[gthumb] desktop background: always create a unique filename to force an update

[Paolo Bacchilega <paobac src gnome org>]

commit 97a904fb9e3c409ee457368bd6bede6b3a0c0ea7
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Fri Jan 27 13:14:35 2017 +0100

    desktop background: always create a unique filename to force an update

 extensions/desktop_background/actions.c |  172 ++++++++++++++++++++++++-------
 gthumb/gth-user-dir.c                   |   18 +++
 gthumb/gth-user-dir.h                   |    7 +-
 3 files changed, 159 insertions(+), 38 deletions(-)
---
diff --git a/extensions/desktop_background/actions.c b/extensions/desktop_background/actions.c
index 642bb8f..3509159 100644
--- a/extensions/desktop_background/actions.c
+++ b/extensions/desktop_background/actions.c
@@ -114,46 +114,127 @@ wallpaper_style_free (WallpaperStyle *style)
 }
 
 
-static GFile *
-get_wallpaper_file_n (int n)
+/* -- get_new_wallpaper_file_async -- */
+
+
+typedef struct {
+       GFile  *folder;
+       int     max_n;
+       GList  *wallpaper_files;
+       GRegex *wallpaper_name_regex;
+} NewWallpaperData;
+
+
+static void
+new_wallpaper_data_free (NewWallpaperData *data)
 {
-       char  *name;
-       GFile *file;
+       _g_object_unref (data->folder);
+       _g_string_list_free (data->wallpaper_files);
+       g_regex_unref (data->wallpaper_name_regex);
+       g_slice_free (NewWallpaperData, data);
+}
 
-       name = g_strdup_printf ("wallpaper%d.jpeg", n);
-       file = gth_user_dir_get_file_for_write (GTH_DIR_DATA, GTHUMB_DIR, name, NULL);
 
-       g_free (name);
+static void
+nw_for_each_file_func (GFile     *file,
+                      GFileInfo *info,
+                      gpointer   user_data)
+{
+       GTask             *task = user_data;
+       NewWallpaperData  *nw_data = g_task_get_task_data (task);
+       const char        *filename;
+       char             **tokens;
+
+       filename = g_file_info_get_name (info);
+       tokens = g_regex_split (nw_data->wallpaper_name_regex, filename, 0);
+       if (g_strv_length (tokens) >= 2) {
+               int n = atoi (tokens[1]);
+               if (n > nw_data->max_n)
+                       nw_data->max_n = n;
+               nw_data->wallpaper_files = g_list_prepend (nw_data->wallpaper_files, g_strdup (filename));
+       }
 
-       return file;
+       g_strfreev (tokens);
 }
 
 
-static GFile *
-get_new_wallpaper_file (WallpaperData *wdata)
+static void
+nw_done_func (GError     *error,
+             gpointer    user_data)
 {
-       GFile *wallpaper_file;
-       int    i;
+       GTask            *task = user_data;
+       NewWallpaperData *nw_data = g_task_get_task_data (task);
+       GList            *scan;
+       char             *display_name;
+       GFile            *proposed_file;
+
+       if (error != NULL) {
+               g_task_return_error (task, error);
+               g_object_unref (task);
+               return;
+       }
+
+       /* delete the old wallpapers */
+       for (scan = nw_data->wallpaper_files; scan; scan = scan->next) {
+               char  *name = scan->data;
+               GFile *file;
 
-       /* Use a new filename to force an update. */
+               file = g_file_get_child (nw_data->folder, name);
+               g_file_delete (file, NULL, NULL);
 
-       wallpaper_file = NULL;
-       for (i = 1; i <= 2; i++) {
-               wallpaper_file = get_wallpaper_file_n (i);
-               if ((wdata->old_style.file == NULL) || ! g_file_equal (wallpaper_file, wdata->old_style.file))
-                       break;
-               g_object_unref (wallpaper_file);
+               g_object_unref (file);
        }
 
-       if (wallpaper_file != NULL)
-               g_file_delete (wallpaper_file, NULL, NULL);
+       /* use a unique name to force a reload */
+       display_name = g_strdup_printf ("wallpaper%d.jpeg", nw_data->max_n + 1);
+       proposed_file = g_file_get_child_for_display_name (nw_data->folder, display_name, NULL);
+       g_task_return_pointer (task, proposed_file, g_object_unref);
 
-       return wallpaper_file;
+       g_free (display_name);
+       g_object_unref (task);
+}
+
+
+static void
+get_new_wallpaper_file_async (GCancellable        *cancellable,
+                             GAsyncReadyCallback  callback,
+                             gpointer             user_data)
+{
+       NewWallpaperData *nw_data;
+       GTask            *task;
+
+       nw_data = g_slice_new (NewWallpaperData);
+       nw_data->folder = gth_user_dir_get_dir_for_write (GTH_DIR_DATA, GTHUMB_DIR, NULL);
+       nw_data->max_n = 0;
+       nw_data->wallpaper_files = NULL;
+       nw_data->wallpaper_name_regex = g_regex_new ("wallpaper([0-9]+).jpeg", 0, 0, NULL);
+
+       task = g_task_new (NULL, cancellable, callback, user_data);
+       g_task_set_task_data (task, nw_data, (GDestroyNotify) new_wallpaper_data_free);
+
+       g_directory_foreach_child (nw_data->folder,
+                                  FALSE,
+                                  FALSE,
+                                  GFILE_NAME_TYPE_ATTRIBUTES,
+                                  cancellable,
+                                  NULL,
+                                  nw_for_each_file_func,
+                                  nw_done_func,
+                                  task);
+}
+
+
+static GFile *
+get_new_wallpaper_file_finish (GAsyncResult  *result,
+                               GError       **error)
+{
+       return g_task_propagate_pointer (G_TASK (result), error);
 }
 
 
 static WallpaperData *
-wallpaper_data_new (GthBrowser *browser)
+wallpaper_data_new (GthBrowser *browser,
+                   GFile      *wallpaper_file)
 {
        WallpaperData *wdata;
 
