Re: regarding gtk and x11 componenets
> I am trying to build gtk-directfb on phoneme …. Why do you assume people would know what "phoneme" is? > how to replace these with similar functions of gtk …… By asking for help on the Interwebs? Or by doing the research and coding required yourself? Which approach would you be more proud of? --tml ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
RE: how to draw something on GtkDrawingArea when I click a button?
As a matter of fact. I would suggest using Cairo. Which will allow you to then
draw in any context (IE Printer, PDF, etc...)
/* Local Variables */
cairo_t *cr;/* Rendering context derived from widget */
/* Get the context to which we need to draw */
cr = gdk_cairo_create(widget->window);
/* Printer context would be:
cr = gtk_print_context_get_cairo_context(context)
where context is a GtkPrinterContext* */
/* If we have a valid context draw valid object */
if (cr != NULL){
/* Boarder rectangle */
cairo_rectangle(cr, 0.00, 0.00, 20.0 , 40.0 );
cairo_stroke(cr);
cairo_set_line_width(cr,line_width / 60);
/* Virtical Seporation lines */
cairo_move_to(cr, 20.0 , 40.0 );
cairo_line_to(cr, 40.0, 40.0);
cairo_stroke(cr);
/* Distroy the context we created */
cairo_destroy(cr);
}
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> Subject: Re: how to draw something on GtkDrawingArea when I click a button?
> From: csaave...@gnome.org
> To: gtk-app-devel-list@gnome.org
> Date: Fri, 19 Mar 2010 08:46:33 +0200
>
> El vie, 19-03-2010 a las 13:34 +0800, Tolic Ma escribió:
> > Hi,everyone!
> >
> > I want to draw something on GtkDrawingArea when I click a GtkButton,but I
> > don't know how to do this...
> >
> > this is my code(it doesn't work...):
> >
> > *void click_button(void){
> >
> >
> > gdk_draw_line(drawing_area,drawing_area->style->white_gc,x,y,width+x,height+y);
> >
> > }
>
> You shouldn't draw directly in your callback for the button. Instead,
> you should call gtk_widget_queue_draw() to tell GTK+ to schedule a paint
> of the widget.
>
> How will the widget be painted? GTK+ will tell your code that the widget
> needs to be painted by emitting the GtkWidget::expose-event signal.
> Then, you should connect to that signal and paint in your callback.
>
> Last but no least, don't forget to paint to the GdkWindow of the drawing
> area, since that's the drawable.
>
> More or less (untested code, just for clarity):
>
> *void
> click_button(GtkButton *button, gpointer data)
> {
>button_clicked = TRUE;
>gtk_widget_queue_draw (drawing_area);
>...
> }
>
> gboolean
> expose_drawing_area (GtkWidget *area,
> GdkExposureEvent *event,
> gpointer data)
> {
>...
>if (button_clicked) {
> gdk_draw_line(drawing_area->window,
> drawing_area->style->white_gc,x,y,width+x,height+y);
>}
>...
> }
>
> int main(int argc,char *argv[]){
>...
>g_signal_connect(button,"clicked",G_CALLBACK(click_button),NULL);
>
> g_signal_connect(drawing_area,"expose-event",G_CALLBACK(expose_drawing_area),NULL);
>...
> }
>
>
> Claudio
>
> --
> Claudio Saavedra
>
> ___
> gtk-app-devel-list mailing list
> gtk-app-devel-list@gnome.org
> http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
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Re: how to draw something on GtkDrawingArea when I click a button?
On Fri, Mar 19, 2010 at 2:46 PM, Claudio Saavedra wrote:
> El vie, 19-03-2010 a las 13:34 +0800, Tolic Ma escribió:
> > Hi,everyone!
> >
> > I want to draw something on GtkDrawingArea when I click a GtkButton,but I
> > don't know how to do this...
> >
> > this is my code(it doesn't work...):
> >
> > *void click_button(void){
> >
> >
> >
> gdk_draw_line(drawing_area,drawing_area->style->white_gc,x,y,width+x,height+y);
> >
> > }
>
> You shouldn't draw directly in your callback for the button. Instead,
> you should call gtk_widget_queue_draw() to tell GTK+ to schedule a paint
> of the widget.
>
> How will the widget be painted? GTK+ will tell your code that the widget
> needs to be painted by emitting the GtkWidget::expose-event signal.
> Then, you should connect to that signal and paint in your callback.
>
> Last but no least, don't forget to paint to the GdkWindow of the drawing
> area, since that's the drawable.
>
> More or less (untested code, just for clarity):
>
> *void
> click_button(GtkButton *button, gpointer data)
> {
> button_clicked = TRUE;
> gtk_widget_queue_draw (drawing_area);
> ...
> }
>
> gboolean
> expose_drawing_area (GtkWidget *area,
> GdkExposureEvent *event,
> gpointer data)
> {
> ...
> if (button_clicked) {
> gdk_draw_line(drawing_area->window,
> drawing_area->style->white_gc,x,y,width+x,height+y);
> }
> ...
> }
>
> int main(int argc,char *argv[]){
> ...
> g_signal_connect(button,"clicked",G_CALLBACK(click_button),NULL);
>
> g_signal_connect(drawing_area,"expose-event",G_CALLBACK(expose_drawing_area),NULL);
> ...
> }
>
>
> Claudio
>
> --
> Claudio Saavedra
>
> ___
> gtk-app-devel-list mailing list
> gtk-app-devel-list@gnome.org
> http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
>
Thank you!
I solved my problem by following your instruction.
Thank you very much!!!
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Ho to use PangoContext returned by pango_xft_get_context()?
Hi All! If I try to use PangoContext returned by pango_xft_get_context() my application SegFault via uninitialized some internal pointer in PangoContext. But if I use gtk_widget_get_pango_context() - all work success. Any ideas or examples? \\wbr Vitaly Chernookiy ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
