What's the name of the little widget with three dots inside a cardview in android?

Question

What\'s the little widget with three dots? How can I add it to my app?

Answer 1

The "original" three dot widget is the android.widget.ActionMenuPresenter.OverflowMenuButton (ActionMenuPresenter.java). Sadly it is a private class. Here a working shorter version:

public class OverflowMenuButton extends AppCompatImageView
{
    public OverflowMenuButton(Context context)
    {
        this(context, null);
    }

    public OverflowMenuButton(Context context, AttributeSet attrs)
    {
        this(context, attrs, 0);
    }

    public OverflowMenuButton(Context context, AttributeSet attrs, int defStyleAttr)
    {
        super(new ContextThemeWrapper(context, R.style.OverflowButtonTheme), attrs, R.attr.actionOverflowButtonStyle);

        setClickable(true);
        setFocusable(true);
        setVisibility(VISIBLE);
        setEnabled(true);
    }
}

Themes of the ContextThemeWrapper to get a dark and light version: