libgdx loader example

package com.nizarium.mygame;

import android.os.Handler.Callback;
import android.os.Message;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Input.Keys;
import com.badlogic.gdx.files.FileHandle;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.TextureData;
import com.badlogic.gdx.graphics.Pixmap.Format;
import com.badlogic.gdx.graphics.TextureData.TextureDataType;
import com.badlogic.gdx.graphics.g2d.BitmapFont.TextBounds;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.badlogic.gdx.scenes.scene2d.Stage;

public class StageLoading extends GameStage
{
    private Callback onLoaded;

    public StageLoading(float width, float height, boolean stretch,
            GameMain main)
    {
        super(width, height, stretch, main);

        init();
    }

    private void init()
    {
        Pixmap blankPixmap = new Pixmap(1, 1, Format.RGBA8888);
        blankPixmap.setColor(1, 1, 1, 1);
        blankPixmap.drawPixel(0, 0);

        final Texture blank = new Texture(blankPixmap);

        this.addActor(new Actor("background")
        {
            @Override
            public Actor hit(float x, float y)
            {
                return null;
            }

            @Override
            public void draw(SpriteBatch batch, float parentAlpha)
            {
                final String loadingStr = "Loading";

                batch.draw(main.getGuiBackground(),
                        this.getStage().centerX() - main.getGuiBackground().getWidth()
                                * 0.5f,
                        this.getStage().centerY() - main.getGuiBackground().getHeight()
                                * 0.5f, main.getGuiBackground().getWidth(),
                                main.getGuiBackground().getHeight(), 0, 0, 1, 1);

                TextBounds bounds = main.getFont().getBounds(loadingStr);
                main.getFont().draw(batch, loadingStr,
                        this.getStage().centerX() - bounds.width * 0.5f,
                        this.getStage().centerY() - bounds.height);

                batch.draw(blank, 0, height() - 5, width() * main.getManager().getProgress(), 5);
            }
        });
    }

    @Override
    public void act(float delta)
    {
        super.act(delta);

        if (main.getManager().getProgress() == 1)
        {
            for (GameData.ObjectTypeData data : GameData.objects.values())
            {
                data.init(main);
            }

            if (onLoaded != null)
                onLoaded.handleMessage(new Message());
        }
    }

    @Override
    public boolean keyDown(int keycode)
    {
        if (keycode == Keys.BACK)
        {
            System.exit(0);
            return true;
        }

        return super.keyDown(keycode);
    }

    public Callback getOnLoaded()
    {
        return onLoaded;
    }

    public void setOnLoaded(Callback onLoaded)
    {
        this.onLoaded = onLoaded;
    }
}