From 4e678ff6d5bb6c12ab8e2a76c00600eb61de897d Mon Sep 17 00:00:00 2001
From: Fedor Kudasov <kudasov@google.com>
Date: Thu, 11 Nov 2021 21:10:03 +0000
Subject: [PATCH] Separate getTaskViewAt usage

getTaskViewAt is used in two different contexts with different
assumptions:
1. In the context of iterating over the all TaskViews, where
the valid tasks indices are know.
2. In the context of requesting some TaskView by index, where
the caller expects null when the input index is invalid.
The nullability status of the method differs in these contexts
and therefore getTaskViewAt usage can be separated into two
different methods.

Bug: 205828770
Test: m LauncherGoResLib
Change-Id: I42c04c115c309f1849f9dfbb05c74b9b080acf13
(cherry picked from commit 4da3b4bdddbbff7a0dee1f57b3a74c616231e100)
---
 .../android/quickstep/views/RecentsView.java  | 84 +++++++++++--------
 1 file changed, 47 insertions(+), 37 deletions(-)

diff --git a/quickstep/src/com/android/quickstep/views/RecentsView.java b/quickstep/src/com/android/quickstep/views/RecentsView.java
index 3aa8d4637b..e270cb7c1c 100644
--- a/quickstep/src/com/android/quickstep/views/RecentsView.java
+++ b/quickstep/src/com/android/quickstep/views/RecentsView.java
@@ -107,6 +107,7 @@ import android.widget.ListView;
 import android.widget.OverScroller;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.UiThread;
 import androidx.core.graphics.ColorUtils;
@@ -181,6 +182,7 @@ import com.android.wm.shell.pip.IPipAnimationListener;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Objects;
 import java.util.function.Consumer;
 
 /**
@@ -822,7 +824,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
     @Override
     public void onTaskIconChanged(String pkg, UserHandle user) {
         for (int i = 0; i < getTaskViewCount(); i++) {
-            TaskView tv = getTaskViewAt(i);
+            TaskView tv = requireTaskViewAt(i);
             Task task = tv.getTask();
             if (task != null && task.key != null && pkg.equals(task.key.getPackageName())
                     && task.key.userId == user.getIdentifier()) {
@@ -1104,7 +1106,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         }
 
         for (int i = 0; i < getTaskViewCount(); i++) {
-            TaskView taskView = getTaskViewAt(i);
+            TaskView taskView = requireTaskViewAt(i);
             int[] taskIds = taskView.getTaskIds();
             if (taskIds[0] == taskId || taskIds[1] == taskId) {
                 return taskView;
@@ -1181,7 +1183,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         if (showAsGrid()) {
             int taskCount = getTaskViewCount();
             for (int i = 0; i < taskCount; i++) {
-                TaskView taskView = getTaskViewAt(i);
+                TaskView taskView = requireTaskViewAt(i);
                 if (isTaskViewVisible(taskView) && taskView.offerTouchToChildren(ev)) {
                     // Keep consuming events to pass to delegate
                     return true;
@@ -1418,7 +1420,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
             if (runningTaskId != -1) {
                 targetPage = indexOfChild(newRunningTaskView);
             } else if (getTaskViewCount() > 0) {
-                targetPage = indexOfChild(getTaskViewAt(0));
+                targetPage = indexOfChild(requireTaskViewAt(0));
             }
         } else if (currentTaskId != -1) {
             currentTaskView = getTaskViewByTaskId(currentTaskId);
@@ -1452,7 +1454,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
 
     private void removeTasksViewsAndClearAllButton() {
         for (int i = getTaskViewCount() - 1; i >= 0; i--) {
-            removeView(getTaskViewAt(i));
+            removeView(requireTaskViewAt(i));
         }
         if (indexOfChild(mClearAllButton) != -1) {
             removeView(mClearAllButton);
@@ -1498,7 +1500,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
 
     public void resetTaskVisuals() {
         for (int i = getTaskViewCount() - 1; i >= 0; i--) {
-            TaskView taskView = getTaskViewAt(i);
+            TaskView taskView = requireTaskViewAt(i);
             if (mIgnoreResetTaskId != taskView.getTaskIds()[0]) {
                 taskView.resetViewTransforms();
                 taskView.setIconScaleAndDim(mTaskIconScaledDown ? 0 : 1);
@@ -1529,7 +1531,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         mFullscreenProgress = fullscreenProgress;
         int taskCount = getTaskViewCount();
         for (int i = 0; i < taskCount; i++) {
-            getTaskViewAt(i).setFullscreenProgress(mFullscreenProgress);
+            requireTaskViewAt(i).setFullscreenProgress(mFullscreenProgress);
         }
         mClearAllButton.setFullscreenProgress(fullscreenProgress);
 
