLATION_OFFSET, 1);
+                for (int i = 0; i < taskCount; i++) {
+                    TaskView taskView = getTaskViewAt(i);
+                    anim.setFloat(taskView, TaskView.GRID_END_TRANSLATION_X, longGridRowWidthDiff,
+                            clampToProgress(LINEAR, dismissTranslationInterpolationEnd, 1));
+                    dismissTranslationInterpolationEnd = Utilities.boundToRange(
+                            dismissTranslationInterpolationEnd
+                                    - halfAdditionalDismissTranslationOffset,
+                            END_DISMISS_TRANSLATION_INTERPOLATION_OFFSET, 1);
+                    if (ENABLE_QUICKSTEP_LIVE_TILE.get() && mEnableDrawingLiveTile
+                            && taskView.isRunningTask()) {
+                        anim.addOnFrameCallback(() -> {
+                            runActionOnRemoteHandles(
+                                    remoteTargetHandle ->
+                                            remoteTargetHandle.mTaskViewSimulator
+                                                    .taskPrimaryTranslation.value =
+                                                    TaskView.GRID_END_TRANSLATION_X.get(taskView));
+                            redrawLiveTile();
+                        });
+                    }
+                }
+
+                // Change alpha of clear all if translating grid to hide it
+                if (isClearAllHidden) {
+                    anim.setFloat(mClearAllButton, DISMISS_ALPHA, 0, LINEAR);
+                    anim.addListener(new AnimatorListenerAdapter() {
+                        @Override
+                        public void onAnimationEnd(Animator animation) {
+                            super.onAnimationEnd(animation);
+                            mClearAllButton.setDismissAlpha(1);
+                        }
+                    });
+                }
+            }
+        }
+
         int distanceFromDismissedTask = 0;
         for (int i = 0; i < count; i++) {
             View child = getChildAt(i);
@@ -2755,22 +2882,25 @@
                 float animationStartProgress = Utilities.boundToRange(
                         INITIAL_DISMISS_TRANSLATION_INTERPOLATION_OFFSET
                                 + ADDITIONAL_DISMISS_TRANSLATION_INTERPOLATION_OFFSET
-                                * ++distanceFromDismissedTask, 0f, 1f);
+                                * ++distanceFromDismissedTask, 0f,
+                        dismissTranslationInterpolationEnd);
                 if (taskView == nextFocusedTaskView) {
                     // Enlarge the task to be focused next, and translate into focus position.
                     float scale = mTaskWidth / (float) mLastComputedGridTaskSize.width();
                     anim.setFloat(taskView, TaskView.SNAPSHOT_SCALE, scale,
-                            clampToProgress(LINEAR, animationStartProgress, 1f));
+                            clampToProgress(LINEAR, animationStartProgress,
+                                    dismissTranslationInterpolationEnd));
                     anim.setFloat(taskView, taskView.getPrimaryDismissTranslationProperty(),
                             mIsRtl ? dismissedTaskWidth : -dismissedTaskWidth,
-                            clampToProgress(LINEAR, animationStartProgress, 1f));
+                            clampToProgress(LINEAR, animationStartProgress,
+                                    dismissTranslationInterpolationEnd));
                     float secondaryTranslation = -mTaskGridVerticalDiff;
                     if (!nextFocusedTaskFromTop) {
                         secondaryTranslation -= mTopBottomRowHeightDiff;
                     }
                     anim.setFloat(taskView, taskView.getSecondaryDissmissTranslationProperty(),
-                            secondaryTranslation,
-                            clampToProgress(LINEAR, animationStartProgress, 1f));
+                            secondaryTranslation, clampToProgress(LINEAR, animationStartProgress,
+                                    dismissTranslationInterpolationEnd));
                     anim.setFloat(taskView, TaskView.FOCUS_TRANSITION, 0f,
                             clampToProgress(LINEAR, 0f, ANIMATION_DISMISS_PROGRESS_MIDPOINT));
                 } else {
@@ -2778,7 +2908,8 @@
                             isFocusedTaskDismissed ? nextFocusedTaskWidth : dismissedTaskWidth;
                     anim.setFloat(taskView, taskView.getPrimaryDismissTranslationProperty(),
                             mIsRtl ? primaryTranslation : -primaryTranslation,
-                            clampToProgress(LINEAR, animationStartProgress, 1f));
+                            clampToProgress(LINEAR, animationStartProgress,
+                                    dismissTranslationInterpolationEnd));
                 }
             }
         }
@@ -2794,6 +2925,7 @@
 
