mutter/clutter/clutter-backend.c
Emmanuele Bassi 26f4467392 Try to mop up the default stage mess
The default stage was a neat concept when we started Clutter out,
somewhere in the Jurassic era; a singleton instance that gets created at
initialization time, and remains the same for the entire duration of the
process.

Worked well enough when Clutter was a small library meant to be used to
write fullscreen media browsers, but since the introduction of multiple
stages, and Clutter being used to create all sorts of applications, the
default stage is just a vestigial remainder of that past, like an
appendix; something that complicates the layout of the code and
introduces weird behaviour, so that you notice its existence only when
something goes wrong.

Some platforms we do support, though, only have one framebuffer, so it
makes sense for them to have only one stage.

At this point, the only sane thing to do is to go through the same code
paths on all platforms, and that code path is the stage instance
creation and initialization — i.e. clutter_stage_new() (or
g_object_new() with CLUTTER_TYPE_STAGE).

For platforms that support multiple stages, nothing has changed: the stage
created by clutter_stage_get_default() will be set as the default one;
if nobody calls it, the default stage is never created, and it just
lives on as a meaningless check.

For platforms that only support one stage, clutter_stage_new() and
clutter_stage_get_default() will behave exactly the same the first time
they are called: both will create a stage, and set it as the default.
Calling clutter_stage_new() a second time is treated as a programmer
error, and will result in Clutter aborting. This is a behavioural change
because the existing behaviour or creating a new ClutterStage instance
with the same ClutterStageWindow private implementation is, simply put,
utterly braindamaged and I should have *never* had written it, and I
apologize for it. In my defence, I didn't know any better at the time.

This is the first step towards the complete deprecation of
clutter_stage_get_default() and clutter_stage_is_default(), which will
come later.
2011-11-10 15:37:51 +00:00

1294 lines
35 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By:
* Matthew Allum <mallum@openedhand.com>
* Emmanuele Bassi <ebassi@linux.intel.com>
*
* Copyright (C) 2006, 2007, 2008 OpenedHand Ltd
* Copyright (C) 2009, 2010 Intel Corp
*
* 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, see <http://www.gnu.org/licenses/>.
*/
/**
* 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-private.h"
#include "clutter-debug.h"
#include "clutter-event-private.h"
#include "clutter-marshal.h"
#include "clutter-private.h"
#include "clutter-profile.h"
#include "clutter-stage-manager-private.h"
#include "clutter-stage-private.h"
#include "clutter-stage-window.h"
#include "clutter-version.h"
#include <cogl/cogl.h>
#ifdef CLUTTER_INPUT_X11
#include "x11/clutter-backend-x11.h"
#endif
#ifdef CLUTTER_INPUT_WIN32
#include "win32/clutter-backend-win32.h"
#endif
#ifdef CLUTTER_INPUT_OSX
#include "osx/clutter-backend-osx.h"
#endif
#ifdef CLUTTER_INPUT_GDK
#include "gdk/clutter-backend-gdk.h"
#endif
#ifdef CLUTTER_INPUT_EVDEV
#include "evdev/clutter-device-manager-evdev.h"
#endif
#ifdef CLUTTER_INPUT_TSLIB
/* XXX - should probably warn, here */
#include "tslib/clutter-event-tslib.h"
#endif
G_DEFINE_ABSTRACT_TYPE (ClutterBackend, clutter_backend, G_TYPE_OBJECT);
#define DEFAULT_FONT_NAME "Sans 10"
#define CLUTTER_BACKEND_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), CLUTTER_TYPE_BACKEND, ClutterBackendPrivate))
struct _ClutterBackendPrivate
{
cairo_font_options_t *font_options;
gchar *font_name;
gfloat units_per_em;
gint32 units_serial;
GList *event_translators;
};
enum
{
RESOLUTION_CHANGED,
FONT_CHANGED,
SETTINGS_CHANGED,
LAST_SIGNAL
};
static guint backend_signals[LAST_SIGNAL] = { 0, };
