mutter/clutter/clutter-backend.c
Emmanuele Bassi b8b8b155c4 Add signals for Backend options
The ClutterBackend instance at the moment lacks the ability to
notify runtime changes of the font options and the resolution.

For this reason, this commit adds a ::resolution-changed and a
::font-changed signals to the Backend class.

The ::resolution-changed signal is emitted when set_resolution()
is called with a different DPI; ::font-changed is emitted when the
cairo_font_options_t* changes from the default.
2008-12-23 13:55:51 +00:00

517 lines
13 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2006 OpenedHand
*
* This library 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 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that 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 library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:clutter-backend
* @short_description: Backend abstraction
*
* Clutter can be compiled against different backends. Each backend
* has to implement a set of functions, in order to be used by Clutter.
*
* #ClutterBackend is the base class abstracting the various implementation;
* it provides a basic API to query the backend for generic information
* and settings.
*
* #ClutterBackend is available since Clutter 0.4
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-backend.h"
#include "clutter-debug.h"
#include "clutter-fixed.h"
#include "clutter-marshal.h"
#include "clutter-private.h"
G_DEFINE_ABSTRACT_TYPE (ClutterBackend, clutter_backend, G_TYPE_OBJECT);
#define CLUTTER_BACKEND_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), CLUTTER_TYPE_BACKEND, ClutterBackendPrivate))
struct _ClutterBackendPrivate
{
/* settings */
guint double_click_time;
guint double_click_distance;
ClutterFixed resolution;
cairo_font_options_t *font_options;
};
enum
{
RESOLUTION_CHANGED,
FONT_CHANGED,
LAST_SIGNAL
};
static guint backend_signals[LAST_SIGNAL] = { 0, };
static void
clutter_backend_dispose (GObject *gobject)
{
ClutterMainContext *clutter_context;
clutter_context = clutter_context_get_default ();
if (clutter_context && clutter_context->events_queue)
{
g_queue_foreach (clutter_context->events_queue, (GFunc) clutter_event_free, NULL);
g_queue_free (clutter_context->events_queue);
clutter_context->events_queue = NULL;
}
clutter_backend_set_font_options (CLUTTER_BACKEND (gobject), NULL);
G_OBJECT_CLASS (clutter_backend_parent_class)->dispose (gobject);
}
static void
clutter_backend_class_init (ClutterBackendClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->dispose = clutter_backend_dispose;
g_type_class_add_private (gobject_class, sizeof (ClutterBackendPrivate));
backend_signals[RESOLUTION_CHANGED] =
g_signal_new (I_("resolution-changed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterBackendClass, resolution_changed),
NULL, NULL,
clutter_marshal_VOID__VOID,
G_TYPE_NONE, 0);
backend_signals[FONT_CHANGED] =
g_signal_new (I_("font-changed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterBackendClass, font_changed),
NULL, NULL,
clutter_marshal_VOID__VOID,
G_TYPE_NONE, 0);
}
static void
clutter_backend_init (ClutterBackend *backend)
{
ClutterBackendPrivate *priv;
priv = backend->priv = CLUTTER_BACKEND_GET_PRIVATE(backend);
priv->resolution = -1.0;
}
void
_clutter_backend_add_options (ClutterBackend *backend,
GOptionGroup *group)
{
ClutterBackendClass *klass;
g_return_if_fail (CLUTTER_IS_BACKEND (backend));
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->add_options)
klass->add_options (backend, group);
}
gboolean
_clutter_backend_pre_parse (ClutterBackend *backend,
GError **error)
{
ClutterBackendClass *klass;
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), FALSE);
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->pre_parse)
return klass->pre_parse (backend, error);
return TRUE;
}
gboolean
_clutter_backend_post_parse (ClutterBackend *backend,
GError **error)
{
ClutterBackendClass *klass;
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), FALSE);
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->post_parse)
return klass->post_parse (backend, error);
return TRUE;
}
ClutterActor *
_clutter_backend_create_stage (ClutterBackend *backend,
