What is the ButtonBarLayout and how should we use it?

Question

When I developed, I found a new widget called android.support.v7.widget.ButtonBarLayout unexpectedly. I tried to search it on the internet, but nothing was found, e

Answer 1

The source code describes ButtonBarLayout as follows:

/**
 * An extension of LinearLayout that automatically switches to vertical
 * orientation when it can't fit its child views horizontally.
 */

So, in essence, it is nothing but a smart LinearLayout which manages auto-switching orientations based on available space on screen.

The same ButtonBarLayout.java file describes mAllowStacking in comments as follows:

/** Whether the current configuration allows stacking. */

Source Code Here