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

   1 /* CSS Theming/Multiple Backgrounds :: css_multiplebgs.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 gboolean
  57 drawing_area_draw (GtkWidget *widget,
  58                    cairo_t *cr)
  59 {
  60   GtkStyleContext *context = gtk_widget_get_style_context (widget);
  61
  62   gtk_render_background (context, cr,
  63                          0, 0,
  64                          gtk_widget_get_allocated_width (widget),
  65                          gtk_widget_get_allocated_height (widget));
  66   gtk_render_frame (context, cr,
  67                     0, 0,
  68                     gtk_widget_get_allocated_width (widget),
  69                     gtk_widget_get_allocated_height (widget));
  70
  71   return FALSE;
  72 }
  73
  74 static void
  75 apply_css (GtkWidget *widget, GtkStyleProvider *provider)
  76 {
  77   gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
  78   if (GTK_IS_CONTAINER (widget))
  79     gtk_container_forall (GTK_CONTAINER (widget), (GtkCallback) apply_css, provider);
  80 }
  81
  82 GtkWidget *
  83 do_css_multiplebgs (GtkWidget *do_widget)
  84 {
  85   if (!window)
  86     {
  87       GtkWidget *paned, *container, *child;
  88       GtkStyleProvider *provider;
  89       GtkTextBuffer *text;
  90       GBytes *bytes;
  91
  92       window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  93       gtk_window_set_transient_for (GTK_WINDOW (window), GTK_WINDOW (do_widget));
  94       gtk_window_set_default_size (GTK_WINDOW (window), 400, 300);
  95       g_signal_connect (window, "destroy",
  96                         G_CALLBACK (gtk_widget_destroyed), &window);
  97
  98       container = gtk_overlay_new ();
  99       gtk_widget_add_events (container,
 100                              GDK_ENTER_NOTIFY_MASK |
 101                              GDK_LEAVE_NOTIFY_MASK |
 102                              GDK_POINTER_MOTION_MASK);
 103       gtk_container_add (GTK_CONTAINER (window), container);
 104
 105       child = gtk_drawing_area_new ();
 106       gtk_widget_set_name (child, "canvas");
 107       g_signal_connect (child, "draw",
 108                         G_CALLBACK (drawing_area_draw), NULL);
 109       gtk_container_add (GTK_CONTAINER (container), child);
 110
 111       child = gtk_button_new ();
 112       gtk_widget_add_events (child,
 113                              GDK_ENTER_NOTIFY_MASK |
 114                              GDK_LEAVE_NOTIFY_MASK |
 115                              GDK_POINTER_MOTION_MASK);
 116       gtk_overlay_add_overlay (GTK_OVERLAY (container), child);
 117       gtk_widget_set_name (child, "bricks-button");
 118       gtk_widget_set_halign (child, GTK_ALIGN_CENTER);
 119       gtk_widget_set_valign (child, GTK_ALIGN_CENTER);
 120       gtk_widget_set_size_request (child, 200, 80);
 121
 122       paned = gtk_paned_new (GTK_ORIENTATION_VERTICAL);
 123       gtk_overlay_add_overlay (GTK_OVERLAY (container), paned);
 124
 125       /* Need a filler so we get a handle */
 126       child = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
 127       gtk_container_add (GTK_CONTAINER (paned), child);
 128
 129       text = gtk_text_buffer_new (NULL);
 130       gtk_text_buffer_create_tag (text,
 131                                   "warning",
 132                                   "underline", PANGO_UNDERLINE_SINGLE,
 133                                   NULL);
 134       gtk_text_buffer_create_tag (text,
 135                                   "error",
 136                                   "underline", PANGO_UNDERLINE_ERROR,
 137                                   NULL);
 138
 139       provider = GTK_STYLE_PROVIDER (gtk_css_provider_new ());
 140
 141       container = gtk_scrolled_window_new (NULL, NULL);
 142       gtk_container_add (GTK_CONTAINER (paned), container);
 143       child = gtk_text_view_new_with_buffer (text);
 144       gtk_container_add (GTK_CONTAINER (container), child);
 145       g_signal_connect (text,
 146                         "changed",
 147                         G_CALLBACK (css_text_changed),
 148                         provider);
 149
 150       bytes = g_resources_lookup_data ("/css_multiplebgs/css_multiplebgs.css", 0, NULL);
 151       gtk_text_buffer_set_text (text, g_bytes_get_data (bytes, NULL), g_bytes_get_size (bytes));
 152       g_bytes_unref (bytes);
 153
 154       g_signal_connect (provider,
 155                         "parsing-error",
 156                         G_CALLBACK (show_parsing_error),
 157                         gtk_text_view_get_buffer (GTK_TEXT_VIEW (child)));
 158
 159       apply_css (window, provider);
 160     }
 161
 162   if (!gtk_widget_get_visible (window))
 163     gtk_widget_show_all (window);
 164   else
 165     {
 166       gtk_widget_destroy (window);
 167       window = NULL;
 168     }
 169
 170   return window;
 171 }