Re:

[Stefan Salewski <mail ssalewski de>]

On Wed, 2019-02-20 at 11:07 -0600, Igor Korot via gtk-list wrote:
> Hi, ALL,
> This link https://developer.gnome.org/gtk3/stable/GtkToolbar.html#Gtk
> Toolbar-popup-context-menu
> states that the parameter "button" can be "-1".
>
> What is the scenario when this occurs, i.e. it should be the button
> number that was clicked IIUC?
>
> Thank you for clarification.

Please use a more meaningful Subject next time.

And you may consider reading the API docs you linked to more carefully:

https://developer.gnome.org/gtk3/stable/GtkToolbar.html#GtkToolbar-popup-context-menu

"Emitted when the user right-clicks the toolbar or uses the
keybinding to display a popup menu."

So it seems to be obviously that button = -1 is the case when a
keybinding is used to display a popup menu. (Because for this case
there is no button involved.)

When you continue reading the API docs, it is even more clear:

"The mouse button number is given by the button parameter. If the menu
was popped up using the keybaord, button is -1."