Signal 'show' not emitted from GUI constructed with GtkBuilder?

Question

I am trying to initialize a GtkEntry widget from GSettings, through a signal handler for the 'show' signal. This works as expected when manually building the user interface, but fails to work when using GtkBuilder. The same applies to other GtkWidget signals; GtkEntry signals work as expected. It looks like the signal is never emitted?

#include <gtk/gtk.h>


void activated (GtkEntry *entry,
               gpointer  user_data){

    GtkWidget *dialog = gtk_message_dialog_new(GTK_WINDOW(user_data), GTK_DIALOG_DESTROY_WITH_PARENT,
                                               GTK_MESSAGE_INFO, GTK_BUTTONS_CLOSE,
                                               gtk_entry_get_text(entry));
    gtk_dialog_run(GTK_DIALOG(dialog));
    gtk_widget_destroy(dialog);

}



void shown (GtkWidget *widget,
               gpointer   user_data){
    GtkWidget *dialog = gtk_message_dialog_new(GTK_WINDOW(user_data), GTK_DIALOG_DESTROY_WITH_PARENT,
                                               GTK_MESSAGE_INFO, GTK_BUTTONS_CLOSE,
                                               "SHOWN!");
    gtk_dialog_run(GTK_DIALOG(dialog));
    gtk_widget_destroy(dialog);

}



int main(int argc, char **argv){
    GtkWidget *window1, *window2, *entry;
    GtkBuilder *builder;


    gtk_init(&argc, &argv);

    // Construct working window 1

    window1 = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(window1),"Working");
    entry=gtk_entry_new();

    g_signal_connect(entry, "activate", G_CALLBACK(activated), window1);
    g_signal_connect(entry, "show", G_CALLBACK(shown), window1);

    gtk_container_add(GTK_WINDOW(window1), entry);


    // Construct not working window 2

    builder=gtk_builder_new_from_file ("window.glade");
    window2 = GTK_WIDGET(gtk_builder_get_object(builder, "window2"));
    gtk_builder_connect_signals(builder, NULL);
    g_object_unref(builder);


    gtk_widget_show_all(window1);
    gtk_widget_show_all(window2);


    gtk_main();

    return 0;
}

window.glade:

<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.18.3 -->
<interface>
  <requires lib="gtk+" version="3.12"/>
  <object class="GtkWindow" id="window2">
    <property name="can_focus">False</property>
    <property name="title" translatable="yes">Not working</property>
    <child>
      <object class="GtkEntry" id="entry1">
        <property name="visible">True</property>
        <property name="can_focus">True</property>
        <property name="shadow_type">none</property>
        <signal name="activate" handler="activated" object="window2" swapped="no"/>
        <signal name="show" handler="shown" object="window2" swapped="no"/>
      </object>
    </child>
  </object>
</interface>

Just a note. As far as I'm aware it is better to use **map** event for purposes for which show is intended to be used. This works the exactly way as **show**, no need to change anything in glade. And show were called as "No, not really. It's one of those weird historical things from pre-1.0". You can check this link https://blogs.gnome.org/jnelson/2010/10/13/those-realize-map-widget-signals/ — likern, Mar 09 '18 at 01:45

José Fonte · Accepted Answer · 2017-10-18T16:22:17.393

Set the visible flag in GLADE to false (untick) so that when GtkBuilder instantiates the glade file contents, the widget isn't shown; then when you do gtk_widget_show_all for window2, the signal will get emmited.

Alternatively, edit window.glade and set the visible property to False or remove it (I think that by default the widget isn't visible), eg:

 ...
 <object class="GtkEntry" id="entry1">
    <property name="visible">False</property>
 ...

Signal 'show' not emitted from GUI constructed with GtkBuilder?

1 Answers1