Refactoring RecentsView to handle non-TaskViews

Change-Id: I0bc28ef670a1dad9a3912ca5360c9bab18afd4b2

quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/states/BackgroundAppState.java

@@ -19,7 +19,6 @@ import static com.android.launcher3.LauncherAnimUtils.OVERVIEW_TRANSITION_MS;
 
 import com.android.launcher3.AbstractFloatingView;
 import com.android.launcher3.Launcher;
-import com.android.launcher3.Utilities;
 import com.android.launcher3.allapps.AllAppsTransitionController;
 import com.android.launcher3.userevent.nano.LauncherLogProto;
 import com.android.quickstep.util.LayoutUtils;
@@ -69,8 +68,16 @@ public class BackgroundAppState extends OverviewState {
         if (taskCount == 0) {
             return super.getOverviewScaleAndTranslation(launcher);
         }
-        TaskView dummyTask = recentsView.getTaskViewAt(Utilities.boundToRange(
+        TaskView dummyTask;
-                recentsView.getCurrentPage(), 0, taskCount - 1));
+        if (recentsView.getCurrentPage() >= 0) {
+            if (recentsView.getCurrentPage() <= taskCount - 1) {
+                dummyTask = recentsView.getCurrentPageTaskView();
+            } else {
+                dummyTask = recentsView.getTaskViewAt(taskCount - 1);
+            }
+        } else {
+            dummyTask = recentsView.getTaskViewAt(0);
+        }
         return recentsView.getTempClipAnimationHelper().updateForFullscreenOverview(dummyTask)
                 .getScaleAndTranslation();
     }

quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/touchcontrollers/PortraitOverviewStateTouchHelper.java

@@ -47,9 +47,9 @@ public final class PortraitOverviewStateTouchHelper {
      * @return true if we should intercept the motion event
      */
     boolean canInterceptTouch(MotionEvent ev) {
-        if (mRecentsView.getChildCount() > 0) {
+        if (mRecentsView.getTaskViewCount() > 0) {
             // Allow swiping up in the gap between the hotseat and overview.
-            return ev.getY() >= mRecentsView.getChildAt(0).getBottom();
+            return ev.getY() >= mRecentsView.getTaskViewAt(0).getBottom();
         } else {
             // If there are no tasks, we only intercept if we're below the hotseat height.
             return isTouchOverHotseat(mLauncher, ev);
@@ -63,7 +63,7 @@ public final class PortraitOverviewStateTouchHelper {
      * @return true if going back should take the user to the currently running task
      */
     boolean shouldSwipeDownReturnToApp() {
-        TaskView taskView = mRecentsView.getTaskViewAt(mRecentsView.getNextPage());
+        TaskView taskView = mRecentsView.getNextPageTaskView();
         return taskView != null && mRecentsView.shouldSwipeDownLaunchApp();
     }
 
@@ -76,7 +76,7 @@ public final class PortraitOverviewStateTouchHelper {
      */
     PendingAnimation createSwipeDownToTaskAppAnimation(long duration) {
         mRecentsView.setCurrentPage(mRecentsView.getPageNearestToCenterOfScreen());
-        TaskView taskView = mRecentsView.getTaskViewAt(mRecentsView.getCurrentPage());
+        TaskView taskView = mRecentsView.getCurrentPageTaskView();
         if (taskView == null) {
             throw new IllegalStateException("There is no task view to animate to.");
         }

quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/touchcontrollers/QuickSwitchTouchController.java

@@ -50,7 +50,6 @@ import com.android.quickstep.SysUINavigationMode;
 import com.android.quickstep.SysUINavigationMode.Mode;
 import com.android.quickstep.views.RecentsView;
 import com.android.quickstep.views.TaskView;
-import com.android.systemui.shared.system.QuickStepContract;
 
 /**
  * Handles quick switching to a recent task from the home screen.

