Adding upstream version 2.10.36.upstream/2.10.36

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 897 insertions, 0 deletions

diff --git a/app/widgets/gimphelp.c b/app/widgets/gimphelp.c
new file mode 100644
index 0000000..242454d
--- /dev/null
+++ b/app/widgets/gimphelp.c
@@ -0,0 +1,897 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimphelp.c
+ * Copyright (C) 1999-2004 Michael Natterer <mitch@gimp.org>
+ *                         Henrik Brix Andersen <brix@gimp.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "widgets-types.h"
+
+#include "config/gimpguiconfig.h"
+
+#include "core/gimp.h"
+#include "core/gimpparamspecs.h"
+#include "core/gimpprogress.h"
+#include "core/gimp-utils.h"
+
+#include "pdb/gimppdb.h"
+#include "pdb/gimpprocedure.h"
+
+#include "plug-in/gimpplugin.h"
+#include "plug-in/gimppluginmanager-help-domain.h"
+#include "plug-in/gimptemporaryprocedure.h"
+
+#include "gimphelp.h"
+#include "gimphelp-ids.h"
+#include "gimplanguagecombobox.h"
+#include "gimplanguagestore-parser.h"
+#include "gimpmessagebox.h"
+#include "gimpmessagedialog.h"
+#include "gimpmessagedialog.h"
+#include "gimpwidgets-utils.h"
+
+#include "gimp-log.h"
+#include "gimp-intl.h"
+
+
+typedef struct _GimpIdleHelp GimpIdleHelp;
+
+struct _GimpIdleHelp
+{
+  Gimp         *gimp;
+  GimpProgress *progress;
+  gchar        *help_domain;
+  gchar        *help_locales;
+  gchar        *help_id;
+
+  GtkDialog    *query_dialog;
+};
+
+
+/*  local function prototypes  */
+
+static gboolean   gimp_idle_help          (GimpIdleHelp  *idle_help);
+static void       gimp_idle_help_free     (GimpIdleHelp  *idle_help);
+
+static gboolean   gimp_help_browser       (Gimp          *gimp,
+                                           GimpProgress  *progress);
+static void       gimp_help_browser_error (Gimp          *gimp,
+                                           GimpProgress  *progress,
+                                           const gchar   *title,
+                                           const gchar   *primary,
+                                           const gchar   *text);
+
+static void       gimp_help_call          (Gimp          *gimp,
+                                           GimpProgress  *progress,
+                                           const gchar   *procedure_name,
+                                           const gchar   *help_domain,
+                                           const gchar   *help_locales,
+                                           const gchar   *help_id);
+
+static gint       gimp_help_get_help_domains         (Gimp    *gimp,
+                                                      gchar ***domain_names,
+                                                      gchar ***domain_uris);
+static gchar    * gimp_help_get_default_domain_uri   (Gimp    *gimp);
+static gchar    * gimp_help_get_locales              (Gimp    *gimp);
+
+static GFile    * gimp_help_get_user_manual_basedir  (void);
+
+static void       gimp_help_query_alt_user_manual    (GimpIdleHelp *idle_help);
+
+static void       gimp_help_language_combo_changed   (GtkComboBox  *combo,
+                                                      GimpIdleHelp *idle_help);
+
+/*  public functions  */
+
+void
+gimp_help_show (Gimp         *gimp,
+                GimpProgress *progress,
+                const gchar  *help_domain,
+                const gchar  *help_id)
+{
+  GimpGuiConfig *config;
+
+  g_return_if_fail (GIMP_IS_GIMP (gimp));
+  g_return_if_fail (progress == NULL || GIMP_IS_PROGRESS (progress));
+
+  config = GIMP_GUI_CONFIG (gimp->config);
+
+  if (config->use_help)
+    {
+      GimpIdleHelp *idle_help = g_slice_new0 (GimpIdleHelp);
+
+      idle_help->gimp     = gimp;
+      idle_help->progress = progress;
+
+      if (help_domain && strlen (help_domain))
+        idle_help->help_domain = g_strdup (help_domain);
+
+      idle_help->help_locales = gimp_help_get_locales (gimp);
+
+      if (help_id && strlen (help_id))
+        idle_help->help_id = g_strdup (help_id);
+
+      GIMP_LOG (HELP, "request for help-id '%s' from help-domain '%s'",
+                help_id     ? help_id      : "(null)",
