What's the purpose of the GtkWidget.events property for (like) GtkTreeView widgets?

Question

I have a Glade GUI description file with a GtkTreeView in a GtkHBox in a window; and there's a handler for the row_activated signal. Now, Glade has automatically set the "events" property (inherited from GtkWidget) of that treeview to some value (GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK). And there are two strange things with this:

• removing the pre-set value (so that the property is empty) doesn't seem to break the application (at least not with the old GTK 2.10 I have atm).
• in fact, an annoying bug I has seen before (where the treeview items would not correctly react to expand or collapse clicks) is now gone!

I have yet to test this with a newer GTK version, but the question is already there: exactly what is the purpose for this events property? And why does Glade automatically and unnecessarily set it to some value? Does this have some side effects I'm not aware of?

Answer 1

It's a bug in glade, it always sets the event property of widgets it create. It has no notion of the default value of a property so it always sets it.

Answer 2

Doesn't this mask indicate the events you're willing to receive? In this case, you'll probably want to receive notification that the user has clicked or double-clicked an item in the GtkTreeView, and you'll want to register callbacks to handle these events.

Answer 3

me.yahoo.com/a/kUQ7zeQ: but even if I set the property to an empty string as mentioned, the row_activated handler is still called when I double-click on a row (or press Enter or Space). So the treeview still gets events...