[Android] Battery Status API: some tweaks to the BatteryStatusManager.java.

content/public/android/java/src/org/chromium/content/browser/BatteryStatusManager.java

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.content.browser;
 
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.os.BatteryManager;
+import android.os.Build;
 import android.util.Log;
 
 import com.google.common.annotations.VisibleForTesting;
 
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
 
 /**
  * Android implementation of the battery status APIs.
  */
@@ skipping 59 matching lines @@
         }
     }
 
     @VisibleForTesting
     void onReceive(Intent intent) {
        if (!intent.getAction().equals(Intent.ACTION_BATTERY_CHANGED)) {
            Log.e(TAG, "Unexpected intent.");
            return;
        }
 
+       boolean present = intent.getBooleanExtra(BatteryManager.EXTRA_PRESENT, false)
+               || batteryPresentByDefault();

[mlamouri (slow - plz ping), 2014/06/19 18:54:07]

What about this:

boolean present = ignoreBatteryPresentState() ||
intent.getBooleanExtra(BatteryManager.EXTRA_PRESENT, false);

[timvolodine, 2014/06/20 12:32:43]

yes that's slightly different semantics so I've made it:
ignoreBatteryPresentState() ? true :
intent.getBooleanExtra(BatteryManager.EXTRA_PRESENT, false);
Done.

+
+       if (!present) {
+           // No battery, return default values.
+           gotBatteryStatus(true, 0, Double.POSITIVE_INFINITY, 1);
+           return;
+       }
+
        int current = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
        int max = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
        double level = (double)current / (double)max;
+       if (level < 0 || level > 1) {
+           // Sanity check, assume default value in this case.
+           level = 1.0;
+       }
 
        int status = intent.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
-       // by default assume a battery is present
-       boolean present = intent.getBooleanExtra(BatteryManager.EXTRA_PRESENT, true);
-       boolean charging = (present && status == BatteryManager.BATTERY_STATUS_DISCHARGING)
-               ? false : true;
+       boolean charging = !(status == BatteryManager.BATTERY_STATUS_DISCHARGING);
 
-       //TODO(timvolodine) : add proper projection for chargingTime, dischargingTime.
-       double chargingTime = (!present || status == BatteryManager.BATTERY_STATUS_FULL)
+       // TODO(timvolodine) : add proper projection for chargingTime, dischargingTime.
+       double chargingTime = (status == BatteryManager.BATTERY_STATUS_FULL)
                ? 0 : Double.POSITIVE_INFINITY;
        double dischargingTime = Double.POSITIVE_INFINITY;
 
        gotBatteryStatus(charging, chargingTime, dischargingTime, level);
     }
 
+    protected boolean batteryPresentByDefault() {

[mlamouri (slow - plz ping), 2014/06/19 18:54:07]

Could you add a small comment explaining at a high level what this is doing? The
comment inside the definition is fine, it explains the problem for the specific
device. Also, I would name this function something more clear. Maybe
ignoreBatteryPresentState() ?

What about:
/**
 * Returns whether the BatteryStatusManager should ignore the battery present
state.
 * It might be required for some devices that have a broken EXTRA_PRESENT.
 */
protected boolean ignoreBatteryPresentState() {

[timvolodine, 2014/06/20 12:32:43]

Done.

+        // BatteryManager.EXTRA_PRESENT appears to be unreliable on Galaxy Nexus,
+        // Android 4.2.1, it always reports false. See crbug.com/384348.
+        return Build.MODEL.equals("Galaxy Nexus");
+    }
+
     protected void gotBatteryStatus(boolean charging, double chargingTime,
             double dischargingTime, double level) {
         synchronized (mNativePtrLock) {
             if (mNativePtr != 0) {
                 nativeGotBatteryStatus(mNativePtr, charging, chargingTime, dischargingTime, level);
             }
         }
     }
 
     /**
      * Native JNI call
      * see content/browser/battery_status/battery_status_manager.cc
      */
     private native void nativeGotBatteryStatus(long nativeBatteryStatusManager,
             boolean charging, double chargingTime, double dischargingTime, double level);
 }