Implement intermediate brigthness control on header.

This just reuses the views from BrigthnessDialog. Later, we will move
to a model where we only have one single slider.

Change-Id: Ib8116741802b7de930331648e50ff55fc869d7af

3 files changed, 20 insertions, 11 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/settings/BrightnessController.java b/packages/SystemUI/src/com/android/systemui/settings/BrightnessController.java
index 327e715..1747e6e 100644
--- a/packages/SystemUI/src/com/android/systemui/settings/BrightnessController.java
+++ b/packages/SystemUI/src/com/android/systemui/settings/BrightnessController.java
@@ -119,7 +119,6 @@ public class BrightnessController implements ToggleSlider.Listener {
             }
         };
         mBrightnessObserver = new BrightnessObserver(mHandler);
-        mBrightnessObserver.startObserving();
 
         PowerManager pm = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
         mMinimumBacklight = pm.getMinimumScreenBrightnessSetting();
@@ -128,13 +127,6 @@ public class BrightnessController implements ToggleSlider.Listener {
         mAutomaticAvailable = context.getResources().getBoolean(
                 com.android.internal.R.bool.config_automatic_brightness_available);
         mPower = IPowerManager.Stub.asInterface(ServiceManager.getService("power"));
-
-        // Update the slider and mode before attaching the listener so we don't receive the
-        // onChanged notifications for the initial values.
-        updateMode();
-        updateSlider();
-
-        control.setOnChangedListener(this);
     }
 
     public void addStateChangedCallback(BrightnessStateChangeCallback cb) {
@@ -150,11 +142,24 @@ public class BrightnessController implements ToggleSlider.Listener {
         // Do nothing
     }
 
+    public void registerCallbacks() {
+        mBrightnessObserver.startObserving();
+        mUserTracker.startTracking();
+
+        // Update the slider and mode before attaching the listener so we don't receive the
+        // onChanged notifications for the initial values.
+        updateMode();
+        updateSlider();
+
+        mControl.setOnChangedListener(this);
+    }
+
     /** Unregister all call backs, both to and from the controller */
     public void unregisterCallbacks() {
         mBrightnessObserver.stopObserving();
         mChangeCallbacks.clear();
         mUserTracker.stopTracking();
+        mControl.setOnChangedListener(null);
     }
 
     public void onChanged(ToggleSlider view, boolean tracking, boolean automatic, int value) {
diff --git a/packages/SystemUI/src/com/android/systemui/settings/BrightnessDialog.java b/packages/SystemUI/src/com/android/systemui/settings/BrightnessDialog.java
index bd5e5e8..27881c4 100644
--- a/packages/SystemUI/src/com/android/systemui/settings/BrightnessDialog.java
+++ b/packages/SystemUI/src/com/android/systemui/settings/BrightnessDialog.java
@@ -92,6 +92,7 @@ public class BrightnessDialog extends Dialog implements
         mBrightnessController = new BrightnessController(getContext(),
                 (ImageView) findViewById(R.id.brightness_icon),
                 (ToggleSlider) findViewById(R.id.brightness_slider));
+        mBrightnessController.registerCallbacks();
         dismissBrightnessDialog(mBrightnessDialogLongTimeout);
         mBrightnessController.addStateChangedCallback(this);
     }
diff --git a/packages/SystemUI/src/com/android/systemui/settings/CurrentUserTracker.java b/packages/SystemUI/src/com/android/systemui/settings/CurrentUserTracker.java
index 036bd4f..f8ff616 100644
--- a/packages/SystemUI/src/com/android/systemui/settings/CurrentUserTracker.java
+++ b/packages/SystemUI/src/com/android/systemui/settings/CurrentUserTracker.java
@@ -29,9 +29,6 @@ public abstract class CurrentUserTracker extends BroadcastReceiver {
     private int mCurrentUserId;
 
     public CurrentUserTracker(Context context) {
-        IntentFilter filter = new IntentFilter(Intent.ACTION_USER_SWITCHED);
-        context.registerReceiver(this, filter);
-        mCurrentUserId = ActivityManager.getCurrentUser();
         mContext = context;
     }
 
@@ -50,6 +47,12 @@ public abstract class CurrentUserTracker extends BroadcastReceiver {
         }
     }
 
+    public void startTracking() {
+        mCurrentUserId = ActivityManager.getCurrentUser();
+        IntentFilter filter = new IntentFilter(Intent.ACTION_USER_SWITCHED);
+        mContext.registerReceiver(this, filter);
+    }
+
     public void stopTracking() {
         mContext.unregisterReceiver(this);
     }