[gtk/master.win32: 7/8] demos: Fix running on Visual Studio builds

[Chun-wei Fan <fanchunwei src gnome org>]

commit c97979873a9e72e97f36d0c53ea96a98c3a389f7
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Mon Jul 27 17:02:00 2020 +0800

    demos: Fix running on Visual Studio builds
    
    We need to mark the non-static callback functions for export.

 demos/gtk-demo/fishbowl.c   | 8 ++++----
 demos/gtk-demo/iconscroll.c | 6 +++---
 2 files changed, 7 insertions(+), 7 deletions(-)
---
diff --git a/demos/gtk-demo/fishbowl.c b/demos/gtk-demo/fishbowl.c
index bc3848fb18..40c8203726 100644
--- a/demos/gtk-demo/fishbowl.c
+++ b/demos/gtk-demo/fishbowl.c
@@ -209,7 +209,7 @@ set_widget_type (GtkFishbowl *fishbowl,
                         widget_types[selected_widget_type].name);
 }
 
-void
+G_MODULE_EXPORT void
 fishbowl_next_button_clicked_cb (GtkButton *source,
                                  gpointer   user_data)
 {
@@ -224,7 +224,7 @@ fishbowl_next_button_clicked_cb (GtkButton *source,
   set_widget_type (fishbowl, new_index);
 }
 
-void
+G_MODULE_EXPORT void
 fishbowl_prev_button_clicked_cb (GtkButton *source,
                                  gpointer   user_data)
 {
@@ -239,7 +239,7 @@ fishbowl_prev_button_clicked_cb (GtkButton *source,
   set_widget_type (fishbowl, new_index);
 }
 
-void
+G_MODULE_EXPORT void
 fishbowl_changes_toggled_cb (GtkToggleButton *button,
                              gpointer         user_data)
 {
@@ -249,7 +249,7 @@ fishbowl_changes_toggled_cb (GtkToggleButton *button,
     gtk_button_set_icon_name (GTK_BUTTON (button), "changes-allow");
 }
 
-char *
+G_MODULE_EXPORT char *
 format_header_cb (GObject *object,
                   guint    count,
                   double   fps)
diff --git a/demos/gtk-demo/iconscroll.c b/demos/gtk-demo/iconscroll.c
index a8518b81ec..22e7448c56 100644
--- a/demos/gtk-demo/iconscroll.c
+++ b/demos/gtk-demo/iconscroll.c
@@ -220,7 +220,7 @@ set_widget_type (int type)
   tick_cb = gtk_widget_add_tick_callback (window, scroll_cb, NULL, NULL);
 }
 
-void
+G_MODULE_EXPORT void
 iconscroll_next_clicked_cb (GtkButton *source,
                             gpointer   user_data)
 {
@@ -235,7 +235,7 @@ iconscroll_next_clicked_cb (GtkButton *source,
   set_widget_type (new_index);
 }
 
-void
+G_MODULE_EXPORT void
 iconscroll_prev_clicked_cb (GtkButton *source,
                             gpointer   user_data)
 {
@@ -249,7 +249,7 @@ iconscroll_prev_clicked_cb (GtkButton *source,
   set_widget_type (new_index);
 }
 
-GtkWidget *
+G_MODULE_EXPORT GtkWidget *
 do_iconscroll (GtkWidget *do_widget)
 {
   if (!window)