static void
clutter_backend_dispose (GObject *gobject)
{
ClutterBackendPrivate *priv = CLUTTER_BACKEND (gobject)->priv;
/* clear the events still in the queue of the main context */
_clutter_clear_events_queue ();
/* remove all event translators */
if (priv->event_translators != NULL)
{
g_list_free (priv->event_translators);
priv->event_translators = NULL;
}
G_OBJECT_CLASS (clutter_backend_parent_class)->dispose (gobject);
}
static void
clutter_backend_finalize (GObject *gobject)
{
ClutterBackend *backend = CLUTTER_BACKEND (gobject);
g_free (backend->priv->font_name);
clutter_backend_set_font_options (backend, NULL);
G_OBJECT_CLASS (clutter_backend_parent_class)->finalize (gobject);
}
static gfloat
get_units_per_em (ClutterBackend *backend,
PangoFontDescription *font_desc)
{
gfloat units_per_em = -1.0;
gboolean free_font_desc = FALSE;
gdouble dpi;
dpi = clutter_backend_get_resolution (backend);
if (font_desc == NULL)
{
ClutterSettings *settings;
gchar *font_name = NULL;
settings = clutter_settings_get_default ();
g_object_get (settings, "font-name", &font_name, NULL);
if (G_LIKELY (font_name != NULL && *font_name != '\0'))
{
font_desc = pango_font_description_from_string (font_name);
free_font_desc = TRUE;
g_free (font_name);
}
}
if (font_desc != NULL)
{
gdouble font_size = 0;
gint pango_size;
gboolean is_absolute;
pango_size = pango_font_description_get_size (font_desc);
is_absolute = pango_font_description_get_size_is_absolute (font_desc);
/* "absolute" means "device units" (usually, pixels); otherwise,
* it means logical units (points)
*/
if (is_absolute)
font_size = (gdouble) pango_size / PANGO_SCALE;
else
font_size = (gdouble) pango_size / PANGO_SCALE
* dpi
/ 96.0f;
/* 10 points at 96 DPI is 13.3 pixels */
units_per_em = (1.2f * font_size)
* dpi
/ 96.0f;
}
else
units_per_em = -1.0f;
if (free_font_desc)
pango_font_description_free (font_desc);
return units_per_em;
}
static void
clutter_backend_real_resolution_changed (ClutterBackend *backend)
{
ClutterBackendPrivate *priv = backend->priv;
ClutterMainContext *context;
ClutterSettings *settings;
gint dpi;
settings = clutter_settings_get_default ();
g_object_get (settings, "font-dpi", &dpi, NULL);
context = _clutter_context_get_default ();
if (context->font_map != NULL)
cogl_pango_font_map_set_resolution (context->font_map, dpi / 1024.0);
priv->units_per_em = get_units_per_em (backend, NULL);
priv->units_serial += 1;
CLUTTER_NOTE (BACKEND, "Units per em: %.2f", priv->units_per_em);
}
static void
clutter_backend_real_font_changed (ClutterBackend *backend)
{
ClutterBackendPrivate *priv = backend->priv;
priv->units_per_em = get_units_per_em (backend, NULL);
priv->units_serial += 1;
CLUTTER_NOTE (BACKEND, "Units per em: %.2f", priv->units_per_em);
}
static gboolean
clutter_backend_real_create_context (ClutterBackend *backend,
GError **error)
{
ClutterBackendClass *klass;
CoglSwapChain *swap_chain;
GError *internal_error;
if (backend->cogl_context != NULL)
return TRUE;
klass = CLUTTER_BACKEND_GET_CLASS (backend);
swap_chain = NULL;
internal_error = NULL;
CLUTTER_NOTE (BACKEND, "Creating Cogl renderer");
if (klass->get_renderer != NULL)
backend->cogl_renderer = klass->get_renderer (backend, &internal_error);
else
backend->cogl_renderer = cogl_renderer_new ();
if (backend->cogl_renderer == NULL)
goto error;
CLUTTER_NOTE (BACKEND, "Connecting the renderer");
if (!cogl_renderer_connect (backend->cogl_renderer, &internal_error))
goto error;
CLUTTER_NOTE (BACKEND, "Creating Cogl swap chain");
swap_chain = cogl_swap_chain_new ();
CLUTTER_NOTE (BACKEND, "Creating Cogl display");
if (klass->get_display != NULL)
{
backend->cogl_display = klass->get_display (backend,
backend->cogl_renderer,
swap_chain,
&internal_error);
}
else
{
CoglOnscreenTemplate *tmpl;
gboolean res;
tmpl = cogl_onscreen_template_new (swap_chain);
/* XXX: I have some doubts that this is a good design.
