drawing area and events win32

["jaykumar" <jaykumar mettatechnology com>]

Hi,
I am new to gtk development, currently I have used gtk -win32  version
2.6.7 for creating a video player.
the ui consists of few buttons ( in vbox1) and and a drawing area ( in
vbox2); and both boxes are packed in Hbox which is loaded in mainwindow.

problem statement:
        I had used expose event to display content of RGB buffer on drawing
area (darea), this event is emitted explicitly by a timer (according to
framerate) when completed rgb buffer loading.
       video playes smooth and continuous until I press any of the buttons
which are in other part of GUI ( vbox1)     leads to player crash with
following message from MS Windows:
       >>>>>>>>>>>>>>>>>>
       Gdk-ERROR **: file gdkgc-win32.c: line912 (gdk_win32_hdc_get):
assertion failed (win32_gc->hdc == NULL)
       aborting......   [ok]

  followed by

       Runtime error!
       program :    ......myprog.exe
       this program has requested Runtime to terminate it in a unusual way
.......:-D

       >>>>>>>>>>>>>>>>>>>windows as usual>>>>>>>>>

      when video is paused or not being played ( more better I can say no
expose events generated, say @30 fps).
       i had added fake handler for this unused events, but it had just
decreased rate of crash from per video played to 2/5 th.   :-(

I dont know if my code is a broken GTk program or i had missed few lines.

if some one can suggest clues


following is my code snippet:
---------------------------------------------------------------------
-------------------timer-------------
void CALLBACK onDisplayframe(int arg, BOOL TimerOrWaitFired)

{

g_signal_emit_by_name(GTK_OBJECT(darea),"expose_event", 0 );

}



-----------main program---------------
int main(int argc,char *argv[])

{

GtkWidget *play_button, *pause_button, *stop_button, *quit_button,
*open_button, *step_button, *text;

GtkWidget *vbox1_fixed, *hbox, *vbox1, *vbox2;

mainwindow = gtk_window_new (GTK_WINDOW_TOPLEVEL);

g_signal_connect (G_OBJECT (mainwindow), "destroy",G_CALLBACK (destroy),
NULL);

g_signal_connect_swapped (G_OBJECT (mainwindow), "delete_event",G_CALLBACK
(delete_event), NULL);

..........

darea = gtk_drawing_area_new();

gtk_container_add(GTK_CONTAINER(vbox1), darea);

gtk_drawing_area_size((GtkDrawingArea *)darea,890,590);

gtk_signal_connect(GTK_OBJECT (darea), "expose-event",GTK_SIGNAL_FUNC
(on_darea_expose), NULL);

gtk_widget_set_events (darea, GDK_EXPOSURE_MASK |GDK_LEAVE_NOTIFY_MASK
|GDK_BUTTON_PRESS_MASK);




open_button = gtk_button_new_with_label ("Open");

//g_signal_connect (G_OBJECT (open_button), "clicked",G_CALLBACK
(file_dialog), NULL);

g_signal_connect (G_OBJECT (open_button), "focus_in_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (open_button), "focus_out_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (open_button), "leave_notify_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (open_button), "button_release_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (open_button), "button_press_event",G_CALLBACK
(file_dialog), NULL);

gtk_widget_set_size_request (open_button, 100, 30);



play_button = gtk_button_new_with_label ("Play");

//g_signal_connect (G_OBJECT (play_button), "clicked",G_CALLBACK (OnPlay),
NULL);

g_signal_connect (G_OBJECT (play_button), "focus_in_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (play_button), "focus_out_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (play_button), "leave_notify_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (play_button), "button_release_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (play_button), "button_press_event",G_CALLBACK
(OnPlay), NULL);

gtk_widget_set_size_request (play_button, 100, 30);



repeat_button = gtk_check_button_new_with_label ("Repeat");

gtk_toggle_button_set_active((GtkToggleButton *)repeat_button,TRUE);

g_signal_connect (G_OBJECT (repeat_button), "clicked",G_CALLBACK
(OnRepeat),NULL);

g_signal_connect (G_OBJECT (repeat_button), "focus_in_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (repeat_button), "focus_out_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (repeat_button), "leave_notify_event",G_CALLBACK
(default_func), NULL);

gtk_widget_set_size_request (repeat_button, 100, 20);



pause_button = gtk_button_new_with_label ("Pause");

//g_signal_connect (G_OBJECT (pause_button), "clicked",G_CALLBACK (OnPause),
NULL);

g_signal_connect (G_OBJECT (pause_button), "focus_in_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (pause_button), "focus_out_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (pause_button), "leave_notify_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (pause_button), "button_release_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (pause_button), "button_press_event",G_CALLBACK
(OnPause), NULL);

gtk_widget_set_size_request (pause_button, 100, 30);




stop_button = gtk_button_new_with_label ("Stop");

//g_signal_connect (G_OBJECT (stop_button), "clicked",G_CALLBACK (OnStop),
NULL);

g_signal_connect (G_OBJECT (stop_button), "focus_in_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (stop_button), "focus_out_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (stop_button), "leave_notify_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (stop_button), "button_release_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (stop_button), "button_press_event",G_CALLBACK
(OnStop), NULL);

gtk_widget_set_size_request (stop_button, 100, 30);



quit_button = gtk_button_new_with_label ("Quit");

g_signal_connect (G_OBJECT (quit_button), "clicked",G_CALLBACK
(OnExit),NULL);

g_signal_connect_swapped (G_OBJECT (quit_button), "clicked",G_CALLBACK
(gtk_widget_destroy),G_OBJECT (mainwindow));

g_signal_connect (G_OBJECT (quit_button), "focus_in_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (quit_button), "focus_out_event",G_CALLBACK
(default_func), NULL);

g_signal_connect (G_OBJECT (quit_button), "leave_notify_event",G_CALLBACK
(default_func), NULL);

gtk_widget_set_size_request (quit_button, 100, 30);




gtk_widget_show (open_button);

gtk_widget_show (play_button);

gtk_widget_show (repeat_button);

gtk_widget_show (pause_button);

gtk_widget_show (step_button);

gtk_widget_show (stop_button);

gtk_widget_show (quit_button);

gtk_widget_show (vbox1_fixed);


gtk_box_pack_start(GTK_BOX(hbox), vbox1, FALSE, FALSE, 0);

gtk_widget_show(vbox1);


gtk_box_pack_end(GTK_BOX(hbox), vbox2, FALSE, FALSE, 0);

gtk_widget_show(vbox2);


gtk_container_add(GTK_CONTAINER(mainwindow), hbox);

gtk_widget_show(hbox);

gtk_widget_show(mainwindow);


gtk_main();

return 0;

}

------------------expose event handler------------

gboolean on_darea_expose (GtkWidget *widget, GdkEventExpose *event, gpointer
user_data)

{

gdk_draw_rgb_image(widget->window, widget->style->fg_gc[GTK_STATE_NORMAL],0,
0, mvsheader.colCount,mvsheader.rowCount,GDK_RGB_DITHER_MAX,
myrgbbuff_gfx.rgbbuffer, mvsheader.colCount * 3);

return TRUE;

}

------------------fake handler-------------------

BOOL default_func(void)

{

return TRUE;

}