@@ -1656,7 +1658,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
 
         float accumulatedTranslationX = 0;
         for (int i = 0; i < taskCount; i++) {
-            TaskView taskView = getTaskViewAt(i);
+            TaskView taskView = requireTaskViewAt(i);
             taskView.updateTaskSize();
             taskView.getPrimaryNonGridTranslationProperty().set(taskView, accumulatedTranslationX);
             taskView.getSecondaryNonGridTranslationProperty().set(taskView, 0f);
@@ -1802,7 +1804,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
 
         // Update the task data for the in/visible children
         for (int i = 0; i < getTaskViewCount(); i++) {
-            TaskView taskView = getTaskViewAt(i);
+            TaskView taskView = requireTaskViewAt(i);
             Task task = taskView.getTask();
             int index = indexOfChild(taskView);
             boolean visible;
@@ -1945,7 +1947,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         }
 
         for (int i = 0; i < getTaskViewCount(); i++) {
-            TaskView taskView = getTaskViewAt(i);
+            TaskView taskView = requireTaskViewAt(i);
             if (taskView.getTaskViewId() == taskViewId) {
                 return taskView;
             }
@@ -2043,7 +2045,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         int runningIndex = getCurrentPage();
         AnimatorSet as = new AnimatorSet();
         for (int i = 0; i < getTaskViewCount(); i++) {
-            View taskView = getTaskViewAt(i);
+            View taskView = requireTaskViewAt(i);
             if (runningIndex == i && taskView.getAlpha() != 0) {
                 continue;
             }
@@ -2054,7 +2056,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
 
     private void updateChildTaskOrientations() {
         for (int i = 0; i < getTaskViewCount(); i++) {
-            getTaskViewAt(i).setOrientationState(mOrientationState);
+            requireTaskViewAt(i).setOrientationState(mOrientationState);
         }
         TaskMenuView tv = (TaskMenuView) getTopOpenViewWithType(mActivity, TYPE_TASK_MENU);
         if (tv != null) {
@@ -2259,7 +2261,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
             mTaskIconScaledDown = isScaledDown;
             int taskCount = getTaskViewCount();
             for (int i = 0; i < taskCount; i++) {
-                getTaskViewAt(i).setIconScaleAndDim(mTaskIconScaledDown ? 0 : 1);
+                requireTaskViewAt(i).setIconScaleAndDim(mTaskIconScaledDown ? 0 : 1);
             }
         }
     }
@@ -2275,7 +2277,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         mTaskIconScaledDown = false;
         int taskCount = getTaskViewCount();
         for (int i = 0; i < taskCount; i++) {
-            TaskView taskView = getTaskViewAt(i);
+            TaskView taskView = requireTaskViewAt(i);
             taskView.setIconScaleAnimStartProgress(0f);
             taskView.animateIconScaleAndDimIntoView();
         }
@@ -2347,7 +2349,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
             mTopRowIdSet.clear();
         }
         for (int i = 0; i < taskCount; i++) {
-            TaskView taskView = getTaskViewAt(i);
+            TaskView taskView = requireTaskViewAt(i);
             int taskWidthAndSpacing = taskView.getLayoutParams().width + mPageSpacing;
             // Evenly distribute tasks between rows unless rearranging due to task dismissal, in
             // which case keep tasks in their respective rows. For the running task, don't join
@@ -2412,7 +2414,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
                         if (j == focusedTaskIndex) {
                             continue;
                         }
-                        widthOffset += getTaskViewAt(j).getLayoutParams().width + mPageSpacing;
+                        widthOffset += requireTaskViewAt(j).getLayoutParams().width + mPageSpacing;
                     }
 
                     float currentTaskTranslationX = mIsRtl ? widthOffset : -widthOffset;
@@ -2431,7 +2433,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
                         if (j == focusedTaskIndex) {
                             continue;
                         }
-                        widthOffset += getTaskViewAt(j).getLayoutParams().width + mPageSpacing;
+                        widthOffset += requireTaskViewAt(j).getLayoutParams().width + mPageSpacing;
                     }
 
                     float currentTaskTranslationX = mIsRtl ? widthOffset : -widthOffset;
@@ -2509,7 +2511,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         }
 