*
* Conceptually should we be able to check an onscreen_template
* without more details about the CoglDisplay configuration?
*/
res = cogl_renderer_check_onscreen_template (backend->cogl_renderer,
tmpl,
&internal_error);
if (!res)
goto error;
backend->cogl_display = cogl_display_new (backend->cogl_renderer, tmpl);
/* the display owns the template */
cogl_object_unref (tmpl);
}
if (backend->cogl_display == NULL)
goto error;
CLUTTER_NOTE (BACKEND, "Setting up the display");
if (!cogl_display_setup (backend->cogl_display, &internal_error))
goto error;
CLUTTER_NOTE (BACKEND, "Creating the Cogl context");
backend->cogl_context = cogl_context_new (backend->cogl_display, &internal_error);
if (backend->cogl_context == NULL)
goto error;
/* the display owns the renderer and the swap chain */
cogl_object_unref (backend->cogl_renderer);
cogl_object_unref (swap_chain);
return TRUE;
error:
if (backend->cogl_display != NULL)
{
cogl_object_unref (backend->cogl_display);
backend->cogl_display = NULL;
}
if (backend->cogl_renderer != NULL)
{
cogl_object_unref (backend->cogl_renderer);
backend->cogl_renderer = NULL;
}
if (swap_chain != NULL)
cogl_object_unref (swap_chain);
if (internal_error != NULL)
g_propagate_error (error, internal_error);
else
g_set_error_literal (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_BACKEND,
_("Unable to initialize the Clutter backend"));
return FALSE;
}
static void
clutter_backend_real_ensure_context (ClutterBackend *backend,
ClutterStage *stage)
{
ClutterStageWindow *stage_impl;
CoglFramebuffer *framebuffer;
if (stage == NULL)
return;
stage_impl = _clutter_stage_get_window (stage);
if (stage_impl == NULL)
return;
framebuffer = _clutter_stage_window_get_active_framebuffer (stage_impl);
if (framebuffer == NULL)
return;
cogl_set_framebuffer (framebuffer);
}
static ClutterFeatureFlags
clutter_backend_real_get_features (ClutterBackend *backend)
{
ClutterFeatureFlags flags = 0;
if (cogl_clutter_winsys_has_feature (COGL_WINSYS_FEATURE_MULTIPLE_ONSCREEN))
{
CLUTTER_NOTE (BACKEND, "Cogl supports multiple onscreen framebuffers");
flags |= CLUTTER_FEATURE_STAGE_MULTIPLE;
}
else
{
CLUTTER_NOTE (BACKEND, "Cogl only supports one onscreen framebuffer");
flags |= CLUTTER_FEATURE_STAGE_STATIC;
}
if (cogl_clutter_winsys_has_feature (COGL_WINSYS_FEATURE_SWAP_THROTTLE))
{
CLUTTER_NOTE (BACKEND, "Cogl supports swap buffers throttling");
flags |= CLUTTER_FEATURE_SYNC_TO_VBLANK;
}
else
CLUTTER_NOTE (BACKEND, "Cogl doesn't support swap buffers throttling");
if (cogl_clutter_winsys_has_feature (COGL_WINSYS_FEATURE_SWAP_BUFFERS_EVENT))
{
CLUTTER_NOTE (BACKEND, "Cogl supports swap buffers complete events");
flags |= CLUTTER_FEATURE_SWAP_EVENTS;
}
return flags;
}
static ClutterStageWindow *
clutter_backend_real_create_stage (ClutterBackend *backend,
ClutterStage *wrapper,
GError **error)
{
ClutterBackendClass *klass;
if (!clutter_feature_available (CLUTTER_FEATURE_STAGE_MULTIPLE))
{
ClutterStageManager *manager = clutter_stage_manager_get_default ();
if (clutter_stage_manager_get_default_stage (manager) != NULL)
{
g_set_error (error, CLUTTER_INIT_ERROR,
CLUTTER_INIT_ERROR_BACKEND,
_("The backend of type '%s' does not support "
"creating multiple stages"),
G_OBJECT_TYPE_NAME (backend));
return NULL;
}
}
klass = CLUTTER_BACKEND_GET_CLASS (backend);
g_assert (klass->stage_window_type != G_TYPE_INVALID);
