perl tk canvas events hiding

[ori1139]

Hi.
I'm new to PerlTk.
What I'm trying to achieve is getting the message "oval was pressed" even when I press the rectangle.

Below there a simplified version of the code.

require v5.8.5;

use Tk;
my $window = MainWindow->new;
my $drawing = $window->Canvas(-width => 400, -height => 300, -background => "white") -> pack;

$ov = $drawing->createOval(100,50,300,250,-fill=>"black");
$rec = $drawing->createRectangle(150,100,250,200,-fill=>"white");

$drawing-> bind( $ov, '<Button-1>',sub{$window -> messageBox(-type=>"ok", -message=>"oval was pressed");});

MainLoop;


Thanks!

 

[PinkeyNBrain]

Wouldn't you just need an additional bind?

$drawing-> bind( [u]$rec[/u], '<Button-1>',sub{$window -> messageBox(-type=>"ok", -message=>"oval was pressed");});

 

[ori1139]

The code I've posted is just a simplified version of what I really need to do.

What I'm really trying to do is to draw a map with layer of information. The problem is that for example lines from the grid of the map hide events from the layer beneath them.


Thanks

Ori

 

[PinkeyNBrain]

Haven't worked with canvas's much but this idea may work:

Instead of putting the bind on the shape, add a bind to the canvas. The routine the canvas calls can pick up your @x,@y values and map that against the area with in all of your shapes. Wouldn't be efficient, but would get things done if you don't have 1000's of shapes.

I don't know if the canvas widget provides a calculator that will provide a clean yes/no to this (I'm thinking of the TclTk's text widget that does provides a comparable function) The mathematical formulas to calculate this on the fly aren't too bad, but could be problematic to maintain if your shapes become non-geometrical.

 

[ori1139]

This is eventually what I did. I was just wondering if there is some other more elegant way to do it. Any way this is the way I calculated the corrected position of y-Axe:



$self->{canvas}->CanvasBind("<Button-3>", [ \&popup_menu, Ev1('%y') ]);

sub popup_menu
{
my ($canv, $y) = @_;
my $offsetY = $canv->canvasy(0);
$corrected_y =$offsetY+ $y;
print "popup corrected y ".$corrected_y;
}