Vibration API: plumbing from Blink to Java.

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

+// Copyright (c) 2013 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.Context;
+import android.os.Vibrator;
+
+import org.chromium.base.CalledByNative;
+import org.chromium.base.JNINamespace;
+
+@JNINamespace("content")

[bulach, 2013/06/20 14:21:04]

nit:
/**
 * This is the implementation of the C++ counterpart VibrationService.
 */

[Michael van Ouwerkerk, 2013/06/20 17:34:09]

Done.

+class VibrationService {
+
+    private final Vibrator mVibrator;
+
+    @CalledByNative
+    public static VibrationService create(Context context) {
+        return new VibrationService(context);
+    }
+
+    @CalledByNative
+    public void vibrate(int milliseconds) {
+        mVibrator.vibrate(milliseconds);

[bulach, 2013/06/20 14:21:04]

should we have some kind of throttling at this level?
the 10s max is good, but how about some kind of exponential backoff to prevent
pages from constantly buzzing the device?

[Michael van Ouwerkerk, 2013/06/20 17:34:09]

It's a bit tricky, because there is a valid use case in games for frequent and /
or long vibrations. Ultimately, if the page misbehaves the user can just close
it.

If we really want to further throttle usage of this service, we have a few
options:
* Minimum pauses
* Maximum amount of vibration over time, e.g. cannot vibrate more than 50% of
the time.

I'm not convinced we need to throttle it any further, and would be comfortable
with sending this out in the Beta release and see if we get any negative
feedback on this.

+    }
+
+    @CalledByNative
+    public void cancelVibration() {

[bulach, 2013/06/20 14:21:04]

nit: make these whole lot private.. we tend to use the java qualifiers just for
java code..

[Michael van Ouwerkerk, 2013/06/20 17:34:09]

Done.

+        mVibrator.cancel();
+    }
+
+    private VibrationService(Context context) {
+        mVibrator = (Vibrator) context.getSystemService(Context.VIBRATOR_SERVICE);
+    }
+}