MutableStateObservable.java
/*
* Copyright 2021 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.camera.core.impl;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;
/**
* A {@link StateObservable} whose state can be set.
*
* @param <T> The state type.
*/
@RequiresApi(21) // TODO(b/200306659): Remove and replace with annotation on package-info.java
public class MutableStateObservable<T> extends StateObservable<T> {
private MutableStateObservable(@Nullable Object initialState, boolean isError) {
super(initialState, isError);
}
/**
* Creates a mutable state observer with the provided initial state.
*
* @param initialState The initial state
* @param <T> The state type
* @return A mutable state observable initialized with the given initial state.
*/
@NonNull
public static <T> MutableStateObservable<T> withInitialState(@Nullable T initialState) {
return new MutableStateObservable<>(initialState, false);
}
/**
* Creates a mutable state observer in an initial error state containing the provided
* {@link Throwable}.
*
* @param initialError The {@link Throwable} contained by the error state.
* @param <T> The state type
* @return A mutable state observable initialized in an error state containing the provided
* {@link Throwable}.
*/
@NonNull
public static <T> MutableStateObservable<T> withInitialError(@NonNull Throwable initialError) {
return new MutableStateObservable<>(initialError, true);
}
/**
* Posts a new state to be used as the current state of this Observable.
*/
public void setState(@Nullable T state) {
updateState(state);
}
/**
* Posts a new {@link Throwable} to be used in the new error state of this Observable.
*/
public void setError(@NonNull Throwable error) {
updateStateAsError(error);
}
}