return g_object_new (klass->stage_window_type,
"backend", backend,
"wrapper", wrapper,
NULL);
}
static void
clutter_backend_real_redraw (ClutterBackend *backend,
ClutterStage *stage)
{
ClutterStageWindow *impl;
if (CLUTTER_ACTOR_IN_DESTRUCTION (stage))
return;
impl = _clutter_stage_get_window (stage);
if (impl == NULL)
return;
_clutter_stage_window_redraw (impl);
}
static void
clutter_backend_real_init_events (ClutterBackend *backend)
{
const char *input_backend = NULL;
input_backend = g_getenv ("CLUTTER_INPUT_BACKEND");
if (input_backend != NULL)
input_backend = g_intern_string (input_backend);
#ifdef CLUTTER_INPUT_OSX
if (clutter_check_windowing_backend (CLUTTER_WINDOWING_OSX) &&
(input_backend == NULL || input_backend == I_(CLUTTER_INPUT_OSX)))
{
_clutter_backend_osx_events_init (backend);
}
else
#endif
#ifdef CLUTTER_INPUT_WIN32
if (clutter_check_windowing_backend (CLUTTER_WINDOWING_WIN32) &&
(input_backend == NULL || input_backend == I_(CLUTTER_INPUT_WIN32)))
{
_clutter_backend_win32_events_init (backend);
}
else
#endif
#ifdef CLUTTER_INPUT_X11
if (clutter_check_windowing_backend (CLUTTER_WINDOWING_X11) &&
(input_backend == NULL || input_backend == I_(CLUTTER_INPUT_X11)))
{
_clutter_backend_x11_events_init (backend);
}
else
#endif
#ifdef CLUTTER_INPUT_GDK
if (clutter_check_windowing_backend (CLUTTER_WINDOWING_GDK) &&
(input_backend == NULL || input_backend == I_(CLUTTER_INPUT_GDK)))
{
_clutter_backend_gdk_events_init (backend);
}
else
#endif
#ifdef CLUTTER_INPUT_EVDEV
/* Evdev can be used regardless of the windowing system */
if (input_backend != NULL &&
strcmp (input_backend, CLUTTER_INPUT_EVDEV) == 0)
{
_clutter_events_evdev_init (backend);
}
else
#endif
#ifdef CLUTTER_INPUT_TSLIB
/* Tslib can be used regardless of the windowing system */
if (input_backend != NULL &&
strcmp (input_backend, CLUTTER_INPUT_TSLIB) == 0)
{
_clutter_events_tslib_init (backend);
}
else
#endif
if (input_backend != NULL)
{
if (input_backend != I_(CLUTTER_INPUT_NULL))
g_error ("Unrecognized input backend '%s'", input_backend);
}
else
g_error ("Unknown input backend");
}
static ClutterDeviceManager *
clutter_backend_real_get_device_manager (ClutterBackend *backend)
{
if (G_UNLIKELY (backend->device_manager == NULL))
{
g_critical ("No device manager available, expect broken input");
return NULL;
}
return backend->device_manager;
}
static gboolean
clutter_backend_real_translate_event (ClutterBackend *backend,
gpointer native,
ClutterEvent *event)
{
ClutterBackendPrivate *priv = backend->priv;
GList *l;
for (l = priv->event_translators;
l != NULL;
l = l->next)
{
ClutterEventTranslator *translator = l->data;
ClutterTranslateReturn retval;
retval = _clutter_event_translator_translate_event (translator,
native,
event);
if (retval == CLUTTER_TRANSLATE_QUEUE)
return TRUE;
if (retval == CLUTTER_TRANSLATE_REMOVE)
return FALSE;
}
return FALSE;
}
static void
clutter_backend_class_init (ClutterBackendClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->dispose = clutter_backend_dispose;
gobject_class->finalize = clutter_backend_finalize;
g_type_class_add_private (gobject_class, sizeof (ClutterBackendPrivate));
klass->stage_window_type = G_TYPE_INVALID;
/**
* ClutterBackend::resolution-changed:
* @backend: the #ClutterBackend that emitted the signal
*
* The ::resolution-changed signal is emitted each time the font
* resolutions has been changed through #ClutterSettings.
