GTK+ How to make notebook's tab bar resizable

Question

I want to make a tab-bar on the left in GTK app with GLade. And I want to get the resizable tab-bar area like this:

But I couldn't find the Resize option of Notebook widget.

Anybody knows how I can do this with GLade or has any ideas?

Answer 1

The tabs area of a GtkNotebook is not user resizable. There are workarounds though. A solution would be to remove the tabs from the GtkNotebook and simulate a tab bar with buttons. This way you can separate both and contain them inside a GtkPaned.

A simple glade file following this approach (named myui.glade):

<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.19.0 -->
<interface>
  <requires lib="gtk+" version="3.16"/>
  <object class="GtkWindow" id="window1">
    <property name="can_focus">False</property>
    <property name="default_width">440</property>
    <property name="default_height">250</property>
    <child>
      <object class="GtkPaned" id="paned1">
        <property name="visible">True</property>
        <property name="can_focus">True</property>
        <child>
          <object class="GtkBox" id="box1">
            <property name="visible">True</property>
            <property name="can_focus">False</property>
            <property name="orientation">vertical</property>
            <child>
              <object class="GtkButton" id="page1">
                <property name="label" translatable="yes">Page 1</property>
                <property name="visible">True</property>
                <property name="can_focus">True</property>
                <property name="receives_default">True</property>
              </object>
              <packing>
                <property name="expand">False</property>
                <property name="fill">True</property>
                <property name="position">0</property>
              </packing>
            </child>
            <child>
              <object class="GtkButton" id="page2">
                <property name="label" translatable="yes">Page 2</property>
                <property name="visible">True</property>
                <property name="can_focus">True</property>
                <property name="receives_default">True</property>
              </object>
              <packing>
                <property name="expand">False</property>
                <property name="fill">True</property>
                <property name="position">1</property>
              </packing>
            </child>
            <child>
              <object class="GtkButton" id="page3">
                <property name="label" translatable="yes">Page 3</property>
                <property name="visible">True</property>
                <property name="can_focus">True</property>
                <property name="receives_default">True</property>
              </object>
              <packing>
                <property name="expand">False</property>
                <property name="fill">True</property>
                <property name="position">2</property>
              </packing>
            </child>
          </object>
          <packing>
            <property name="resize">False</property>
            <property name="shrink">True</property>
          </packing>
        </child>
        <child>
          <object class="GtkNotebook" id="notebook1">
            <property name="visible">True</property>
            <property name="can_focus">True</property>
            <property name="show_tabs">False</property>
            <child>
              <object class="GtkLabel" id="label4">
                <property name="visible">True</property>
                <property name="can_focus">False</property>
                <property name="label" translatable="yes">This is Page 1</property>
              </object>
            </child>
            <child type="tab">
              <object class="GtkLabel" id="label1">
                <property name="visible">True</property>
                <property name="can_focus">False</property>
                <property name="label" translatable="yes">page 1</property>
              </object>
              <packing>
                <property name="tab_fill">False</property>
              </packing>
            </child>
            <child>
              <object class="GtkLabel" id="label6">
                <property name="visible">True</property>
                <property name="can_focus">False</property>
                <property name="label" translatable="yes">This is Page 2</property>
              </object>
              <packing>
                <property name="position">1</property>
              </packing>
            </child>
            <child type="tab">
              <object class="GtkLabel" id="label2">
                <property name="visible">True</property>
                <property name="can_focus">False</property>
                <property name="label" translatable="yes">page 2</property>
              </object>
              <packing>
                <property name="position">1</property>
                <property name="tab_fill">False</property>
              </packing>
            </child>
            <child>
              <object class="GtkLabel" id="label5">
                <property name="visible">True</property>
                <property name="can_focus">False</property>
                <property name="label" translatable="yes">This is Page 3</property>
              </object>
              <packing>
                <property name="position">2</property>
              </packing>
            </child>
            <child type="tab">
              <object class="GtkLabel" id="label3">
                <property name="visible">True</property>
                <property name="can_focus">False</property>
                <property name="label" translatable="yes">page 3</property>
              </object>
              <packing>
                <property name="position">2</property>
                <property name="tab_fill">False</property>
              </packing>
            </child>
          </object>
          <packing>
            <property name="resize">True</property>
            <property name="shrink">True</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
</interface>

To switch between GtkNotebook pages we must handle button clicks and switch to the corresponding page.

A simple implementation for the behavior can be (named main.c):

#include <gtk/gtk.h>

void on_page1_button_clicked (GtkButton *button, gpointer user_data) {
   GtkNotebook *notebook = GTK_NOTEBOOK(user_data);
   gtk_notebook_set_current_page(notebook, 0);
}

void on_page2_button_clicked (GtkButton *button, gpointer user_data) {
   GtkNotebook *notebook = GTK_NOTEBOOK(user_data);
   gtk_notebook_set_current_page(notebook, 1);
}

void on_page3_button_clicked (GtkButton *button, gpointer user_data) {
   GtkNotebook *notebook = GTK_NOTEBOOK(user_data);
   gtk_notebook_set_current_page(notebook, 2);
}


int main(int argc, char *argv[]) {
   GtkWidget *page1;
   GtkWidget *page2;
   GtkWidget *page3;
   GtkWidget *window;
   GtkWidget *notebook;
   GtkBuilder *builder;

   gtk_init (&argc,&argv);

   builder = gtk_builder_new_from_file("myui.glade");

   page1 = GTK_WIDGET(gtk_builder_get_object(builder, "page1"));
   page2 = GTK_WIDGET(gtk_builder_get_object(builder, "page2"));
   page3 = GTK_WIDGET(gtk_builder_get_object(builder, "page3"));
   window = GTK_WIDGET(gtk_builder_get_object(builder, "window1"));
   notebook = GTK_WIDGET(gtk_builder_get_object(builder, "notebook1"));

   g_signal_connect (page1, "clicked", G_CALLBACK(on_page1_button_clicked), notebook);
   g_signal_connect (page2, "clicked", G_CALLBACK(on_page2_button_clicked), notebook);
   g_signal_connect (page3, "clicked", G_CALLBACK(on_page3_button_clicked), notebook);

   g_signal_connect (window, "destroy", G_CALLBACK(gtk_main_quit), NULL);

   gtk_widget_show_all(GTK_WIDGET(window));

   gtk_main();

   return 0;
}

Compile with:

gcc -o notebook main.c `pkg-config --cflags --libs gtk+-3.0`

The result: