add the ability to switch tabs using [ctrl+tab] and [ctrl+shift+tab]

If true the gsettings key "ctrl-tab-switch-tabs" into "org.mate.caja.preferences"

Closes #768

Author: sc0w

libcaja-private/org.mate.caja.gschema.xml

@@ -76,6 +76,11 @@
       <summary>Where to position newly open tabs in browser windows.</summary>
       <description>If set to "after-current-tab", then new tabs are inserted after the current tab. If set to "end", then new tabs are appended to the end of the tab list.</description>
     </key>
+    <key name="ctrl-tab-switch-tabs" type="b">
+      <default>false</default>
+      <summary>Switch tabs with [ctrl] + [tab]</summary>
+      <description>If true, it enables the ability to switch tabs using [ctrl + tab] and [ctrl + shift + tab].</description>
+    </key>
     <key name="exit-with-last-window" type="b">
       <default>false</default>
       <summary>Caja will exit when last window destroyed.</summary>

src/caja-navigation-window.c

@@ -520,6 +520,52 @@ caja_navigation_window_key_press_event (GtkWidget *widget,
 
     window = CAJA_NAVIGATION_WINDOW (widget);
 
+    if (event->state & GDK_CONTROL_MASK)
+    {
+        GSettings *settings = g_settings_new ("org.mate.caja.preferences");
+        gboolean handled = FALSE;
+
+        if (g_settings_get_boolean (settings, "ctrl-tab-switch-tabs"))
+        {
+            CajaWindow *cajawin;
+            CajaWindowSlot *slot;
+            CajaNavigationWindowPane *pane;
+            CajaNotebook *cajanotebook;
+            GtkNotebook *notebook;
+            int pages;
+            int page_num;
+
+            cajawin = CAJA_WINDOW (window);
+            slot = caja_window_get_active_slot (cajawin);
+            pane = CAJA_NAVIGATION_WINDOW_PANE (slot->pane);
+            cajanotebook = CAJA_NOTEBOOK (pane->notebook);
+            notebook = GTK_NOTEBOOK (cajanotebook);
+            pages = gtk_notebook_get_n_pages (notebook);
+            page_num = gtk_notebook_get_current_page (notebook);
+
+            if (event->keyval == GDK_KEY_ISO_Left_Tab)
+            {
+                if (page_num != 0)
+                    gtk_notebook_prev_page (notebook);
+                else
+                    gtk_notebook_set_current_page (notebook, (pages - 1));
+                handled = TRUE;
+            }
+            if (event->keyval == GDK_KEY_Tab)
+            {
+                if (page_num != (pages -1))
+                    gtk_notebook_next_page (notebook);
+                else
+                    gtk_notebook_set_current_page (notebook, 0);
+                handled = TRUE;
+            }
+        }
+        g_object_unref (settings);
+
+        if (handled)
+            return TRUE;
+    }
+
     for (i = 0; i < G_N_ELEMENTS (extra_navigation_window_keybindings); i++)
     {
         if (extra_navigation_window_keybindings[i].keyval == event->keyval)