[gimp/gimp-2-10] app: append insensitive reason to GimpAction proxy tooltip.

[Jacob Boerema <jboerema src gnome org>]

commit bf9a2927234715a04876e176b5dfc9530b20f43e
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).
    
    (cherry picked from commit 13a02aea236821707e2636f016ff415f1c4cb10c)

 app/widgets/gimpaction.c | 30 ++++++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)
---
diff --git a/app/widgets/gimpaction.c b/app/widgets/gimpaction.c
index 88cae45fa0..b96af124a2 100644
--- a/app/widgets/gimpaction.c
+++ b/app/widgets/gimpaction.c
@@ -368,12 +368,30 @@ static void
 gimp_action_set_proxy_tooltip (GimpAction *action,
                                GtkWidget  *proxy)
 {
-  const gchar *tooltip = gimp_action_get_tooltip (action);
-
-  if (tooltip)
-    gimp_help_set_help_data (proxy, tooltip,
-                             g_object_get_qdata (G_OBJECT (proxy),
-                                                 GIMP_HELP_ID));
+  const gchar *tooltip;
+  const gchar *reason         = NULL;
+  gchar       *escaped_reason = NULL;
+  gchar       *markup;
+
+  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