StubExtension.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.extensions;
import android.os.IBinder;
import androidx.annotation.NonNull;
import java.util.HashSet;
import java.util.Set;
/**
* Basic implementation of the {@link ExtensionInterface}. An OEM can choose to use it as the base
* class for their implementation.
*/
abstract class StubExtension implements ExtensionInterface {
private ExtensionCallback mExtensionCallback;
private final Set<IBinder> mWindowLayoutChangeListenerTokens = new HashSet<>();
private boolean mDeviceStateChangeListenerRegistered;
@Override
public void setExtensionCallback(@NonNull ExtensionCallback callback) {
mExtensionCallback = callback;
}
@Override
public void onWindowLayoutChangeListenerAdded(@NonNull IBinder windowToken) {
mWindowLayoutChangeListenerTokens.add(windowToken);
onListenersChanged();
}
@Override
public void onWindowLayoutChangeListenerRemoved(@NonNull IBinder windowToken) {
mWindowLayoutChangeListenerTokens.remove(windowToken);
onListenersChanged();
}
@Override
public void onDeviceStateListenersChanged(boolean isEmpty) {
mDeviceStateChangeListenerRegistered = !isEmpty;
onListenersChanged();
}
protected void updateDeviceState(@NonNull ExtensionDeviceState newState) {
if (mExtensionCallback != null) {
mExtensionCallback.onDeviceStateChanged(newState);
}
}
protected void updateWindowLayout(@NonNull IBinder windowToken,
@NonNull ExtensionWindowLayoutInfo newLayout) {
if (mExtensionCallback != null) {
mExtensionCallback.onWindowLayoutChanged(windowToken, newLayout);
}
}
@NonNull
protected Set<IBinder> getWindowsListeningForLayoutChanges() {
return mWindowLayoutChangeListenerTokens;
}
protected boolean hasListeners() {
return !mWindowLayoutChangeListenerTokens.isEmpty() || mDeviceStateChangeListenerRegistered;
}
/** Notification to the OEM level that the registered listeners changed. */
protected abstract void onListenersChanged();
}