+                help_domain ? help_domain  : "(null)");
+
+      g_idle_add ((GSourceFunc) gimp_idle_help, idle_help);
+    }
+}
+
+gboolean
+gimp_help_browser_is_installed (Gimp *gimp)
+{
+  g_return_val_if_fail (GIMP_IS_GIMP (gimp), FALSE);
+
+  if (gimp_pdb_lookup_procedure (gimp->pdb, "extension-gimp-help-browser"))
+    return TRUE;
+
+  return FALSE;
+}
+
+gboolean
+gimp_help_user_manual_is_installed (Gimp *gimp)
+{
+  GFile    *basedir;
+  gboolean  found = FALSE;
+
+  g_return_val_if_fail (GIMP_IS_GIMP (gimp), FALSE);
+
+  /*  if GIMP2_HELP_URI is set, assume that the manual can be found there  */
+  if (g_getenv ("GIMP2_HELP_URI"))
+    return TRUE;
+
+  basedir = gimp_help_get_user_manual_basedir ();
+
+  if (g_file_query_file_type (basedir, G_FILE_QUERY_INFO_NONE, NULL) ==
+      G_FILE_TYPE_DIRECTORY)
+    {
+      gchar       *locales = gimp_help_get_locales (gimp);
+      const gchar *s       = locales;
+      const gchar *p;
+
+      for (p = strchr (s, ':'); p && !found; p = strchr (s, ':'))
+        {
+          gchar *locale = g_strndup (s, p - s);
+          GFile *file1  = g_file_get_child (basedir, locale);
+          GFile *file2  = g_file_get_child (file1, "gimp-help.xml");
+
+          found = (g_file_query_file_type (file2, G_FILE_QUERY_INFO_NONE,
+                                           NULL) == G_FILE_TYPE_REGULAR);
+
+          g_object_unref (file1);
+          g_object_unref (file2);
+          g_free (locale);
+
+          s = p + 1;
+        }
+
+      g_free (locales);
+
+      if (! found)
+        {
+          GFile *file1  = g_file_get_child (basedir, "en");
+          GFile *file2  = g_file_get_child (file1, "gimp-help.xml");
+
+          found = (g_file_query_file_type (file2, G_FILE_QUERY_INFO_NONE,
+                                           NULL) == G_FILE_TYPE_REGULAR);
+
+          g_object_unref (file1);
+          g_object_unref (file2);
+        }
+    }
+
+  g_object_unref (basedir);
+
+  return found;
+}
+
+void
+gimp_help_user_manual_changed (Gimp *gimp)
+{
+  GimpProcedure *procedure;
+
+  g_return_if_fail (GIMP_IS_GIMP (gimp));
+
+  /*  Check if a help parser is running  */
+  procedure = gimp_pdb_lookup_procedure (gimp->pdb, "extension-gimp-help-temp");
+
+  if (GIMP_IS_TEMPORARY_PROCEDURE (procedure))
+    {
+      gimp_plug_in_close (GIMP_TEMPORARY_PROCEDURE (procedure)->plug_in, TRUE);
+    }
+}
+
+GList *
+gimp_help_get_installed_languages (void)
+{
+  GList *manuals = NULL;
+  GFile *basedir;
+
+  /*  if GIMP2_HELP_URI is set, assume that the manual can be found there  */
+  if (g_getenv ("GIMP2_HELP_URI"))
+    basedir = g_file_new_for_uri (g_getenv ("GIMP2_HELP_URI"));
+  else
+    basedir = gimp_help_get_user_manual_basedir ();
+
+  if (g_file_query_file_type (basedir, G_FILE_QUERY_INFO_NONE, NULL) ==
+      G_FILE_TYPE_DIRECTORY)
+    {
+      GFileEnumerator *enumerator;
+
+      enumerator = g_file_enumerate_children (basedir,
+                                              G_FILE_ATTRIBUTE_STANDARD_NAME ","
+                                              G_FILE_ATTRIBUTE_STANDARD_TYPE,
+                                              G_FILE_QUERY_INFO_NONE,
+                                              NULL, NULL);
+
+      if (enumerator)
+        {
+          GFileInfo *info;
+
+          while ((info = g_file_enumerator_next_file (enumerator,
+                                                      NULL, NULL)))
+            {
+              if (g_file_info_get_file_type (info) == G_FILE_TYPE_DIRECTORY)
+                {
+                  GFile *locale_dir;
+                  GFile *file;
+
+                  locale_dir = g_file_enumerator_get_child (enumerator, info);
+                  file  = g_file_get_child (locale_dir, "gimp-help.xml");
+                  if (g_file_query_file_type (file, G_FILE_QUERY_INFO_NONE,
+                                              NULL) == G_FILE_TYPE_REGULAR)
+                    {
+                      manuals = g_list_prepend (manuals,
+                                                g_strdup (g_file_info_get_name (info)));
+                    }
+                  g_object_unref (locale_dir);
+                  g_object_unref (file);