quickstep/recents_ui_overrides/src/com/android/quickstep/BaseSwipeUpHandler.java

@@ -227,10 +227,10 @@ public abstract class BaseSwipeUpHandler<T extends BaseDraggingActivity, Q exten
         // Launch the task user scrolled to (mRecentsView.getNextPage()).
         if (ENABLE_QUICKSTEP_LIVE_TILE.get()) {
             // We finish recents animation inside launchTask() when live tile is enabled.
-            mRecentsView.getTaskViewAt(mRecentsView.getNextPage()).launchTask(false /* animate */,
+            mRecentsView.getNextPageTaskView().launchTask(false /* animate */,
                     true /* freezeTaskList */);
         } else {
-            int taskId = mRecentsView.getTaskViewAt(mRecentsView.getNextPage()).getTask().key.id;
+            int taskId = mRecentsView.getNextPageTaskView().getTask().key.id;
             mFinishingRecentsAnimationForNewTaskId = taskId;
             mRecentsAnimationWrapper.finish(true /* toRecents */, () -> {
                 if (!mCanceled) {

quickstep/recents_ui_overrides/src/com/android/quickstep/LauncherActivityControllerHelper.java

@@ -268,7 +268,7 @@ public final class LauncherActivityControllerHelper implements ActivityControlHe
                         INDEX_RECENTS_FADE_ANIM, attached ? 1 : 0);
 
                 int runningTaskIndex = recentsView.getRunningTaskIndex();
-                if (runningTaskIndex == 0) {
+                if (runningTaskIndex == recentsView.getTaskViewStartIndex()) {
                     // If we are on the first task (we haven't quick switched), translate recents in
                     // from the side. Calculate the start translation based on current scale/scroll.
                     float currScale = recentsView.getScaleX();
@@ -351,8 +351,7 @@ public final class LauncherActivityControllerHelper implements ActivityControlHe
     private void playScaleDownAnim(AnimatorSet anim, Launcher launcher, LauncherState fromState,
             LauncherState endState) {
         RecentsView recentsView = launcher.getOverviewPanel();
-        TaskView v = recentsView.getTaskViewAt(recentsView.getCurrentPage());
+        if (recentsView.getCurrentPageTaskView() == null) {
-        if (v == null) {
             return;
         }
 
@@ -380,7 +379,7 @@ public final class LauncherActivityControllerHelper implements ActivityControlHe
             // recents as a whole needs to translate further to keep up with the app window.
             TaskView runningTaskView = recentsView.getRunningTaskView();
             if (runningTaskView == null) {
-                runningTaskView = recentsView.getTaskViewAt(recentsView.getCurrentPage());
+                runningTaskView = recentsView.getCurrentPageTaskView();
             }
             TimeInterpolator oldInterpolator = translateY.getInterpolator();
             Rect fallbackInsets = launcher.getDeviceProfile().getInsets();

quickstep/recents_ui_overrides/src/com/android/quickstep/OverviewCommandHelper.java

@@ -109,7 +109,7 @@ public class OverviewCommandHelper {
                 TaskView taskView = rv.getNextTaskView();
                 if (taskView == null) {
                     if (rv.getTaskViewCount() > 0) {
-                        taskView = (TaskView) rv.getPageAt(0);
+                        taskView = rv.getTaskViewAt(0);
                         taskView.requestFocus();
                     } else {
                         rv.requestFocus();

quickstep/recents_ui_overrides/src/com/android/quickstep/WindowTransformSwipeHandler.java

