setAlphaSliderVisible() not working properly

[mianaliasjad]

if i set alpha slider visibility through XML then it works as intended. But when i set it when colorPicker view is shown then it does not work. i am setting on a button click but it is not doing anything.
Scenario:
in XML make app:cpv_alphaChannelVisible="false" and in code on button click colorPickerView.setAlphaSliderVisible(true);