+                }
+              g_object_unref (info);
+            }
+          g_object_unref (enumerator);
+        }
+    }
+  g_object_unref (basedir);
+
+  return manuals;
+}
+
+/*  private functions  */
+
+static gboolean
+gimp_idle_help (GimpIdleHelp *idle_help)
+{
+  GimpGuiConfig *config         = GIMP_GUI_CONFIG (idle_help->gimp->config);
+  const gchar   *procedure_name = NULL;
+
+  if (! idle_help->help_domain       &&
+      ! config->user_manual_online   &&
+      ! gimp_help_user_manual_is_installed (idle_help->gimp))
+    {
+      /*  The user manual is not installed locally, propose alternative
+       *  manuals (other installed languages or online version).
+       */
+      gimp_help_query_alt_user_manual (idle_help);
+
+      return FALSE;
+    }
+
+  if (config->help_browser == GIMP_HELP_BROWSER_GIMP)
+    {
+      if (gimp_help_browser (idle_help->gimp, idle_help->progress))
+        procedure_name = "extension-gimp-help-browser-temp";
+    }
+
+  if (config->help_browser == GIMP_HELP_BROWSER_WEB_BROWSER)
+    {
+      /*  FIXME: should check for procedure availability  */
+      procedure_name = "plug-in-web-browser";
+    }
+
+  if (procedure_name)
+    gimp_help_call (idle_help->gimp,
+                    idle_help->progress,
+                    procedure_name,
+                    idle_help->help_domain,
+                    idle_help->help_locales,
+                    idle_help->help_id);
+
+  gimp_idle_help_free (idle_help);
+
+  return FALSE;
+}
+
+static void
+gimp_idle_help_free (GimpIdleHelp *idle_help)
+{
+  g_free (idle_help->help_domain);
+  g_free (idle_help->help_locales);
+  g_free (idle_help->help_id);
+
+  g_slice_free (GimpIdleHelp, idle_help);
+}
+
+static gboolean
+gimp_help_browser (Gimp         *gimp,
+                   GimpProgress *progress)
+{
+  static gboolean  busy = FALSE;
+  GimpProcedure   *procedure;
+
+  if (busy)
+    return TRUE;
+
+  busy = TRUE;
+
+  /*  Check if a help browser is already running  */
+  procedure = gimp_pdb_lookup_procedure (gimp->pdb,
+                                         "extension-gimp-help-browser-temp");
+
+  if (! procedure)
+    {
+      GimpValueArray *args         = NULL;
+      gint            n_domains    = 0;
+      gchar         **help_domains = NULL;
+      gchar         **help_uris    = NULL;
+      GError         *error        = NULL;
+
+      procedure = gimp_pdb_lookup_procedure (gimp->pdb,
+                                             "extension-gimp-help-browser");
+
+      if (! procedure)
+        {
+          gimp_help_browser_error (gimp, progress,
+                                   _("Help browser is missing"),
+                                   _("The GIMP help browser is not available."),
+                                   _("The GIMP help browser plug-in appears "
+                                     "to be missing from your installation. "
+                                     "You may instead use the web browser "
+                                     "for reading the help pages."));
+          busy = FALSE;
+
+          return FALSE;
+        }
+
+      n_domains = gimp_help_get_help_domains (gimp, &help_domains, &help_uris);
+
+      args = gimp_procedure_get_arguments (procedure);
+      gimp_value_array_truncate (args, 5);
+
+      g_value_set_int             (gimp_value_array_index (args, 0),
+                                   GIMP_RUN_INTERACTIVE);
+      g_value_set_int             (gimp_value_array_index (args, 1),
+                                   n_domains);
+      gimp_value_take_stringarray (gimp_value_array_index (args, 2),
+                                   help_domains, n_domains);
+      g_value_set_int             (gimp_value_array_index (args, 3),
+                                   n_domains);
+      gimp_value_take_stringarray (gimp_value_array_index (args, 4),
+                                   help_uris, n_domains);
+
+      gimp_procedure_execute_async (procedure, gimp,
+                                    gimp_get_user_context (gimp),
+                                    NULL, args, NULL, &error);
+
+      gimp_value_array_unref (args);
+
+      if (error)
