Allow a window on a secondary display to have focus.

If any window on the default display has focus, then it
gets focus as usual.  If no window on the default display
has focus, then we consider windows on the secondary display.

In the future we will need more elaborate schemes for
managing focus across multiple displays, but this is enough
for testing purposes now.

Bug: 7183618
Change-Id: I21ddb9904eb9e574e42d28743aeca51f4ffebf64

Author: Jeff Brown

services/java/com/android/server/wm/WindowManagerService.java

@@ -9777,7 +9777,7 @@ private boolean updateFocusedWindowLocked(int mode, boolean updateInputWindows)
                 if (moveInputMethodWindowsIfNeededLocked(
                         mode != UPDATE_FOCUS_WILL_ASSIGN_LAYERS &&
                         mode != UPDATE_FOCUS_WILL_PLACE_SURFACES)) {
-                    getDefaultDisplayContentLocked().layoutNeeded = true;
+                    displayContent.layoutNeeded = true;
                 }
                 if (mode == UPDATE_FOCUS_PLACING_SURFACES) {
                     performLayoutLockedInner(displayContent, true /*initial*/, updateInputWindows);
@@ -9791,7 +9791,7 @@ private boolean updateFocusedWindowLocked(int mode, boolean updateInputWindows)
 
             if ((focusChanged & WindowManagerPolicy.FINISH_LAYOUT_REDO_LAYOUT) != 0) {
                 // The change in focus caused us to need to do a layout.  Okay.
-                getDefaultDisplayContentLocked().layoutNeeded = true;
+                displayContent.layoutNeeded = true;
                 if (mode == UPDATE_FOCUS_PLACING_SURFACES) {
                     performLayoutLockedInner(displayContent, true /*initial*/, updateInputWindows);
                 }
@@ -9814,22 +9814,29 @@ private void finishUpdateFocusedWindowAfterAssignLayersLocked(boolean updateInpu
     }
 
     private WindowState computeFocusedWindowLocked() {
-        WindowState result = null;
-        WindowState win;
-
         if (mAnimator.mUniverseBackground != null
                 && mAnimator.mUniverseBackground.mWin.canReceiveKeys()) {
             return mAnimator.mUniverseBackground.mWin;
         }
 
+        final int displayCount = mDisplayContents.size();
+        for (int i = 0; i < displayCount; i++) {
+            final DisplayContent displayContent = mDisplayContents.valueAt(i);
+            WindowState win = findFocusedWindowLocked(displayContent);
+            if (win != null) {
+                return win;
+            }
+        }
+        return null;
+    }
+
+    private WindowState findFocusedWindowLocked(DisplayContent displayContent) {
         int nextAppIndex = mAppTokens.size()-1;
-        WindowToken nextApp = nextAppIndex >= 0
-            ? mAppTokens.get(nextAppIndex) : null;
+        WindowToken nextApp = nextAppIndex >= 0 ? mAppTokens.get(nextAppIndex) : null;
 
-        // TODO(multidisplay): IMEs are only supported on the default display.
-        WindowList windows = getDefaultWindowListLocked();
+        final WindowList windows = displayContent.getWindowList();
         for (int i = windows.size() - 1; i >= 0; i--) {
-            win = windows.get(i);
+            final WindowState win = windows.get(i);
 
             if (localLOGV || DEBUG_FOCUS) Slog.v(
                 TAG, "Looking for focus: " + i
@@ -9879,12 +9886,10 @@ private WindowState computeFocusedWindowLocked() {
             if (win.canReceiveKeys()) {
                 if (DEBUG_FOCUS) Slog.v(
                         TAG, "Found focus @ " + i + " = " + win);
-                result = win;
-                break;
+                return win;
             }
         }
-
-        return result;
+        return null;
     }
 
     private void startFreezingDisplayLocked(boolean inTransaction,