+static cairo_surface_t *
+create_h_surface (GtkWidget *widget)
+{
+ cairo_t *cr;
+ cairo_surface_t *surface;
+ gint width, height, stride;
+ cairo_surface_t *tmp;
+ guint red, green, blue;
+ guint32 *data, *p;
+ gdouble h;
+ gdouble r, g, b;
+ gdouble f;
+ gint x, y;
+
+ if (!gtk_widget_get_realized (widget))
+ return NULL;
+
+ width = gtk_widget_get_allocated_width (widget);
+ height = gtk_widget_get_allocated_height (widget);
+
+ surface = gdk_window_create_similar_surface (gtk_widget_get_window (widget),
+ CAIRO_CONTENT_COLOR,
+ width, height);
+
+ if (width == 1 || height == 1)
+ return surface;
+
+ stride = cairo_format_stride_for_width (CAIRO_FORMAT_RGB24, width);
+
+ data = g_malloc (height * stride);
+
+ f = 1.0 / (height - 1);
+ for (y = 0; y < height; y++)
+ {
+ h = CLAMP (y * f, 0.0, 1.0);
+ p = data + y * (stride / 4);
+ for (x = 0; x < width; x++)
+ {
+ gtk_hsv_to_rgb (h, 1, 1, &r, &g, &b);
+ red = CLAMP (r * 255, 0, 255);
+ green = CLAMP (g * 255, 0, 255);
+ blue = CLAMP (b * 255, 0, 255);
+ p[x] = (red << 16) | (green << 8) | blue;
+ }
+ }
+
+ tmp = cairo_image_surface_create_for_data ((guchar *)data, CAIRO_FORMAT_RGB24,
+ width, height, stride);
+ cr = cairo_create (surface);
+
+ cairo_set_source_surface (cr, tmp, 0, 0);
+ cairo_paint (cr);
+
+ cairo_destroy (cr);
+ cairo_surface_destroy (tmp);
+ g_free (data);
+
+ return surface;
+}
+
+static gboolean
+h_draw (GtkWidget *widget,
+ cairo_t *cr,
+ GtkColorEditor *editor)
+{
+ cairo_surface_t *surface;
+ gint width, height;
+
+ width = gtk_widget_get_allocated_width (widget);
+ height = gtk_widget_get_allocated_height (widget);
+
+ if (!editor->priv->h_surface)
+ editor->priv->h_surface = create_h_surface (widget);
+ surface = editor->priv->h_surface;
+
+ cairo_save (cr);
+
+ cairo_rectangle (cr, 1, 1, width - 2, height - 2);
+ cairo_clip (cr);
+ cairo_set_source_surface (cr, surface, 0, 0);
+ cairo_paint (cr);
+
+ cairo_restore (cr);
+
+ return FALSE;
+}
+
+static cairo_surface_t *
+create_a_surface (GtkWidget *widget,
+ GdkRGBA *color)
+{
+ cairo_t *cr;
+ cairo_surface_t *surface;
+ cairo_pattern_t *pattern;
+ cairo_matrix_t matrix;
+ gint width, height;
+
+ if (!gtk_widget_get_realized (widget))
+ return NULL;
+
+ width = gtk_widget_get_allocated_width (widget);
+ height = gtk_widget_get_allocated_height (widget);
+
+ surface = gdk_window_create_similar_surface (gtk_widget_get_window (widget),
+ CAIRO_CONTENT_COLOR,
+ width, height);
+
+ if (width == 1 || height == 1)
+ return surface;
+
+ cr = cairo_create (surface);
+
+ cairo_set_source_rgb (cr, 0.33, 0.33, 0.33);
+ cairo_paint (cr);
+ cairo_set_source_rgb (cr, 0.66, 0.66, 0.66);
+
+ pattern = get_checkered_pattern ();
+ cairo_matrix_init_scale (&matrix, 0.125, 0.125);
+ cairo_pattern_set_matrix (pattern, &matrix);
+ cairo_mask (cr, pattern);
+ cairo_pattern_destroy (pattern);
+
+ pattern = cairo_pattern_create_linear (0, 0, width, 0);
+ cairo_pattern_add_color_stop_rgba (pattern, 0, color->red, color->green, color->blue, 0);
+ cairo_pattern_add_color_stop_rgba (pattern, width, color->red, color->green, color->blue, 1);
+ cairo_set_source (cr, pattern);
+ cairo_paint (cr);
+ cairo_pattern_destroy (pattern);
+
+ cairo_destroy (cr);
+
+ return surface;
+}
+
+static gboolean
+a_draw (GtkWidget *widget,
+ cairo_t *cr,
+ GtkColorEditor *editor)
+{
+ cairo_surface_t *surface;
+ gint width, height;
+
+ width = gtk_widget_get_allocated_width (widget);
+ height = gtk_widget_get_allocated_height (widget);
+
+ if (!editor->priv->a_surface)
+ editor->priv->a_surface = create_a_surface (widget, &editor->priv->color);
+ surface = editor->priv->a_surface;
+
+ cairo_save (cr);
+
+ cairo_rectangle (cr, 1, 1, width - 2, height - 2);
+ cairo_clip (cr);
+ cairo_set_source_surface (cr, surface, 0, 0);
+ cairo_paint (cr);
+
+ cairo_restore (cr);
+
+ return FALSE;
+}
+