decription of Java Game Development (LibGDX) | Request 3

http://youtube.com/LegitzDestroy asked for a way to memorize the concepts. In my opinion, a good way to do this is to remember the order of things you have to do to create a new Screen from scratch.

Short summary:
1: create class that implements Screen 00:58
2: create fields that you'll need: Stage, Skin 01:25
3: make sure to dispose everything in dispose() 04:38
4: make sure dispose() is called by putting it in hide() 05:43
5: clear the screen, update and render the stage in render() 06:14
6: resize the stage and optionally other things in resize() 07:39
5: set them in the show() method, basically create the menu there 09:45
5.1: stage = new Stage();
5.2: don't forget Gdx.input.setInputProcessor(stage);
5.2: skin = new Skin(Gdx.files.internal("ui/skinFile.json"), new TextureAtlas("ui/atlas.pack"));
5.3: create all the Actors you want
5.4: put actors in each other (e.g. buttons in table, table in stage)
5.5: put actors in the stage

Or like this:
--------------------
public class Concepts implements Screen {

    // 1. setup variables
    private Stage stage;
    private Skin skin;

    // 2. create objects
    @Override
    public void show() {
        stage = new Stage();
        skin = new Skin(Gdx.files.internal("ui/creditsSkin.json"), new TextureAtlas("ui/atlas.pack"));
    }

    // 3. dispose stuff
    @Override
    public void dispose() {
        stage.dispose();
        skin.dispose();
    }

    // 4. actually dispose
    @Override
    public void hide() {
        dispose();
    }

    // 5. render
    @Override
    public void render(float delta) {
        // 5.1 clear screen
        Gdx.gl.glClearColor(0, 0, 0, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        // 5.2 update
        stage.act(delta);

        // 5.3 draw
        stage.draw();
    }

    // 6. resize if needed
    @Override
    public void resize(int width, int height) {
        stage.setViewport(width, height, false);
    }

    @Override
    public void pause() {
    }

    @Override
    public void resume() {
    }

}

--------------------

Concept for the TweenEngine:
1. write Accessors (implementing TweenAccessor<Class>):
 - make a switch statement that takes tweenType
 - set returnValues to values of target / set attributes of target with newValues
2. create a TweenManager
 - tweenManger = new TweenManager(); // as simple as that
 - update it in render method: tweenManager.update(delta); // simple again
3. register TweenAccessors:
 - e.g. Tween.registerAccessor(Actor.class, new ActorAccessor());
4. create animations:
 - Tween.to(buttonPlay, ActorAccessor.ALPHA, 2).target(1).start(tweenManager); // alpha transparency goes to 1 in 2 seconds
 - Tween.from(buttonPlay, ActorAccessor.ALPHA, 2).target(0)).start(tweenManager); // alpha transpareny comes from 0 to what is has been before in 2 seconds
5. you can create Timelines:
 - Timeline.create[Sequence/Parallel]().begin[Sequence/Parallel]().push(animation).push(infinite_more_animations).end().start(tweenManager);

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Sorry for no uploads in a long time. If you want to know about the current progress, you can have a look at https://trello.com/b/Y3az2rtU/development.