Re: Various Gtk2::DrawingArea questions

[Kevin Ryde <user42 zip com au>]

Aaron Lewis <alewis1970 yahoo com> writes:
> I don't know how to detect the combination of mouse click +
> SHIFT/CTRL.

$event->state gives the "GdkModifierType" keys (per Gtk2::Gdk::Event).

> 3. I also want the user to be able to select multiple rectangles by
>    dragging the mouse across a portion of the DrawingArea.

I made a Gtk2::Ex::Lasso (on cpan).  It's "xor" based so depends on a
mostly single colour background but the drawing is fast.

It's basically button-press to start then motion-notify for the drag and
button-release to end.  But you might want to listen for Escape key or
something to abort a selection.

> 4. The call to Gtk2::Gdk::Drawable->draw_rectangle produces a
>    rectangle that's a different size, depending on whether it's filled
>    in, or not.

Yes.  That's an artifact of the x11 pixel rule "on the boundary left or
above".  It comes from an unfilled rectangle being a 1-wide line but
filled being a 0-wide boundary ... more or less.

> 7. It's pretty easy to set up tooltips for a Gtk2::Button or
>    Gtk2::Label, but I haven't had any luck with the drawing area
>    yet. I found a 'query_tooltip' signal but I can't get it to work,
>    nor can I find any perl scripts which do this job.

I think it's supposed to work.  $tooltip->set_text with whatever new
string you want to show.  Post a failing program if not.

You might prefer to show something in a statusbar as the mouse moves.
(In which case motion-notify-event and enter,leave.)

> 'pointer-motion-hint-mask',

Remember to $window->get_pointer() if using that.  Otherwise you don't
get any more motion events.



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