@@ -479,8 +479,8 @@ public class WindowTransformSwipeHandler<T extends BaseDraggingActivity>
             recentsAttachedToAppWindow = mIsShelfPeeking || mIsLikelyToStartNewTask;
             if (animate) {
                 // Only animate if an adjacent task view is visible on screen.
-                TaskView adjacentTask1 = mRecentsView.getTaskViewAt(runningTaskIndex + 1);
+                TaskView adjacentTask1 = mRecentsView.getNextTaskView();
-                TaskView adjacentTask2 = mRecentsView.getTaskViewAt(runningTaskIndex - 1);
+                TaskView adjacentTask2 = mRecentsView.getPreviousTaskView();
                 float prevTranslationX = mRecentsView.getTranslationX();
                 mRecentsView.setTranslationX(0);
                 animate = (adjacentTask1 != null && adjacentTask1.getGlobalVisibleRect(TEMP_RECT))
@@ -590,8 +590,7 @@ public class WindowTransformSwipeHandler<T extends BaseDraggingActivity>
      */
     private void updateSysUiFlags(float windowProgress) {
         if (mRecentsView != null) {
-            TaskView centermostTask = mRecentsView.getTaskViewAt(mRecentsView
+            TaskView centermostTask = mRecentsView.getTaskViewNearestToCenterOfScreen();
-                    .getPageNearestToCenterOfScreen());
             int centermostTaskFlags = centermostTask == null ? 0
                     : centermostTask.getThumbnail().getSysUiStatusNavFlags();
             boolean useHomeScreenFlags = windowProgress > 1 - UPDATE_SYSUI_FLAGS_THRESHOLD;

quickstep/recents_ui_overrides/src/com/android/quickstep/fallback/FallbackRecentsView.java

@@ -176,7 +176,7 @@ public class FallbackRecentsView extends RecentsView<RecentsActivity> {
     protected void applyLoadPlan(ArrayList<Task> tasks) {
         // When quick-switching on 3p-launcher, we add a "dummy" tile corresponding to Launcher
         // as well. This tile is never shown as we have setCurrentTaskHidden, but allows use to
-        // track the index of the next task appropriately, as it we are switching on any other app.
+        // track the index of the next task appropriately, as if we are switching on any other app.
         if (mRunningTaskInfo != null && mRunningTaskInfo.taskId == mRunningTaskId) {
             // Check if the task list has running task
             boolean found = false;

quickstep/recents_ui_overrides/src/com/android/quickstep/views/RecentsView.java

@@ -306,6 +306,9 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
     private Layout mEmptyTextLayout;
     private LiveTileOverlay mLiveTileOverlay;
 
+    // Keeps track of the index where the first TaskView should be
+    private int mTaskViewStartIndex = 0;
+
     private BaseActivity.MultiWindowModeChangedListener mMultiWindowModeChangedListener =
             (inMultiWindowMode) -> {
         if (!inMultiWindowMode && mOverviewStateEnabled) {
@@ -329,7 +332,6 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
         mClearAllButton = (ClearAllButton) LayoutInflater.from(context)
                 .inflate(R.layout.overview_clear_all_button, this, false);
         mClearAllButton.setOnClickListener(this::dismissAllTasks);
-
         mTaskViewPool = new ViewPool<>(context, this, R.layout.task, 20 /* max size */,
                 10 /* initial size */);
 
@@ -430,7 +432,7 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
         super.onViewRemoved(child);
 
         // Clear the task data for the removed child if it was visible
-        if (child != mClearAllButton) {
+        if (child instanceof TaskView) {
             TaskView taskView = (TaskView) child;
             mHasVisibleTaskData.delete(taskView.getTask().key.id);
             mTaskViewPool.recycle(taskView);
@@ -444,7 +446,7 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
 
     public TaskView getTaskView(int taskId) {
         for (int i = 0; i < getTaskViewCount(); i++) {
-            TaskView tv = (TaskView) getChildAt(i);
+            TaskView tv = getTaskViewAt(i);
             if (tv.getTask() != null && tv.getTask().key != null && tv.getTask().key.id == taskId) {
                 return tv;
             }
@@ -536,28 +538,26 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
         }
 
         if (tasks == null || tasks.isEmpty()) {
-            removeAllViews();
+            removeTasksViewsAndClearAllButton();
             onTaskStackUpdated();
             return;
         }
 
-        int oldChildCount = getChildCount();
-
         // Unload existing visible task data
         unloadVisibleTaskData();
 
