usage of StateListDrawable

StateListDrawableTest.java

import android.app.Activity;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.StateListDrawable;
import android.os.Bundle;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;

public class StateListDrawableTest extends Activity {
   @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        Button button = new Button(this);
        button.setText("click!");
        button.setBackgroundDrawable(getStateListDrawable());
        addContentView(button, new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));
    }
    
    private static Drawable getStateListDrawable() {
        StateListDrawable drawable = new StateListDrawable();
        
        int pressed = android.R.attr.state_pressed;
        drawable.addState(new int[]{pressed}, new ColorDrawable(Color.RED));
        drawable.addState(new int[]{-pressed}, new ColorDrawable(Color.BLUE));
        
        return drawable;
    }
}