Ensure Taskbar stashes when launching an app from folder

We use the folder closing callback to trigger a call to stash the
taskbar if an app was launched. We can check whether an app was launched
from a folder based on whether a folder's view is open when
an app is launched. This ensures that the taskbar only stashes after the
folder is done animating.

Flag: NA
Fix: 295296529
Test: Launched an app in a folder on taskbar. Also ensured that other
taskbar behavior remains unchanged.

Change-Id: Ib5a797186978ee960e44b6b62c833eead03bccd0
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarActivityContext.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarActivityContext.java
index 988ef80..a79cdc6 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarActivityContext.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarActivityContext.java
@@ -982,15 +982,20 @@
             FolderIcon folderIcon = (FolderIcon) view;
             Folder folder = folderIcon.getFolder();
 
-            folder.setOnFolderStateChangedListener(newState -> {
-                if (newState == Folder.STATE_OPEN) {
-                    setTaskbarWindowFocusableForIme(true);
-                } else if (newState == Folder.STATE_CLOSED) {
-                    // Defer by a frame to ensure we're no longer fullscreen and thus won't jump.
-                    getDragLayer().post(() -> setTaskbarWindowFocusableForIme(false));
-                    folder.setOnFolderStateChangedListener(null);
-                }
-            });
+            folder.setPriorityOnFolderStateChangedListener(
+                    new Folder.OnFolderStateChangedListener() {
+                        @Override
+                        public void onFolderStateChanged(int newState) {
+                            if (newState == Folder.STATE_OPEN) {
+                                setTaskbarWindowFocusableForIme(true);
+                            } else if (newState == Folder.STATE_CLOSED) {
+                                // Defer by a frame to ensure we're no longer fullscreen and thus
+                                // won't jump.
+                                getDragLayer().post(() -> setTaskbarWindowFocusableForIme(false));
+                                folder.setPriorityOnFolderStateChangedListener(null);
+                            }
+                        }
+                    });
 
             setTaskbarWindowFullscreen(true);
 
@@ -1050,7 +1055,21 @@
                         Log.e(TAG, "Unable to launch. tag=" + info + " intent=" + intent, e);
                         return;
                     }
+                }
 
+                // If the app was launched from a folder, stash the taskbar after it closes
+                Folder f = Folder.getOpen(this);
+                if (f != null && f.getInfo().id == info.container) {
+                    f.addOnFolderStateChangedListener(new Folder.OnFolderStateChangedListener() {
+                        @Override
+                        public void onFolderStateChanged(int newState) {
+                            if (newState == Folder.STATE_CLOSED) {
+                                f.removeOnFolderStateChangedListener(this);
+                                mControllers.taskbarStashController
+                                        .updateAndAnimateTransientTaskbar(true);
+                            }
+                        }
+                    });
                 }
                 mControllers.uiController.onTaskbarIconLaunched(info);
                 mControllers.taskbarStashController.updateAndAnimateTransientTaskbar(true);
diff --git a/src/com/android/launcher3/folder/Folder.java b/src/com/android/launcher3/folder/Folder.java
index 8bf7ec2..76e74c0 100644
--- a/src/com/android/launcher3/folder/Folder.java
+++ b/src/com/android/launcher3/folder/Folder.java
@@ -210,7 +210,9 @@
                     @ViewDebug.IntToString(from = STATE_OPEN, to = "STATE_OPEN"),
             })
     private int mState = STATE_CLOSED;
-    private OnFolderStateChangedListener mOnFolderStateChangedListener;
+    private final List<OnFolderStateChangedListener> mOnFolderStateChangedListeners =
+            new ArrayList<>();
+    private OnFolderStateChangedListener mPriorityOnFolderStateChangedListener;
     @ViewDebug.ExportedProperty(category = "launcher")
     private boolean mRearrangeOnClose = false;
     boolean mItemsInvalidated = false;
@@ -1665,18 +1667,43 @@
         return windowBottomPx - folderBottomPx;
     }
 
+    /**
+     * Save this listener for the special case of when we update the state and concurrently
+     * add another listener to {@link #mOnFolderStateChangedListeners} to avoid a
+     * ConcurrentModificationException
+     */
+    public void setPriorityOnFolderStateChangedListener(OnFolderStateChangedListener listener) {
+        mPriorityOnFolderStateChangedListener = listener;
+    }
+
     private void setState(@FolderState int newState) {
         mState = newState;
-        if (mOnFolderStateChangedListener != null) {
-            mOnFolderStateChangedListener.onFolderStateChanged(mState);
+        if (mPriorityOnFolderStateChangedListener != null) {
+            mPriorityOnFolderStateChangedListener.onFolderStateChanged(mState);
+        }
+        for (OnFolderStateChangedListener listener : mOnFolderStateChangedListeners) {
+            if (listener != null) {
+                listener.onFolderStateChanged(mState);
+            }
         }
     }
 
-    public void setOnFolderStateChangedListener(@Nullable OnFolderStateChangedListener listener) {
-        mOnFolderStateChangedListener = listener;
+    /**
+     * Adds the provided listener to the running list of Folder listeners
+     * {@link #mOnFolderStateChangedListeners}
+     */
+    public void addOnFolderStateChangedListener(@Nullable OnFolderStateChangedListener listener) {
+        if (listener != null) {
+            mOnFolderStateChangedListeners.add(listener);
+        }
     }
 
-    /** Listener that can be registered via {@link Folder#setOnFolderStateChangedListener} */
+    /** Removes the provided listener from the running list of Folder listeners */
+    public void removeOnFolderStateChangedListener(OnFolderStateChangedListener listener) {
+        mOnFolderStateChangedListeners.remove(listener);
+    }
+
+    /** Listener that can be registered via {@link #addOnFolderStateChangedListener} */
     public interface OnFolderStateChangedListener {
         /** See {@link Folder.FolderState} */
         void onFolderStateChanged(@FolderState int newState);