diff --git a/quickstep/src/com/android/quickstep/views/RecentsView.java b/quickstep/src/com/android/quickstep/views/RecentsView.java
index 3f212c6..9cf76b3 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.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 java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Objects;
 import java.util.function.Consumer;
 
 /**
@@ -822,7 +824,7 @@
     @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 @@
         }
 
         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 @@
         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 @@
             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 @@
 
     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 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);
@@ -1539,7 +1541,7 @@
         mFullscreenProgress = fullscreenProgress;
         int taskCount = getTaskViewCount();
         for (int i = 0; i < taskCount; i++) {
-            getTaskViewAt(i).setFullscreenProgress(mFullscreenProgress);
+            requireTaskViewAt(i).setFullscreenProgress(mFullscreenProgress);
         }
         mClearAllButton.setFullscreenProgress(fullscreenProgress);
 
@@ -1666,7 +1668,7 @@
 
         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);
@@ -1812,7 +1814,7 @@
 
         // 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;
@@ -1955,7 +1957,7 @@
         }
 
         for (int i = 0; i < getTaskViewCount(); i++) {
-            TaskView taskView = getTaskViewAt(i);
+            TaskView taskView = requireTaskViewAt(i);
             if (taskView.getTaskViewId() == taskViewId) {
                 return taskView;
             }
@@ -2053,7 +2055,7 @@
         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;
             }
@@ -2064,7 +2066,7 @@
 
     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) {
@@ -2269,7 +2271,7 @@
             mTaskIconScaledDown = isScaledDown;
             int taskCount = getTaskViewCount();
             for (int i = 0; i < taskCount; i++) {
-                getTaskViewAt(i).setIconScaleAndDim(mTaskIconScaledDown ? 0 : 1);
+                requireTaskViewAt(i).setIconScaleAndDim(mTaskIconScaledDown ? 0 : 1);
             }
         }
     }
@@ -2285,7 +2287,7 @@
         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();
         }
@@ -2357,7 +2359,7 @@
             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
@@ -2422,7 +2424,7 @@
                         if (j == focusedTaskIndex) {
                             continue;
                         }
-                        widthOffset += getTaskViewAt(j).getLayoutParams().width + mPageSpacing;
+                        widthOffset += requireTaskViewAt(j).getLayoutParams().width + mPageSpacing;
                     }
 
                     float currentTaskTranslationX = mIsRtl ? widthOffset : -widthOffset;
@@ -2441,7 +2443,7 @@
                         if (j == focusedTaskIndex) {
                             continue;
                         }
-                        widthOffset += getTaskViewAt(j).getLayoutParams().width + mPageSpacing;
+                        widthOffset += requireTaskViewAt(j).getLayoutParams().width + mPageSpacing;
                     }
 
                     float currentTaskTranslationX = mIsRtl ? widthOffset : -widthOffset;
@@ -2519,7 +2521,7 @@
         }
 
         for (int i = 0; i < taskCount; i++) {
-            TaskView taskView = getTaskViewAt(i);
+            TaskView taskView = requireTaskViewAt(i);
             taskView.setGridTranslationX(gridTranslations[i] - snappedTaskGridTranslationX
                     + snappedTaskNonGridScrollAdjustment);
         }
@@ -2560,7 +2562,7 @@
         mGridProgress = gridProgress;
 
         for (int i = 0; i < taskCount; i++) {
-            getTaskViewAt(i).setGridProgress(gridProgress);
+            requireTaskViewAt(i).setGridProgress(gridProgress);
         }
         mClearAllButton.setGridProgress(gridProgress);
     }
@@ -2723,7 +2725,7 @@
                         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;
                     }
@@ -2826,7 +2828,7 @@
                                 + (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(
@@ -3142,7 +3144,7 @@
                             // 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(
@@ -3240,7 +3242,7 @@
         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);
             }
@@ -3259,7 +3261,7 @@
         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);
             }
@@ -3329,7 +3331,7 @@
 
         int count = getTaskViewCount();
         for (int i = 0; i < count; i++) {
-            addDismissedTaskAnimations(getTaskViewAt(i), duration, anim);
+            addDismissedTaskAnimations(requireTaskViewAt(i), duration, anim);
         }
 
         mPendingAnimation = anim;
@@ -3452,7 +3454,7 @@
         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)) {
@@ -3553,6 +3555,14 @@
         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;
     }
@@ -3769,7 +3779,7 @@
     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(
@@ -3779,14 +3789,14 @@
 
     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);
         }
     }
@@ -3794,7 +3804,7 @@
     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;
             }
@@ -3808,7 +3818,7 @@
     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);
@@ -3850,7 +3860,7 @@
      */
     public void resetSplitPrimaryScrollOffset() {
         for (int i = 0; i < getTaskViewCount(); i++) {
-            getTaskViewAt(i).setSplitScrollOffsetPrimary(0);
+            requireTaskViewAt(i).setSplitScrollOffsetPrimary(0);
         }
         mClearAllButton.setSplitSelectScrollOffsetPrimary(0);
     }
@@ -4077,8 +4087,8 @@
         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());
         }
@@ -4559,7 +4569,7 @@
 
         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)
@@ -4727,7 +4737,7 @@
         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);
         }
     }
 
@@ -4881,7 +4891,7 @@
         mColorTint = tintAmount;
 
         for (int i = 0; i < getTaskViewCount(); i++) {
-            getTaskViewAt(i).setColorTint(mColorTint, mTintingColor);
+            requireTaskViewAt(i).setColorTint(mColorTint, mTintingColor);
         }
 
         Drawable scrimBg = mActivity.getScrimView().getBackground();