-        TaskView ignoreRestTaskView =
+        TaskView ignoreResetTaskView =
                 mIgnoreResetTaskId == -1 ? null : getTaskView(mIgnoreResetTaskId);
 
         final int requiredTaskCount = tasks.size();
         if (getTaskViewCount() != requiredTaskCount) {
-            if (oldChildCount > 0) {
+            if (indexOfChild(mClearAllButton) != -1) {
                 removeView(mClearAllButton);
             }
-            for (int i = getChildCount(); i < requiredTaskCount; i++) {
+            for (int i = getTaskViewCount(); i < requiredTaskCount; i++) {
                 addView(mTaskViewPool.getView());
             }
-            while (getChildCount() > requiredTaskCount) {
+            while (getTaskViewCount() > requiredTaskCount) {
                 removeView(getChildAt(getChildCount() - 1));
             }
             if (requiredTaskCount > 0) {
@@ -567,17 +567,20 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
 
         // Rebind and reset all task views
         for (int i = requiredTaskCount - 1; i >= 0; i--) {
-            final int pageIndex = requiredTaskCount - i - 1;
+            final int pageIndex = requiredTaskCount - i - 1 + mTaskViewStartIndex;
             final Task task = tasks.get(i);
             final TaskView taskView = (TaskView) getChildAt(pageIndex);
             taskView.bind(task);
         }
+
         TaskView runningTaskView = getRunningTaskView();
         if (runningTaskView != null) {
             setCurrentPage(indexOfChild(runningTaskView));
+        } else if (getTaskViewCount() > 0) {
+            setCurrentPage(indexOfChild(getTaskViewAt(0)));
         }
 
-        if (mIgnoreResetTaskId != -1 && getTaskView(mIgnoreResetTaskId) != ignoreRestTaskView) {
+        if (mIgnoreResetTaskId != -1 && getTaskView(mIgnoreResetTaskId) != ignoreResetTaskView) {
             // If the taskView mapping is changing, do not preserve the visuals. Since we are
             // mostly preserving the first task, and new taskViews are added to the end, it should
             // generally map to the same task.
@@ -588,17 +591,28 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
         updateEnabledOverlays();
     }
 
+    private void removeTasksViewsAndClearAllButton() {
+        for (int i = getTaskViewCount() - 1; i >= 0; i--) {
+            removeView(getTaskViewAt(i));
+        }
+        if (indexOfChild(mClearAllButton) != -1) {
+            removeView(mClearAllButton);
+        }
+    }
+
     public int getTaskViewCount() {
-        // Account for the clear all button.
+        int taskViewCount = getChildCount() - mTaskViewStartIndex;
-        int childCount = getChildCount();
+        if (indexOfChild(mClearAllButton) != -1) {
-        return childCount == 0 ? 0 : childCount - 1;
+            taskViewCount--;
+        }
+        return taskViewCount;
     }
 
     protected void onTaskStackUpdated() { }
 
     public void resetTaskVisuals() {
         for (int i = getTaskViewCount() - 1; i >= 0; i--) {
-            TaskView taskView = (TaskView) getChildAt(i);
+            TaskView taskView = getTaskViewAt(i);
             if (mIgnoreResetTaskId != taskView.getTask().key.id) {
                 taskView.resetVisualProperties();
                 taskView.setStableAlpha(mContentAlpha);
@@ -704,7 +718,7 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
     }
 
     /**
-     * Iterates through all thet asks, and loads the associated task data for newly visible tasks,
+     * Iterates through all the tasks, and loads the associated task data for newly visible tasks,
      * and unloads the associated task data for tasks that are no longer visible.
      */
     public void loadVisibleTaskData() {
@@ -715,15 +729,16 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
         }
 
         int centerPageIndex = getPageNearestToCenterOfScreen();
-        int numChildren = getTaskViewCount();
+        int numChildren = getChildCount();
         int lower = Math.max(0, centerPageIndex - 2);
         int upper = Math.min(centerPageIndex + 2, numChildren - 1);
 