         mPendingAnimation = anim;
         final TaskView finalNextFocusedTaskView = nextFocusedTaskView;
+        final boolean finalCloseGapBetweenClearAll = closeGapBetweenClearAll;
         mPendingAnimation.addEndListener(new Consumer<Boolean>() {
             @Override
             public void accept(Boolean success) {
@@ -2829,49 +2961,68 @@
                     resetTaskVisuals();
 
                     int pageToSnapTo = mCurrentPage;
+                    mCurrentPageScrollDiff = 0;
                     int taskViewIdToSnapTo = -1;
                     if (showAsGrid) {
-                        // Get the id of the task view we will snap to based on the current
-                        // page's relative position as the order of indices change over time due
-                        // to dismissals.
-                        TaskView snappedTaskView = getTaskViewAtByAbsoluteIndex(mCurrentPage);
-                        if (snappedTaskView != null) {
-                            if (snappedTaskView.getTaskViewId() == mFocusedTaskViewId) {
-                                if (finalNextFocusedTaskView != null) {
-                                    taskViewIdToSnapTo = finalNextFocusedTaskView.getTaskViewId();
-                                } else {
-                                    taskViewIdToSnapTo = mFocusedTaskViewId;
+                        if (finalCloseGapBetweenClearAll) {
+                            if (taskCount > 2) {
+                                pageToSnapTo = indexOfChild(mClearAllButton);
+                                if (isClearAllHidden) {
+                                    int clearAllWidth = mOrientationHandler.getPrimarySize(
+                                            mClearAllButton);
+                                    mCurrentPageScrollDiff =
+                                            isRtl() ? clearAllWidth : -clearAllWidth;
                                 }
-                            } else {
-                                int snappedTaskViewId = snappedTaskView.getTaskViewId();
-                                boolean isSnappedTaskInTopRow = mTopRowIdSet.contains(
-                                        snappedTaskViewId);
-                                IntArray taskViewIdArray =
-                                        isSnappedTaskInTopRow ? getTopRowIdArray()
-                                                : getBottomRowIdArray();
-                                int snappedIndex = taskViewIdArray.indexOf(snappedTaskViewId);
-                                taskViewIdArray.removeValue(dismissedTaskViewId);
-                                if (snappedIndex < taskViewIdArray.size()) {
-                                    taskViewIdToSnapTo = taskViewIdArray.get(snappedIndex);
-                                } else if (snappedIndex == taskViewIdArray.size()) {
-                                    // If the snapped task is the last item from the dismissed row,
-                                    // snap to the same column in the other grid row
-                                    IntArray inverseRowTaskViewIdArray =
-                                            isSnappedTaskInTopRow ? getBottomRowIdArray()
-                                                    : getTopRowIdArray();
-                                    if (snappedIndex < inverseRowTaskViewIdArray.size()) {
-                                        taskViewIdToSnapTo = inverseRowTaskViewIdArray.get(
-                                                snappedIndex);
+                            } else if (isClearAllHidden) {
+                                // Snap to focused task if clear all is hidden.
+                                pageToSnapTo = 0;
+                            }
+                        } else {
+                            // Get the id of the task view we will snap to based on the current
+                            // page's relative position as the order of indices change over time due
+                            // to dismissals.
+                            TaskView snappedTaskView = getTaskViewAtByAbsoluteIndex(mCurrentPage);
+                            if (snappedTaskView != null) {
+                                if (snappedTaskView.getTaskViewId() == mFocusedTaskViewId) {
+                                    if (finalNextFocusedTaskView != null) {
+                                        taskViewIdToSnapTo =
+                                                finalNextFocusedTaskView.getTaskViewId();
+                                    } else {
+                                        taskViewIdToSnapTo = mFocusedTaskViewId;
+                                    }
+                                } else {
+                                    int snappedTaskViewId = snappedTaskView.getTaskViewId();
+                                    boolean isSnappedTaskInTopRow = mTopRowIdSet.contains(
+                                            snappedTaskViewId);
+                                    IntArray taskViewIdArray =
+                                            isSnappedTaskInTopRow ? getTopRowIdArray()
+                                                    : getBottomRowIdArray();
+                                    int snappedIndex = taskViewIdArray.indexOf(snappedTaskViewId);
+                                    taskViewIdArray.removeValue(dismissedTaskViewId);
+                                    if (snappedIndex < taskViewIdArray.size()) {
+                                        taskViewIdToSnapTo = taskViewIdArray.get(snappedIndex);
+                                    } else if (snappedIndex == taskViewIdArray.size()) {
+                                        // If the snapped task is the last item from the
+                                        // dismissed row,
+                                        // snap to the same column in the other grid row
+                                        IntArray inverseRowTaskViewIdArray =
+                                                isSnappedTaskInTopRow ? getBottomRowIdArray()
+                                                        : getTopRowIdArray();
+                                        if (snappedIndex < inverseRowTaskViewIdArray.size()) {
+                                            taskViewIdToSnapTo = inverseRowTaskViewIdArray.get(
+                                                    snappedIndex);
+                                        }
                                     }
                                 }
                             }
-                        }
 
