Checking types of objects in signal handlers

Desktop Ruby-Gnome 2
1

in the example on
http://ruby-gnome2.sourceforge.jp/hiki.cgi?Gtk%3A%3AMenu
it says:

window.signal_connect(“button_press_event”) do |widget, event|
if event.kind_of? Gdk::EventButton
if (event.button == 3)
menu.popup(nil, nil, event.button, event.time)
end
end
end

isn’t the event.kind_of? test redundant, or is this test something
all signal handlers should be doing?

martin

2

Seems redundant to me since the signal is only emitted
if the button was pressed. But maybe the additional
check is important to ensure that something is a
Gdk::EventButton (but i cant think of a reason, maybe
someone could add a # comment that explains this briefly)

Also I think using :button_press_event would be nicer and
the

if (event.button == 3)

() parens arent needed afaik

Martin P. wrote:

in the example on
http://ruby-gnome2.sourceforge.jp/hiki.cgi?Gtk%3A%3AMenu
it says:

window.signal_connect(“button_press_event”) do |widget, event|
if event.kind_of? Gdk::EventButton
if (event.button == 3)
menu.popup(nil, nil, event.button, event.time)
end
end
end

isn’t the event.kind_of? test redundant, or is this test something
all signal handlers should be doing?

martin

3

Hi,

On Wed, 03 Oct 2007 10:39:16 +0100
Martin P. [email protected] wrote:

isn’t the event.kind_of? test redundant, or is this test something
all signal handlers should be doing?

Sure. You don’t need this here.
I removed this from the tutorial.

BTW, if you use “event” instead of “button_press_event”,
you’ll need to check kind_of?.

window.signal_connect(“event”) do |widget, event|
if event.kind_of? Gdk::EventButton
if (event.button == 3)
menu.popup(nil, nil, event.button, event.time)
end
end
end

–
.:% Masao M.[email protected]