Hi Luca, have a look at this file: https://garage.maemo.org/plugins/scmsvn/viewcvs.php/trunk/conboy/src/fullscreenmanager.c?revision=517&root=conboy&view=markup
The creation of the overlay window is done in fullscreen_ui_create() and the cairo drawing on the window is in on_expose_event(). This code works. It creates a small semi-transparent window which is shown over the main window. I first clear the surface, then I draw a semi-transparent rectangle with a rounded upper-left corner and then I add a pixmap with an alpha channel. I think the most important parts are: - Setting the color map of the window. gtk_widget_set_colormap (widget, gdk_screen_get_rgba_colormap (screen)); - Clearing the cairo surface. cairo_set_operator (ctx, CAIRO_OPERATOR_CLEAR); cairo_paint (ctx); Hope that helps! Conny On Fri, 2009-10-30 at 14:36 +0100, Luca Donaggio wrote: > Thanks Conny and Kimmo, > > here are my progresses: > > I'm able to draw to the GtkWindow using Cairo only if I do it in a > callback attached to the expose event of the window itself, but I'm > still getting no transparency! > I'm sure this is the problem with the window manager that Kimmo > pointed out, but I don't know how to set the override-redirect flag > apart from passing the correct value inside a GdkWindowAttr struct > when manually creating a GdkWindow with gdk_window_new(), but I'm not > doing this manually, so I'm lost here! > > Luca Donaggio > > 2009/10/30 Kimmo Hämäläinen <kimmo.hamalai...@nokia.com> > On Thu, 2009-10-29 at 17:29 +0100, ext Luca Donaggio wrote: > > I'm trying to create a transparent, non-decorated popup > GtkWindow on > > top af my app HildonWindow and draw something on its > underlying > > GdkWindow object using cairo. > > All I was able to obtain so far is a black (or whatever is > the > > background colour of the selected theme) rectangle -ie it's > not > > transparent and everything I paint in its GdkWindow with > Cairo is not > > showed at all. > > > You may hit (at least) this hard-coded limitation: > http://maemo.gitorious.org/fremantle-hildon- > desktop/libmatchbox2/blobs/master/matchbox/core/mb-wm-client.c#line173 > > Currently alpha in dialogs and application windows is ignored > because it > allows for optimisations in the compositor. But if you set the > override- > redirect flag for the window, that should go around that > (because the > type of your window would be MBWMClientTypeOverride). > > -Kimmo > > > > Here is the code I'm using: > > > > void create_image_details(GtkWidget *callerobj,app_data_t > *myapp) { > > PangoLayout *textbuff; > > cairo_t *cr; > > gint x0, y0, r, txtwidth, txtheight; > > > > /* For the widget itself let's use a GtkWindow */ > > if ((myapp->imgparamwin != NULL) & GTK_IS_WINDOW(myapp- > > >imgparamwin)) gtk_widget_destroy(myapp->imgparamwin); > > myapp->imgparamwin = gtk_window_new(GTK_WINDOW_POPUP); > > gtk_window_set_decorated(GTK_WINDOW > (myapp->imgparamwin),FALSE); > > gtk_window_set_opacity(GTK_WINDOW > (myapp->imgparamwin),0); > > gtk_widget_set_app_paintable(myapp->imgparamwin,TRUE); > > gtk_widget_realize(myapp->imgparamwin); > > /* gdk_window_set_back_pixmap(myapp->imgparamwin- > > >window,NULL,FALSE); */ > > /* Get the Cairo context */ > > cr = gdk_cairo_create(GDK_DRAWABLE > (myapp->imgparamwin->window)); > > textbuff = pango_cairo_create_layout(cr); > > pango_layout_set_markup(textbuff,myapp->imgparam,-1); > > > pango_layout_get_pixel_size(textbuff,&txtwidth,&txtheight); > > /* Draw a rounded rectangle */ > > > > [cairo stuff is here] > > > > cairo_destroy(cr); > > g_object_unref(textbuff); > > /* Show the widget */ > > gtk_window_resize(GTK_WINDOW > (myapp->imgparamwin),txtwidth + (r * > > 2),txtheight + (r * 2)); > > gtk_window_move(GTK_WINDOW (myapp->imgparamwin),30,30); > > > gdk_window_reparent(myapp->imgparamwin->window,myapp->image- > > >window,30,30); > > gtk_widget_show_all(myapp->imgparamwin); > > } > > > > The window dimension after the gtk_window_resize() are > correct -ie the > > dimension of the PangoLayout containing the text to be > rendered, so > > something is definitely going on under the hood... but > nothing is > > displayed! > > If I add some widget to the popoup window (for example a > GtkLabel with > > some text in it), it's rendered correctly, but, of course > it's not > > transparent! > > > > Any help, as always, is much appreciated! > > > > Luca Donaggio > > > > _______________________________________________ > maemo-developers mailing list > maemo-developers@maemo.org > https://lists.maemo.org/mailman/listinfo/maemo-developers _______________________________________________ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
