[ghex/gtk4-port: 73/91] Don't create a new prefs dialog if already shown.

[Logan Rathbone <larathbone src gnome org>]

commit 0dd48c48a3ebaed21989cb7537355d0d0edabccb
Author: Logan Rathbone <poprocks gmail com>
Date:   Wed Feb 3 12:40:11 2021 -0500

    Don't create a new prefs dialog if already shown.

 src/ghex-application-window.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)
---
diff --git a/src/ghex-application-window.c b/src/ghex-application-window.c
index 84fb83ed..3eba2729 100644
--- a/src/ghex-application-window.c
+++ b/src/ghex-application-window.c
@@ -54,6 +54,7 @@ struct _GHexApplicationWindow
        GtkWidget *jump_dialog;
        GtkWidget *chartable;
        GtkWidget *converter;
+       GtkWidget *prefs_dialog;
        GtkWidget *paste_special_dialog;
        GtkWidget *copy_special_dialog;
 
@@ -1283,7 +1284,6 @@ open_about (GtkWidget *widget,
                GVariant *parameter)
 {
        GHexApplicationWindow *self = GHEX_APPLICATION_WINDOW(widget);
-       GtkWidget *prefs_dialog;
 
        (void)parameter, (void)action_name;             /* unused */
 
@@ -1296,12 +1296,13 @@ open_preferences (GtkWidget *widget,
                GVariant *parameter)
 {
        GHexApplicationWindow *self = GHEX_APPLICATION_WINDOW(widget);
-       GtkWidget *prefs_dialog;
 
        (void)parameter, (void)action_name;             /* unused */
 
-       prefs_dialog = create_preferences_dialog (GTK_WINDOW(self));
-       gtk_widget_show (prefs_dialog);
+       if (! GTK_IS_WIDGET (self->prefs_dialog)) {
+               self->prefs_dialog = create_preferences_dialog (GTK_WINDOW(self));
+       }
+       gtk_widget_show (self->prefs_dialog);
 }
 
 /* --- */