1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_ANDROID_APPLICATION_STATUS_LISTENER_H_ 6 #define BASE_ANDROID_APPLICATION_STATUS_LISTENER_H_ 7 8 #include <jni.h> 9 10 #include "base/android/jni_android.h" 11 #include "base/base_export.h" 12 #include "base/macros.h" 13 #include "base/memory/ref_counted.h" 14 #include "base/memory/singleton.h" 15 #include "base/observer_list_threadsafe.h" 16 17 namespace base { 18 namespace android { 19 20 // Define application state values like APPLICATION_STATE_VISIBLE in a 21 // way that ensures they're always the same than their Java counterpart. 22 // 23 // Note that these states represent the most visible Activity state. 24 // If there are activities with states paused and stopped, only 25 // HAS_PAUSED_ACTIVITIES should be returned. 26 // 27 // A Java counterpart will be generated for this enum. 28 // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.base 29 enum ApplicationState { 30 APPLICATION_STATE_UNKNOWN = 0, 31 APPLICATION_STATE_HAS_RUNNING_ACTIVITIES = 1, 32 APPLICATION_STATE_HAS_PAUSED_ACTIVITIES = 2, 33 APPLICATION_STATE_HAS_STOPPED_ACTIVITIES = 3, 34 APPLICATION_STATE_HAS_DESTROYED_ACTIVITIES = 4 35 }; 36 37 // A native helper class to listen to state changes of the Android 38 // Application. This mirrors org.chromium.base.ApplicationStatus. 39 // any thread. 40 // 41 // To start listening, create a new instance, passing a callback to a 42 // function that takes an ApplicationState parameter. To stop listening, 43 // simply delete the listener object. The implementation guarantees 44 // that the callback will always be called on the thread that created 45 // the listener. 46 // 47 // Example: 48 // 49 // void OnApplicationStateChange(ApplicationState state) { 50 // ... 51 // } 52 // 53 // // Start listening. 54 // ApplicationStatusListener* my_listener = 55 // new ApplicationStatusListener( 56 // base::Bind(&OnApplicationStateChange)); 57 // 58 // ... 59 // 60 // // Stop listening. 61 // delete my_listener 62 // 63 class BASE_EXPORT ApplicationStatusListener { 64 public: 65 typedef base::Callback<void(ApplicationState)> ApplicationStateChangeCallback; 66 67 explicit ApplicationStatusListener( 68 const ApplicationStateChangeCallback& callback); 69 ~ApplicationStatusListener(); 70 71 // Internal use: must be public to be called from base_jni_registrar.cc 72 static bool RegisterBindings(JNIEnv* env); 73 74 // Internal use only: must be public to be called from JNI and unit tests. 75 static void NotifyApplicationStateChange(ApplicationState state); 76 77 // Expose jni call for ApplicationStatus.getStateForApplication. 78 static ApplicationState GetState(); 79 80 private: 81 void Notify(ApplicationState state); 82 83 ApplicationStateChangeCallback callback_; 84 85 DISALLOW_COPY_AND_ASSIGN(ApplicationStatusListener); 86 }; 87 88 } // namespace android 89 } // namespace base 90 91 #endif // BASE_ANDROID_APPLICATION_STATUS_LISTENER_H_ 92
