[gimp] app: append insensitive reason to GimpAction proxy tooltip.

[Jehan <jehanp src gnome org>]

commit 13a02aea236821707e2636f016ff415f1c4cb10c
Author: Jehan <jehan girinstud io>
Date:   Fri Apr 23 19:45:48 2021 +0200

    app: append insensitive reason to GimpAction proxy tooltip.
    
    With my previous commit, I improved the search action display and search
    algorithm (which was returning wrong results), but we had lost showing
    the non-sensitive reason in menu item tooltips. This fixes it, by
    actually appending the reason, but only in the end, on the GtkWidget
    tooltip (not in the action's tooltip itself).

 app/widgets/gimpaction.c | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)
---
diff --git a/app/widgets/gimpaction.c b/app/widgets/gimpaction.c
index e3954b19be..982e8f5322 100644
--- a/app/widgets/gimpaction.c
+++ b/app/widgets/gimpaction.c
@@ -399,12 +399,30 @@ static void
 gimp_action_set_proxy_tooltip (GimpAction *action,
                                GtkWidget  *proxy)
 {
-  const gchar *tooltip = gimp_action_get_tooltip (action);
+  const gchar *tooltip;
+  const gchar *reason         = NULL;
+  gchar       *escaped_reason = NULL;
+  gchar       *markup;
 
-  if (tooltip)
-    gimp_help_set_help_data (proxy, tooltip,
-                             g_object_get_qdata (G_OBJECT (proxy),
-                                                 GIMP_HELP_ID));
+  tooltip = gimp_action_get_tooltip (action);
+
+  gimp_action_get_sensitive (action, &reason);
+  if (reason)
+    escaped_reason = g_markup_escape_text (reason, -1);
+
+  markup = g_strdup_printf ("%s%s"                                   /* Action tooltip  */
+                            "<i><span weight='light'>%s</span></i>", /* Inactive reason */
+                            tooltip,
+                            escaped_reason && tooltip ? "\n" : "",
+                            escaped_reason);
+
+  if (tooltip || escaped_reason)
+    gimp_help_set_help_data_with_markup (proxy, markup,
+                                         g_object_get_qdata (G_OBJECT (proxy),
+                                                             GIMP_HELP_ID));
+
+  g_free (escaped_reason);
+  g_free (markup);
 }
 
 static void