[gtk/ebassi/run-dialog-run: 4/7] Remove gtk_dialog_run() from GtkPrintUnixDialog

[Emmanuele Bassi <ebassi src gnome org>]

commit 0a6848d70bd49d67034ceae005ce972386f08553
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Thu Apr 30 18:45:01 2020 +0100

    Remove gtk_dialog_run() from GtkPrintUnixDialog
    
    Replace it with an explicit nested main loop, as we need to block the
    signal handler currently being emitted depending on the response of the
    overwrite confirmation dialog.
    
    This is a bit of a hack, and the only reason we need it is that the
    print dialog will load the last used path as the output file name, when
    printing to a file; this means that, in theory, it would be possible to
    press Print without selecting a file, and accidentally overwriting an
    existing file.
    
    It would be much simpler if we did not store the last used path, and
    always explicitly asked the user to select a file; this would avoid
    destructive actions, and would allow us to rely on the overwrite
    confirmation dialog right inside the file chooser.

 gtk/gtkprintunixdialog.c | 74 ++++++++++++++++++++++++++++++++----------------
 1 file changed, 49 insertions(+), 25 deletions(-)
---
diff --git a/gtk/gtkprintunixdialog.c b/gtk/gtkprintunixdialog.c
index eb9d008a04..6b9730f1a0 100644
--- a/gtk/gtkprintunixdialog.c
+++ b/gtk/gtkprintunixdialog.c
@@ -150,7 +150,7 @@ static void     printer_status_cb                  (GtkPrintBackend    *backend,
                                                     GtkPrintUnixDialog *dialog);
 static void     update_collate_icon                (GtkToggleButton    *toggle_button,
                                                     GtkPrintUnixDialog *dialog);
-static gboolean error_dialogs                      (GtkPrintUnixDialog *print_dialog,
+static void     error_dialogs                      (GtkPrintUnixDialog *print_dialog,
                                                    gint                print_dialog_response_id,
                                                    gpointer            data);
 static void     emit_ok_response                   (GtkTreeView        *tree_view,
@@ -604,31 +604,42 @@ set_busy_cursor (GtkPrintUnixDialog *dialog,
     gtk_widget_set_cursor (widget, NULL);
 }
 
+typedef struct {
+  GMainLoop *loop;
+  int response;
+} ConfirmationData;
+
+static void
+on_confirmation_dialog_response (GtkWidget *dialog,
+                                 int        response,
+                                 gpointer   user_data)
+{
+  ConfirmationData *data = user_data;
+
+  data->response = response;
+
+  g_main_loop_quit (data->loop);
+
+  gtk_window_destroy (GTK_WINDOW (dialog));
+}
+
 /* This function handles error messages before printing.
  */
-static gboolean
+static void
 error_dialogs (GtkPrintUnixDialog *dialog,
                gint                dialog_response_id,
                gpointer            data)
 {
-  GtkPrinterOption          *option = NULL;
-  GtkPrinter                *printer = NULL;
-  GtkWindow                 *toplevel = NULL;
-  GFile                     *file = NULL;
-  gchar                     *basename = NULL;
-  gchar                     *dirname = NULL;
-  int                        response;
-
   if (dialog != NULL && dialog_response_id == GTK_RESPONSE_OK)
     {
-      printer = gtk_print_unix_dialog_get_selected_printer (dialog);
+      GtkPrinter *printer = gtk_print_unix_dialog_get_selected_printer (dialog);
 
       if (printer != NULL)
         {
           if (dialog->request_details_tag || !gtk_printer_is_accepting_jobs (printer))
             {
               g_signal_stop_emission_by_name (dialog, "response");
-              return TRUE;
+              return;
             }
 
           /* Shows overwrite confirmation dialog in the case of printing
@@ -636,18 +647,22 @@ error_dialogs (GtkPrintUnixDialog *dialog,
            */
           if (gtk_printer_is_virtual (printer))
             {
-              option = gtk_printer_option_set_lookup (dialog->options,
-                                                      "gtk-main-page-custom-input");
+              GtkPrinterOption *option =
+                gtk_printer_option_set_lookup (dialog->options,
+                                               "gtk-main-page-custom-input");
 
               if (option != NULL &&
                   option->type == GTK_PRINTER_OPTION_TYPE_FILESAVE)
                 {
-                  file = g_file_new_for_uri (option->value);
+                  GFile *file = g_file_new_for_uri (option->value);
 
                   if (g_file_query_exists (file, NULL))
                     {
-                      GFile *parent;
                       GtkWidget *message_dialog;
+                      GtkWindow *toplevel;
+                      char *basename;
+                      char *dirname;
+                      GFile *parent;
 
                       toplevel = get_toplevel (GTK_WIDGET (dialog));
 
@@ -682,19 +697,29 @@ error_dialogs (GtkPrintUnixDialog *dialog,
                         gtk_window_group_add_window (gtk_window_get_group (toplevel),
                                                      GTK_WINDOW (message_dialog));
 
-                      response = gtk_dialog_run (GTK_DIALOG (message_dialog));
+                      gtk_window_present (GTK_WINDOW (message_dialog));
+
+                      /* Block on the confirmation dialog until we have a response,
+                       * so that we can stop the "response" signal emission on the
+                       * print dialog
+                       */
+                      ConfirmationData cdata;
 
-                      gtk_window_destroy (GTK_WINDOW (message_dialog));
+                      cdata.loop = g_main_loop_new (NULL, FALSE);
+                      cdata.response = 0;
+
+                      g_signal_connect (message_dialog, "response",
+                                        G_CALLBACK (on_confirmation_dialog_response),
+                                        &cdata);
+
+                      g_main_loop_run (cdata.loop);
+                      g_main_loop_unref (cdata.loop);
 
                       g_free (dirname);
                       g_free (basename);
 
-                      if (response != GTK_RESPONSE_ACCEPT)
-                        {
-                          g_signal_stop_emission_by_name (dialog, "response");
-                          g_object_unref (file);
-                          return TRUE;
-                        }
+                      if (cdata.response != GTK_RESPONSE_ACCEPT)
+                        g_signal_stop_emission_by_name (dialog, "response");
                     }
 
                   g_object_unref (file);
@@ -702,7 +727,6 @@ error_dialogs (GtkPrintUnixDialog *dialog,
             }
         }
     }
-  return FALSE;
 }
 
 static void