         for (int i = 0; i < taskCount; i++) {
-            TaskView taskView = getTaskViewAt(i);
+            TaskView taskView = requireTaskViewAt(i);
             taskView.setGridTranslationX(gridTranslations[i] - snappedTaskGridTranslationX
                     + snappedTaskNonGridScrollAdjustment);
         }
@@ -2550,7 +2552,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         mGridProgress = gridProgress;
 
         for (int i = 0; i < taskCount; i++) {
-            getTaskViewAt(i).setGridProgress(gridProgress);
+            requireTaskViewAt(i).setGridProgress(gridProgress);
         }
         mClearAllButton.setGridProgress(gridProgress);
     }
@@ -2713,7 +2715,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
                         mTopRowIdSet.size() > 0 && mTopRowIdSet.size() >= (taskCount - 1) / 2f;
                 // Pick the next focused task from the preferred row.
                 for (int i = 0; i < taskCount; i++) {
-                    TaskView taskView = getTaskViewAt(i);
+                    TaskView taskView = requireTaskViewAt(i);
                     if (taskView == dismissedTaskView) {
                         continue;
                     }
@@ -2816,7 +2818,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
                                 + (taskCount - 1) * halfAdditionalDismissTranslationOffset,
                         END_DISMISS_TRANSLATION_INTERPOLATION_OFFSET, 1);
                 for (int i = 0; i < taskCount; i++) {
-                    TaskView taskView = getTaskViewAt(i);
+                    TaskView taskView = requireTaskViewAt(i);
                     anim.setFloat(taskView, TaskView.GRID_END_TRANSLATION_X, longGridRowWidthDiff,
                             clampToProgress(LINEAR, dismissTranslationInterpolationEnd, 1));
                     dismissTranslationInterpolationEnd = Utilities.boundToRange(
@@ -3132,7 +3134,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
                             // Rebalance tasks in the grid
                             int highestVisibleTaskIndex = getHighestVisibleTaskIndex();
                             if (highestVisibleTaskIndex < Integer.MAX_VALUE) {
-                                TaskView taskView = getTaskViewAt(highestVisibleTaskIndex);
+                                TaskView taskView = requireTaskViewAt(highestVisibleTaskIndex);
 
                                 boolean shouldRebalance;
                                 int screenStart = mOrientationHandler.getPrimaryScroll(
@@ -3229,7 +3231,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         IntArray topArray = new IntArray(mTopRowIdSet.size());
         int taskViewCount = getTaskViewCount();
         for (int i = 0; i < taskViewCount; i++) {
-            int taskViewId = getTaskViewAt(i).getTaskViewId();
+            int taskViewId = requireTaskViewAt(i).getTaskViewId();
             if (mTopRowIdSet.contains(taskViewId)) {
                 topArray.add(taskViewId);
             }
@@ -3248,7 +3250,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         IntArray bottomArray = new IntArray(bottomRowIdArraySize);
         int taskViewCount = getTaskViewCount();
         for (int i = 0; i < taskViewCount; i++) {
-            int taskViewId = getTaskViewAt(i).getTaskViewId();
+            int taskViewId = requireTaskViewAt(i).getTaskViewId();
             if (!mTopRowIdSet.contains(taskViewId) && taskViewId != mFocusedTaskViewId) {
                 bottomArray.add(taskViewId);
             }
@@ -3318,7 +3320,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
 
         int count = getTaskViewCount();
         for (int i = 0; i < count; i++) {
-            addDismissedTaskAnimations(getTaskViewAt(i), duration, anim);
+            addDismissedTaskAnimations(requireTaskViewAt(i), duration, anim);
         }
 
         mPendingAnimation = anim;
@@ -3441,7 +3443,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         mContentAlpha = alpha;
         int runningTaskId = getTaskIdsForRunningTaskView()[0];
         for (int i = getTaskViewCount() - 1; i >= 0; i--) {
-            TaskView child = getTaskViewAt(i);
+            TaskView child = requireTaskViewAt(i);
             int[] childTaskIds = child.getTaskIds();
             if (!mRunningTaskTileHidden ||
                     (childTaskIds[0] != runningTaskId && childTaskIds[1] != runningTaskId)) {
@@ -3542,6 +3544,14 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         return child instanceof TaskView ? (TaskView) child : null;
     }
 
