[Predictive Back] Swipe back within taskbar all apps should only scale down content view, rather than whole all apps sheet

Bug: 335467443
Test: manual - took a video
Flag: aconfig com.android.launcher3.enable_predictive_back_gesture TRUNKFOOD
Change-Id: I45980329f70ac1a8a8fc0e84be007f3385e40f58

quickstep/src/com/android/launcher3/taskbar/allapps/TaskbarAllAppsSlideInView.java

@@ -206,13 +206,6 @@ public class TaskbarAllAppsSlideInView extends AbstractSlideInView<TaskbarOverla
         super.dispatchDraw(canvas);
     }
 
-    @Override
-    protected void onUserSwipeToDismissProgressChanged() {
-        super.onUserSwipeToDismissProgressChanged();
-        mAppsView.setClipChildren(!mIsDismissInProgress);
-        mAppsView.getAppsRecyclerViewContainer().setClipChildren(!mIsDismissInProgress);
-    }
-
     @Override
     protected void onLayout(boolean changed, int l, int t, int r, int b) {
         super.onLayout(changed, l, t, r, b);
@@ -259,12 +252,28 @@ public class TaskbarAllAppsSlideInView extends AbstractSlideInView<TaskbarOverla
         return getPopupContainer().isEventOverView(mAppsView.getVisibleContainerView(), ev);
     }
 
+    /**
+     * In taskbar all apps search mode, we should scale down content inside all apps, rather
+     * than the whole all apps bottom sheet, to indicate we will navigate back within the all apps.
+     */
+    @Override
+    public boolean shouldAnimateContentViewInBackSwipe() {
+        return mAllAppsCallbacks.canHandleSearchBackInvoked();
+    }
+
+    @Override
+    protected void onUserSwipeToDismissProgressChanged() {
+        super.onUserSwipeToDismissProgressChanged();
+        mAppsView.setClipChildren(!mIsDismissInProgress);
+        mAppsView.getAppsRecyclerViewContainer().setClipChildren(!mIsDismissInProgress);
+    }
+
     @Override
     public void onBackInvoked() {
         if (mAllAppsCallbacks.handleSearchBackInvoked()) {
             // We need to scale back taskbar all apps if we navigate back within search inside all
             // apps
-            animateSwipeToDismissProgressToStart();
+            post(this::animateSwipeToDismissProgressToStart);
         } else {
             super.onBackInvoked();
         }

quickstep/src/com/android/launcher3/taskbar/allapps/TaskbarAllAppsViewController.java

@@ -143,6 +143,11 @@ final class TaskbarAllAppsViewController {
             }
         }
 
+        /** Check if search session can handle back. This check doesn't perform any action. */
+        boolean canHandleSearchBackInvoked() {
+            return mSearchSessionController.canHandleBackInvoked();
+        }
+
         /** Invoked on back press, returning {@code true} if the search session handled it. */
         boolean handleSearchBackInvoked() {
             return mSearchSessionController.handleBackInvoked();

quickstep/src/com/android/launcher3/taskbar/allapps/TaskbarSearchSessionController.kt

@@ -49,6 +49,8 @@ open class TaskbarSearchSessionController : ResourceBasedOverride, AllAppsTransi
     /** Creates a [PreDragCondition] for [view], if it is a search result that requires one. */
     open fun createPreDragConditionForSearch(view: View): PreDragCondition? = null
 
+    open fun canHandleBackInvoked(): Boolean = false
+
     open fun handleBackInvoked(): Boolean = false
 
     open fun onAllAppsAnimationPending(