DO NOT MERGE Fix the cutout of magnification border

If the window is unmagnifiable, it might cause the cutout of
magnification region.
To fix it, we set the flag when the touchable region is not the
entier window frame.

Bug: 196510717
Test: manual test on gestural and 3-button navigation
Change-Id: Ida2bb5bf120038ac9153e12790b93bdec195adbc
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarActivityContext.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarActivityContext.java
index 72d9d5b..ae647db 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarActivityContext.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarActivityContext.java
@@ -510,4 +510,20 @@
     protected boolean isUserSetupComplete() {
         return mIsUserSetupComplete;
     }
+
+    /**
+     * Called when we determine the touchable region.
+     *
+     * @param exclude {@code true} then the magnification region computation will omit the window.
+     */
+    public void excludeFromMagnificationRegion(boolean exclude) {
+        if (exclude) {
+            mWindowLayoutParams.privateFlags |=
+                    WindowManager.LayoutParams.PRIVATE_FLAG_EXCLUDE_FROM_SCREEN_MAGNIFICATION;
+        } else {
+            mWindowLayoutParams.privateFlags &=
+                    ~WindowManager.LayoutParams.PRIVATE_FLAG_EXCLUDE_FROM_SCREEN_MAGNIFICATION;
+        }
+        mWindowManager.updateViewLayout(mDragLayer, mWindowLayoutParams);
+    }
 }
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarDragLayerController.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarDragLayerController.java
index cec892f..8c6185c 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarDragLayerController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarDragLayerController.java
@@ -137,12 +137,14 @@
             // Always have nav buttons be touchable
             mControllers.navbarButtonsViewController.addVisibleButtonsRegion(
                     mTaskbarDragLayer, insetsInfo.touchableRegion);
+            boolean insetsIsTouchableRegion = true;
 
             if (mTaskbarDragLayer.getAlpha() < AlphaUpdateListener.ALPHA_CUTOFF_THRESHOLD) {
                 // Let touches pass through us.
                 insetsInfo.setTouchableInsets(TOUCHABLE_INSETS_REGION);
             } else if (mControllers.navbarButtonsViewController.isImeVisible()) {
                 insetsInfo.setTouchableInsets(TOUCHABLE_INSETS_CONTENT);
+                insetsIsTouchableRegion = false;
             } else if (!mControllers.uiController.isTaskbarTouchable()) {
                 // Let touches pass through us.
                 insetsInfo.setTouchableInsets(TOUCHABLE_INSETS_REGION);
@@ -151,9 +153,11 @@
                 // Taskbar has some touchable elements, take over the full taskbar area
                 insetsInfo.setTouchableInsets(mActivity.isTaskbarWindowFullscreen()
                         ? TOUCHABLE_INSETS_FRAME : TOUCHABLE_INSETS_CONTENT);
+                insetsIsTouchableRegion = false;
             } else {
                 insetsInfo.setTouchableInsets(TOUCHABLE_INSETS_REGION);
             }
+            mActivity.excludeFromMagnificationRegion(insetsIsTouchableRegion);
         }
 
         /**