SavedStateHandleController.java
/*
* Copyright 2019 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.lifecycle;
import androidx.annotation.NonNull;
import androidx.savedstate.SavedStateRegistry;
final class SavedStateHandleController implements LifecycleEventObserver {
private final String mKey;
private boolean mIsAttached = false;
private final SavedStateHandle mHandle;
SavedStateHandleController(String key, SavedStateHandle handle) {
mKey = key;
mHandle = handle;
}
boolean isAttached() {
return mIsAttached;
}
void attachToLifecycle(SavedStateRegistry registry, Lifecycle lifecycle) {
if (mIsAttached) {
throw new IllegalStateException("Already attached to lifecycleOwner");
}
mIsAttached = true;
lifecycle.addObserver(this);
registry.registerSavedStateProvider(mKey, mHandle.savedStateProvider());
}
@Override
public void onStateChanged(@NonNull LifecycleOwner source, @NonNull Lifecycle.Event event) {
if (event == Lifecycle.Event.ON_DESTROY) {
mIsAttached = false;
source.getLifecycle().removeObserver(this);
}
}
SavedStateHandle getHandle() {
return mHandle;
}
}