[gtk+] Don't hang print dialog when remote CUPS printer is not available

[Marek Kašík <mkasik src gnome org>]

commit 5f4915f62403ddb2502fa7b431a97943c9b56b88
Author: Marek Kasik <mkasik redhat com>
Date:   Wed Sep 23 14:35:26 2009 +0200

    Don't hang print dialog when remote CUPS printer is not available
    
    This patch tests availability of remote host before getting ppd file
    for selected printer (#586207). It also adds a state message for
    failure of getting details.

 gtk/gtkprintunixdialog.c                         |   28 ++++++++-----
 modules/printbackends/cups/gtkprintbackendcups.c |   47 ++++++++++++++++++++--
 modules/printbackends/cups/gtkprintercups.c      |    8 ++++
 modules/printbackends/cups/gtkprintercups.h      |    5 ++
 4 files changed, 74 insertions(+), 14 deletions(-)
---
diff --git a/gtk/gtkprintunixdialog.c b/gtk/gtkprintunixdialog.c
index d08cdfb..5f9d8d2 100644
--- a/gtk/gtkprintunixdialog.c
+++ b/gtk/gtkprintunixdialog.c
@@ -596,7 +596,7 @@ gtk_print_unix_dialog_destroy (GtkPrintUnixDialog *dialog)
 }
 
 static void
-disconnect_printer_details_request (GtkPrintUnixDialog *dialog)
+disconnect_printer_details_request (GtkPrintUnixDialog *dialog, gboolean details_failed)
 {
   GtkPrintUnixDialogPrivate *priv = dialog->priv;
 
@@ -606,12 +606,20 @@ disconnect_printer_details_request (GtkPrintUnixDialog *dialog)
                                    priv->request_details_tag);
       priv->request_details_tag = 0;
       set_busy_cursor (dialog, FALSE);
-      gtk_list_store_set (GTK_LIST_STORE (priv->printer_list),
-                          g_object_get_data (G_OBJECT (priv->request_details_printer),
-                                             "gtk-print-tree-iter"),
-                          PRINTER_LIST_COL_STATE,
-                          gtk_printer_get_state_message (priv->request_details_printer),
-                          -1);
+      if (details_failed)
+        gtk_list_store_set (GTK_LIST_STORE (priv->printer_list),
+                            g_object_get_data (G_OBJECT (priv->request_details_printer),
+                                               "gtk-print-tree-iter"),
+                            PRINTER_LIST_COL_STATE,
+                             _("Getting printer information failed"),
+                            -1);
+      else
+        gtk_list_store_set (GTK_LIST_STORE (priv->printer_list),
+                            g_object_get_data (G_OBJECT (priv->request_details_printer),
+                                               "gtk-print-tree-iter"),
+                            PRINTER_LIST_COL_STATE,
+                            gtk_printer_get_state_message (priv->request_details_printer),
+                            -1);
       g_object_unref (priv->request_details_printer);
       priv->request_details_printer = NULL;
     }
@@ -626,7 +634,7 @@ gtk_print_unix_dialog_finalize (GObject *object)
   GList *node;
 
   unschedule_idle_mark_conflicts (dialog);
-  disconnect_printer_details_request (dialog);
+  disconnect_printer_details_request (dialog, FALSE);
 
   if (priv->current_printer)
     {
@@ -1781,7 +1789,7 @@ printer_details_acquired (GtkPrinter         *printer,
 {
   GtkPrintUnixDialogPrivate *priv = dialog->priv;
 
-  disconnect_printer_details_request (dialog);
+  disconnect_printer_details_request (dialog, !success);
 
   if (success)
     {
@@ -1809,7 +1817,7 @@ selected_printer_changed (GtkTreeSelection   *selection,
       priv->waiting_for_printer = NULL;
     }
 
-  disconnect_printer_details_request (dialog);
+  disconnect_printer_details_request (dialog, FALSE);
 
   printer = NULL;
   if (gtk_tree_selection_get_selected (selection, NULL, &filter_iter))
diff --git a/modules/printbackends/cups/gtkprintbackendcups.c b/modules/printbackends/cups/gtkprintbackendcups.c
index 92d4b9b..f13090c 100644
--- a/modules/printbackends/cups/gtkprintbackendcups.c
+++ b/modules/printbackends/cups/gtkprintbackendcups.c
@@ -154,7 +154,7 @@ static GList *              cups_printer_list_papers               (GtkPrinter
 static GtkPageSetup *       cups_printer_get_default_page_size     (GtkPrinter                        *printer);
 static void                 cups_printer_request_details           (GtkPrinter                        *printer);
 static gboolean             cups_request_default_printer           (GtkPrintBackendCups               *print_backend);
-static void                 cups_request_ppd                       (GtkPrinter                        *printer);
+static gboolean             cups_request_ppd                       (GtkPrinter                        *printer);
 static void                 cups_printer_get_hard_margins          (GtkPrinter                        *printer,
 								    double                            *top,
 								    double                            *bottom,
@@ -1686,6 +1686,8 @@ cups_request_printer_list_cb (GtkPrintBackendCups *cups_backend,
       else
 	g_object_ref (printer);
 
