Using the blur property for applications

[FunkyM]

I have modified the gnome-main-menu (http://svn.gnome.org/viewcvs/gnome-main-menu/trunk/) to support composited drawing.
Additionally, I wanted to blur the transparent parts with the compiz blur hint which seems to fail.

The related code is simply:
if(priv->have_alpha) {
long data[2];
data[0] = 2; /* threshold */
data[1] = 0; /* filter */

XChangeProperty (
xdisplay,
GDK_WINDOW_XID (priv->slab_window->window),
XInternAtom (xdisplay, "_COMPIZ_WM_WINDOW_BLUR", FALSE),
XA_INTEGER,
32,
PropModeReplace, (guchar *) data,
2);
}

Any ideas why it doesn't work? Maybe due to the window being created with glade?

The patches for the change are available here (http://bugzilla.gnome.org/show_bug.cgi?id=419840) and currently it looks like this (note the terminal with blur):

http://media.sukimashita.com/temp/10-gnome-main-menu-2.png

[wfarr]

Nice start.


I'd be even more excited if the GNOME people included Recently Used Applications support so I didn't have to disable it on my SLAB built from SVN on Ubuntu. =/

[lowfi]

You have to enable alpha_blur otherwise it won't work. Setting the blur atom doesn't make any difference. It's only useful if want a specific region to be blurred and not the whole transparent area or if you want a different filter for your window (but i think compiz just ignores the filter type atm).

[lowfi]

Here is some demo code which uses regions.

And i think i found a bug in the blur plugin. If i move the transparent window over a firefox window, the region suddenly doesn't work anymore and whole window becomes blurred. If i move the window to another position above the firefox window the region works again. Very strange.

Maybe it's a bug in my app, but that's unlikely :)

Can somebody confirm this?

#include <gtk/gtk.h>
#include <gdk/gdkx.h>
#include <X11/Xlib.h>
#include <X11/Xatom.h>

#define GRAVITY_NORTHWEST ((1 << 0) | (1 << 2))
#define BLUR_REGION TRUE

static gboolean
expose (GtkWidget *win, GdkEventExpose *eev, gpointer rect)
{
cairo_t *cr;

cr = gdk_cairo_create (win->window);
cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
cairo_set_source_rgba (cr, 1.0, 1.0, 1.0, 0.5);
cairo_paint (cr);

cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
gdk_cairo_rectangle (cr, (GdkRectangle *) rect);
cairo_fill_preserve (cr);
cairo_set_source_rgba (cr, 0.0, 0.5, 1.0, 0.8);
cairo_stroke (cr);

cairo_destroy (cr);

return TRUE;
}

static void
set_compiz_blur (GdkWindow *window, GdkRectangle *rect)
{
Display *dpy;
long data [8];
guint n = 0;

dpy = GDK_DISPLAY_XDISPLAY(gdk_display_get_default ());

data[n++] = 2;
data[n++] = 0;

if (rect) {
data[n++] = GRAVITY_NORTHWEST;
data[n++] = rect->x;
data[n++] = rect->y;
data[n++] = GRAVITY_NORTHWEST;
data[n++] = rect->x + rect->width;
data[n++] = rect->y + rect->height;
}

XChangeProperty (dpy, GDK_WINDOW_XID(window),
XInternAtom (dpy, "_COMPIZ_WM_WINDOW_BLUR", FALSE),
XA_INTEGER, 32, PropModeReplace, (guchar *)data, n);
}

int
main (int argc, char **argv)
{
GtkWidget *win;
GdkColormap *cm;
GdkRectangle rect;

gtk_init (&argc, &argv);

rect.x = 100;
rect.y = 100;
rect.width = 400;
rect.height = 200;

win = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_widget_set_app_paintable (win, TRUE);
gtk_widget_set_size_request (win, 600, 400);

cm = gdk_screen_get_rgba_colormap (gtk_widget_get_screen (win));
gtk_widget_set_colormap (win, cm);
g_object_unref (cm);

g_signal_connect (G_OBJECT(win), "delete-event", G_CALLBACK(gtk_main_quit), NULL);
g_signal_connect (G_OBJECT(win), "expose-event", G_CALLBACK(expose), (gpointer)&rect);

gtk_widget_show (win);

if (BLUR_REGION)
set_compiz_blur (win->window, &rect);
else
set_compiz_blur (win->window, NULL);

gtk_main ();

return 0;
}

btw, forum attachments would rock :wink:

[FunkyM]

Your (cool) example works correctly for me, even over Firefox windows.
I use alpha_blur and updated the screenshot to reflect this.

My problem might be caused by the applet API creating another window and embedding the slab-main-menu, thus I think I need to set the hint on that one instead (just curious how to retrieve it).

Once that works I'll set it to only apply blur to the transparent region.

[FunkyM]

Thanks, it's working now. I guess due to Glade the realization order is a bit different for the windows, thus I had tried to put the property change into the allocate callback which worked out.

http://media.sukimashita.com/temp/10-gnome-main-menu-3.png