*
* Since: 1.0
*/
backend_signals[RESOLUTION_CHANGED] =
g_signal_new (I_("resolution-changed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST,
G_STRUCT_OFFSET (ClutterBackendClass, resolution_changed),
NULL, NULL,
_clutter_marshal_VOID__VOID,
G_TYPE_NONE, 0);
/**
* ClutterBackend::font-changed:
* @backend: the #ClutterBackend that emitted the signal
*
* The ::font-changed signal is emitted each time the font options
* have been changed through #ClutterSettings.
*
* Since: 1.0
*/
backend_signals[FONT_CHANGED] =
g_signal_new (I_("font-changed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST,
G_STRUCT_OFFSET (ClutterBackendClass, font_changed),
NULL, NULL,
_clutter_marshal_VOID__VOID,
G_TYPE_NONE, 0);
/**
* ClutterBackend::settings-changed:
* @backend: the #ClutterBackend that emitted the signal
*
* The ::settings-changed signal is emitted each time the #ClutterSettings
* properties have been changed.
*
* Since: 1.4
*/
backend_signals[SETTINGS_CHANGED] =
g_signal_new (I_("settings-changed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST,
G_STRUCT_OFFSET (ClutterBackendClass, settings_changed),
NULL, NULL,
_clutter_marshal_VOID__VOID,
G_TYPE_NONE, 0);
klass->resolution_changed = clutter_backend_real_resolution_changed;
klass->font_changed = clutter_backend_real_font_changed;
klass->init_events = clutter_backend_real_init_events;
klass->get_device_manager = clutter_backend_real_get_device_manager;
klass->translate_event = clutter_backend_real_translate_event;
klass->create_context = clutter_backend_real_create_context;
klass->ensure_context = clutter_backend_real_ensure_context;
klass->get_features = clutter_backend_real_get_features;
klass->create_stage = clutter_backend_real_create_stage;
klass->redraw = clutter_backend_real_redraw;
}
static void
clutter_backend_init (ClutterBackend *backend)
{
ClutterBackendPrivate *priv;
priv = backend->priv = CLUTTER_BACKEND_GET_PRIVATE (backend);
priv->units_per_em = -1.0;
priv->units_serial = 1;
}
void
_clutter_backend_add_options (ClutterBackend *backend,
GOptionGroup *group)
{
ClutterBackendClass *klass;
g_assert (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_assert (CLUTTER_IS_BACKEND (backend));
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_assert (CLUTTER_IS_BACKEND (backend));
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->post_parse)
return klass->post_parse (backend, error);
return TRUE;
}
ClutterStageWindow *
_clutter_backend_create_stage (ClutterBackend *backend,
ClutterStage *wrapper,
GError **error)
{
ClutterBackendClass *klass;
ClutterStageWindow *stage_window;
g_assert (CLUTTER_IS_BACKEND (backend));
g_assert (CLUTTER_IS_STAGE (wrapper));
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->create_stage != NULL)
