[nautilus] destructive-action: set style for permanent delete button

[Carlos Soriano <csoriano src gnome org>]

commit 310c77554f23b07861d664444a5ab726f469d523
Author: Eduard Čuba <cuba edo gmail com>
Date:   Mon Feb 20 17:36:50 2017 +0100

    destructive-action: set style for permanent delete button
    
    Delete button in confirmation dialog of nautilus-file-operations
    does not follow GNOME Human Interface Guidelines.
    https://developer.gnome.org/hig/stable/buttons.html.en
    
    To fix this use 'destructive-action' style class
    for this button. Class changes button color to red,
    preventing user from permanently deleting his files
    by accident.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=771356

 src/nautilus-file-operations.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)
---
diff --git a/src/nautilus-file-operations.c b/src/nautilus-file-operations.c
index c62c755..ac6d491 100644
--- a/src/nautilus-file-operations.c
+++ b/src/nautilus-file-operations.c
@@ -1182,6 +1182,7 @@ do_run_simple_dialog (gpointer _data)
     RunSimpleDialogData *data = _data;
     const char *button_title;
     GtkWidget *dialog;
+    GtkWidget *button;
     int result;
     int response_id;
 
@@ -1209,8 +1210,14 @@ do_run_simple_dialog (gpointer _data)
             continue;
         }
 
-        gtk_dialog_add_button (GTK_DIALOG (dialog), button_title, response_id);
+        button = gtk_dialog_add_button (GTK_DIALOG (dialog), button_title, response_id);
         gtk_dialog_set_default_response (GTK_DIALOG (dialog), response_id);
+
+        if (g_strcmp0(button_title, DELETE) == 0)
+        {
+            gtk_style_context_add_class(gtk_widget_get_style_context(button),
+                                        "destructive-action");
+        }
     }
 
     if (data->details_text)