[gtk+/gtk-3-22] font chooser dialog: Improve sensitivity handling

[Matthias Clasen <matthiasc src gnome org>]

commit 5f675181ceec8cc73a48b8caca44d1218194cdc4
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Jan 18 19:48:12 2018 -0500

    font chooser dialog: Improve sensitivity handling
    
    Enable the select button when a font is selected, as it should be.

 gtk/gtkfontchooserdialog.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkfontchooserdialog.c b/gtk/gtkfontchooserdialog.c
index ac11ba9..4805ad3 100644
--- a/gtk/gtkfontchooserdialog.c
+++ b/gtk/gtkfontchooserdialog.c
@@ -160,6 +160,20 @@ gtk_font_chooser_dialog_class_init (GtkFontChooserDialogClass *klass)
 }
 
 static void
+update_button (GtkFontChooserDialog *dialog)
+{
+  GtkFontChooserDialogPrivate *priv = dialog->priv;
+  PangoFontDescription *desc;
+
+  desc = gtk_font_chooser_get_font_desc (GTK_FONT_CHOOSER (priv->fontchooser));
+
+  gtk_widget_set_sensitive (priv->select_button, desc != NULL);
+
+  if (desc)
+    pango_font_description_free (desc);
+}
+
+static void
 gtk_font_chooser_dialog_init (GtkFontChooserDialog *fontchooserdiag)
 {
   GtkFontChooserDialogPrivate *priv;
@@ -182,6 +196,10 @@ G_GNUC_END_IGNORE_DEPRECATIONS
 
   _gtk_font_chooser_set_delegate (GTK_FONT_CHOOSER (fontchooserdiag),
                                   GTK_FONT_CHOOSER (priv->fontchooser));
+
+  g_signal_connect_swapped (priv->fontchooser, "notify::font-desc",
+                            G_CALLBACK (update_button), fontchooserdiag);
+  update_button (fontchooserdiag);
 }
 
 /**