Aw: Motion events in a DrawingArea

[max augsburg gmx de]

Dear Dan,

 

I think the simplest solution would be to use my GooCanvas2 module (see https://metacpan.org/pod/GooCanvas2 ). The module works exactly as the C Api (it's a pure Glib::IO binding). Therefore https://developer.gnome.org/goocanvas/unstable/ is a good starting point... Especially the GooCanvas2::CanvasItem has an item press event and such things: https://developer.gnome.org/goocanvas2/stable/GooCanvasItem.html#GooCanvasItem-button-press-event

 

Perhaps this is helpful...

 

The Gtk3 canvas element (from which I think DrawingArea inherits its painting capabilities) is hard to handle for event purposes...

 

Best wishes,

Max

 

 

Gesendet: Mittwoch, 16. August 2017 um 14:12 Uhr
Von: "Daniel Kasak" <d j kasak dk gmail com>
An: "gtk-perl mailing list" <gtk-perl-list gnome org>
Betreff: Motion events in a DrawingArea

Hi all.

I'm trying to capture mouse events in a DrawingArea ( in Gtk3 ). I'm
adapting code at http://www.perlmonks.org/?node_id=583578 ... but when
I go:

$self->{drawing_area}->set_events(
[ qw/ exposure-mask
leave-notify-mask
button-press-mask
pointer-motion-mask
pointer-motion-hint-mask
/
]
);

... I get a warning:

Gtk-CRITICAL **: gtk_widget_set_events: assertion
'!_gtk_widget_get_realized (widget)' failed

I've tried putting this later on in the code when I guess the widget
*should* be realized, eg at the end of the render_graph() method which
I hook up thus:

$self->{drawing_area}->signal_connect( draw => sub {
$self->render_graph( @_ ) } );

... but it still gives the same error.

Next I try to connect to a signal handler anyway:

$self->{drawing_area}->signal_connect(
'motion_notify_event'
, sub { $self->handle_graph_mouse_move( @_ ) }
);

... but this handler never gets called.

I guess things have changed in Gtk3? I haven't been able to find an
updated demo, even in C. Any hints as to what I'm missing?

Dan
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