Merge "Added documentation for various window frame types." into lmp-mr1-dev

1 files changed, 23 insertions, 3 deletions

diff --git a/services/core/java/com/android/server/wm/WindowState.java b/services/core/java/com/android/server/wm/WindowState.java
index 806f7c532513..e5cf7644ffb9 100644
--- a/services/core/java/com/android/server/wm/WindowState.java
+++ b/services/core/java/com/android/server/wm/WindowState.java
@@ -227,13 +227,33 @@ final class WindowState implements WindowManagerPolicy.WindowState {
     final Rect mCompatFrame = new Rect();
 
     final Rect mContainingFrame = new Rect();
+
+    final Rect mParentFrame = new Rect();
+
+    // The entire screen area of the device.
     final Rect mDisplayFrame = new Rect();
+
+    // The region of the display frame that the display type supports displaying content on. This
+    // is mostly a special case for TV where some displays don’t have the entire display usable.
+    // {@link WindowManager.LayoutParams#FLAG_LAYOUT_IN_OVERSCAN} flag can be used to allow
+    // window display contents to extend into the overscan region.
     final Rect mOverscanFrame = new Rect();
+
+    // The display frame minus the stable insets. This value is always constant regardless of if
+    // the status bar or navigation bar is visible.
+    final Rect mStableFrame = new Rect();
+
+    // The area not occupied by the status and navigation bars. So, if both status and navigation
+    // bars are visible, the decor frame is equal to the stable frame.
+    final Rect mDecorFrame = new Rect();
+
+    // Equal to the decor frame if the IME (e.g. keyboard) is not present. Equal to the decor frame
+    // minus the area occupied by the IME if the IME is present.
     final Rect mContentFrame = new Rect();
-    final Rect mParentFrame = new Rect();
+
+    // Legacy stuff. Generally equal to the content frame expect when the IME for older apps
+    // displays hint text.
     final Rect mVisibleFrame = new Rect();
-    final Rect mDecorFrame = new Rect();
-    final Rect mStableFrame = new Rect();
 
     boolean mContentChanged;