gtk/demos/gtk-demo/listview_words.c

/* Lists/Words
 *
 * This demo shows filtering a long list - of words.
 *
 * You should have the file `/usr/share/dict/words` installed for
 * this demo to work.
 */

#include <gtk/gtk.h>

static GtkWidget *window = NULL;
static GtkWidget *progress;

const char *factory_text =
"<?xml version='1.0' encoding='UTF-8'?>\n"
"<interface>\n"
"  <template class='GtkListItem'>\n"
"    <property name='child'>\n"
"      <object class='GtkLabel'>\n"
"        <property name='ellipsize'>end</property>\n"
"        <property name='xalign'>0</property>\n"
"        <binding name='label'>\n"
"          <lookup name='string' type='GtkStringObject'>\n"
"            <lookup name='item'>GtkListItem</lookup>\n"
"          </lookup>\n"
"        </binding>\n"
"      </object>\n"
"    </property>\n"
"  </template>\n"
"</interface>\n";

static void
update_title_cb (GtkFilterListModel *model)
{
  guint total;
  char *title;
  guint pending;

  total = g_list_model_get_n_items (gtk_filter_list_model_get_model (model));
  pending = gtk_filter_list_model_get_pending (model);

  title = g_strdup_printf ("%u lines", g_list_model_get_n_items (G_LIST_MODEL (model)));

  gtk_widget_set_visible (progress, pending != 0);
  gtk_progress_bar_set_fraction (GTK_PROGRESS_BAR (progress), (total - pending) / (double) total);
  gtk_window_set_title (GTK_WINDOW (window), title);
  g_free (title);
}

static void
read_lines_cb (GObject      *object,
               GAsyncResult *result,
               gpointer      data)
{
  GBufferedInputStream *stream = G_BUFFERED_INPUT_STREAM (object);
  GtkStringList *stringlist = data;
  GError *error = NULL;
  gsize size;
  GPtrArray *lines;
  gssize n_filled;
  const char *buffer, *newline;

  n_filled = g_buffered_input_stream_fill_finish (stream, result, &error);
  if (n_filled < 0)
    {
      g_print ("Could not read data: %s\n", error->message);
      g_clear_error (&error);
      return;
    }

  buffer = g_buffered_input_stream_peek_buffer (stream, &size);

  if (n_filled == 0)
    {
      if (size)
        gtk_string_list_take (stringlist, g_utf8_make_valid (buffer, size));
      return;
    }

  lines = NULL;
  while ((newline = memchr (buffer, '\n', size)))
    {
      if (newline > buffer)
        {
          if (lines == NULL)
            lines = g_ptr_array_new_with_free_func (g_free);
          g_ptr_array_add (lines, g_utf8_make_valid (buffer, newline - buffer));
        }
      if (g_input_stream_skip (G_INPUT_STREAM (stream), newline - buffer + 1, NULL, &error) < 0)
        {
          g_clear_error (&error);
          break;
        }
      buffer = g_buffered_input_stream_peek_buffer (stream, &size);
    }
  if (lines == NULL)
    {
      g_buffered_input_stream_set_buffer_size (stream, g_buffered_input_stream_get_buffer_size (stream) + 4096);
    }
  else
    {
      g_ptr_array_add (lines, NULL);
      gtk_string_list_splice (stringlist, g_list_model_get_n_items (G_LIST_MODEL (stringlist)), 0, (const char **) lines->pdata);
      g_ptr_array_free (lines, TRUE);
    }

  g_buffered_input_stream_fill_async (stream, -1, G_PRIORITY_HIGH_IDLE, NULL, read_lines_cb, data);
}
               
static void
file_is_open_cb (GObject      *file,
                 GAsyncResult *result,
                 gpointer      data)
{
  GError *error = NULL;
  GFileInputStream *file_stream;
  GBufferedInputStream *stream;

  file_stream = g_file_read_finish (G_FILE (file), result, &error);
  if (file_stream == NULL)
    {
      g_print ("Could not open file: %s\n", error->message);
      g_error_free (error);
      return;
    }

  stream = G_BUFFERED_INPUT_STREAM (g_buffered_input_stream_new (G_INPUT_STREAM (file_stream)));
  g_buffered_input_stream_fill_async (stream, -1, G_PRIORITY_HIGH_IDLE, NULL, read_lines_cb, data);
  g_object_unref (stream);
}

static void
load_file (GtkStringList *list,
           GFile         *file)
{
  gtk_string_list_splice (list, 0, g_list_model_get_n_items (G_LIST_MODEL (list)), NULL);
  g_file_read_async (file, G_PRIORITY_HIGH_IDLE, NULL, file_is_open_cb, list);
}

static void
file_selected_cb (GtkWidget     *button,
                  GtkStringList *stringlist)
{
  GFile *file = gtk_file_chooser_get_file (GTK_FILE_CHOOSER (button));

  if (file)
    {
      load_file (stringlist, file);
      g_object_unref (file);
    }
}

