Re: Help replacing GtkDrawingArea with GtkLayout

[Richard Shann <richard rshann plus com>]

On Tue, 2014-03-11 at 13:18 +0100, Joël Krähemann wrote:
> On Tue, 2014-03-11 at 08:12 +0000, Richard Shann wrote:
> > On Tue, 2014-03-11 at 04:43 +0100, Joël Krähemann wrote:
> > > On Mon, 2014-03-10 at 09:52 +0000, Richard Shann wrote:
> > > > On Mon, 2014-03-10 at 09:29 +0100, Joël Krähemann wrote:
> > > > > On Mon, 2014-03-10 at 09:26 +0100, Joël Krähemann wrote:
> > > > > > On Sun, 2014-03-09 at 14:03 +0000, Richard Shann wrote:
> > > > > > > > From: Jo?l Kr?hemann <joel weedlight ch>
> > > > > > > > To: gtk-app-devel-list gnome org
> > > > > > > > Subject: Re: Help replacing GtkDrawingArea with GtkLayout
> > > > > > > > Message-ID: <1394327737 3369 3 camel debian>
> > > > > > > > Content-Type: text/plain; charset="us-ascii"
> > > > > > > >
> > > > > > > > Hi,
> > > > > > > >
> > > > > > > > Didn't before but may be check the following:
> > > > > > > >
> > > > > > > > g_object_set(G_OBJECT(layout),
> > > > > > > >   "app-paintable\0", TRUE, 
> > > > > > > >   NULL);
> > > > > > >
> > > > > > > Hmm, I hadn't noticed that property. It is presumably set ok since I can
> > > > > > > draw and place widgets on the GtkLayout. It was the configure and scroll
> > > > > > > events that I didn't receive.
> > > > > > > BTW why do you have two NULL bytes at the end of the property name
> > > > > > > (AFAIK only one is needed)?
> > > > > > >
> > > > > > > Richard
> > > > > >
> > > > > > Assumed you get annoyed by warnings, you can slightly disable it. It's
> > > > > > distribution depend what flags are per default on. For further reading:
> > > > > >
> > > > > > http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
> > > > > >
> > > > > > regards
> > > > > > Joël
> > > > > >
> > > > > >
> > > > > > _______________________________________________
> > > > > > gtk-app-devel-list mailing list
> > > > > > gtk-app-devel-list gnome org
> > > > > > https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
> > > > >
> > > > > You should ask why I forget to add GDK_SCROLL_MASK
> > > >
> > > > Well, I didn't ask because I already tried it. The GtkLayout didn't
> > > > receive that nor the configure signal even with setting
> > > > GDK_ALL_EVENTS_MASK. What *did* work is receiving the events on the
> > > > parent.
> > > > But I am still curious why you have two NULL bytes termination your
> > > > signal name strings, the extra one must surely get ignored...
> > > >
> > > > Richard
> > > >
> > > >
> > > > > gtk_widget_set_events (GTK_WIDGET (layout),
> > > > >   GDK_EXPOSURE_MASK 
> > > > >   | GDK_LEAVE_NOTIFY_MASK 
> > > > >   | GDK_BUTTON_PRESS_MASK 
> > > > >   | GDK_BUTTON_RELEASE_MASK 
> > > > >   | GDK_POINTER_MOTION_MASK 
> > > > >   | GDK_POINTER_MOTION_HINT_MASK 
> > > > >   | GDK_SCROLL_MASK
> > > > >   );
> > > > >
> > > > > then you have to
> > > > >
> > > > > g_signal_connect(G_OBJECT(layout), "scroll-event\0",
> > > > >   G_CALLBACK(layout_callback), NULL);
> > > > >
> > > > >
> > > > > gboolean
> > > > > layout_callback(GtkWidget *widget, GdkEvent *event, gpointer user_data)
> > > > > {
> > > > >   /* do your thing */
> > > > >
> > > > >   return(FALSE);
> > > > > }
> > > Is your code somewhere online? Are you using
> > > gtk_widget_set_size_request()?
> >
> > I gave a minimal example earlier in the thread:
> >
> > https://mail.gnome.org/archives/gtk-app-devel-list/2014-March/msg00007.html
> >
> >
> > Richard
> Much better! As someone told you before the widget is realized you have
> to set the appropriate flags.

The widget is not realized before the flags are set. Indeed gtk_main()
has not even been called, so no signals have been emitted when the flags
are set.
Here is the code with the sequence altered as you suggest:

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#include <gtk/gtk.h>
static gboolean
configure_event ()
{
    fprintf (stderr, "configure-event\n");
    gtk_main_quit ();
    return FALSE;
}

int main(int argc, char *argv[])
{
    GtkWidget *window;
    GtkWidget *layout;
    GtkWidget *label1;

    gtk_init (&argc, &argv);

    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
   
    layout = gtk_layout_new (NULL, NULL);
    gtk_widget_add_events (layout, GDK_ALL_EVENTS_MASK);
    gtk_container_add (GTK_CONTAINER (window), layout);
   

    label1 = gtk_label_new ("label 1");

    gtk_layout_put (GTK_LAYOUT (layout), label1, 10, 50);
  

    gtk_widget_show_all (window);

    GdkWindow *win = gtk_widget_get_window(layout); 
    g_print("win is %p initial mask 0x%x\n", win, gdk_window_get_events
(win));
    gdk_window_set_events (win, gdk_window_get_events (win) |
GDK_STRUCTURE_MASK);
    g_print("After adding GDK_STRUCTURE_MASK mask 0x%x\n",
gdk_window_get_events (win));
    
    g_signal_connect (layout, "configure-event", G_CALLBACK
(configure_event), NULL);

    gtk_main ();

    return 0;
}

8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><

As you can verify, it makes no difference - it would be very bizarre if
it did.

> layout = gtk_layout_new (NULL, NULL);
>
> /* SET FLAGS HERE */
>
> gtk_container_add (GTK_CONTAINER (window), layout);
>
>
> and don't forget to add the missing parameters.

The parameters in the definition of the callback function
configure_event(void) are not missing, it is deliberately declared not
to have them. It is not a good idea to declare the callback with
parameters if they are not going to be used.

Richard


> gboolean
> configure_event(GtkWidget *widget, GdkEventConfigure *event, gpointer
> user_data){
>   /* YOUR CODE HERE */
> }