Hi,

It's not a Win32-GUI problem either - it's a windows thing. When a window is resized windows clears the area *before* the paint event is fired, resulting in that flash/flicker.

You can work around this by associating a class to the window (which, I think, from memory stops the event that clears the window):

my  $WC = new Win32::GUI::Class(
    -name => "test",
    -style => 0,
  );


then:

 $WIN = new Win32::GUI::Window(
 -left => 200, -top => 200, -width => 300, -height => 300,
 -name => "WIN",
 -text => "Static-DC-Test v3",
-class => $WC,
 #-noflicker => 1, # Will not work with the Paint-event
 );

and that should stop the flicker. I didn't test the above, but it should work:)

Cheers,

Jeremy.

> From: win32gui@rabanti.ch
> To: perl-win32-gui-users@lists.sourceforge.net
> Date: Fri, 13 Mar 2009 13:33:05 +0100
> Subject: [perl-win32-gui-users] WG: flickering static-DC
>
> Hi @ all
>
> Here is a sample-programm for displaying a static DC over a memory-DC.
> The sample is adapted from 'Region.pl'.
> Flickering while moving the window, or moving an other window over the DC is
> gone. Only while resizing the window, flickering appears. I think that is
> not a DC-problem, but a win32-gui-problem
>
> -----------------
> # proper displaying and refreshing of a static DC
> # Please see the demo 'Region.pl' for further explanations
> use strict;
> use Win32::GUI();
> our $WIN;
> our %DC;
> our @DATA; # Sample Data for the graph
>
> $DATA[0] = {'x' => 10, 'y' => 100};
> $DATA[1] = {'x' => 50, 'y' => 30};
> $DATA[2] = {'x' => 90, 'y' => 200};
> $DATA[3] = {'x' => 130, 'y' => 180};
> $DATA[4] = {'x' => 170, 'y' => 210};
> $DATA[5] = {'x' => 210, 'y' => 150};
>
> &build_gui; # Inizialize program
> Win32::GUI::Dialog();
>
> sub build_gui # Building the GUI
> {
> $WIN = new Win32::GUI::Window(
> -left => 200, -top => 200, -width => 300, -height => 300,
> -name => "WIN",
> -text => "Static-DC-Test v3",
> #-noflicker => 1, # Will not work with the Paint-event
> );
> $WIN->Show();
> # Defining the DC-styles
> $DC{'color'}{'white'} = [255,255,255];
> $DC{'color'}{'red'} = [255,0,0];
> $DC{'color'}{'grey'} = [100,100,100];
> $DC{'pen'} = new Win32::GUI::Pen( -color => $DC{'color'}{'red'}, -width =>
> 3, );
> $DC{'grid'} = new Win32::GUI::Pen( -color => $DC{'color'}{'grey'}, -width =>
> 1, );
> $DC{'brush'} = new Win32::GUI::Brush( -color => $DC{'color'}{'white'},
> -width => 1, );
> &repaint; # Generate the DC (first time)
> }
>
> sub WIN_Terminate { return -1; }
>
> sub WIN_Paint # re-/paint-event of the window
> { &repaint; }
>
> sub repaint # Create/rebuild DC-Object
> {
> # preparing the DC (memory-DC)
> $DC{'dc'}{'object'} = $WIN -> GetDC; # Creating DC
> $DC{'dc'}{'mem_object'} = $DC{'dc'}{'object'} -> CreateCompatibleDC(); #
> Creating compatible DC
> $DC{'dc'}{'bitmap'} = $DC{'dc'}{'object'} ->
> CreateCompatibleBitmap(250,250); # Creating compatible Bitmap
> $DC{'dc'}{'old_bitmap'} = $DC{'dc'}{'mem_object'} ->
> SelectObject($DC{'dc'}{'bitmap'}); # Selecting the bitmap into the new DC
>
> # Drawing into the memory-DC
> $DC{'dc'}{'mem_object'} -> FillRect(10, 10, 260, 260,$DC{'brush'});
> $DC{'dc'}{'mem_object'} -> SelectObject($DC{'grid'});
> for (my $i = 10;$i < 270; $i+=24) # Create y-grid
> {$DC{'dc'}{'mem_object'} -> Line(10,$i,250,$i);}
> for (my $i = 10;$i < 280; $i+=24) # Create x-grid
> {$DC{'dc'}{'mem_object'} -> Line($i,10,$i,260);}
>
> $DC{'dc'}{'mem_object'} -> SelectObject($DC{'pen'});
> $DC{'dc'}{'mem_object'} -> BeginPath();
> $DC{'dc'}{'mem_object'} -> MoveTo($DATA[0]{'x'}, $DATA[0]{'y'}); # Create
> graph (first point)
> for (my $i = 1;$i < scalar @DATA;$i++)
> { $DC{'dc'}{'mem_object'} -> LineTo($DATA[$i]{'x'}, $DATA[$i]{'y'}); } #
> Steps
> $DC{'dc'}{'mem_object'} -> EndPath();
> $DC{'dc'}{'mem_object'} -> StrokePath();
>
> $DC{'dc'}{'object'} -> BitBlt(10, 10, 250,250,$DC{'dc'}{'mem_object'}, 10,
> 10); # Updating the screen
