WindowBackend.java
/*
* Copyright 2020 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.window;
import android.content.Context;
import androidx.annotation.NonNull;
import androidx.core.util.Consumer;
import java.util.concurrent.Executor;
/**
* Backing interface for {@link WindowManager} instances that server as the default information
* supplier. By default {@link ExtensionWindowBackend} implementation is used in
* {@link WindowManager#WindowManager(Context, WindowBackend)}, but it can be replaced with
* a stub for testing.
*/
public interface WindowBackend {
/**
* Get current window layout information for the provided {@link Context}. Must be called
* only after the it is attached to the window and the layout pass has happened.
*/
@NonNull
WindowLayoutInfo getWindowLayoutInfo(@NonNull Context context);
/**
* Get the current device state.
*/
@NonNull
DeviceState getDeviceState();
/**
* Register a callback for layout changes of the window of the current visual {@link Context}.
* Must be called only after the it is attached to the window.
*/
void registerLayoutChangeCallback(@NonNull Context context, @NonNull Executor executor,
@NonNull Consumer<WindowLayoutInfo> callback);
/**
* Unregister a callback for window layout changes of the {@link Context} window.
*/
void unregisterLayoutChangeCallback(@NonNull Consumer<WindowLayoutInfo> callback);
/**
* Register a callback for device state changes.
*/
void registerDeviceStateChangeCallback(@NonNull Executor executor,
@NonNull Consumer<DeviceState> callback);
/**
* Unregister a callback for device state changes.
*/
void unregisterDeviceStateChangeCallback(@NonNull Consumer<DeviceState> callback);
}