stage_window = klass->create_stage (backend, wrapper, error);
else
stage_window = NULL;
if (stage_window == NULL)
return NULL;
g_assert (CLUTTER_IS_STAGE_WINDOW (stage_window));
return stage_window;
}
void
_clutter_backend_redraw (ClutterBackend *backend,
ClutterStage *stage)
{
CLUTTER_STATIC_COUNTER (redraw_counter,
"_clutter_backend_redraw counter",
"Increments for each _clutter_backend_redraw call",
0 /* no application private data */);
CLUTTER_STATIC_TIMER (redraw_timer,
"Master Clock", /* parent */
"Redrawing",
"The time spent redrawing everything",
0 /* no application private data */);
CLUTTER_COUNTER_INC (_clutter_uprof_context, redraw_counter);
CLUTTER_TIMER_START (_clutter_uprof_context, redraw_timer);
CLUTTER_BACKEND_GET_CLASS (backend)->redraw (backend, stage);
CLUTTER_TIMER_STOP (_clutter_uprof_context, redraw_timer);
}
gboolean
_clutter_backend_create_context (ClutterBackend *backend,
GError **error)
{
ClutterBackendClass *klass;
klass = CLUTTER_BACKEND_GET_CLASS (backend);
return klass->create_context (backend, error);
}
void
_clutter_backend_ensure_context_internal (ClutterBackend *backend,
ClutterStage *stage)
{
ClutterBackendClass *klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (G_LIKELY (klass->ensure_context))
klass->ensure_context (backend, stage);
}
void
_clutter_backend_ensure_context (ClutterBackend *backend,
ClutterStage *stage)
{
static ClutterStage *current_context_stage = NULL;
g_assert (CLUTTER_IS_BACKEND (backend));
g_assert (CLUTTER_IS_STAGE (stage));
if (current_context_stage != stage || !CLUTTER_ACTOR_IS_REALIZED (stage))
{
ClutterStage *new_stage = NULL;
if (!CLUTTER_ACTOR_IS_REALIZED (stage))
{
new_stage = NULL;
CLUTTER_NOTE (BACKEND,
"Stage [%p] is not realized, unsetting the stage",
stage);
}
else
{
new_stage = stage;
CLUTTER_NOTE (BACKEND,
"Setting the new stage [%p]",
new_stage);
}
/* XXX: Until Cogl becomes fully responsible for backend windows
* Clutter need to manually keep it informed of the current window size
*
* NB: This must be done after we ensure_context above because Cogl
* always assumes there is a current GL context.
*/
if (new_stage != NULL)
{
float width, height;
_clutter_backend_ensure_context_internal (backend, new_stage);
clutter_actor_get_size (CLUTTER_ACTOR (stage), &width, &height);
cogl_onscreen_clutter_backend_set_size (width, height);
/* Eventually we will have a separate CoglFramebuffer for
* each stage and each one will track private projection
* matrix and viewport state, but until then we need to make
* sure we update the projection and viewport whenever we
* switch between stages.
*
* This dirty mechanism will ensure they are asserted before
* the next paint...