> $DC{'dc'}{'mem_object'} -> SelectObject($DC{'dc'}{'old_bitmap'}); #
> Restoring original bitmap
> $DC{'dc'}{'mem_object'} -> DeleteDC(); # Removing the memory-DC
> }
> -----------------
> Hope, the mail-linebreaks don't messing up the code
>
> Greetings,
> Raphael
>
> -----Ursprüngliche Nachricht-----
> Von: Raphael Stoeckli [mailto:win32gui@....ch]
> Gesendet: Mittwoch, 11. März 2009 00:53
> An: 'zak3'
> Cc: perl-win32-gui-users@lists.sourceforge.net
> Betreff: Re: [perl-win32-gui-users] flickering static-DC
>
> Hi Zak
>
> I run probably an old version of ASPerl (5.8.6.811). There is an error, when
> I try to run test8.pl or test13.pl. Hook ‘Perl_newXS_flags’ was not found in
> perl58.dll. I think, I remained on 5.8.6.811, because of some
> PAR-compatibility-issues (most likely obsolote now). I will try it on an
> other machine with 5.8.8 or 5.10 the next days.
> My program works now pretty good, without much flickering, only with
> win32-GUI-corefunctions. I will also try to move my window-DC into a
> memory-DC the next days, as I said in my last post. I will post some
> sample-code when I finished that.
> To tell the truth, DIBitmap and GD frighten me a little bit. Is not that I
> don't understand it – already worked with DIBitmap intensively. But my
> program will be a standalone-binary for PCs without Perl. Even though
> 1TB-HDDs are on the advance, I am still skeptic if I have a binary of more
> than 3 or 4 MB in front of me, to run a really simple program. Maybe I am
> too conservative :-)
>
> Anyhow, much thanks for your hint. I will also study the two posts from
> mail-archive.com.
>
> Greetings,
> Raphael
>
> -----Ursprüngliche Nachricht-----
> Von: zak3 [mailto:zak31415@.....com]
> Gesendet: Montag, 9. März 2009 12:57
> An: perl-win32-gui-users@lists.sourceforge.net
> Betreff: Re: [perl-win32-gui-users] flickering static-DC
>
>
> Hi
> also look to this link about drawing and refreshing:
> http://www.nabble.com/Draw-on-click-and-refresh-the-window---resolved-td1809
> 3899.html
> and the two tutorials by rob may about drawing and refreshing:
> http://www.mail-archive.com/perl-win32-gui-users@lists.sourceforge.net/msg05
> 194.html
> http://www.mail-archive.com/perl-win32-gui-users@lists.sourceforge.net/msg05
> 195.html
>
> also before three days i have found an example in the win32gui demos :
> demos\DIBitmap\ the first is test8.pl and test13.pl they draw a circle
> without any flickering, they use GD graphics with DIBitmap, first install GD
> Graphics from this site:http://www.bribes.org/perl/ppmdir.html
> using the command:
> ppm install http://www.bribes.org/perl/ppm/GD.ppd
> and try the test8.pl and test13.pl, the GD graphics have many plotting
> statements for drawing lines, polygons, points, etc
>
>
> Raphael Stoeckli wrote:
> >
> > Hi @ all
> >
> > I try to plot a static DC-Object (means: the graphic is calculated
> > uniquely
> > at runtime, depending of several parameters, and does not change while
> > displaying the window) in a window.
> > The problem is that this object continuously needs to be redrawn, because
> > it
> > vanishes during moving the window around, or if an other window is moving
> > over it.
> > I thought, a repaint-routine like that would solve the problem:
> > -------------------------------------
> > use strict;
> > use Win32::GUI();
> > our $WIN;
> > our %DC;
> >
> > &build_gui;
> > Win32::GUI::Dialog();
> >
> > sub build_gui # Building the GUI
> > {
> > $WIN = new Win32::GUI::Window(
> > -left => 200, -top => 200, -width => 300, -height => 300,
> > -name => "WIN",
> > -text => "Static-DC-Test",
> > #-noflicker => 1, # Useless/worse result
> > );
> > $WIN->Show();
> > $DC{'color'}{'white'} = [255,255,255];
> > $DC{'color'}{'red'} = [255,0,0];
> > $DC{'pen'} = new Win32::GUI::Pen( -color => $DC{'color'}{'red'}, -width =>
> > 3, );
> > $DC{'brush'} = new Win32::GUI::Brush( -color => $DC{'color'}{'white'},
> > -width => 1, );
> > &repaint;