-                        int primaryScroll = mOrientationHandler.getPrimaryScroll(RecentsView.this);
-                        int currentPageScroll = getScrollForPage(pageToSnapTo);
-                        mCurrentPageScrollDiff = primaryScroll - currentPageScroll;
+                            int primaryScroll = mOrientationHandler.getPrimaryScroll(
+                                    RecentsView.this);
+                            int currentPageScroll = getScrollForPage(pageToSnapTo);
+                            mCurrentPageScrollDiff = primaryScroll - currentPageScroll;
+                        }
                     } else if (dismissedIndex < pageToSnapTo || pageToSnapTo == taskCount - 1) {
-                        pageToSnapTo -= 1;
+                        pageToSnapTo--;
                     }
                     removeViewInLayout(dismissedTaskView);
                     mTopRowIdSet.remove(dismissedTaskViewId);
@@ -2936,7 +3087,13 @@
                             }
                         }
                         setCurrentPage(pageToSnapTo);
+                        // Update various scroll depedent UI.
                         dispatchScrollChanged();
+                        updateActionsViewScrollAlpha();
+                        if (isClearAllHidden()) {
+                            mActionsView.updateDisabledFlags(OverviewActionsView.DISABLED_SCROLLING,
+                                    false);
+                        }
                     }
                 }
                 onDismissAnimationEnds();
diff --git a/quickstep/src/com/android/quickstep/views/TaskView.java b/quickstep/src/com/android/quickstep/views/TaskView.java
index bfe6ca4..85b1b66 100644
--- a/quickstep/src/com/android/quickstep/views/TaskView.java
+++ b/quickstep/src/com/android/quickstep/views/TaskView.java
@@ -343,6 +343,19 @@
                 }
             };
 
+    public static final FloatProperty<TaskView> GRID_END_TRANSLATION_X =
+            new FloatProperty<TaskView>("gridEndTranslationX") {
+                @Override
+                public void setValue(TaskView taskView, float v) {
+                    taskView.setGridEndTranslationX(v);
+                }
+
+                @Override
+                public Float get(TaskView taskView) {
+                    return taskView.mGridEndTranslationX;
+                }
+            };
+
     public static final FloatProperty<TaskView> SNAPSHOT_SCALE =
             new FloatProperty<TaskView>("snapshotScale") {
                 @Override
@@ -381,6 +394,8 @@
     // The following grid translations scales with mGridProgress.
     private float mGridTranslationX;
     private float mGridTranslationY;
+    // The following grid translation is used to animate closing the gap between grid and clear all.
+    private float mGridEndTranslationX;
     // Applied as a complement to gridTranslation, for adjusting the carousel overview and quick
     // switch.
     private float mNonGridTranslationX;
@@ -950,8 +965,8 @@
     protected void resetViewTransforms() {
         // fullscreenTranslation and accumulatedTranslation should not be reset, as
         // resetViewTransforms is called during Quickswitch scrolling.
-        mDismissTranslationX = mTaskOffsetTranslationX = mTaskResistanceTranslationX =
-                mSplitSelectTranslationX = 0f;
+        mDismissTranslationX = mTaskOffsetTranslationX =
+                mTaskResistanceTranslationX = mSplitSelectTranslationX = mGridEndTranslationX = 0f;
         mDismissTranslationY = mTaskOffsetTranslationY = mTaskResistanceTranslationY =
                 mSplitSelectTranslationY = 0f;
         setSnapshotScale(1f);
@@ -1162,6 +1177,11 @@
         return mGridTranslationY;
     }
 
+    private void setGridEndTranslationX(float gridEndTranslationX) {
+        mGridEndTranslationX = gridEndTranslationX;
+        applyTranslationX();
+    }
+
     public float getScrollAdjustment(boolean fullscreenEnabled, boolean gridEnabled) {
         float scrollAdjustment = 0;
         if (gridEnabled) {
@@ -1191,7 +1211,7 @@
 
     private void applyTranslationX() {
         setTranslationX(mDismissTranslationX + mTaskOffsetTranslationX + mTaskResistanceTranslationX
-                + mSplitSelectTranslationX + getPersistentTranslationX());
+                + mSplitSelectTranslationX + mGridEndTranslationX + getPersistentTranslationX());
     }
 
     private void applyTranslationY() {