+        {
+          gimp_message_literal (gimp, G_OBJECT (progress), GIMP_MESSAGE_ERROR,
+                                error->message);
+          g_error_free (error);
+        }
+     }
+
+  /*  Check if the help browser started properly  */
+  procedure = gimp_pdb_lookup_procedure (gimp->pdb,
+                                         "extension-gimp-help-browser-temp");
+
+  if (! procedure)
+    {
+      gimp_help_browser_error (gimp, progress,
+                               _("Help browser doesn't start"),
+                               _("Could not start the GIMP help browser "
+                                 "plug-in."),
+                               _("You may instead use the web browser "
+                                 "for reading the help pages."));
+      busy = FALSE;
+
+      return FALSE;
+    }
+
+  busy = FALSE;
+
+  return TRUE;
+}
+
+static void
+gimp_help_browser_error (Gimp         *gimp,
+                         GimpProgress *progress,
+                         const gchar  *title,
+                         const gchar  *primary,
+                         const gchar  *text)
+{
+  GtkWidget *dialog;
+
+  dialog = gimp_message_dialog_new (title, GIMP_ICON_HELP_USER_MANUAL,
+                                    NULL, 0,
+                                    NULL, NULL,
+
+                                    _("_Cancel"),          GTK_RESPONSE_CANCEL,
+                                    _("Use _Web Browser"), GTK_RESPONSE_OK,
+
+                                    NULL);
+
+  gtk_dialog_set_alternative_button_order (GTK_DIALOG (dialog),
+                                           GTK_RESPONSE_OK,
+                                           GTK_RESPONSE_CANCEL,
+                                           -1);
+
+  if (progress)
+    {
+      guint32 window_id = gimp_progress_get_window_id (progress);
+
+      if (window_id)
+        gimp_window_set_transient_for (GTK_WINDOW (dialog), window_id);
+    }
+
+  gimp_message_box_set_primary_text (GIMP_MESSAGE_DIALOG (dialog)->box,
+                                     "%s", primary);
+  gimp_message_box_set_text (GIMP_MESSAGE_DIALOG (dialog)->box, "%s", text);
+
+  if (gimp_dialog_run (GIMP_DIALOG (dialog)) == GTK_RESPONSE_OK)
+    {
+      g_object_set (gimp->config,
+                    "help-browser", GIMP_HELP_BROWSER_WEB_BROWSER,
+                    NULL);
+    }
+
+  gtk_widget_destroy (dialog);
+}
+
+static void
+gimp_help_call (Gimp         *gimp,
+                GimpProgress *progress,
+                const gchar  *procedure_name,
+                const gchar  *help_domain,
+                const gchar  *help_locales,
+                const gchar  *help_id)
+{
+  GimpProcedure *procedure;
+
+  /*  Special case the help browser  */
+  if (! strcmp (procedure_name, "extension-gimp-help-browser-temp"))
+    {
+      GimpValueArray *return_vals;
+      GError         *error = NULL;
+
+      GIMP_LOG (HELP, "Calling help via %s: %s %s %s",
+                procedure_name,
+                help_domain  ? help_domain  : "(null)",
+                help_locales ? help_locales : "(null)",
+                help_id      ? help_id      : "(null)");
+
+      return_vals =
+        gimp_pdb_execute_procedure_by_name (gimp->pdb,
+                                            gimp_get_user_context (gimp),
+                                            progress, &error,
+                                            procedure_name,
+                                            G_TYPE_STRING, help_domain,
+                                            G_TYPE_STRING, help_locales,
+                                            G_TYPE_STRING, help_id,
+                                            G_TYPE_NONE);
+
+      gimp_value_array_unref (return_vals);
+
+      if (error)
+        {
+          gimp_message_literal (gimp, NULL, GIMP_MESSAGE_ERROR, error->message);
+          g_error_free (error);
+        }
+
+      return;
+    }
+
+  /*  Check if a help parser is already running  */
+  procedure = gimp_pdb_lookup_procedure (gimp->pdb, "extension-gimp-help-temp");
+
+  if (! procedure)
+    {
+      GimpValueArray  *args         = NULL;
