libgdx button up down no effect - button

Question

val playTexture = assetManager?.get(A.image.gamePlayBtn, Texture::class.java)
val skin: Skin = Skin()
skin.add("up", TextureRegion(playTexture, 0, 0, 296, 96))
skin.add("down", TextureRegion(playTexture, 0, 96, 296, 96))
val playButton: ImageTextButton = ImageTextButton("PLAY THE GAME", with(ImageTextButton.ImageTextButtonStyle()) {
up = skin.getDrawable("up")
down = skin.getDrawable("down")
font = BitmapFont()
font.data.setScale(3f)
font.color = Color.ORANGE
this
})
OnClick events work ok, but there is no button background change for onClicked state(down). Where I'm wrong?

Answer 1

I've tested your code, that's working fine. Added complete text code :
class Main : ApplicationAdapter(){
internal lateinit var stage: Stage
override fun create() {
stage= Stage()
stage.setDebugAll(true)
Gdx.input.setInputProcessor(stage)
var skin= Skin()
var tex1 =Texture("badlogic.jpg")
skin.add("up", TextureRegion(tex1, 0, 0, 100, 50))
skin.add("down", TextureRegion(tex1, 0, 96, 100, 50))
var playButton: ImageTextButton = ImageTextButton("Play The Game", with(ImageTextButton.ImageTextButtonStyle()){
up = skin.getDrawable("up")
down = skin.getDrawable("down")
font = BitmapFont()
font.data.setScale(3f)
font.color = Color.ORANGE
this
});
playButton.setPosition(0F,100F)
playButton.addListener(object : ClickListener(){
override fun clicked(event: InputEvent?, x: Float, y: Float) {
print("clicked")
super.clicked(event, x, y)
}
})
stage.addActor(playButton)
}
override fun render() {
Gdx.gl.glClearColor(1f, 0f, 0f, 1f)
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT)
stage.draw()
stage.act()
}
}

Answer 2

You have to update your button.
There is updateImage() function, but its protected so u have to do it using Stage.
So here is what u do:
Create stage.
Add your button to stage.
Call stage.draw() in render function.
...
Stage stage = new Stage();
//create button
stage.addActor(playButton);
...
#Override
public void render() {
stage.draw();
}