Fix unresponsive back button in keyguard.

When keyguard doesn't have focus, events weren't being propagated to
keyguard properly.  The fix is to grab the back-button event from the
top-level view and handle it there.

Change-Id: Ied9761919cff30173f43f03e4c2a1732387e618e

Author: Jim Miller

policy/src/com/android/internal/policy/impl/keyguard/KeyguardHostView.java

@@ -254,17 +254,6 @@ private void showDialog(String title, String message) {
         dialog.show();
     }
 
-    @Override
-    public boolean dispatchKeyEvent(KeyEvent event) {
-        if (event.getAction() == KeyEvent.ACTION_UP
-                && event.getKeyCode() == KeyEvent.KEYCODE_BACK
-                && mCurrentSecuritySelection != SecurityMode.None) {
-            mCallback.dismiss(false);
-            return true;
-        }
-        return super.dispatchKeyEvent(event);
-    }
-
     private void showTimeoutDialog() {
         int timeoutInSeconds = (int) LockPatternUtils.FAILED_ATTEMPT_TIMEOUT_MS / 1000;
         int messageId = 0;
@@ -856,4 +845,12 @@ public void goToUserSwitcher() {
         mAppWidgetContainer.setCurrentPage(getWidgetPosition(R.id.keyguard_multi_user_selector));
     }
 
+    public boolean handleBackKey() {
+        if (mCurrentSecuritySelection != SecurityMode.None) {
+            mCallback.dismiss(false);
+            return true;
+        }
+        return false;
+    }
+
 }

policy/src/com/android/internal/policy/impl/keyguard/KeyguardViewManager.java

@@ -126,6 +126,18 @@ protected void onConfigurationChanged(Configuration newConfig) {
             super.onConfigurationChanged(newConfig);
             maybeCreateKeyguardLocked(shouldEnableScreenRotation(), null);
         }
+
+        @Override
+        public boolean dispatchKeyEvent(KeyEvent event) {
+            if (event.getAction() == KeyEvent.ACTION_DOWN
+                    && event.getKeyCode() == KeyEvent.KEYCODE_BACK
+                    && mKeyguardView != null) {
+                if (mKeyguardView.handleBackKey()) {
+                    return true;
+                }
+            }
+            return super.dispatchKeyEvent(event);
+        }
     }
 
     SparseArray<Parcelable> mStateContainer = new SparseArray<Parcelable>();