+      gint             n_domains    = 0;
+      gchar          **help_domains = NULL;
+      gchar          **help_uris    = NULL;
+      GError          *error        = NULL;
+
+      procedure = gimp_pdb_lookup_procedure (gimp->pdb, "extension-gimp-help");
+
+      if (! procedure)
+        /*  FIXME: error msg  */
+        return;
+
+      n_domains = gimp_help_get_help_domains (gimp, &help_domains, &help_uris);
+
+      args = gimp_procedure_get_arguments (procedure);
+      gimp_value_array_truncate (args, 4);
+
+      g_value_set_int             (gimp_value_array_index (args, 0),
+                                   n_domains);
+      gimp_value_take_stringarray (gimp_value_array_index (args, 1),
+                                   help_domains, n_domains);
+      g_value_set_int             (gimp_value_array_index (args, 2),
+                                   n_domains);
+      gimp_value_take_stringarray (gimp_value_array_index (args, 3),
+                                   help_uris, n_domains);
+
+      gimp_procedure_execute_async (procedure, gimp,
+                                    gimp_get_user_context (gimp), progress,
+                                    args, NULL, &error);
+
+      gimp_value_array_unref (args);
+
+      if (error)
+        {
+          gimp_message_literal (gimp, NULL, GIMP_MESSAGE_ERROR, error->message);
+          g_error_free (error);
+        }
+    }
+
+  /*  Check if the help parser started properly  */
+  procedure = gimp_pdb_lookup_procedure (gimp->pdb, "extension-gimp-help-temp");
+
+  if (procedure)
+    {
+      GimpValueArray *return_vals;
+      GError         *error = NULL;
+
+      GIMP_LOG (HELP, "Calling help via %s: %s %s %s",
+                procedure_name,
+                help_domain  ? help_domain  : "(null)",
+                help_locales ? help_locales : "(null)",
+                help_id      ? help_id      : "(null)");
+
+      return_vals =
+        gimp_pdb_execute_procedure_by_name (gimp->pdb,
+                                            gimp_get_user_context (gimp),
+                                            progress, &error,
+                                            "extension-gimp-help-temp",
+                                            G_TYPE_STRING, procedure_name,
+                                            G_TYPE_STRING, help_domain,
+                                            G_TYPE_STRING, help_locales,
+                                            G_TYPE_STRING, help_id,
+                                            G_TYPE_NONE);
+
+      gimp_value_array_unref (return_vals);
+
+      if (error)
+        {
+          gimp_message_literal (gimp, NULL, GIMP_MESSAGE_ERROR, error->message);
+          g_error_free (error);
+        }
+    }
+}
+
+static gint
+gimp_help_get_help_domains (Gimp    *gimp,
+                            gchar ***domain_names,
+                            gchar ***domain_uris)
+{
+  gchar **plug_in_domains = NULL;
+  gchar **plug_in_uris    = NULL;
+  gint    i, n_domains;
+
+  n_domains = gimp_plug_in_manager_get_help_domains (gimp->plug_in_manager,
+                                                     &plug_in_domains,
+                                                     &plug_in_uris);
+
+  *domain_names = g_new0 (gchar *, n_domains + 1);
+  *domain_uris  = g_new0 (gchar *, n_domains + 1);
+
+  (*domain_names)[0] = g_strdup ("https://www.gimp.org/help");
+  (*domain_uris)[0]  = gimp_help_get_default_domain_uri (gimp);
+
+  for (i = 0; i < n_domains; i++)
+    {
+      (*domain_names)[i + 1] = plug_in_domains[i];
+      (*domain_uris)[i + 1]  = plug_in_uris[i];
+    }
+
+  g_free (plug_in_domains);
+  g_free (plug_in_uris);
+
+  return n_domains + 1;
+}
+
+static gchar *
+gimp_help_get_default_domain_uri (Gimp *gimp)
+{
+  GimpGuiConfig *config = GIMP_GUI_CONFIG (gimp->config);
+  GFile         *dir;
+  gchar         *uri;
+
+  if (g_getenv ("GIMP2_HELP_URI"))
+    return g_strdup (g_getenv ("GIMP2_HELP_URI"));
+
+  if (config->user_manual_online)
+    return g_strdup (config->user_manual_online_uri);
+
+  dir = gimp_help_get_user_manual_basedir ();
+  uri = g_file_get_uri (dir);
+  g_object_unref (dir);
+
