Clean up, simplify and fix AlarmTile class and logic

This commit cleans up the AlarmTile class by removing the unnecessary
listener on the alarm intent. It now listens only to the next alarm
setting value, which was fetched after receiving the intent anyway.

These changes also fix a bug that would cause the tile to not show up
after some actions, like reordering the tiles due to the visibility not
being set on tile creation.

Lastly, some minor code styling issues have been fixed.

Patch set CyanogenDefy#2: collapse onNextAlarmChanged into onChangeUri, remove
mEnabled, use TextUtils to check for string emptiness and mark
updateQuickSettings explicitly as public.

Change-Id: Ic5871a9cc4874f33181dfac14e25a89499c182f2

packages/SystemUI/src/com/android/systemui/quicksettings/AlarmTile.java

@@ -1,38 +1,30 @@
 package com.android.systemui.quicksettings;
 
-import android.content.BroadcastReceiver;
 import android.content.ComponentName;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
-import android.content.IntentFilter;
 import android.net.Uri;
 import android.os.Handler;
 import android.provider.Settings;
+import android.text.TextUtils;
 import android.view.LayoutInflater;
 import android.view.View;
 
 import com.android.systemui.R;
 import com.android.systemui.statusbar.phone.QuickSettingsController;
 import com.android.systemui.statusbar.phone.QuickSettingsContainerView;
 
-public class AlarmTile extends QuickSettingsTile{
-
-    private boolean enabled = false;
+public class AlarmTile extends QuickSettingsTile {
 
     public AlarmTile(Context context, LayoutInflater inflater,
             QuickSettingsContainerView container,
             QuickSettingsController qsc, Handler handler) {
         super(context, inflater, container, qsc);
 
         mDrawable = R.drawable.ic_qs_alarm_on;
-        String nextAlarmTime = Settings.System.getString(mContext.getContentResolver(), Settings.System.NEXT_ALARM_FORMATTED);
-        if(nextAlarmTime != null){
-            mLabel = nextAlarmTime;
-        }
 
         mOnClick = new View.OnClickListener() {
-
             @Override
             public void onClick(View v) {
                 Intent intent = new Intent();
@@ -42,36 +34,30 @@ public void onClick(View v) {
                 startSettingsActivity(intent);
             }
         };
-        qsc.registerAction(Intent.ACTION_ALARM_CHANGED, this);
+
         qsc.registerObservedContent(Settings.System.getUriFor(
                 Settings.System.NEXT_ALARM_FORMATTED), this);
-    }
-
-    @Override
-    public void onReceive(Context context, Intent intent) {
-        onAlarmChanged(intent);
+        updateStatus();
     }
 
     @Override
     public void onChangeUri(ContentResolver resolver, Uri uri) {
-        onNextAlarmChanged();
-    }
-
-    void onAlarmChanged(Intent intent) {
-        enabled = intent.getBooleanExtra("alarmSet", false);
-        updateQuickSettings();
-    }
-
-    void onNextAlarmChanged() {
-        mLabel = Settings.System.getString(mContext.getContentResolver(),
-                Settings.System.NEXT_ALARM_FORMATTED);
+        updateStatus();
         updateQuickSettings();
     }
 
     @Override
-    void updateQuickSettings() {
-        mTile.setVisibility(enabled ? View.VISIBLE : View.GONE);
+    public void updateQuickSettings() {
+        mTile.setVisibility(!TextUtils.isEmpty(mLabel) ? View.VISIBLE : View.GONE);
         super.updateQuickSettings();
     }
 
+    /**
+     * Updates the alarm status shown on the tile.
+     */
+    private void updateStatus() {
+        mLabel = Settings.System.getString(mContext.getContentResolver(),
+            Settings.System.NEXT_ALARM_FORMATTED);
+    }
+
 }