gtk2/demos/gtk-demo/css_multiplebgs.c
2013-07-03 14:39:25 +02:00

172 lines
5.9 KiB
C

/* CSS Theming/Multiple Backgrounds
*
* Gtk themes are written using CSS. Every widget is build of multiple items
* that you can style very similarly to a regular website.
*
*/
#include <gtk/gtk.h>
static GtkWidget *window = NULL;
static void
show_parsing_error (GtkCssProvider *provider,
GtkCssSection *section,
const GError *error,
GtkTextBuffer *buffer)
{
GtkTextIter start, end;
const char *tag_name;
gtk_text_buffer_get_iter_at_line_index (buffer,
&start,
gtk_css_section_get_start_line (section),
gtk_css_section_get_start_position (section));
gtk_text_buffer_get_iter_at_line_index (buffer,
&end,
gtk_css_section_get_end_line (section),
gtk_css_section_get_end_position (section));
if (g_error_matches (error, GTK_CSS_PROVIDER_ERROR, GTK_CSS_PROVIDER_ERROR_DEPRECATED))
tag_name = "warning";
else
tag_name = "error";
gtk_text_buffer_apply_tag_by_name (buffer, tag_name, &start, &end);
}
static void
css_text_changed (GtkTextBuffer *buffer,
GtkCssProvider *provider)
{
GtkTextIter start, end;
char *text;
gtk_text_buffer_get_start_iter (buffer, &start);
gtk_text_buffer_get_end_iter (buffer, &end);
gtk_text_buffer_remove_all_tags (buffer, &start, &end);
text = gtk_text_buffer_get_text (buffer, &start, &end, FALSE);
gtk_css_provider_load_from_data (provider, text, -1, NULL);
g_free (text);
gtk_style_context_reset_widgets (gdk_screen_get_default ());
}
static gboolean
drawing_area_draw (GtkWidget *widget,
cairo_t *cr)
{
GtkStyleContext *context = gtk_widget_get_style_context (widget);
gtk_render_background (context, cr,
0, 0,
gtk_widget_get_allocated_width (widget),
gtk_widget_get_allocated_height (widget));
gtk_render_frame (context, cr,
0, 0,
gtk_widget_get_allocated_width (widget),
gtk_widget_get_allocated_height (widget));
return FALSE;
}
static void
apply_css (GtkWidget *widget, GtkStyleProvider *provider)
{
gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
if (GTK_IS_CONTAINER (widget))
gtk_container_forall (GTK_CONTAINER (widget), (GtkCallback) apply_css, provider);
}
GtkWidget *
do_css_multiplebgs (GtkWidget *do_widget)
{
if (!window)
{
GtkWidget *paned, *container, *child;
GtkStyleProvider *provider;
GtkTextBuffer *text;
GBytes *bytes;
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_transient_for (GTK_WINDOW (window), GTK_WINDOW (do_widget));
gtk_window_set_default_size (GTK_WINDOW (window), 400, 300);
g_signal_connect (window, "destroy",
G_CALLBACK (gtk_widget_destroyed), &window);
container = gtk_overlay_new ();
gtk_widget_add_events (container,
GDK_ENTER_NOTIFY_MASK |
GDK_LEAVE_NOTIFY_MASK |
GDK_POINTER_MOTION_MASK);
gtk_container_add (GTK_CONTAINER (window), container);
child = gtk_drawing_area_new ();
gtk_widget_set_name (child, "canvas");
g_signal_connect (child, "draw",
G_CALLBACK (drawing_area_draw), NULL);
gtk_container_add (GTK_CONTAINER (container), child);
child = gtk_button_new ();
gtk_widget_add_events (child,
GDK_ENTER_NOTIFY_MASK |
GDK_LEAVE_NOTIFY_MASK |
GDK_POINTER_MOTION_MASK);
gtk_overlay_add_overlay (GTK_OVERLAY (container), child);
gtk_widget_set_name (child, "bricks-button");
gtk_widget_set_halign (child, GTK_ALIGN_CENTER);
gtk_widget_set_valign (child, GTK_ALIGN_CENTER);
gtk_widget_set_size_request (child, 250, 84);
paned = gtk_paned_new (GTK_ORIENTATION_VERTICAL);
gtk_overlay_add_overlay (GTK_OVERLAY (container), paned);
/* Need a filler so we get a handle */
child = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
gtk_container_add (GTK_CONTAINER (paned), child);
text = gtk_text_buffer_new (NULL);
gtk_text_buffer_create_tag (text,
"warning",
"underline", PANGO_UNDERLINE_SINGLE,
NULL);
gtk_text_buffer_create_tag (text,
"error",
"underline", PANGO_UNDERLINE_ERROR,
NULL);
provider = GTK_STYLE_PROVIDER (gtk_css_provider_new ());
container = gtk_scrolled_window_new (NULL, NULL);
gtk_container_add (GTK_CONTAINER (paned), container);
child = gtk_text_view_new_with_buffer (text);
gtk_container_add (GTK_CONTAINER (container), child);
g_signal_connect (text,
"changed",
G_CALLBACK (css_text_changed),
provider);
bytes = g_resources_lookup_data ("/css_multiplebgs/css_multiplebgs.css", 0, NULL);
gtk_text_buffer_set_text (text, g_bytes_get_data (bytes, NULL), g_bytes_get_size (bytes));
g_bytes_unref (bytes);
g_signal_connect (provider,
"parsing-error",
G_CALLBACK (show_parsing_error),
gtk_text_view_get_buffer (GTK_TEXT_VIEW (child)));
apply_css (window, provider);
}
if (!gtk_widget_get_visible (window))
gtk_widget_show_all (window);
else
{
gtk_widget_destroy (window);
window = NULL;
}
return window;
}