blob: b6b9c082a25c1ca0fe4c1cad49ff0feb5d6d984d [file] [log] [blame]
// 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.
#ifndef BASE_ANDROID_APPLICATION_STATUS_LISTENER_H_
#define BASE_ANDROID_APPLICATION_STATUS_LISTENER_H_
#include <jni.h>
#include "base/android/jni_android.h"
#include "base/base_export.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/singleton.h"
#include "base/observer_list_threadsafe.h"
#include "starboard/types.h"
namespace base {
namespace android {
// Define application state values like APPLICATION_STATE_VISIBLE in a
// way that ensures they're always the same than their Java counterpart.
//
// Note that these states represent the most visible Activity state.
// If there are activities with states paused and stopped, only
// HAS_PAUSED_ACTIVITIES should be returned.
//
// A Java counterpart will be generated for this enum.
// GENERATED_JAVA_ENUM_PACKAGE: org.chromium.base
enum ApplicationState {
APPLICATION_STATE_UNKNOWN = 0,
APPLICATION_STATE_HAS_RUNNING_ACTIVITIES = 1,
APPLICATION_STATE_HAS_PAUSED_ACTIVITIES = 2,
APPLICATION_STATE_HAS_STOPPED_ACTIVITIES = 3,
APPLICATION_STATE_HAS_DESTROYED_ACTIVITIES = 4
};
// A native helper class to listen to state changes of the Android
// Application. This mirrors org.chromium.base.ApplicationStatus.
// any thread.
//
// To start listening, create a new instance, passing a callback to a
// function that takes an ApplicationState parameter. To stop listening,
// simply delete the listener object. The implementation guarantees
// that the callback will always be called on the thread that created
// the listener.
//
// Example:
//
// void OnApplicationStateChange(ApplicationState state) {
// ...
// }
//
// // Start listening.
// auto my_listener = ApplicationStatusListener::New(
// base::BindRepeating(&OnApplicationStateChange));
//
// ...
//
// // Stop listening.
// my_listener.reset();
//
class BASE_EXPORT ApplicationStatusListener {
public:
using ApplicationStateChangeCallback =
base::RepeatingCallback<void(ApplicationState)>;
virtual ~ApplicationStatusListener();
// Sets the callback to call when application state changes.
virtual void SetCallback(const ApplicationStateChangeCallback& callback) = 0;
// Notify observers that application state has changed.
virtual void Notify(ApplicationState state) = 0;
// Create a new listener. This object should only be used on a single thread.
static std::unique_ptr<ApplicationStatusListener> New(
const ApplicationStateChangeCallback& callback);
// Internal use only: must be public to be called from JNI and unit tests.
static void NotifyApplicationStateChange(ApplicationState state);
// Expose jni call for ApplicationStatus.getStateForApplication.
static ApplicationState GetState();
protected:
ApplicationStatusListener();
private:
DISALLOW_COPY_AND_ASSIGN(ApplicationStatusListener);
};
} // namespace android
} // namespace base
#endif // BASE_ANDROID_APPLICATION_STATUS_LISTENER_H_