Remove crypto pattern after two seconds

Currently pattern is left on after a failed attempt. This change removes
it after a timeout.

Change-Id: I77830510b17396f6e64a482816f6041af0fdc166

src/com/android/settings/CryptKeeper.java

@@ -65,6 +65,8 @@ import com.android.internal.widget.LockPatternUtils;
 import com.android.internal.widget.LockPatternView;
 import com.android.internal.widget.LockPatternView.Cell;
 
+import static com.android.internal.widget.LockPatternView.DisplayMode;
+
 import java.util.List;
 
 /**
@@ -123,6 +125,15 @@ public class CryptKeeper extends Activity implements TextView.OnEditorActionList
     /** Number of calls to {@link #notifyUser()} before we release the wakelock */
     private int mReleaseWakeLockCountdown = 0;
 
+    // how long we wait to clear a wrong pattern
+    private static final int WRONG_PATTERN_CLEAR_TIMEOUT_MS = 1500;
+
+    private Runnable mClearPatternRunnable = new Runnable() {
+        public void run() {
+            mLockPatternView.clearPattern();
+        }
+    };
+
     /**
      * Used to propagate state through configuration changes (e.g. screen rotation)
      */
@@ -175,15 +186,22 @@ public class CryptKeeper extends Activity implements TextView.OnEditorActionList
             } else if (failedAttempts == MAX_FAILED_ATTEMPTS) {
                 // Factory reset the device.
                 sendBroadcast(new Intent("android.intent.action.MASTER_CLEAR"));
-            } else if ((failedAttempts % COOL_DOWN_ATTEMPTS) == 0) {
+            } else {
+                // Wrong entry. Handle pattern case.
                 if (mLockPatternView != null) {
-                    mLockPatternView.clearPattern();
+                    mLockPatternView.setDisplayMode(DisplayMode.Wrong);
+                    mLockPatternView.removeCallbacks(mClearPatternRunnable);
+                    mLockPatternView.postDelayed(mClearPatternRunnable, WRONG_PATTERN_CLEAR_TIMEOUT_MS);
                 }
+                if ((failedAttempts % COOL_DOWN_ATTEMPTS) == 0) {
                     mCooldown = COOL_DOWN_INTERVAL;
                     cooldown();
                 } else {
                     final TextView status = (TextView) findViewById(R.id.status);
                     status.setText(R.string.try_again);
+                    if (mLockPatternView != null) {
+                        mLockPatternView.setDisplayMode(DisplayMode.Wrong);
+                    }
                     // Reenable the password entry
                     if (mPasswordEntry != null) {
                         mPasswordEntry.setEnabled(true);
@@ -194,6 +212,7 @@ public class CryptKeeper extends Activity implements TextView.OnEditorActionList
                 }
             }
         }
+    }
 
     private class ValidationTask extends AsyncTask<Void, Void, Boolean> {
         @Override
@@ -587,6 +606,7 @@ public class CryptKeeper extends Activity implements TextView.OnEditorActionList
 
         @Override
         public void onPatternStart() {
+            mLockPatternView.removeCallbacks(mClearPatternRunnable);
         }
 
         @Override