ClutterStage *wrapper,
GError **error)
{
ClutterMainContext *context;
ClutterBackendClass *klass;
ClutterActor *stage = NULL;
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), FALSE);
g_return_val_if_fail (CLUTTER_IS_STAGE (wrapper), FALSE);
context = clutter_context_get_default ();
if (!context->stage_manager)
context->stage_manager = clutter_stage_manager_get_default ();
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->create_stage)
stage = klass->create_stage (backend, wrapper, error);
if (!stage)
return NULL;
g_assert (CLUTTER_IS_STAGE_WINDOW (stage));
_clutter_stage_set_window (wrapper, CLUTTER_STAGE_WINDOW (stage));
_clutter_stage_manager_add_stage (context->stage_manager, wrapper);
return stage;
}
void
_clutter_backend_redraw (ClutterBackend *backend,
ClutterStage *stage)
{
ClutterBackendClass *klass;
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (G_LIKELY (klass->redraw))
klass->redraw (backend, stage);
}
void
_clutter_backend_ensure_context (ClutterBackend *backend,
ClutterStage *stage)
{
ClutterBackendClass *klass;
static ClutterStage *current_context_stage = NULL;
g_return_if_fail (CLUTTER_IS_BACKEND (backend));
g_return_if_fail (CLUTTER_IS_STAGE (stage));
if (current_context_stage != stage || !CLUTTER_ACTOR_IS_REALIZED (stage))
{
if (!CLUTTER_ACTOR_IS_REALIZED (stage))
{
CLUTTER_NOTE (MULTISTAGE, "Stage is not realized, unsetting");
stage = NULL;
}
else
CLUTTER_NOTE (MULTISTAGE, "Setting the new stage [%p]", stage);
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (G_LIKELY (klass->ensure_context))
klass->ensure_context (backend, stage);
/* FIXME: With a NULL stage and thus no active context it may make more
* sense to clean the context but then re call with the default stage
* so at least there is some kind of context in place (as to avoid
* potential issue of GL calls with no context)
*/
current_context_stage = stage;
if (stage)
CLUTTER_SET_PRIVATE_FLAGS (stage, CLUTTER_ACTOR_SYNC_MATRICES);
}
else
CLUTTER_NOTE (MULTISTAGE, "Stage is the same");
}
ClutterFeatureFlags
_clutter_backend_get_features (ClutterBackend *backend)
{
ClutterBackendClass *klass;
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), 0);
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->get_features)
return klass->get_features (backend);
return 0;
}
void
_clutter_backend_init_events (ClutterBackend *backend)
{
ClutterBackendClass *klass;
ClutterMainContext *clutter_context;
clutter_context = clutter_context_get_default ();
g_return_if_fail (CLUTTER_IS_BACKEND (backend));
g_return_if_fail (clutter_context != NULL);
clutter_context->events_queue = g_queue_new ();
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->init_events)
klass->init_events (backend);
}
/**
* clutter_get_default_backend:
*
* FIXME
*
* Return value: the default backend. You should not ref or
* unref the returned object. Applications should not rarely need
* to use this.
*
* Since: 0.4
*/
ClutterBackend *
clutter_get_default_backend (void)
{
ClutterMainContext *clutter_context;
clutter_context = clutter_context_get_default ();
return clutter_context->backend;
}
/* FIXME: below should probably be moved into clutter_main */
/**
* clutter_backend_set_double_click_time:
* @backend: a #ClutterBackend
* @msec: milliseconds between two button press events
*
* Sets the maximum time between two button press events, used to
* verify whether it's a double click event or not.
*
* Since: 0.4
*/
void
clutter_backend_set_double_click_time (ClutterBackend *backend,
guint msec)
{
g_return_if_fail (CLUTTER_IS_BACKEND (backend));
backend->priv->double_click_time = msec;
}
/**
* clutter_backend_get_double_click_time:
* @backend: a #ClutterBackend
*
* Gets the maximum time between two button press events, as set
* by clutter_backend_set_double_click_time().
*
* Return value: a time in milliseconds
*
* Since: 0.4
*/
guint
clutter_backend_get_double_click_time (ClutterBackend *backend)
{
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), 0);
return backend->priv->double_click_time;
}
/**
* clutter_backend_set_double_click_distance:
* @backend: a #ClutterBackend
* @distance: a distance, in pixels
*
* Sets the maximum distance used to verify a double click event.
