How to add the dropdown menu in ActionMode's contextual menu

Question

I want to add a dropdown menu in ActionMode which looks like the one in Android's official Gallery app, it allows you to 'select all' or 'deselect all' images. As seen in the picture below:

The only way I found is using custom view by calling setCustomView and doing all the other stuffs by myself. But I believe there must be some native method to enable this feature, can any one give any ideas?

Answer 1

Well, I got it finally. The drop down menu is added by calling setCustomView, it replaced the default TextView.

I thought that method would replace the whole ActionMode view, what a low-level mistake.