/*
* Copyright 2016 Square Inc.
*
* 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 flow;
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
public final class Traversal {
/** May be null if this is a traversal into the start state. */
@Nullable public final History origin;
@NonNull public final History destination;
@NonNull public final Direction direction;
private final KeyManager keyManager;
Traversal(@Nullable History from, @NonNull History to, @NonNull Direction direction,
KeyManager keyManager) {
this.origin = from;
this.destination = to;
this.direction = direction;
this.keyManager = keyManager;
}
/**
* Creates a Context for the given key.
*
* Contexts can be created only for keys at the top of the origin and destination Histories.
*/
@NonNull public Context createContext(@NonNull Object key, @NonNull Context baseContext) {
return new FlowContextWrapper(keyManager.findServices(key), baseContext);
}
@NonNull public State getState(@NonNull Object key) {
return keyManager.getState(key);
}
}