+    /**
+     * A version of {@link #getTaskViewAt} when the caller is sure about the input index.
+     */
+    @NonNull
+    private TaskView requireTaskViewAt(int index) {
+        return Objects.requireNonNull(getTaskViewAt(index));
+    }
+
     public void setOnEmptyMessageUpdatedListener(OnEmptyMessageUpdatedListener listener) {
         mOnEmptyMessageUpdatedListener = listener;
     }
@@ -3758,7 +3768,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
     protected void setTaskViewsResistanceTranslation(float translation) {
         mTaskViewsSecondaryTranslation = translation;
         for (int i = 0; i < getTaskViewCount(); i++) {
-            TaskView task = getTaskViewAt(i);
+            TaskView task = requireTaskViewAt(i);
             task.getTaskResistanceTranslationProperty().set(task, translation / getScaleY());
         }
         runActionOnRemoteHandles(
@@ -3768,14 +3778,14 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
 
     private void updateTaskViewsSnapshotRadius() {
         for (int i = 0; i < getTaskViewCount(); i++) {
-            getTaskViewAt(i).updateSnapshotRadius();
+            requireTaskViewAt(i).updateSnapshotRadius();
         }
     }
 
     protected void setTaskViewsPrimarySplitTranslation(float translation) {
         mTaskViewsPrimarySplitTranslation = translation;
         for (int i = 0; i < getTaskViewCount(); i++) {
-            TaskView task = getTaskViewAt(i);
+            TaskView task = requireTaskViewAt(i);
             task.getPrimarySplitTranslationProperty().set(task, translation);
         }
     }
@@ -3783,7 +3793,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
     protected void setTaskViewsSecondarySplitTranslation(float translation) {
         mTaskViewsSecondarySplitTranslation = translation;
         for (int i = 0; i < getTaskViewCount(); i++) {
-            TaskView taskView = getTaskViewAt(i);
+            TaskView taskView = requireTaskViewAt(i);
             if (taskView == mSplitHiddenTaskView) {
                 continue;
             }
@@ -3797,7 +3807,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
     public void applySplitPrimaryScrollOffset() {
         if (isSplitPlaceholderFirstInGrid()) {
             for (int i = 0; i < getTaskViewCount(); i++) {
-                getTaskViewAt(i).setSplitScrollOffsetPrimary(mSplitPlaceholderSize);
+                requireTaskViewAt(i).setSplitScrollOffsetPrimary(mSplitPlaceholderSize);
             }
         } else if (isSplitPlaceholderLastInGrid()) {
             mClearAllButton.setSplitSelectScrollOffsetPrimary(-mSplitPlaceholderSize);
@@ -3839,7 +3849,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
      */
     public void resetSplitPrimaryScrollOffset() {
         for (int i = 0; i < getTaskViewCount(); i++) {
-            getTaskViewAt(i).setSplitScrollOffsetPrimary(0);
+            requireTaskViewAt(i).setSplitScrollOffsetPrimary(0);
         }
         mClearAllButton.setSplitSelectScrollOffsetPrimary(0);
     }
@@ -4066,8 +4076,8 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         mTaskViewDeadZoneRect.setEmpty();
         int count = getTaskViewCount();
         if (count > 0) {
-            final View taskView = getTaskViewAt(0);
-            getTaskViewAt(count - 1).getHitRect(mTaskViewDeadZoneRect);
+            final View taskView = requireTaskViewAt(0);
+            requireTaskViewAt(count - 1).getHitRect(mTaskViewDeadZoneRect);
             mTaskViewDeadZoneRect.union(taskView.getLeft(), taskView.getTop(), taskView.getRight(),
                     taskView.getBottom());
         }
@@ -4548,7 +4558,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
 
         final int taskCount = getTaskViewCount();
         for (int i = 0; i < taskCount; i++) {
-            TaskView taskView = getTaskViewAt(i);
+            TaskView taskView = requireTaskViewAt(i);
             float scrollDiff = taskView.getScrollAdjustment(showAsFullscreen, showAsGrid);
             int pageScroll = newPageScrolls[i] + (int) scrollDiff;
             if ((mIsRtl && pageScroll < clearAllScroll + clearAllWidth)
@@ -4716,7 +4726,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         int overlayEnabledPage = mOverlayEnabled ? getNextPage() : -1;
         int taskCount = getTaskViewCount();
         for (int i = 0; i < taskCount; i++) {
-            getTaskViewAt(i).setOverlayEnabled(i == overlayEnabledPage);
+            requireTaskViewAt(i).setOverlayEnabled(i == overlayEnabledPage);
         }
     }
 
@@ -4870,7 +4880,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         mColorTint = tintAmount;
 
         for (int i = 0; i < getTaskViewCount(); i++) {
-            getTaskViewAt(i).setColorTint(mColorTint, mTintingColor);
+            requireTaskViewAt(i).setColorTint(mColorTint, mTintingColor);
         }
 
         Drawable scrimBg = mActivity.getScrimView().getBackground();