> > $DC{'timer'} = $WIN ->AddTimer("timer", 100);
> > }
> >
> > sub ::timer_Timer # Repaint DC with interval of 'timer'
> > { &repaint; }
> >
> > sub WIN_Terminate { return -1; }
> >
> > sub repaint # Create/rebuild DC-Object
> > {
> > $DC{'dc'}{'object'} = $WIN -> GetDC;
> > $DC{'dc'}{'object'} -> FillRect(10, 10, 280, 260,$DC{'brush'});
> > $DC{'dc'}{'object'} -> SelectObject($DC{'pen'});
> > $DC{'dc'}{'object'} -> BeginPath();
> > $DC{'dc'}{'object'} -> MoveTo(10, 10);
> > $DC{'dc'}{'object'} -> LineTo(280, 260);
> > $DC{'dc'}{'object'} -> EndPath();
> > $DC{'dc'}{'object'} -> StrokePath();
> > #$DC{'dc'}{'object'} -> Save(); # ??? Save() --> Restore() ???
> > }
> > -------------------------------------
> > But the result of the code above is a flickering, annoying graphic.
> > So the next thought, was to generate a bitmap from the DC. There is, if
> > I’m
> > not wrong, a method with DIBitmap. But, I would like to refrain from
> > binding
> > in that module, only for converting a single graphic, because it’s
> > bloating
> > up the program/PAR-binary.
> >
> >
> > Sadly, the DC-Documentation is frequent a sealed book for me.
> > Does anyone know an easy method (I also like to take a complex solution
> > :-))
> > to convert a DC into a bitmap-object, without using DIBitmap? Or, even
> > better, a way to prevent that flickering during the repaint?
> >
> > Thanks a lot.
> >
> > Regards,
> > Raphael
> >
> >
> >
> ----------------------------------------------------------------------------
> --
> > Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco,
> > CA
> > -OSBC tackles the biggest issue in open source: Open Sourcing the
> > Enterprise
> > -Strategies to boost innovation and cut costs with open source
> > participation
> > -Receive a $600 discount off the registration fee with the source code:
> > SFAD
> > http://p.sf.net/sfu/XcvMzF8H
> > _______________________________________________
> > Perl-Win32-GUI-Users mailing list
> > Perl-Win32-GUI-Users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/perl-win32-gui-users
> > http://perl-win32-gui.sourceforge.net/
> >
> >
>
> --
> View this message in context:
> http://www.nabble.com/flickering-static-DC-tp22404906p22411762.html
> Sent from the perl-win32-gui-users mailing list archive at Nabble.com.
>
>
> ----------------------------------------------------------------------------
> --
> _______________________________________________
> Perl-Win32-GUI-Users mailing list
> Perl-Win32-GUI-Users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/perl-win32-gui-users
> http://perl-win32-gui.sourceforge.net/
>
>
> ----------------------------------------------------------------------------
> --
> Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are
> powering Web 2.0 with engaging, cross-platform capabilities. Quickly and
> easily build your RIAs with Flex Builder, the Eclipse(TM)based development
> software that enables intelligent coding and step-through debugging.
> Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com
> _______________________________________________
> Perl-Win32-GUI-Users mailing list
> Perl-Win32-GUI-Users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/perl-win32-gui-users
> http://perl-win32-gui.sourceforge.net/
>
>
> ------------------------------------------------------------------------------
> Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are
> powering Web 2.0 with engaging, cross-platform capabilities. Quickly and
> easily build your RIAs with Flex Builder, the Eclipse(TM)based development
> software that enables intelligent coding and step-through debugging.
> Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com
> _______________________________________________
> Perl-Win32-GUI-Users mailing list
> Perl-Win32-GUI-Users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/perl-win32-gui-users
> http://perl-win32-gui.sourceforge.net/


Windows Live just got better. Find out more!