android - libGDX Alert Dialog

Question

I have used code below:

 AlertDialog.Builder bld;

 if (android.os.Build.VERSION.SDK_INT <= 10) {
     //With default theme looks perfect:
     bld = new AlertDialog.Builder(AndroidLauncher.this);
 } else {
     //With Holo theme appears the double Dialog:
     bld = new AlertDialog.Builder(AndroidLauncher.this, android.R.style.Theme_Holo_Dialog_MinWidth);
 }

 bld.setIcon(R.drawable.ic_launcher);
 bld.setTitle("Exit");
 bld.setMessage("Are you sure you want to exit?");
 bld.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
     @Override
     public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); }
 });
 bld.setPositiveButton("Exit", new DialogInterface.OnClickListener() {
     @Override
     public void onClick(DialogInterface dialog, int which) { finish(); }
 });
 bld.setCancelable(false);
 bld.create().show();

It seems fine, but it says "import android.app.AlertDialog cannot resolve". It is a standard libGDX project in Android Studio.

Answer 1

In libgdx you should use a scene2d dialog instead of the native Android DialogInterface. Below is how you would add a completely skinned dialog to the stage in libgdx with custom button images and background image. You would just need to substitute your own background and button image textures and font, then call quitGameConfirm() when you're ready to display the dialog...

import com.badlogic.gdx.scenes.scene2d.ui.Dialog;

public void quitGameConfirm() {

    LabelStyle style = new LabelStyle(_fontChat, Color.WHITE);
    Label label1 = new Label("Are you sure that you want to exit?", style);
    label1.setAlignment(Align.center);
    //style.font.setScale(1, -1);
    style.fontColor = Color.WHITE;

    Skin tileSkin = new Skin();
    Texture tex = new Texture(myButtontexture);
    tex.setFilter(TextureFilter.Linear, TextureFilter.Linear);
    tileSkin.add("white", tex);
    tileSkin.add("default", new BitmapFont());

    TextButton.TextButtonStyle textButtonStyle = new TextButton.TextButtonStyle();
    textButtonStyle.up = tileSkin.newDrawable("white");
    textButtonStyle.down = tileSkin.newDrawable("white", Color.DARK_GRAY);
    textButtonStyle.checked = tileSkin.newDrawable("white",
            Color.LIGHT_GRAY);
    textButtonStyle.over = tileSkin.newDrawable("white", Color.LIGHT_GRAY);
    textButtonStyle.font = _myTextBitmapFont;
    textButtonStyle.font.setScale(1, -1);
    textButtonStyle.fontColor = Color.WHITE;
    tileSkin.add("default", textButtonStyle);

    TextButton btnYes = new TextButton("Exit", tileSkin);
    TextButton btnNo = new TextButton("Cancel", tileSkin);

    // /////////////////
    Skin skinDialog = new Skin(Gdx.files.internal("data/uiskin.json"));
    final Dialog dialog = new Dialog("", skinDialog) {
        @Override
        public float getPrefWidth() {
            // force dialog width
            // return Gdx.graphics.getWidth() / 2;
            return 700f;
        }

        @Override
        public float getPrefHeight() {
            // force dialog height
            // return Gdx.graphics.getWidth() / 2;
            return 400f;
        }
    };
    dialog.setModal(true);
    dialog.setMovable(false);
    dialog.setResizable(false);

    btnYes.addListener(new InputListener() {
        @Override
        public boolean touchDown(InputEvent event, float x, float y,
                int pointer, int button) {

            // Do whatever here for exit button

            _parent.changeState("StateMenu");
            dialog.hide();
            dialog.cancel();
            dialog.remove();                

            return true;
        }

    });

    btnNo.addListener(new InputListener() {
        @Override
        public boolean touchDown(InputEvent event, float x, float y,
                int pointer, int button) {

            //Do whatever here for cancel

            dialog.cancel();
            dialog.hide();

            return true;
        }

    });

    TextureRegion myTex = new TextureRegion(_dialogBackgroundTextureRegion);
    myTex.flip(false, true);
    myTex.getTexture().setFilter(TextureFilter.Linear, TextureFilter.Linear);
    Drawable drawable = new TextureRegionDrawable(myTex);
    dialog.setBackground(drawable);

    float btnSize = 80f;
    Table t = new Table();
    // t.debug();

    dialog.getContentTable().add(label1).padTop(40f);

    t.add(btnYes).width(btnSize).height(btnSize);
    t.add(btnNo).width(btnSize).height(btnSize);

    dialog.getButtonTable().add(t).center().padBottom(80f);
    dialog.show(stage).setPosition(
            (MyGame.VIRTUAL_WIDTH / 2) - (720 / 2),
            (MyGame.VIRTUAL_HEIGHT) - (MyGame.VIRTUAL_HEIGHT - 40));

    dialog.setName("quitDialog");
    stage.addActor(dialog);

}