Folder support in Taskbar

- Add TaskbarActivityContext which allows shared Launcher elements to
  "just work" using existing generic ActivityContext.
- TaskbarContainerView extends BaseDragLayer<TaskbarActivityContext>.
- Inflate FolderIcon and Folder using TaskbarActivityContext to be
  shown in TaskbarContainerView.
- Use TaskbarActivityContext's DeviceProfile to determine icon size
  instead of overriding in styles. This also ensures that normal
  BubbleTextView icons have the same size as FolderIcons.

Test: Place a folder in home screen hotseat, ensure it shows up in
taskbar and can be opened, and that apps inside it can be launched
or dragged.
Bug: 171917176

Change-Id: Ic25d2f84bcd7e3399c88989305ea565497c030d9

quickstep/src/com/android/launcher3/taskbar/TaskbarContainerView.java

@@ -19,19 +19,29 @@ import static com.android.systemui.shared.system.ViewTreeObserverWrapper.InsetsI
 import static com.android.systemui.shared.system.ViewTreeObserverWrapper.InsetsInfo.TOUCHABLE_INSETS_REGION;
 
 import android.content.Context;
+import android.graphics.Rect;
 import android.util.AttributeSet;
-import android.widget.FrameLayout;
+import android.view.View;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
+import com.android.launcher3.R;
 import com.android.launcher3.anim.AlphaUpdateListener;
+import com.android.launcher3.util.TouchController;
+import com.android.launcher3.views.BaseDragLayer;
 import com.android.systemui.shared.system.ViewTreeObserverWrapper;
 
 /**
  * Top-level ViewGroup that hosts the TaskbarView as well as Views created by it such as Folder.
  */
-public class TaskbarContainerView extends FrameLayout {
+public class TaskbarContainerView extends BaseDragLayer<TaskbarActivityContext> {
+
+    private final int[] mTempLoc = new int[2];
+    private final int mFolderMargin;
+
+    // Initialized in TaskbarController constructor.
+    private TaskbarController.TaskbarContainerViewCallbacks mControllerCallbacks;
 
     // Initialized in init.
     private TaskbarView mTaskbarView;
@@ -52,12 +62,23 @@ public class TaskbarContainerView extends FrameLayout {
 
     public TaskbarContainerView(@NonNull Context context, @Nullable AttributeSet attrs,
             int defStyleAttr, int defStyleRes) {
-        super(context, attrs, defStyleAttr, defStyleRes);
+        super(context, attrs, 1 /* alphaChannelCount */);
+        mFolderMargin = getResources().getDimensionPixelSize(R.dimen.taskbar_folder_margin);
+    }
+
+    protected void construct(TaskbarController.TaskbarContainerViewCallbacks callbacks) {
+        mControllerCallbacks = callbacks;
     }
 
     protected void init(TaskbarView taskbarView) {
         mTaskbarView = taskbarView;
         mTaskbarInsetsComputer = createTaskbarInsetsComputer();
+        recreateControllers();
+    }
+
+    @Override
+    public void recreateControllers() {
+        mControllers = new TouchController[0];
     }
 
     private ViewTreeObserverWrapper.OnComputeInsetsListener createTaskbarInsetsComputer() {
@@ -70,6 +91,17 @@ public class TaskbarContainerView extends FrameLayout {
                  // We're visible again, accept touches anywhere in our bounds.
                 insetsInfo.setTouchableInsets(TOUCHABLE_INSETS_FRAME);
             }
+
+            // TaskbarContainerView provides insets to other apps based on contentInsets. These
+            // insets should stay consistent even if we expand TaskbarContainerView's bounds, e.g.
+            // to show a floating view like Folder. Thus, we set the contentInsets to be where
+            // mTaskbarView is, since its position never changes and insets rather than overlays.
+            int[] loc = mTempLoc;
+            mTaskbarView.getLocationInWindow(loc);
+            insetsInfo.contentInsets.left = loc[0];
+            insetsInfo.contentInsets.top = loc[1];
+            insetsInfo.contentInsets.right = getWidth() - (loc[0] + mTaskbarView.getWidth());
+            insetsInfo.contentInsets.bottom = getHeight() - (loc[1] + mTaskbarView.getHeight());
         };
     }
 
@@ -91,4 +123,30 @@ public class TaskbarContainerView extends FrameLayout {
 
         cleanup();
     }
+
+    @Override
+    protected boolean canFindActiveController() {
+        // Unlike super class, we want to be able to find controllers when touches occur in the
+        // gesture area. For example, this allows Folder to close itself when touching the Taskbar.
+        return true;
+    }
+
+    @Override
+    public void onViewRemoved(View child) {
+        super.onViewRemoved(child);
+        mControllerCallbacks.onViewRemoved();
+    }
+
+    /**
+     * @return Bounds (in our coordinates) where an opened Folder can display.
+     */
+    protected Rect getFolderBoundingBox() {
+        Rect boundingBox = new Rect(0, 0, getWidth(), getHeight() - mTaskbarView.getHeight());
+        boundingBox.inset(mFolderMargin, mFolderMargin);
+        return boundingBox;
+    }
+
+    protected TaskbarActivityContext getTaskbarActivityContext() {
+        return mActivity;
+    }
 }