*/
_clutter_stage_dirty_viewport (stage);
_clutter_stage_dirty_projection (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 = new_stage;
}
else
CLUTTER_NOTE (BACKEND, "Stage is the same");
}
ClutterFeatureFlags
_clutter_backend_get_features (ClutterBackend *backend)
{
ClutterBackendClass *klass;
GError *error;
g_assert (CLUTTER_IS_BACKEND (backend));
klass = CLUTTER_BACKEND_GET_CLASS (backend);
/* we need to have a context here; so we create the
* GL context first and the ask for features. if the
* context already exists this should be a no-op
*/
error = NULL;
if (klass->create_context != NULL)
{
gboolean res;
res = klass->create_context (backend, &error);
if (!res)
{
if (error)
{
g_critical ("Unable to create a context: %s", error->message);
g_error_free (error);
}
else
g_critical ("Unable to create a context: unknown error");
return 0;
}
}
if (klass->get_features)
return klass->get_features (backend);
return 0;
}
void
_clutter_backend_init_events (ClutterBackend *backend)
{
ClutterBackendClass *klass;
g_assert (CLUTTER_IS_BACKEND (backend));
klass = CLUTTER_BACKEND_GET_CLASS (backend);
klass->init_events (backend);
}
gfloat
_clutter_backend_get_units_per_em (ClutterBackend *backend,
PangoFontDescription *font_desc)
{
ClutterBackendPrivate *priv;
priv = backend->priv;
/* recompute for the font description, but do not cache the result */
if (font_desc != NULL)
return get_units_per_em (backend, font_desc);
if (priv->units_per_em < 0)
priv->units_per_em = get_units_per_em (backend, NULL);
return priv->units_per_em;
}
void
_clutter_backend_copy_event_data (ClutterBackend *backend,
const ClutterEvent *src,
ClutterEvent *dest)
{
ClutterBackendClass *klass;
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->copy_event_data != NULL)
klass->copy_event_data (backend, src, dest);
}
void
_clutter_backend_free_event_data (ClutterBackend *backend,
ClutterEvent *event)
{
ClutterBackendClass *klass;
klass = CLUTTER_BACKEND_GET_CLASS (backend);
if (klass->free_event_data != NULL)
klass->free_event_data (backend, event);
}
/**
* clutter_get_default_backend:
*
* Retrieves the default #ClutterBackend used by Clutter. The
* #ClutterBackend holds backend-specific configuration options.
*
* Return value: (transfer none): the default backend. You should
* not ref or unref the returned object. Applications should 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;
}
/**
* 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
*
* Deprecated: 1.4: Use #ClutterSettings:double-click-time instead
*/
void
clutter_backend_set_double_click_time (ClutterBackend *backend,
guint msec)
{
ClutterSettings *settings = clutter_settings_get_default ();
g_object_set (settings, "double-click-time", msec, NULL);
}
/**
* 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
*
* Deprecated: 1.4: Use #ClutterSettings:double-click-time instead
*/
guint
clutter_backend_get_double_click_time (ClutterBackend *backend)
{
ClutterSettings *settings = clutter_settings_get_default ();
gint retval;
g_object_get (settings, "double-click-time", &retval, NULL);
return retval;
}
/**
* 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
*
* Deprecated: 1.4: Use #ClutterSettings:double-click-distance instead
*/
void
clutter_backend_set_double_click_distance (ClutterBackend *backend,
guint distance)
{
ClutterSettings *settings = clutter_settings_get_default ();
g_object_set (settings, "double-click-distance", distance, NULL);
}
/**
* 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
*
* Deprecated: 1.4: Use #ClutterSettings:double-click-distance instead
*/
guint
clutter_backend_get_double_click_distance (ClutterBackend *backend)
{
ClutterSettings *settings = clutter_settings_get_default ();
gint retval;
g_object_get (settings, "double-click-distance", &retval, NULL);
return retval;
}
/**
* 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
*
* Deprecated: Use #ClutterSettings:font-dpi instead
*/
void
clutter_backend_set_resolution (ClutterBackend *backend,
gdouble dpi)
{
ClutterSettings *settings;
gint resolution;
g_return_if_fail (CLUTTER_IS_BACKEND (backend));
if (dpi < 0)
resolution = -1;
else
resolution = dpi * 1024;
settings = clutter_settings_get_default ();
g_object_set (settings, "font-dpi", resolution, NULL);
}
/**
* clutter_backend_get_resolution:
* @backend: a #ClutterBackend
*
* Gets the resolution for font handling on the screen.
*
* The resolution is a scale factor between points specified in a
* #PangoFontDescription and cairo units. The default value is 96.0,
* meaning that a 10 point font will be 13 units
* high (10 * 96. / 72. = 13.3).
*
* Clutter will set the resolution using the current backend when
* initializing; the resolution is also stored in the
* #ClutterSettings:font-dpi property.
*
* Return value: the current resolution, or -1 if no resolution
* has been set.
