Timing issue seemed to be related to defining the frame smaller than the
sample graphic screen. It wasn't all being painted in one pass and the
capture was happening between paints. Defining the frame to be screen size
solved the problem.
James
Module Version of Screen Capture
-------------------------------------------------
use strict;
use warnings;
package WxScreenCapture;
use parent qw(Exporter);
our @EXPORT = qw(take_screenshot file_entry_dialog_simple
file_entry_dialog_standard);
use Wx qw(:everything);
use Wx::Event qw( EVT_PAINT );
#
# Copy the screen to the output file-similar to wxBook pg 139 example.
#
sub take_screenshot {
my($self, $file ) = @_;
$self->Refresh; # without Refresh and Update
$self->Update; # the underlying window is
captured
my $screen = Wx::ScreenDC->new();
my( $x, $y) = $screen->GetSizeWH();
my $bitmap = Wx::Bitmap->new($x,$y,-1);
my $memory = Wx::MemoryDC->new();
$memory->SelectObject( $bitmap );
$memory->Blit(0,0,$x,$y, $screen, 0, 0); # copy the screen
to the bitmap
$bitmap->SaveFile( $file , wxBITMAP_TYPE_BMP ) ; # copy the
bitmap to the output file
}
#
# Ask for the output filename - simple text entry dialog
#
sub file_entry_dialog_simple {
my( $self ) = @_;
my $textvalue = "capture.bmp";
my $dialog = Wx::TextEntryDialog->new
( $self, "Enter the Screen Capture output filename\n(Cancel will use
the default filename shown below)\n",
"Screen Capture Output File Entry",
$textvalue, wxOK | wxCANCEL );
if( $dialog->ShowModal == wxID_OK ) {
$textvalue = $dialog->GetValue;
}
$dialog->Destroy;
return $textvalue;
}
#
# Ask for the output filename - standard file dialog
#
sub file_entry_dialog_standard {
my ( $self ) = @_;
my $caption = "Choose a Screen Capture Output Filename";
my $wildcard = "*.bmp";
my $defaultDir = ".";
my $defaultFilename = "capture.bmp";
my $filevalue = $defaultFilename;
my $fileDialog = Wx::FileDialog->new($self, $caption, $defaultDir,
$defaultFilename, $wildcard, wxFD_SAVE |
wxFD_OVERWRITE_PROMPT);
if ($fileDialog->ShowModal() == wxID_OK ) {
$filevalue = $fileDialog->GetPath();
}
$fileDialog->Destroy;
return $filevalue;
}
1;
__END__
=head1 NAME
WxScreenCapture.pm
=head1 SYNOPSIS
Module to capture a screen to a file. Written in wxPerl.
=head1 DESCRIPTION
This module exports three subroutines: take_screenshot,
file_entry_dialog_simple, and file_entry_dialog_standard. take_screenshot
uses Wx::ScreenDC and Wx::MemoryDC device contexts and a Wx::Bitmap. Blit
copies the ScreenDC to the MemoryDC Bitmap which is then copied to an
output file. file_entry_dialog_simple provides a text_entry_dialog for
requesting the capture filename. file_entry_dialog_standard provides the
full directory/file entry screen for requesting the capture pathname.
If the frame you wish to capture is smaller than the full screen, the
background windows will also be captured.
=head1 USAGE
use Wx qw(:everything);
use Wx::Event qw( EVT_PAINT );
use WxScreenCapture;
my $app = Wx::SimpleApp->new;
my $frame = Wx::Frame->new(undef, -1, "Screen Capture Module Example",
[0,0], [1024,768] , wxDEFAULT_FRAME_STYLE);
EVT_PAINT( $frame, \&onPaint);
my $file = file_entry_dialog_standard($frame);
$frame->Show;
take_screenshot($frame, $file);
$app->MainLoop;
sub onPaint{} #paint the screen to be captured here.
=head1 AUTHOR
James M. Lynes, Jr. <jmlyne...@gmail.com>
Lakeland, Florida USA October 21,2012.
Original author: "PodMaster" from Perl Monks-2003 (no idea of real
identity-not active for 6+ years)
=head1 BUGS/FEATURES
To capture the complete sample graphic(not included in this module
definition), the frame size
had to be set to the screen size of [1024x768]. Using wxDefaultSize caused
the screen to paint in two passes
and the capture to clip. If the frame is not defined large enough, parts of
underlying
windows will also be captured.
=head1 SEE ALSO
"The wxBook" - Cross-Platform GUI Programming with wxWidgets -
Smart, Hock, and Csomor
The wxWidgets documentation L<http://www.wxwidgets.org/>
The Citrus Perl Distribution L<http://www.citrusperl.com/>
=head1 LICENSE
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
=cut
Test Calling Program
------------------------------
use strict;
use warnings;
use Wx qw(:everything);
use Wx::Event qw( EVT_PAINT );
use WxScreenCapture;
#
# Main Application
#
my $app = Wx::SimpleApp->new;
my $frame = Wx::Frame->new(undef, -1, "Screen Capture Module Example",
[0,0], [1024,768] , wxDEFAULT_FRAME_STYLE);
EVT_PAINT( $frame, \&onPaint);
my $file = file_entry_dialog_standard($frame);
$frame->Show;
take_screenshot($frame, $file);
$app->MainLoop;
#
# Generate a sample graphic screen to capture
#
sub onPaint{
my($self,$event)=@_;
my $screen = Wx::PaintDC->new($self);
$screen->SetBackgroundMode( wxTRANSPARENT );
$screen->SetFont(Wx::Font->new( 12, wxFONTFAMILY_ROMAN, wxNORMAL,
wxBOLD));
for(0..17){
my $c = $_ * 15;
$screen->SetTextForeground( Wx::Colour->newRGB(0,0,$c));
$screen->DrawRotatedText("wxPerl",100 ,100 ,$c);
}
$screen->DrawRotatedText("wxPerl and PodMaster",000 ,400
,0);
$screen->DrawRotatedText("are messing up your screen",000
,450 ,0);
for(0..17){
my $c = $_ * 15;
$screen->SetTextForeground( Wx::Colour->newRGB(0,$c,0));
$screen->DrawRotatedText("wxPerl",200 ,200 ,$c);
}
$screen->DrawRotatedText("wxPerl and PodMaster",100 ,500
,0);
$screen->DrawRotatedText("are messing up your screen",100
,550 ,0);
for(0..17){
my $c = $_ * 15;
$screen->SetTextForeground( Wx::Colour->newRGB($c,0,0));
$screen->DrawRotatedText("wxPerl",300 ,300 ,$c);
}
$screen->DrawRotatedText("wxPerl and PodMaster",200 ,600
,0);
$screen->DrawRotatedText("are messing up your screen",200
,650 ,0);
}