GtkWidget *
do_listview_words (GtkWidget *do_widget)
{
  if (window == NULL)
    {
      GtkWidget *header, *listview, *sw, *vbox, *search_entry, *open_button, *overlay;
      GtkFilterListModel *filter_model;
      GtkNoSelection *selection;
      GtkStringList *stringlist;
      GtkFilter *filter;
      GtkExpression *expression;
      GFile *file;

      file = g_file_new_for_path ("/usr/share/dict/words");
      if (g_file_query_exists (file, NULL))
        {
          stringlist = gtk_string_list_new (NULL);
          load_file (stringlist, file);
        }
      else
        {
          char **words;
          words = g_strsplit ("lorem ipsum dolor sit amet consectetur adipisci elit sed eiusmod tempor incidunt labore et dolore magna aliqua ut enim ad minim veniam quis nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat", " ", -1);
          stringlist = gtk_string_list_new ((const char **) words);
          g_strfreev (words);
        }

      filter = gtk_string_filter_new ();
      expression = gtk_property_expression_new (GTK_TYPE_STRING_OBJECT, NULL, "string");
      gtk_string_filter_set_expression (GTK_STRING_FILTER (filter), expression);
      gtk_expression_unref (expression);
      filter_model = gtk_filter_list_model_new (G_LIST_MODEL (stringlist), filter);
      gtk_filter_list_model_set_incremental (filter_model, TRUE);

      window = gtk_window_new ();
      gtk_window_set_default_size (GTK_WINDOW (window), 400, 600);

      header = gtk_header_bar_new ();
      gtk_header_bar_set_show_title_buttons (GTK_HEADER_BAR (header), TRUE);
      open_button = gtk_file_chooser_button_new ("_Open", GTK_FILE_CHOOSER_ACTION_OPEN);
      g_signal_connect (open_button, "file-set", G_CALLBACK (file_selected_cb), stringlist);
      gtk_header_bar_pack_start (GTK_HEADER_BAR (header), open_button);
      gtk_window_set_titlebar (GTK_WINDOW (window), header);

      gtk_window_set_display (GTK_WINDOW (window),
                              gtk_widget_get_display (do_widget));
      g_object_add_weak_pointer (G_OBJECT (window), (gpointer*)&window);

      vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
      gtk_window_set_child (GTK_WINDOW (window), vbox);

      search_entry = gtk_search_entry_new ();
      g_object_bind_property (search_entry, "text", filter, "search", 0);
      gtk_box_append (GTK_BOX (vbox), search_entry);

      overlay = gtk_overlay_new ();
      gtk_box_append (GTK_BOX (vbox), overlay);

      progress = gtk_progress_bar_new ();
      gtk_widget_set_halign (progress, GTK_ALIGN_FILL);
      gtk_widget_set_valign (progress, GTK_ALIGN_START);
      gtk_widget_set_hexpand (progress, TRUE);
      gtk_overlay_add_overlay (GTK_OVERLAY (overlay), progress);

      sw = gtk_scrolled_window_new ();
      gtk_widget_set_vexpand (sw, TRUE);
      gtk_overlay_set_child (GTK_OVERLAY (overlay), sw);

      listview = gtk_list_view_new_with_factory (
          gtk_builder_list_item_factory_new_from_bytes (NULL,
              g_bytes_new_static (factory_text, strlen (factory_text))));
      gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), listview);
      selection = gtk_no_selection_new (G_LIST_MODEL (filter_model));
      gtk_list_view_set_model (GTK_LIST_VIEW (listview), G_LIST_MODEL (selection));
      g_object_unref (selection);

      g_signal_connect (filter_model, "items-changed", G_CALLBACK (update_title_cb), progress);
      g_signal_connect (filter_model, "notify::pending", G_CALLBACK (update_title_cb), progress);
      update_title_cb (filter_model);

      g_object_unref (filter_model);
    }

  if (!gtk_widget_get_visible (window))
    gtk_widget_show (window);
  else
    gtk_window_destroy (GTK_WINDOW (window));

  return window;
}