Broadcast NotifyTimezoneChange to all RenderProcessHosts when the system time zone changes

content/public/android/java/src/org/chromium/content/browser/TimeZoneMonitor.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.util.Log;
+
+import org.chromium.base.CalledByNative;
+import org.chromium.base.JNINamespace;
+
+/**
+ * Android implementation details for content::TimeZoneMonitorAndroid.
+ */
+@JNINamespace("content")
+class TimeZoneMonitor extends BroadcastReceiver {

[bulach, 2014/04/29 08:33:44]

nit: it's a bit more common to use an anonymous inner class rather than expose
at the top-level, something like:

private final mBroadcastReceiver = new BroadcastReceiver() {
      @Override
      public void onReceive(Context context, Intent intent) {
        if (!intent.getAction().equals(Intent.ACTION_TIMEZONE_CHANGED)) {
            Log.e(TAG, "unexpected intent");
            return;
        } 
        nativeTimeZoneChangedFromJava(mNativePtr);
      }
}

then use this for register / unregister

[Mark Mentovai, 2014/04/29 16:01:05]

bulach wrote:
Done.

I used BatteryStatusManager, a recent addition to this directory, as my
template. Should that file be changed too, or should the CL that added it be
re-reviewed?

+    private static final String TAG = "TimeZoneMonitor";
+
+    private final Context mAppContext;
+    private final IntentFilter mFilter = new IntentFilter(Intent.ACTION_TIMEZONE_CHANGED);
+
+    private long mNativePtr;
+
+    protected TimeZoneMonitor(Context context) {

[bulach, 2014/04/29 08:33:44]

nit: private?

+        mAppContext = context.getApplicationContext();
+    }
+
+    @CalledByNative
+    static TimeZoneMonitor getInstance(Context appContext) {

[bulach, 2014/04/29 08:33:44]

nit: as above, perhaps fold this with start to avoid two jni calls

+        return new TimeZoneMonitor(appContext);
+    }
+
+    /**
+     * Start listening for intents.
+     * @param nativePtr The native content::TimeZoneMonitorAndroid to notify of time zone changes.
+     */
+    @CalledByNative
+    void start(long nativePtr) {
+        mNativePtr = nativePtr;
+        mAppContext.registerReceiver(this, mFilter);
+    }
+
+    /**
+     * Stop listening for intents.
+     */
+    @CalledByNative
+    void stop() {
+        mAppContext.unregisterReceiver(this);
+        mNativePtr = 0;
+    }
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+       if (!intent.getAction().equals(Intent.ACTION_TIMEZONE_CHANGED)) {
+           Log.e(TAG, "unexpected intent");
+           return;
+       }
+
+       nativeTimeZoneChangedFromJava(mNativePtr);
+    }
+
+    /**
+     * Native JNI call to content::TimeZoneMonitorAndroid::TimeZoneChanged.
+     * See content/browser/time_zone_monitor_android.cc.
+     */
+    private native void nativeTimeZoneChangedFromJava(long nativeTimeZoneMonitorAndroid);
+}