         // Update the task data for the in/visible children
-        for (int i = 0; i < numChildren; i++) {
+        for (int i = 0; i < getTaskViewCount(); i++) {
-            TaskView taskView = (TaskView) getChildAt(i);
+            TaskView taskView = getTaskViewAt(i);
             Task task = taskView.getTask();
-            boolean visible = lower <= i && i <= upper;
+            int index = indexOfChild(taskView);
+            boolean visible = lower <= index && index <= upper;
             if (visible) {
                 if (task == mTmpRunningTask) {
                     // Skip loading if this is the task that we are animating into
@@ -798,6 +813,10 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
         return tv == null ? -1 : indexOfChild(tv);
     }
 
+    public int getTaskViewStartIndex() {
+        return mTaskViewStartIndex;
+    }
+
     /**
      * Reloads the view if anything in recents changed.
      */
@@ -853,10 +872,10 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
      */
     public void showCurrentTask(int runningTaskId) {
         if (getTaskView(runningTaskId) == null) {
-            boolean wasEmpty = getChildCount() == 0;
+            boolean wasEmpty = getTaskViewCount() == 0;
             // Add an empty view for now until the task plan is loaded and applied
             final TaskView taskView = mTaskViewPool.getView();
-            addView(taskView, 0);
+            addView(taskView, mTaskViewStartIndex);
             if (wasEmpty) {
                 addView(mClearAllButton);
             }
@@ -922,14 +941,13 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
         if (runningTaskView == null) {
             // Launch the first task
             if (getTaskViewCount() > 0) {
-                getTaskViewAt(0).launchTask(true /* animate */);
+                getTaskViewAt(0).launchTask(true);
             }
         } else {
-            TaskView nextTaskView = getNextTaskView();
+            if (getNextTaskView() != null) {
-            if (nextTaskView != null) {
+                getNextTaskView().launchTask(true);
-                nextTaskView.launchTask(true /* animate */);
             } else {
-                runningTaskView.launchTask(true /* animate */);
+                runningTaskView.launchTask(true);
             }
         }
     }
@@ -1189,7 +1207,7 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
 
         int count = getTaskViewCount();
         for (int i = 0; i < count; i++) {
-            addDismissedTaskAnimations(getChildAt(i), anim, duration);
+            addDismissedTaskAnimations(getTaskViewAt(i), anim, duration);
         }
 
         mPendingAnimation = pendingAnimation;
@@ -1197,7 +1215,7 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
             if (onEndListener.isSuccess) {
                 // Remove all the task views now
                 ActivityManagerWrapper.getInstance().removeAllRecentTasks();
-                removeAllViews();
+                removeTasksViewsAndClearAllButton();
                 startHome();
             }
             mPendingAnimation = null;
@@ -1344,26 +1362,50 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
         child.setAlpha(mContentAlpha);
     }
 
-    /**
-     * @return The most recent task that is older than the currently running task. If there is
-     * currently no running task or there is no task older than it, then return null.
-     */
     @Nullable
     public TaskView getNextTaskView() {
-        TaskView runningTaskView = getRunningTaskView();
+        return getTaskViewAtByAbsoluteIndex(getRunningTaskIndex() + 1);
-        if (runningTaskView == null) {
-            return null;
-        }
-        return getTaskViewAt(indexOfChild(runningTaskView) + 1);
     }
 