*
* Since: 0.4
*/
void
clutter_backend_set_double_click_distance (ClutterBackend *backend,
guint distance)
{
g_return_if_fail (CLUTTER_IS_BACKEND (backend));
backend->priv->double_click_distance = distance;
}
/**
* clutter_backend_get_double_click_distance:
* @backend: a #ClutterBackend
*
* Retrieves the distance used to verify a double click event
*
* Return value: a distance, in pixels.
*
* Since: 0.4
*/
guint
clutter_backend_get_double_click_distance (ClutterBackend *backend)
{
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), 0);
return backend->priv->double_click_distance;
}
/**
* clutter_backend_set_resolution:
* @backend: a #ClutterBackend
* @dpi: the resolution in "dots per inch" (Physical inches aren't
* actually involved; the terminology is conventional).
*
* Sets the resolution for font handling on the screen. This is a
* scale factor between points specified in a #PangoFontDescription
* and cairo units. The default value is 96, meaning that a 10 point
* font will be 13 units high. (10 * 96. / 72. = 13.3).
*
* Applications should never need to call this function.
*
* Since: 0.4
*/
void
clutter_backend_set_resolution (ClutterBackend *backend,
gdouble dpi)
{
ClutterFixed fixed_dpi;
ClutterBackendPrivate *priv;
g_return_if_fail (CLUTTER_IS_BACKEND (backend));
if (dpi < 0)
dpi = -1.0;
priv = backend->priv;
fixed_dpi = COGL_FIXED_FROM_FLOAT (dpi);
if (priv->resolution != fixed_dpi)
priv->resolution = fixed_dpi;
if (CLUTTER_CONTEXT ()->font_map)
cogl_pango_font_map_set_resolution (CLUTTER_CONTEXT ()->font_map, dpi);
g_signal_emit (backend, backend_signals[RESOLUTION_CHANGED], 0);
}
/**
* clutter_backend_get_resolution:
* @backend: a #ClutterBackend
*
* Gets the resolution for font handling on the screen; see
* clutter_backend_set_resolution() for full details.
*
* Return value: the current resolution, or -1 if no resolution
* has been set.
*
* Since: 0.4
*/
gdouble
clutter_backend_get_resolution (ClutterBackend *backend)
{
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), -1.0);
return COGL_FIXED_TO_FLOAT (backend->priv->resolution);
}
/**
* clutter_backend_set_font_options:
* @backend: a #ClutterBackend
* @options: Cairo font options for the backend, or %NULL
*
* Sets the new font options for @backend. If @options is %NULL,
* the first following call to clutter_backend_get_font_options()
* will return the default font options for @backend.
*
* This function is intended for actors creating a Pango layout
* using the PangoCairo API.
*
* Since: 0.8
*/
void
clutter_backend_set_font_options (ClutterBackend *backend,
cairo_font_options_t *options)
{
ClutterBackendPrivate *priv;
g_return_if_fail (CLUTTER_IS_BACKEND (backend));
priv = backend->priv;
if (priv->font_options != options)
{
if (priv->font_options)
cairo_font_options_destroy (priv->font_options);
if (options)
priv->font_options = cairo_font_options_copy (options);
else
priv->font_options = NULL;
g_signal_emit (backend, backend_signals[FONT_CHANGED], 0);
}
}
/**
* clutter_backend_get_font_options:
* @backend: a #ClutterBackend
*
* Retrieves the font options for @backend.
*
* Return value: the font options of the #ClutterBackend
*
* Since: 0.8
*/
cairo_font_options_t *
clutter_backend_get_font_options (ClutterBackend *backend)
{
ClutterBackendPrivate *priv;
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), NULL);
priv = backend->priv;
if (G_LIKELY (priv->font_options))
return priv->font_options;
priv->font_options = cairo_font_options_create ();
cairo_font_options_set_hint_style (priv->font_options,
CAIRO_HINT_STYLE_NONE);
cairo_font_options_set_subpixel_order (priv->font_options,
CAIRO_SUBPIXEL_ORDER_DEFAULT);
cairo_font_options_set_antialias (priv->font_options,
CAIRO_ANTIALIAS_DEFAULT);
return priv->font_options;
}