Android: Integrates native and java SystemMonitor.

base/android/java/src/org/chromium/base/SystemMonitor.java

+// Copyright (c) 2012 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.base;
+
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.os.BatteryManager;
+import android.os.Looper;
+
+
+/**
+ * Integrates native SystemMonitor with the java side.
+ */
+@JNINamespace("base::android")
+public class SystemMonitor {
+
+    private static SystemMonitor sInstance;
+
+    private boolean mIsBatteryPower;
+
+    public static void create(Context context) {
+        if (sInstance == null) {
+            sInstance = new SystemMonitor();
+            IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);

[jar (doing other things), 2012/10/05 17:39:51]

Although the style guide allows for either 80 or 100 characters, can't we stay
under 80 (and be more like the rest of the chrome codebase)?.... or is there a
newer style??

[bulach, 2012/10/05 18:23:52]

depends on what you call "newer" :)
for java, we follow android's style guide (most dramatic changes are indent by 4
and 100 characters)..

see the announcement I made a while ago when we started upstreaming the android
port:
https://groups.google.com/a/chromium.org/forum/?fromgroups=#!topic/chromium-d...

+            Intent batteryStatusIntent = context.registerReceiver(null, ifilter);
+            onBatteryChargingChanged(batteryStatusIntent);
+        }
+    }
+
+    private SystemMonitor() {
+    }
+
+    public static void onBatteryChargingChanged(Intent intent) {
+        if (sInstance == null) {
+            // We may be called by the framework intent-filter before being
+            // fully initialized. This is not a problem, since our constructor
+            // will check for the state later on.
+            return;
+        }
+        int chargePlug = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);
+        // If we're not plugged, assume we're running on battery power.
+        sInstance.mIsBatteryPower = chargePlug != BatteryManager.BATTERY_PLUGGED_USB &&
+                                    chargePlug != BatteryManager.BATTERY_PLUGGED_AC;
+        nativeOnBatteryChargingChanged();
+    }
+
+    @CalledByNative
+    private static boolean isBatteryPower() {
+        return sInstance.mIsBatteryPower;
+    }
+
+    private static native void nativeOnBatteryChargingChanged();
+
+}