Re: Mouse Event coordinates

[Huub Peters]

Steve Cookson wrote:

Hi Guys,

I have a small piece of code which displays a bitmap, then when you click
on the bitmap it should draw a circle round the point you clicked.

It works OK, except that it always returns (0, 0) as the coordinates of the mouse,

where-ever you click.

Where am I going wrong?

Here is the code.

Thanks in advance.

Regards

Steve

#!/usr/bin/perl -w --

use Wx 0.15 qw[:allclasses];
use strict;

package MyFrame;

use Wx qw[:everything];
use base qw(Wx::Frame);
use strict;
our $gl_self;
sub new {
 my( $self, $parent, $id, $title, $pos, $size, $style, $name ) = @_;
 $parent = undef              unless defined $parent;
 $id     = -1                 unless defined $id;
 $title  = ""                 unless defined $title;
 $pos    = wxDefaultPosition  unless defined $pos;
 $size   = wxDefaultSize      unless defined $size;
 $name   = ""                 unless defined $name;

 $style = wxDEFAULT_FRAME_STYLE
  unless defined $style;

$self = $self->SUPER::new( $parent, $id, $title, $pos, $size, $style, $name );

 $self->SetTitle("Drawing on image");

 $gl_self= $self; # Set Global variable for use in EVT handler

# Image for drawing on $self->{image1} = Wx::Image->new( 'C:set_your_own_bitmap.jpg', wxBITMAP_TYPE_ANY, -1 );

 $self->{Loc_Photo_Bmp} = Wx::Bitmap->new( $self->{image1} ) ;

$self->{bitmap_1} = my $static_bitmap = Wx::StaticBitmap->new( $self, -1, $self->{Loc_Photo_Bmp});

 $self->{bitmap_1}->SetCursor(wxCROSS_CURSOR);

# Button to draw image $self->{button_1} = Wx::Button->new($self, -1, "button_1");

 use Wx::Event qw(EVT_BUTTON  EVT_LEFT_UP EVT_LEFT_DOWN);
 EVT_LEFT_DOWN( $self->{bitmap_1}, \&on_button );
 EVT_LEFT_UP( $self->{bitmap_1}, \&on_button );

#
# Sizer
#

 $self->{sizer_1} = Wx::BoxSizer->new(wxVERTICAL);
 $self->{sizer_1}->Add($self->{bitmap_1}, 0, 0, 0);
 $self->{sizer_1}->Add($self->{button_1}, 0, 0, 0);
 $self->SetSizer($self->{sizer_1});
 $self->{sizer_1}->Fit($self);
 $self->Layout();

return $self;

}
sub on_button{

        my ($self, $event) = @_;
 # select it into a memory dc
       if (defined $gl_self->{Loc_Photo_Bmp}){
  my $mdc = Wx::MemoryDC->new();
  $mdc->SelectObject($gl_self->{Loc_Photo_Bmp});
  my $pen = Wx::Pen->new( Wx::Colour->new(255,255,255), 10, wxSOLID);
  $mdc->SetPen( $pen );
  $mdc->SetBrush( wxTRANSPARENT_BRUSH );
# Determine mouse event

You don't need this:

  my $m= Wx::MouseEvent->new($event);

  my $r = 50;

  my $x=$m->GetX();
  my $y=$m->GetY();

Replace this with:
 my $x=$event->GetX();
 my $y=$event->GetY();

# Draw circle round mouse event
  $mdc->DrawCircle( $x, $y, $r );
  $mdc->SelectObject(wxNullBitmap); # deselect the bitmap out of the DC
  $gl_self->{bitmap_1} ->SetBitmap($gl_self->{Loc_Photo_Bmp});
        }

$event->Skip() ;

 return $self;
}

1;


package main;

unless(caller){
 local *Wx::App::OnInit = sub{1};
 my $app = Wx::App->new();
 Wx::InitAllImageHandlers();

 my $frame_1 = MyFrame->new();

 $app->SetTopWindow($frame_1);
 $frame_1->Show(1);
 $app->MainLoop();
}

Untested but if memory serves me right the above patches should work.
Cheers,

Huub