+  return uri;
+}
+
+static gchar *
+gimp_help_get_locales (Gimp *gimp)
+{
+  GimpGuiConfig  *config = GIMP_GUI_CONFIG (gimp->config);
+  gchar         **names;
+  gchar          *locales      = NULL;
+  GList          *locales_list = NULL;
+  GList          *iter;
+  gint            i;
+
+  if (config->help_locales && strlen (config->help_locales))
+    return g_strdup (config->help_locales);
+
+  /* Process locales. */
+  names = (gchar **) g_get_language_names ();
+  for (i = 0; names[i]; i++)
+    {
+      gchar *locale = g_strdup (names[i]);
+      gchar *c;
+
+      /* We don't care about encoding in context of our help system. */
+      c = strchr (locale, '.');
+      if (c)
+        *c = '\0';
+
+      /* We don't care about variants either. */
+      c = strchr (locale, '@');
+      if (c)
+        *c = '\0';
+
+      /* Apparently some systems (i.e. Windows) would return a value as
+       * IETF language tag, which is a different format from POSIX
+       * locale; especially it would separate the lang and the region
+       * with an hyphen instead of an underscore.
+       * Actually the difference is much deeper, and IETF language tags
+       * can have extended language subtags, a script subtag, variants,
+       * moreover using different codes.
+       * We'd actually need to look into this in details (TODO).
+       * this dirty hack should do for easy translation at least (like
+       * "en-GB" -> "en_GB).
+       * Cf. bug 777754.
+       */
+      c = strchr (locale, '-');
+      if (c)
+        *c = '_';
+
+      if (locale && *locale &&
+          ! g_list_find_custom (locales_list, locale,
+                                (GCompareFunc) g_strcmp0))
+        {
+          gchar *base;
+
+          /* Adding this locale. */
+          locales_list = g_list_prepend (locales_list, locale);
+
+          /* Adding the base language as well. */
+          base = strdup (locale);
+          c = strchr (base, '_');
+          if (c)
+            *c = '\0';
+
+          if (base && *base &&
+              ! g_list_find_custom (locales_list, base,
+                                    (GCompareFunc) g_strcmp0))
+            {
+              locales_list = g_list_prepend (locales_list, base);
+            }
+          else
+            {
+              g_free (base);
+            }
+        }
+      else
+        {
+          g_free (locale);
+        }
+    }
+
+  locales_list = g_list_reverse (locales_list);
+
+  /* Finally generate the colon-separated value. */
+  if (locales_list)
+    {
+      locales = g_strdup (locales_list->data);
+      for (iter = locales_list->next; iter; iter = iter->next)
+        {
+          gchar *temp = locales;
+          locales = g_strconcat (temp, ":", iter->data, NULL);
+          g_free (temp);
+        }
+    }
+
+  g_list_free_full (locales_list, g_free);
+
+  return locales;
+}
+
+static GFile *
+gimp_help_get_user_manual_basedir (void)
+{
+  return gimp_data_directory_file ("help", NULL);
+}
+
+static void
+gimp_help_query_online_response (GtkWidget    *dialog,
+                                 gint          response,
+                                 GimpIdleHelp *idle_help)
+{
+  gtk_widget_destroy (dialog);
+
+  if (response == GTK_RESPONSE_ACCEPT)
+    {
+      g_object_set (idle_help->gimp->config,
+                    "user-manual-online", TRUE,
+                    NULL);
+    }
+  if (response != GTK_RESPONSE_YES)
+    {
+      g_object_set (idle_help->gimp->config,
+                    "help-locales", "",
+                    NULL);
+    }
+
+  if (response == GTK_RESPONSE_ACCEPT ||
+      response == GTK_RESPONSE_YES)
+    {
+      gimp_help_show (idle_help->gimp,
+                      idle_help->progress,
+                      idle_help->help_domain,
+                      idle_help->help_id);
+    }
+
+  gimp_idle_help_free (idle_help);
+}
+
+static void
+gimp_help_query_alt_user_manual (GimpIdleHelp *idle_help)
+{
+  GtkWidget *dialog;
+  GList     *manuals;
+
+  dialog = gimp_message_dialog_new (_("GIMP user manual is missing"),
+                                    GIMP_ICON_HELP_USER_MANUAL,
+                                    NULL, 0, NULL, NULL,