+    @Nullable
+    public TaskView getPreviousTaskView() {
+        return getTaskViewAtByAbsoluteIndex(getRunningTaskIndex() - 1);
+    }
+
+    @Nullable
+    public TaskView getCurrentPageTaskView() {
+        return getTaskViewAtByAbsoluteIndex(getCurrentPage());
+    }
+
+    @Nullable
+    public TaskView getNextPageTaskView() {
+        return getTaskViewAtByAbsoluteIndex(getNextPage());
+    }
+
+    @Nullable
+    public TaskView getTaskViewNearestToCenterOfScreen() {
+        return getTaskViewAtByAbsoluteIndex(getPageNearestToCenterOfScreen());
+    }
+
+    /**
+     * Returns null instead of indexOutOfBoundsError when index is not in range
+     */
+    @Nullable
     public TaskView getTaskViewAt(int index) {
-        View child = getChildAt(index);
+        return getTaskViewAtByAbsoluteIndex(index + mTaskViewStartIndex);
-        return child == mClearAllButton ? null : (TaskView) child;
+    }
+
+    @Nullable
+    private TaskView getTaskViewAtByAbsoluteIndex(int index) {
+        if (index < getChildCount() && index >= 0) {
+            View child = getChildAt(index);
+            return child instanceof TaskView ? (TaskView) child : null;
+        }
+        return null;
     }
 
     public void updateEmptyMessage() {
-        boolean isEmpty = getChildCount() == 0;
+        boolean isEmpty = getTaskViewCount() == 0;
         boolean hasSizeChanged = mLastMeasureSize.x != getWidth()
                 || mLastMeasureSize.y != getHeight();
         if (isEmpty == mShowEmptyMessage && !hasSizeChanged) {
@@ -1497,7 +1539,7 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
             throw new IllegalStateException("Another pending animation is still running");
         }
 
-        int count = getChildCount();
+        int count = getTaskViewCount();
         if (count == 0) {
             return new PendingAnimation(new AnimatorSet());
         }
@@ -1670,18 +1712,38 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
 
     @Override
     protected int computeMinScrollX() {
-        if (mIsRtl && mDisallowScrollToClearAll) {
+        if (getTaskViewCount() > 0) {
-            // We aren't showing the clear all button, so use the leftmost task as the min scroll.
+            if (mDisallowScrollToClearAll) {
-            return getScrollForPage(getTaskViewCount() - 1);
+                // We aren't showing the clear all button,
+                // so use the leftmost task as the min scroll.
+                if (mIsRtl) {
+                    return getScrollForPage(indexOfChild(getTaskViewAt(getTaskViewCount() - 1)));
+                }
+                return getScrollForPage(mTaskViewStartIndex);
+            }
+            if (mIsRtl) {
+                return getScrollForPage(indexOfChild(getTaskViewAt(getTaskViewCount() - 1)) + 1);
+            }
+            return getScrollForPage(mTaskViewStartIndex);
         }
         return super.computeMinScrollX();
     }
 
     @Override
     protected int computeMaxScrollX() {
-        if (!mIsRtl && mDisallowScrollToClearAll) {
+        if (getTaskViewCount() > 0) {
-            // We aren't showing the clear all button, so use the rightmost task as the max scroll.
+            if (mDisallowScrollToClearAll) {
-            return getScrollForPage(getTaskViewCount() - 1);
+                // We aren't showing the clear all button,
+                // so use the rightmost task as the min scroll.
+                if (mIsRtl) {
+                    return getScrollForPage(mTaskViewStartIndex);
+                }
+                return getScrollForPage(indexOfChild(getTaskViewAt(getTaskViewCount() - 1)));
+            }
+            if (mIsRtl) {
+                return getScrollForPage(mTaskViewStartIndex);
+            }
+            return getScrollForPage(indexOfChild(getTaskViewAt(getTaskViewCount() - 1)) + 1);
         }
         return super.computeMaxScrollX();
     }
@@ -1733,7 +1795,7 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
         int overlayEnabledPage = mOverlayEnabled ? getNextPage() : -1;
         int taskCount = getTaskViewCount();
         for (int i = 0; i < taskCount; i++) {
-            ((TaskView) getChildAt(i)).setOverlayEnabled(i == overlayEnabledPage);
+            getTaskViewAt(i).setOverlayEnabled(i == overlayEnabledPage);
         }
     }