+      GTK_PRINTER_CUPS (printer)->remote = remote_printer;
+
       gtk_printer_set_is_paused (printer, is_paused);
       gtk_printer_set_is_accepting_jobs (printer, is_accepting_jobs);
 
@@ -1985,7 +1987,7 @@ done:
   GDK_THREADS_LEAVE ();
 }
 
-static void
+static gboolean
 cups_request_ppd (GtkPrinter *printer)
 {
   GError *error;
@@ -2005,6 +2007,26 @@ cups_request_ppd (GtkPrinter *printer)
   GTK_NOTE (PRINTING,
             g_print ("CUPS Backend: %s\n", G_STRFUNC));
 
+  if (cups_printer->remote)
+    {
+      GtkCupsConnectionState state;
+
+      state = gtk_cups_connection_test_get_state (cups_printer->remote_cups_connection_test);
+
+      if (state == GTK_CUPS_CONNECTION_IN_PROGRESS)
+        return TRUE;
+
+      gtk_cups_connection_test_free (cups_printer->remote_cups_connection_test);
+      cups_printer->remote_cups_connection_test = NULL;
+      cups_printer->get_remote_ppd_poll = 0;
+
+      if (state == GTK_CUPS_CONNECTION_NOT_AVAILABLE)
+        {
+          g_signal_emit_by_name (printer, "details-acquired", FALSE);
+          return FALSE;
+        }
+    }
+
   http = httpConnectEncrypt (cups_printer->hostname, 
 			     cups_printer->port,
 			     cupsEncryption ());
@@ -2034,7 +2056,7 @@ cups_request_ppd (GtkPrinter *printer)
       g_free (data);
 
       g_signal_emit_by_name (printer, "details-acquired", FALSE);
-      return;
+      return FALSE;
     }
     
   data->http = http;
@@ -2072,6 +2094,8 @@ cups_request_ppd (GtkPrinter *printer)
 
   g_free (resource);
   g_free (ppd_filename);
+
+  return FALSE;
 }
 
 /* Ordering matters for default preference */
@@ -2369,7 +2393,22 @@ cups_printer_request_details (GtkPrinter *printer)
   cups_printer = GTK_PRINTER_CUPS (printer);
   if (!cups_printer->reading_ppd && 
       gtk_printer_cups_get_ppd (cups_printer) == NULL)
-    cups_request_ppd (printer); 
+    {
+      if (cups_printer->remote)
+        {
+          if (cups_printer->get_remote_ppd_poll == 0)
+            {
+              cups_printer->remote_cups_connection_test = gtk_cups_connection_test_new (cups_printer->hostname);
+
+              if (cups_request_ppd (printer))
+                cups_printer->get_remote_ppd_poll = gdk_threads_add_timeout (200,
+                                                    (GSourceFunc) cups_request_ppd,
+                                                    printer);
+            }
+        }
+      else
+        cups_request_ppd (printer);
+    }
 }
 
 static char *
diff --git a/modules/printbackends/cups/gtkprintercups.c b/modules/printbackends/cups/gtkprintercups.c
index cd27b17..22a9b01 100644
--- a/modules/printbackends/cups/gtkprintercups.c
+++ b/modules/printbackends/cups/gtkprintercups.c
@@ -77,6 +77,9 @@ gtk_printer_cups_init (GtkPrinterCups *printer)
   printer->ppd_file = NULL;
   printer->default_cover_before = NULL;
   printer->default_cover_after = NULL;
+  printer->remote = FALSE;
+  printer->get_remote_ppd_poll = 0;
+  printer->remote_cups_connection_test = NULL;
 }
 
 static void
@@ -98,6 +101,11 @@ gtk_printer_cups_finalize (GObject *object)
   if (printer->ppd_file)
     ppdClose (printer->ppd_file);
 
+  if (printer->get_remote_ppd_poll > 0)
+    g_source_remove (printer->get_remote_ppd_poll);
+
+  gtk_cups_connection_test_free (printer->remote_cups_connection_test);
+
   G_OBJECT_CLASS (gtk_printer_cups_parent_class)->finalize (object);
 }
 
diff --git a/modules/printbackends/cups/gtkprintercups.h b/modules/printbackends/cups/gtkprintercups.h
index cd2b318..b00d086 100644
--- a/modules/printbackends/cups/gtkprintercups.h
+++ b/modules/printbackends/cups/gtkprintercups.h
@@ -23,6 +23,7 @@
 #include <glib-object.h>
 #include <cups/cups.h>
 #include <cups/ppd.h>
+#include "gtkcupsutils.h"
 
 #include <gtk/gtkunixprint.h>
 
@@ -55,6 +56,10 @@ struct _GtkPrinterCups
 
   gchar  *default_cover_before;
   gchar  *default_cover_after;
+
+  gboolean remote;
+  guint get_remote_ppd_poll;
+  GtkCupsConnectionTest *remote_cups_connection_test;
 };
 
 struct _GtkPrinterCupsClass