I C. Its good to know for future development but right now neither saving or zooming are that important right now. Right now I have it so that the user can click and hold to pan, double click to add a waypoint, and when the waypoints are more than one they are connected by a line in sequence. But there are a few more things to do. Right now when there are three waypoints, a line connecting points 1 and 3 making it a circuit but when you add a fourth the previous line stays and then you get two circuits. Its hard to explain so you can get a screenshot here . The line from 3 to 1 should not be there. Any ideas on how to stop this from happening? Also I want the user to be able to remove the waypoints. Is it possible to drop the lines and waypoints into a hash and have canvas draw them after every event? This allows me to manipulate the objects with ease. 
 sub event_handler {
    my ( $widget, $event ) = @_;
    # print $widget ,' ',$event->type,"\n";
    
    #on 2 mouse presses, place waypoint 
    if ( $event->type eq "2button-press" ) {
        print 'x->',$event->x,'  ','y->',$event->y;
        
        #convert UTM to Lat and Long
        my $easting = $ps[0] * $event->x + 0.0 * $event->y + $mtp[3];
        my $northing = (-$ps[1]) * $event->y + 0.0 * $event->x + $mtp[
+4];
        my ($latitude,$longitude)=utm_to_latlon($ellipsoid,$zone,$east
+ing,$northing);
        print " ($latitude, $longitude)\n";
        
        #Drop icon
        my $tgroup = Gnome2::Canvas::Item->new ($root, 'Gnome2::Canvas
+::Group', x => $event->x, y => $event->y);
        Gnome2::Canvas::Item->new($tgroup, 'Gnome2::Canvas::Ellipse',
            x1 => -7.5,
            y1 => -7.5,
            x2 => 7.5,
            y2 => 7.5,
            fill_color => 'purple',
            outline_color => 'black');
        Gnome2::Canvas::Item->new ($tgroup,
            'Gnome2::Canvas::Text',
            "text", "$count",
            "x", 0.0,
            "y", 0.0,
            "font", "Sans Bold",
            "anchor", 'GTK_ANCHOR_NW',
            "weight", 100,
            "fill_color", 'red',
            "size_points", 20);
        
        
        #add waypoints
        $waypoints{$count } = {'x' => $event->x,'y' => $event->y, 'lat
+' => $latitude, 'long' => $longitude};
        print "size of hash:  " . keys( %waypoints ) . ".\n";
        #foreach my $num (sort keys %waypoints){
        #    print "$num = $waypoints{$num}\n";
        #    foreach my $subkey (sort keys %{$waypoints{$num}}){
        #        print "$subkey = $waypoints{$num}{$subkey}\n";
        #    }
        #}

        
        #draw lines to the waypoints
        if ($count >= 2){
            my @points;
            foreach my $key (sort keys %waypoints){
                foreach my $subkey (sort keys %{$waypoints{$key}}){
                    if ($subkey eq 'x' || $subkey eq 'y'){
                        push(@points, $waypoints{$key}{$subkey});
                        print "$key $subkey = $waypoints{$key}{$subkey
+}\n";
                    }
                    
                }
                
            }
            if ($count >= 3){
                push(@points, $waypoints{1}{'x'});
                push(@points, $waypoints{1}{'y'});
            }
            
            my $lgroup = Gnome2::Canvas::Item->new ($root, 'Gnome2::Ca
+nvas::Group');
            Gnome2::Canvas::Item->new ($lgroup,
                'Gnome2::Canvas::Line',
                points => [@points],
                fill_color => 'black',
                width_units => 4.0);
            
            foreach (@points){
                print $_, "\n";
            }   
        }
        #print $count, "\n";
        $tgroup->raise_to_top();
        $count++;
    }
}

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In reply to Re^6: geoTiff Application Building by deadpickle
in thread geoTiff Application Building by deadpickle

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