[gtk/wip/otte/whatever: 6/9] demo: Make words listview load async

[Benjamin Otte <otte src gnome org>]

commit a2eb95d3ea6d24392da8431674242ec3a664f48f
Author: Benjamin Otte <otte redhat com>
Date:   Tue Jun 30 23:31:49 2020 +0200

    demo: Make words listview load async
    
    And add an "Open" button (why are filechooser buttons such a catastrophe
    that I can't make them smaller?).

 demos/gtk-demo/listview_words.c | 123 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 115 insertions(+), 8 deletions(-)
---
diff --git a/demos/gtk-demo/listview_words.c b/demos/gtk-demo/listview_words.c
index c8aab2360d..1d6676e85c 100644
--- a/demos/gtk-demo/listview_words.c
+++ b/demos/gtk-demo/listview_words.c
@@ -45,30 +45,134 @@ update_title_cb (GtkFilterListModel *model)
   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;
+      GtkWidget *header, *listview, *sw, *vbox, *search_entry, *open_button;
       GtkFilterListModel *filter_model;
       GtkStringList *stringlist;
       GtkFilter *filter;
-      char **words;
-      char *usr_dict_words;
       GtkExpression *expression;
+      GFile *file;
 
-      if (g_file_get_contents ("/usr/share/dict/words", &usr_dict_words, NULL, NULL))
+      file = g_file_new_for_path ("/usr/share/dict/words");
+      if (g_file_query_exists (file, NULL))
         {
-          words = g_strsplit (usr_dict_words, "\n", -1);
-          g_free (usr_dict_words);
+          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);
         }
-      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");
@@ -81,6 +185,9 @@ do_listview_words (GtkWidget *do_widget)
       gtk_window_set_title (GTK_WINDOW (window), "Words");
       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),