Button highlight behavior changed on Froyo?

On Android 2.1, just as on most graphical computer OSes, pressing the mouse while in a button, then dragging away, then dragging back, then releasing (while within the button rectangle) would result in a button press. It would also highlight while the mouse pointer was within (or actually near) the button, going off as the pointer left the zone, then back on when the pointer returned.

This behavior allows the user to cancel, mid-press, by dragging away from the button until its highlight is off and releasing; it also allows the user to change her mind about cancelling, so long as the mouse is still down, and go back into the button to "rescue" the click.

In 2.2, it appears that Android no longer allows a return to the button. Dragging开发者_运维百科 away cancels the highlight, but returning with the mouse still held down does not re-highlight the button, nor does an away-and-return click generate a click event.

So, my questions: Is this change real (has anyone else seen it)? and: Is it intentional? What is the rationale for this change, if it is intentional?

Since I tested in an Android 4.0.4, I can guess this was intentional.

My guess is that they made the change to prevent some problems with people who are not used to touchable screens. It can also be to improve usability for people with disabilities. However, I'm not Google nor know the real reason of the change. Those were just my guesses.