@@ -161,7 +242,7 @@ wallpaper_data_new (GthBrowser *browser)
        wdata->browser = browser;
        wallpaper_style_init_from_current (&wdata->old_style);
        wallpaper_style_init (&wdata->new_style);
-       wdata->new_style.file = get_new_wallpaper_file (wdata);
+       wdata->new_style.file = g_object_ref (wallpaper_file);
 
        return wdata;
 }
@@ -361,20 +442,30 @@ copy_wallpaper_ready_cb (GObject      *source_object,
 }
 
 
-void
-gth_browser_activate_set_desktop_background (GSimpleAction *action,
-                                            GVariant      *parameter,
-                                            gpointer       user_data)
+static void
+wallpaper_file_read_cb (GObject      *source_object,
+                       GAsyncResult *res,
+                       gpointer      user_data)
 {
-       GthBrowser    *browser = GTH_BROWSER (user_data);
-       WallpaperData *wdata;
-       gboolean       saving_wallpaper = FALSE;
-       GList         *items;
-       GList         *file_list;
-       GthFileData   *file_data;
-       const char    *mime_type;
+       GthBrowser     *browser = GTH_BROWSER (user_data);
+       GFile          *wallpaper_file;
+       GError        **error = NULL;
+       WallpaperData  *wdata;
+       gboolean        saving_wallpaper = FALSE;
+       GList          *items;
+       GList          *file_list;
+       GthFileData    *file_data;
+       const char     *mime_type;
+
+       wallpaper_file = get_new_wallpaper_file_finish (res, error);
+       if (wallpaper_file == NULL) {
+               _gtk_error_dialog_from_gerror_show (GTK_WINDOW (browser),  _("Could not set the desktop 
background"), *error);
+               g_clear_error (error);
+               return;
+       }
 
-       wdata = wallpaper_data_new (browser);
+       wdata = wallpaper_data_new (browser, wallpaper_file);
+       g_object_unref (wallpaper_file);
 
        items = gth_file_selection_get_selected (GTH_FILE_SELECTION (gth_browser_get_file_list_view 
(browser)));
        file_list = gth_file_list_get_files (GTH_FILE_LIST (gth_browser_get_file_list (browser)), items);
@@ -437,3 +528,12 @@ gth_browser_activate_set_desktop_background (GSimpleAction *action,
        _g_object_list_unref (file_list);
        _gtk_tree_path_list_free (items);
 }
+
+
+void
+gth_browser_activate_set_desktop_background (GSimpleAction *action,
+                                            GVariant      *parameter,
+                                            gpointer       user_data)
+{
+       get_new_wallpaper_file_async (NULL, wallpaper_file_read_cb, user_data);
+}
diff --git a/gthumb/gth-user-dir.c b/gthumb/gth-user-dir.c
index 490ec8f..f78b7c1 100644
--- a/gthumb/gth-user-dir.c
+++ b/gthumb/gth-user-dir.c
@@ -128,6 +128,24 @@ gth_user_dir_mkdir_with_parents (GthDir      dir_type,
 
 
 GFile *
+gth_user_dir_get_dir_for_write (GthDir      dir_type,
+                               const char *first_element,
+                                ...)
+{
+       va_list  var_args;
+       GFile   *file;
+
+       va_start (var_args, first_element);
+       file = _gth_user_dir_get_file_va_list (dir_type, first_element, var_args);
+       va_end (var_args);
+
+       _gth_user_dir_mkdir_with_parents (dir_type, file);
+
+       return file;
+}
+
+
+GFile *
 gth_user_dir_get_file_for_read (GthDir      dir_type,
                                const char *first_element,
                                ...)
diff --git a/gthumb/gth-user-dir.h b/gthumb/gth-user-dir.h
index 6999763..c45b946 100644
--- a/gthumb/gth-user-dir.h
+++ b/gthumb/gth-user-dir.h
@@ -36,8 +36,11 @@ typedef enum {
 #define GTHUMB_DIR "gthumb"
 
 void    gth_user_dir_mkdir_with_parents     (GthDir      dir_type,
-                                           const char *first_element,
-                                            ...) G_GNUC_NULL_TERMINATED;
+                                            const char *first_element,
+                                             ...) G_GNUC_NULL_TERMINATED;
+GFile * gth_user_dir_get_dir_for_write      (GthDir      dir_type,
+                                            const char *first_element,
+                                            ...) G_GNUC_NULL_TERMINATED;
 GFile * gth_user_dir_get_file_for_read     (GthDir      dir_type,
                                            const char *first_element,
                                            ...) G_GNUC_NULL_TERMINATED;