gnome-shell/src/st/st-theme-context.h
Simon McVittie dc2ec0a8f9 Keep similar theme nodes so we don't have to recompute CSS so often
Because we calculate and cache CSS properties once per StThemeNode,
and only a certain set of attributes can affect the CSS properties,
it's advantageous for as many widgets as possible to share a single
StThemeNode. Similarly, if a widget changes state and then changes back
(e.g. gaining and losing the :hover pseudo-class), it should ideally
get its original StThemeNode back again when it returns to the old
state.

Here, I'm using the StThemeContext as the location for a cache.
StThemeNodes are currently never freed: this seems OK for Shell's usage
(a finite number of IDs, classes, pseudo-classes and types).

Bug: https://bugzilla.gnome.org/show_bug.cgi?id=687465
Reviewed-by: Jasper St. Pierre <jstpierre@mecheye.net>
2012-11-14 19:24:42 +00:00

71 lines
3.2 KiB
C

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/*
* st-theme-context.c: holds global information about a tree of styled objects
*
* Copyright 2009, 2010 Red Hat, Inc.
* Copyright 2009 Florian Müllner
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 2.1 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
* more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ST_THEME_CONTEXT_H__
#define __ST_THEME_CONTEXT_H__
#include <clutter/clutter.h>
#include <pango/pango.h>
#include "st-theme-node.h"
G_BEGIN_DECLS
/**
* SECTION:st-theme-context
* @short_description: holds global information about a tree of styled objects
*
* #StThemeContext is responsible for managing information global to a tree of styled objects,
* such as the set of stylesheets or the default font. In normal usage, a #StThemeContext
* is bound to a #ClutterStage; a singleton #StThemeContext can be obtained for a #ClutterStage
* by using st_theme_context_get_for_stage().
*/
typedef struct _StThemeContextClass StThemeContextClass;
#define ST_TYPE_THEME_CONTEXT (st_theme_context_get_type ())
#define ST_THEME_CONTEXT(object) (G_TYPE_CHECK_INSTANCE_CAST ((object), ST_TYPE_THEME_CONTEXT, StThemeContext))
#define ST_THEME_CONTEXT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), ST_TYPE_THEME_CONTEXT, StThemeContextClass))
#define ST_IS_THEME_CONTEXT(object) (G_TYPE_CHECK_INSTANCE_TYPE ((object), ST_TYPE_THEME_CONTEXT))
#define ST_IS_THEME_CONTEXT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), ST_TYPE_THEME_CONTEXT))
#define ST_THEME_CONTEXT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), ST_TYPE_THEME_CONTEXT, StThemeContextClass))
GType st_theme_context_get_type (void) G_GNUC_CONST;
StThemeContext *st_theme_context_new (void);
StThemeContext *st_theme_context_get_for_stage (ClutterStage *stage);
void st_theme_context_set_theme (StThemeContext *context,
StTheme *theme);
StTheme * st_theme_context_get_theme (StThemeContext *context);
void st_theme_context_set_font (StThemeContext *context,
const PangoFontDescription *font);
const PangoFontDescription *st_theme_context_get_font (StThemeContext *context);
StThemeNode * st_theme_context_get_root_node (StThemeContext *context);
StThemeNode * st_theme_context_intern_node (StThemeContext *context,
StThemeNode *node);
G_END_DECLS
#endif /* __ST_THEME_CONTEXT_H__ */