*
* Since: 0.4
*/
gdouble
clutter_backend_get_resolution (ClutterBackend *backend)
{
ClutterSettings *settings;
gint resolution;
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), -1.0);
settings = clutter_settings_get_default ();
g_object_get (settings, "font-dpi", &resolution, NULL);
return resolution / 1024.0;
}
/**
* clutter_backend_set_font_options:
* @backend: a #ClutterBackend
* @options: Cairo font options for the backend, or %NULL
*
* Sets the new font options for @backend. The #ClutterBackend will
* copy the #cairo_font_options_t.
*
* 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,
const 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: (transfer none): the font options of the #ClutterBackend.
* The returned #cairo_font_options_t is owned by the backend and should
* not be modified or freed
*
* Since: 0.8
*/
const 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);
g_signal_emit (backend, backend_signals[FONT_CHANGED], 0);
return priv->font_options;
}
/**
* clutter_backend_set_font_name:
* @backend: a #ClutterBackend
* @font_name: the name of the font
*
* Sets the default font to be used by Clutter. The @font_name string
* must either be %NULL, which means that the font name from the
* default #ClutterBackend will be used; or be something that can
* be parsed by the pango_font_description_from_string() function.
*
* Since: 1.0
*
* Deprecated: 1.4: Use #ClutterSettings:font-name instead
*/
void
clutter_backend_set_font_name (ClutterBackend *backend,
const gchar *font_name)
{
ClutterSettings *settings = clutter_settings_get_default ();
g_object_set (settings, "font-name", font_name, NULL);
}
/**
* clutter_backend_get_font_name:
* @backend: a #ClutterBackend
*
* Retrieves the default font name as set by
* clutter_backend_set_font_name().
*
* Return value: the font name for the backend. The returned string is
* owned by the #ClutterBackend and should never be modified or freed
*
* Since: 1.0
*
* Deprecated: 1.4: Use #ClutterSettings:font-name instead
*/
const gchar *
clutter_backend_get_font_name (ClutterBackend *backend)
{
ClutterBackendPrivate *priv;
ClutterSettings *settings;
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), NULL);
priv = backend->priv;
settings = clutter_settings_get_default ();
/* XXX yuck. but we return a const pointer, so we need to
* store it in the backend
*/
g_free (priv->font_name);
g_object_get (settings, "font-name", &priv->font_name, NULL);
return priv->font_name;
}
gint32
_clutter_backend_get_units_serial (ClutterBackend *backend)
{
return backend->priv->units_serial;
}
gboolean
_clutter_backend_translate_event (ClutterBackend *backend,
gpointer native,
ClutterEvent *event)
{
return CLUTTER_BACKEND_GET_CLASS (backend)->translate_event (backend,
native,
event);
}
void
_clutter_backend_add_event_translator (ClutterBackend *backend,
ClutterEventTranslator *translator)
{
ClutterBackendPrivate *priv = backend->priv;
if (g_list_find (priv->event_translators, translator) != NULL)
return;
priv->event_translators =
g_list_prepend (priv->event_translators, translator);
}
void
_clutter_backend_remove_event_translator (ClutterBackend *backend,
ClutterEventTranslator *translator)
{
ClutterBackendPrivate *priv = backend->priv;
if (g_list_find (priv->event_translators, translator) == NULL)
return;
priv->event_translators =
g_list_remove (priv->event_translators, translator);
}
/**
* clutter_backend_get_cogl_context:
* @backend: a #ClutterBackend
*
* Retrieves the #CoglContext associated with the given clutter
* @backend. A #CoglContext is required when using some of the
* experimental 2.0 Cogl API.
*
* <note>Since CoglContext is itself experimental API this API should
* be considered experimental too.</note>
*
* <note>This API is not yet supported on OSX because OSX still
* uses the stub Cogl winsys and the Clutter backend doesn't
* explicitly create a CoglContext.</note>
*
* Return value: The #CoglContext associated with @backend.
*
* Since: 1.8
* Stability: unstable
*/
CoglContext *
clutter_backend_get_cogl_context (ClutterBackend *backend)
{
return backend->cogl_context;
}