how to properly implement a Dialog box using libgdx

Question

I\'m struggling with implementing a dialog box in my program. The main program does not use stage. However when the users lives are at 0 I would like to popup a dialog that

Answer 1

The Dialog class is a little unintuitive without taking a closer look.

That's why I provide a small working example:

import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.ui.Dialog;
import com.badlogic.gdx.scenes.scene2d.ui.Skin;
import com.badlogic.gdx.utils.Timer;
import com.badlogic.gdx.utils.Timer.Task;

public class TestGame extends ApplicationAdapter
{
    Dialog  endDialog;

    Skin    skin;
    Stage   stage;

    @Override
    public void create()
    {
        skin = new Skin(Gdx.files.internal("uiskin.json"));

        stage = new Stage();

        Gdx.input.setInputProcessor(stage);

        endDialog = new Dialog("End Game", skin)
        {
            protected void result(Object object)
            {
                System.out.println("Option: " + object);
                Timer.schedule(new Task()
                {

                    @Override
                    public void run()
                    {
                        endDialog.show(stage);
                    }
                }, 1);
            };
        };

        endDialog.button("Option 1", 1L);
        endDialog.button("Option 2", 2L);

        Timer.schedule(new Task()
        {

            @Override
            public void run()
            {
                endDialog.show(stage);
            }
        }, 1);

    }

    @Override
    public void render()
    {
        Gdx.gl.glClearColor(1, 0, 0, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        stage.act();
        stage.draw();

    }

    @Override
    public void dispose()
    {
        stage.dispose();
    }
}

Each time you click on an Dialog option (option 1 or option 2) the result object is printed on the system.out (here 1L or 2L, can be any object) and the dialog is displayed again in 1 second.

The uiskin is taken from the libgdx tests.

To adapt it more to your needs you can change the result method to:

protected void result(Object object)
{
    if (object.equals(1L))
    {
        gameScreen.setIntLives(3);
        gameScreen.setIntScore(0);
        System.out.println("Button Pressed");
    } else {
        // Goto main menut
    }
};

And add the buttons like this:

endDialog.button("Retry", 1L);
endDialog.button("Main Menu", 2L);

---

Note that the Dialog class is only instantiated once. (so my comment was not correct)

---

Just to give you an idea on what you can do with it:

Since any object can be used you could use reflection:

try
{
    endDialog.button("doX",
            ClassReflection.getDeclaredMethod(this.getClass(), "doX"));
    endDialog.button("doY",
            ClassReflection.getDeclaredMethod(this.getClass(), "doY"));
} catch (ReflectionException e)
{
    // TODO Auto-generated catch block
    e.printStackTrace();
}

And the result method would look like:

protected void result(Object object)
{
    try
    {
        ((Method) object).invoke(TestGame.this);
    } catch (ReflectionException e)
    {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
};

Now you just need to implement these methods:

public void doX()
{
    System.out.println("doX");
}

public void doY()
{
    System.out.println("doY");
}

Just to give you a few ideas.