kr9ly/trout

Trout state holder and change notifier.

Trout - state holder and change notifier

Trout state holder and change notifier.

Usage

Add this to repositories block in your build.gradle

maven { url 'http://kr9ly.github.io/maven/' }

And Add this to dependencies block in your build.gradle

compile 'net.kr9ly:trout:0.0.1'

Basic

1. Create interface for state get/set.

public interface SampleState {

    @Getter("foo") // annotate by net.kr9ly.trout.Getter
    String getFoo();
    
    @Setter("foo") // annotate by net.kr9ly.trout.Setter
    void setFoo(String foo);
    
    @Getter("bar")
    int getBar();
        
    @Setter("bar")
    void setBar(int bar);
}

2. Create StateManager.

StateManager manager = StateManager.newRoot();

3. Update State.

SampleState state = manager.getState(SampleState.class);
state.setFoo("sample");
state.setBar(1);

SampleState another = manager.getState(SampleState.class);
 // no state updates before commit
assert "sample".equals(another.getFoo()) == false;
assert 1 != another.getBar();

4. Commit State.

manager.commit();

5. Get Updated State.

SampleState updated = manager.getState(SampleState.class);
assert "sample".equals(updated.getFoo());
assert 1 != updated.getBar();

Subscribe State Update

1. Create Subscriber.

public class SampleSubscriber {

    @OnUpdate("foo")
    public void onFooUpdated() {
        System.out.println("Updated foo.");
    }
    
    @OnUpdate("bar")
    public void onFooUpdated() {
        System.out.println("Updated bar.");
    }
}

2. Subscribe State Update.

manager.subscribe(SampleState.class, new SampleSubscriber());
SampleState state = manager.getState(SampleState.class);
state.setFoo("updated");
state.setBar(1);
manager.commit();
// -> "Updated foo."
// -> "Updated bar."
state.setFoo("updated");
manager.commit();
// no callback if no state change.

Get Parent State

StateManager root = StateManager.newRoot();
StateManager child = root.newChild();

SampleState state = root.getState(SampleState.class);
state.setFoo("parent state");

SampleState childState = child.getState(SampleState.class);

root.commit();

assert "parent state".equals(childState.getFoo());

StateManager root = StateManager.newRoot();
StateManager child = root.newChild();

SampleState state = root.getState(SampleState.class);
state.setFoo("parent state");

child.subscribe(SampleState.class, new SampleSubscriber());

root.commit();
// -> "Updated foo."

License

Copyright 2015 kr9ly

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.