Announce dynamic content changes in lock confirmation settings.

Also re-orders updateStage() and setText/Selection calls so that text
events don't flush announcements. This does not change functionality.

Bug: 7256500
Change-Id: I8b10d66e9f73c7a630a8c3c5128372e18f26234c

src/com/android/settings/ConfirmLockPattern.java

@@ -180,7 +180,6 @@ public class ConfirmLockPattern extends PreferenceActivity {
         }
 
         private void updateStage(Stage stage) {
-
             switch (stage) {
                 case NeedToUnlock:
                     if (mHeaderText != null) {
@@ -220,6 +219,10 @@ public class ConfirmLockPattern extends PreferenceActivity {
                     mLockPatternView.setEnabled(false); // appearance of being disabled
                     break;
             }
+
+            // Always announce the header for accessibility. This is a no-op
+            // when accessibility is disabled.
+            mHeaderTextView.announceForAccessibility(mHeaderTextView.getText());
         }
 
         private Runnable mClearPatternRunnable = new Runnable() {