Pileus Git - ~andy/gtk/blob - demos/gtk-demo/css_basics.c

   1 /* CSS Theming/CSS Basics :: css_basics.css
   2  *
   3  * Gtk themes are written using CSS. Every widget is build of multiple items
   4  * that you can style very similarly to a regular website.
   5  *
   6  */
   7
   8 #include <gtk/gtk.h>
   9
  10 static GtkWidget *window = NULL;
  11
  12 static void
  13 show_parsing_error (GtkCssProvider *provider,
  14                     GtkCssSection  *section,
  15                     const GError   *error,
  16                     GtkTextBuffer  *buffer)
  17 {
  18   GtkTextIter start, end;
  19   const char *tag_name;
  20
  21   gtk_text_buffer_get_iter_at_line_index (buffer,
  22                                           &start,
  23                                           gtk_css_section_get_start_line (section),
  24                                           gtk_css_section_get_start_position (section));
  25   gtk_text_buffer_get_iter_at_line_index (buffer,
  26                                           &end,
  27                                           gtk_css_section_get_end_line (section),
  28                                           gtk_css_section_get_end_position (section));
  29
  30   if (g_error_matches (error, GTK_CSS_PROVIDER_ERROR, GTK_CSS_PROVIDER_ERROR_DEPRECATED))
  31     tag_name = "warning";
  32   else
  33     tag_name = "error";
  34
  35   gtk_text_buffer_apply_tag_by_name (buffer, tag_name, &start, &end);
  36 }
  37
  38 static void
  39 css_text_changed (GtkTextBuffer  *buffer,
  40                   GtkCssProvider *provider)
  41 {
  42   GtkTextIter start, end;
  43   char *text;
  44
  45   gtk_text_buffer_get_start_iter (buffer, &start);
  46   gtk_text_buffer_get_end_iter (buffer, &end);
  47   gtk_text_buffer_remove_all_tags (buffer, &start, &end);
  48
  49   text = gtk_text_buffer_get_text (buffer, &start, &end, FALSE);
  50   gtk_css_provider_load_from_data (provider, text, -1, NULL);
  51   g_free (text);
  52
  53   gtk_style_context_reset_widgets (gdk_screen_get_default ());
  54 }
  55
  56 static void
  57 apply_css (GtkWidget *widget, GtkStyleProvider *provider)
  58 {
  59   gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
  60   if (GTK_IS_CONTAINER (widget))
  61     gtk_container_forall (GTK_CONTAINER (widget), (GtkCallback) apply_css, provider);
  62 }
  63
  64 GtkWidget *
  65 do_css_basics (GtkWidget *do_widget)
  66 {
  67   if (!window)
  68     {
  69       GtkWidget *container, *child;
  70       GtkStyleProvider *provider;
  71       GtkTextBuffer *text;
  72       GBytes *bytes;
  73
  74       window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  75       gtk_window_set_transient_for (GTK_WINDOW (window), GTK_WINDOW (do_widget));
  76       gtk_window_set_default_size (GTK_WINDOW (window), 400, 300);
  77       g_signal_connect (window, "destroy",
  78                         G_CALLBACK (gtk_widget_destroyed), &window);
  79
  80       text = gtk_text_buffer_new (NULL);
  81       gtk_text_buffer_create_tag (text,
  82                                   "warning",
  83                                   "underline", PANGO_UNDERLINE_SINGLE,
  84                                   NULL);
  85       gtk_text_buffer_create_tag (text,
  86                                   "error",
  87                                   "underline", PANGO_UNDERLINE_ERROR,
  88                                   NULL);
  89
  90       provider = GTK_STYLE_PROVIDER (gtk_css_provider_new ());
  91
  92       container = gtk_scrolled_window_new (NULL, NULL);
  93       gtk_container_add (GTK_CONTAINER (window), container);
  94       child = gtk_text_view_new_with_buffer (text);
  95       gtk_container_add (GTK_CONTAINER (container), child);
  96       g_signal_connect (text,
  97                         "changed",
  98                         G_CALLBACK (css_text_changed),
  99                         provider);
 100
 101       bytes = g_resources_lookup_data ("/css_basics/gtk.css", 0, NULL);
 102       gtk_text_buffer_set_text (text, g_bytes_get_data (bytes, NULL), g_bytes_get_size (bytes));
 103       g_bytes_unref (bytes);
 104
 105       g_signal_connect (provider,
 106                         "parsing-error",
 107                         G_CALLBACK (show_parsing_error),
 108                         gtk_text_view_get_buffer (GTK_TEXT_VIEW (child)));
 109
 110       apply_css (window, provider);
 111     }
 112
 113   if (!gtk_widget_get_visible (window))
 114     gtk_widget_show_all (window);
 115   else
 116     {
 117       gtk_widget_destroy (window);
 118       window = NULL;
 119     }
 120
 121   return window;
 122 }