+                                    _("_Cancel"), GTK_RESPONSE_CANCEL,
+                                    NULL);
+  idle_help->query_dialog = GTK_DIALOG (dialog);
+
+  if (idle_help->progress)
+    {
+      guint32 window_id = gimp_progress_get_window_id (idle_help->progress);
+
+      if (window_id)
+        gimp_window_set_transient_for (GTK_WINDOW (dialog), window_id);
+    }
+
+  gimp_message_box_set_primary_text (GIMP_MESSAGE_DIALOG (dialog)->box,
+                                     _("The GIMP user manual is not installed "
+                                       "in your language."));
+
+  /* Add a list of available manuals instead, if any. */
+  manuals = gimp_help_get_installed_languages ();
+  if (manuals != NULL)
+    {
+      GtkWidget *lang_combo;
+
+      /* Add an additional button. */
+      gtk_dialog_add_button (GTK_DIALOG (dialog),
+                             _("Read Selected _Language"),
+                             GTK_RESPONSE_YES);
+      /* And a dropdown list of available manuals. */
+      lang_combo = gimp_language_combo_box_new (TRUE,
+                                                _("Available manuals..."));
+      gtk_combo_box_set_active (GTK_COMBO_BOX (lang_combo), 0);
+      gtk_dialog_set_response_sensitive (idle_help->query_dialog,
+                                         GTK_RESPONSE_YES, FALSE);
+      g_signal_connect (lang_combo, "changed",
+                        G_CALLBACK (gimp_help_language_combo_changed),
+                        idle_help);
+      gtk_box_pack_start (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (dialog))),
+                          lang_combo, TRUE, TRUE, 0);
+      gtk_widget_show (lang_combo);
+
+      gimp_message_box_set_text (GIMP_MESSAGE_DIALOG (dialog)->box,
+                                 _("You may either select a manual in another "
+                                   "language or read the online version."));
+    }
+  else
+    {
+      gimp_message_box_set_text (GIMP_MESSAGE_DIALOG (dialog)->box,
+                                 _("You may either install the additional help "
+                                   "package or change your preferences to use "
+                                   "the online version."));
+    }
+  gtk_dialog_add_button (GTK_DIALOG (dialog),
+                         _("Read _Online"), GTK_RESPONSE_ACCEPT);
+  gtk_dialog_set_default_response (GTK_DIALOG (dialog), GTK_RESPONSE_ACCEPT);
+  if (manuals != NULL)
+    {
+      gtk_dialog_set_alternative_button_order (GTK_DIALOG (dialog),
+                                               GTK_RESPONSE_ACCEPT,
+                                               GTK_RESPONSE_YES,
+                                               GTK_RESPONSE_CANCEL,
+                                               -1);
+      g_list_free_full (manuals, g_free);
+    }
+  else
+    {
+      gtk_dialog_set_alternative_button_order (GTK_DIALOG (dialog),
+                                               GTK_RESPONSE_ACCEPT,
+                                               GTK_RESPONSE_CANCEL,
+                                               -1);
+    }
+  g_signal_connect (dialog, "response",
+                    G_CALLBACK (gimp_help_query_online_response),
+                    idle_help);
+  gtk_widget_show (dialog);
+}
+
+static void
+gimp_help_language_combo_changed (GtkComboBox  *combo,
+                                  GimpIdleHelp *idle_help)
+{
+  gchar *help_locales = NULL;
+  gchar *code;
+
+  code = gimp_language_combo_box_get_code (GIMP_LANGUAGE_COMBO_BOX (combo));
+  if (code && g_strcmp0 ("", code) != 0)
+    {
+      help_locales = g_strdup_printf ("%s:", code);
+      gtk_dialog_set_response_sensitive (idle_help->query_dialog,
+                                         GTK_RESPONSE_YES, TRUE);
+    }
+  else
+    {
+      gtk_dialog_set_response_sensitive (idle_help->query_dialog,
+                                         GTK_RESPONSE_YES, FALSE);
+    }
+  g_object_set (idle_help->gimp->config,
+                "help-locales", help_locales? help_locales : "",
+                NULL);
+
+  g_free (code);
+  if (help_locales)
+    g_free (help_locales);
+}