open-with-widget: add a "Show more applications" button

So that we don't always show them all unconditionally in HEADINGS mode.

gtk/gtkopenwithwidget.c

@@ -45,9 +45,12 @@ struct _GtkOpenWithWidgetPrivate {
   GtkOpenWithWidgetShowMode show_mode;
 
   GtkWidget *program_list;
+  GtkWidget *show_more;
   GtkListStore *program_list_store;
 
   GtkCellRenderer *padding_renderer;
+
+  gboolean show_more_clicked;
 };
 
 enum {
@@ -500,7 +503,7 @@ gtk_open_with_widget_real_add_items (GtkOpenWithWidget *self)
     }
   else
     {
-      show_all = TRUE;
+      show_all = self->priv->show_more_clicked;
       show_headings = TRUE;
       show_recommended = TRUE;
     }
@@ -769,6 +772,32 @@ gtk_open_with_widget_get_property (GObject *object,
     }
 }
 
+static void
+show_more_button_clicked_cb (GtkButton *button,
+			     gpointer user_data)
+{
+  GtkOpenWithWidget *self = user_data;
+
+  self->priv->show_more_clicked = TRUE;
+  gtk_widget_hide (GTK_WIDGET (button));
+
+  _gtk_open_with_widget_refilter (self);
+}
+
+static void
+gtk_open_with_widget_ensure_show_more_button (GtkOpenWithWidget *self)
+{
+  if (self->priv->show_mode == GTK_OPEN_WITH_WIDGET_SHOW_MODE_HEADINGS)
+    {
+      if (!self->priv->show_more_clicked)
+	gtk_widget_show (self->priv->show_more);
+    }
+  else
+    {
+      gtk_widget_hide (self->priv->show_more);
+    }
+}
+
 static void
 gtk_open_with_widget_constructed (GObject *object)
 {
@@ -779,6 +808,7 @@ gtk_open_with_widget_constructed (GObject *object)
   if (G_OBJECT_CLASS (gtk_open_with_widget_parent_class)->constructed != NULL)
     G_OBJECT_CLASS (gtk_open_with_widget_parent_class)->constructed (object);
 
+  gtk_open_with_widget_ensure_show_more_button (self);
   gtk_open_with_widget_add_items (self);
 }
 
@@ -862,11 +892,12 @@ gtk_open_with_widget_class_init (GtkOpenWithWidgetClass *klass)
 static void
 gtk_open_with_widget_init (GtkOpenWithWidget *self)
 {
-  GtkWidget *scrolled_window;
+  GtkWidget *scrolled_window, *button, *w;
   GtkTreeSelection *selection;
 
   self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self, GTK_TYPE_OPEN_WITH_WIDGET,
 					    GtkOpenWithWidgetPrivate);
+  gtk_orientable_set_orientation (GTK_ORIENTABLE (self), GTK_ORIENTATION_VERTICAL);
 
   gtk_container_set_border_width (GTK_CONTAINER (self), 5);
 
@@ -899,6 +930,18 @@ gtk_open_with_widget_init (GtkOpenWithWidget *self)
   g_signal_connect (self->priv->program_list, "button-press-event",
 		    G_CALLBACK (program_list_button_press_event_cb),
 		    self);
+
+  button = gtk_button_new_with_label (_("Show more applications..."));
+  w = gtk_image_new_from_stock (GTK_STOCK_ADD,
+				GTK_ICON_SIZE_BUTTON);
+
+  gtk_button_set_image (GTK_BUTTON (button), w);
+  gtk_box_pack_start (GTK_BOX (self), button, TRUE, TRUE, 6);
+
+  g_signal_connect (button, "clicked",
+		    G_CALLBACK (show_more_button_clicked_cb), self);
+
+  self->priv->show_more = button;
 }
 
 static GAppInfo *
@@ -921,6 +964,9 @@ gtk_open_with_widget_iface_init (GtkOpenWithIface *iface)
 void
 _gtk_open_with_widget_refilter (GtkOpenWithWidget *self)
 {
+
+  gtk_open_with_widget_ensure_show_more_button (self);
+
   if (self->priv->program_list_store != NULL)
     {
       gtk_list_store_clear (self->priv->program_list_store);
@@ -963,6 +1009,7 @@ gtk_open_with_widget_set_show_mode (GtkOpenWithWidget *self,
       self->priv->show_mode = show_mode;
       g_object_notify (G_OBJECT (self), "show-mode");
 
+      self->priv->show_more_clicked = FALSE;
       _gtk_open_with_widget_refilter (self);
     }
 }