id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	blockedby	blocking	branch_state	votes
3566	Split MSG_ACTION into MSG_ACTION and MSG_NOTIFY	mooffie	andrew_b	"MSG_ACTION is used to ask a widget to execute an action.

But it has also been hijacked to serve as a notification mechanism:

* WListbox uses it to signal the dialog that the selected item has changed.
* WCheckbox uses it similarly.
* WButtonbar uses it to ask a dialog to execute some action **or hand it to some other** widget.
* (Maybe there are more cases; see note below about 'grep'.)

So right now MSG_ACTION serves two different purposes. I suggest to create a new message, MSG_NOTIFY, and use it for the three cases above.

Advantages:

* It will make our code simpler. Currently, there's an ugly ""if (sender != NULL)"" in many MSG_ACTION handlers. (And writing a proper handler is tad tricky: programmers might return MSG_HANDLED, or the opposite, for any MSG_ACTION.)

* We'll be able to 'grep' the source for such notifications. Currently we can't: it's all mixed up."	task	closed	major	4.8.16	mc-core	master	fixed					merged	committed-master