Bug 696038 - (3/3) Battery API Android backend. r=cjones

embedding/android/GeckoApp.java

@@ -87,6 +87,8 @@ abstract public class GeckoApp
     public Handler mMainHandler;
     private IntentFilter mConnectivityFilter;
     private BroadcastReceiver mConnectivityReceiver;
+    private IntentFilter mBatteryFilter;
+    private BroadcastReceiver mBatteryReceiver;
 
     enum LaunchState {PreLaunch, Launching, WaitForDebugger,
                       Launched, GeckoRunning, GeckoExiting};
@@ -408,6 +410,10 @@ abstract public class GeckoApp
         mConnectivityFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
         mConnectivityReceiver = new GeckoConnectivityReceiver();
 
+        mBatteryFilter = new IntentFilter();
+        mBatteryFilter.addAction(Intent.ACTION_BATTERY_CHANGED);
+        mBatteryReceiver = new GeckoBatteryManager();
+
         if (!checkAndSetLaunchState(LaunchState.PreLaunch,
                                     LaunchState.Launching))
             return;
@@ -491,6 +497,7 @@ abstract public class GeckoApp
         super.onPause();
 
         unregisterReceiver(mConnectivityReceiver);
+        unregisterReceiver(mBatteryReceiver);
     }
 
     @Override
@@ -509,6 +516,7 @@ abstract public class GeckoApp
             onNewIntent(getIntent());
 
         registerReceiver(mConnectivityReceiver, mConnectivityFilter);
+        registerReceiver(mBatteryReceiver, mBatteryFilter);
     }
 
     @Override
@@ -526,7 +534,6 @@ abstract public class GeckoApp
         // etc., and generally mark the profile as 'clean', and then
         // dirty it again if we get an onResume.
 
-
         GeckoAppShell.sendEventToGecko(new GeckoEvent(GeckoEvent.ACTIVITY_STOPPING));
         super.onStop();
         GeckoAppShell.putChildInBackground();

embedding/android/GeckoBatteryManager.java

@@ -37,15 +37,93 @@
 
 package org.mozilla.gecko;
 
+import java.lang.Math;
+
+import android.util.Log;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+
+import android.os.BatteryManager;
+
 public class GeckoBatteryManager
+  extends BroadcastReceiver
 {
+  private final static float   kDefaultLevel       = 1.0f;
+  private final static boolean kDefaultCharging    = true;
+  private final static float   kMinimumLevelChange = 0.01f;
+
+  private static boolean sNotificationsEnabled     = false;
+  private static float   sLevel                    = kDefaultLevel;
+  private static boolean sCharging                 = kDefaultCharging;
+
+  @Override
+  public void onReceive(Context context, Intent intent) {
+    if (!intent.getAction().equals(Intent.ACTION_BATTERY_CHANGED)) {
+      Log.e("GeckoBatteryManager", "Got an unexpected intent!");
+      return;
+    }
+
+    boolean previousCharging = isCharging();
+    float previousLevel = getLevel();
+
+    if (intent.getBooleanExtra(BatteryManager.EXTRA_PRESENT, false)) {
+      int plugged = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);
+      if (plugged == -1) {
+        sCharging = kDefaultCharging;
+        Log.e("GeckoBatteryManager", "Failed to get the plugged status!");
+      } else {
+        // Likely, if plugged > 0, it's likely plugged and charging but the doc
+        // isn't clear about that.
+        sCharging = plugged != 0;
+      }
+
+      // We need two floats because sLevel is a float.
+      float current =  (float)intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
+      float max = (float)intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
+      if (current == -1 || max == -1) {
+        Log.e("GeckoBatteryManager", "Failed to get battery level!");
+        sLevel = kDefaultLevel;
+      } else {
+        sLevel = current / max;
+      }
+    } else {
+      sLevel = kDefaultLevel;
+      sCharging = kDefaultCharging;
+    }
+
+    /*
+     * We want to inform listeners if the following conditions are fulfilled:
+     *  - we have at least one observer;
+     *  - the charging state has changed
+     *    OR
+     *    the level has changed of at least kMinimumLevelChange
+     */
+    if (sNotificationsEnabled &&
+        (previousCharging != isCharging() ||
+         Math.abs(previousLevel - getLevel()) >= kMinimumLevelChange)) {
+      GeckoAppShell.notifyBatteryChange(sLevel, sCharging);
+    }
+  }
+
+  public static boolean isCharging() {
+    return sCharging;
+  }
+
+  public static float getLevel() {
+    return sLevel;
+  }
+
   public static void enableNotifications() {
+    sNotificationsEnabled = true;
   }
 
   public static void disableNotifications() {
+    sNotificationsEnabled = false;
   }
 
   public static float[] getCurrentInformation() {
-    return new float[] { 1.0f, 1.0f };
+    return new float[] { getLevel(), isCharging() ? 1.0f : 0.0f };
   }
 }