355555c1bf
Instead of recomputing the number of units needed to fit in an em each time clutter_units_em() is called, we can store this value into the default Backend along with the resolution and font name. The value should also be updated each time the resolution and font are changed, to keep it up to date.
651 lines
17 KiB
C
651 lines
17 KiB
C
/*
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* Clutter.
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*
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* An OpenGL based 'interactive canvas' library.
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*
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* Authored By Matthew Allum <mallum@openedhand.com>
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*
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* Copyright (C) 2006 OpenedHand
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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/**
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* SECTION:clutter-backend
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* @short_description: Backend abstraction
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*
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* Clutter can be compiled against different backends. Each backend
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* has to implement a set of functions, in order to be used by Clutter.
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*
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* #ClutterBackend is the base class abstracting the various implementation;
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* it provides a basic API to query the backend for generic information
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* and settings.
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*
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* #ClutterBackend is available since Clutter 0.4
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "clutter-backend.h"
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#include "clutter-debug.h"
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#include "clutter-fixed.h"
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#include "clutter-marshal.h"
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#include "clutter-private.h"
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G_DEFINE_ABSTRACT_TYPE (ClutterBackend, clutter_backend, G_TYPE_OBJECT);
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#define DEFAULT_FONT_NAME "Sans 10"
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#define CLUTTER_BACKEND_GET_PRIVATE(obj) \
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(G_TYPE_INSTANCE_GET_PRIVATE ((obj), CLUTTER_TYPE_BACKEND, ClutterBackendPrivate))
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struct _ClutterBackendPrivate
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{
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/* settings */
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guint double_click_time;
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guint double_click_distance;
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gdouble resolution;
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gdouble units_per_em;
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cairo_font_options_t *font_options;
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gchar *font_name;
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};
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enum
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{
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RESOLUTION_CHANGED,
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FONT_CHANGED,
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LAST_SIGNAL
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};
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static guint backend_signals[LAST_SIGNAL] = { 0, };
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static void
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clutter_backend_dispose (GObject *gobject)
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{
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ClutterBackendPrivate *priv = CLUTTER_BACKEND (gobject)->priv;
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ClutterMainContext *clutter_context;
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clutter_context = clutter_context_get_default ();
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if (clutter_context && clutter_context->events_queue)
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{
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g_queue_foreach (clutter_context->events_queue,
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(GFunc) clutter_event_free,
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NULL);
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g_queue_free (clutter_context->events_queue);
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clutter_context->events_queue = NULL;
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}
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g_free (priv->font_name);
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clutter_backend_set_font_options (CLUTTER_BACKEND (gobject), NULL);
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G_OBJECT_CLASS (clutter_backend_parent_class)->dispose (gobject);
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}
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static inline void
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update_units_per_em (ClutterBackend *backend)
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{
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ClutterBackendPrivate *priv = backend->priv;
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const gchar *font_name;
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gdouble dpi;
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font_name = clutter_backend_get_font_name (backend);
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dpi = clutter_backend_get_resolution (backend);
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if (G_LIKELY (font_name != NULL && *font_name != '\0'))
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{
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PangoFontDescription *font_desc;
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gdouble font_size = 0;
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font_desc = pango_font_description_from_string (font_name);
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if (G_LIKELY (font_desc != NULL))
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{
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gint pango_size;
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gboolean is_absolute;
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pango_size = pango_font_description_get_size (font_desc);
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is_absolute =
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pango_font_description_get_size_is_absolute (font_desc);
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if (!is_absolute)
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font_size = ((gdouble) font_size) / PANGO_SCALE;
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pango_font_description_free (font_desc);
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}
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/* 10 points at 96 DPI is 12 pixels */
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priv->units_per_em = 1.2 * font_size
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* dpi
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/ 96.0;
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}
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else
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priv->units_per_em = -1.0;
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}
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static void
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clutter_backend_real_resolution_changed (ClutterBackend *backend)
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{
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update_units_per_em (backend);
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}
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static void
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clutter_backend_real_font_changed (ClutterBackend *backend)
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{
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update_units_per_em (backend);
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}
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static void
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clutter_backend_class_init (ClutterBackendClass *klass)
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{
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GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
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gobject_class->dispose = clutter_backend_dispose;
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g_type_class_add_private (gobject_class, sizeof (ClutterBackendPrivate));
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backend_signals[RESOLUTION_CHANGED] =
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g_signal_new (I_("resolution-changed"),
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G_TYPE_FROM_CLASS (klass),
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G_SIGNAL_RUN_FIRST,
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G_STRUCT_OFFSET (ClutterBackendClass, resolution_changed),
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NULL, NULL,
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clutter_marshal_VOID__VOID,
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G_TYPE_NONE, 0);
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backend_signals[FONT_CHANGED] =
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g_signal_new (I_("font-changed"),
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G_TYPE_FROM_CLASS (klass),
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G_SIGNAL_RUN_FIRST,
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G_STRUCT_OFFSET (ClutterBackendClass, font_changed),
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NULL, NULL,
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clutter_marshal_VOID__VOID,
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G_TYPE_NONE, 0);
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klass->resolution_changed = clutter_backend_real_resolution_changed;
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klass->font_changed = clutter_backend_real_font_changed;
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}
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static void
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clutter_backend_init (ClutterBackend *backend)
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{
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ClutterBackendPrivate *priv;
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priv = backend->priv = CLUTTER_BACKEND_GET_PRIVATE (backend);
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priv->resolution = -1.0;
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priv->units_per_em = -1.0;
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}
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void
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_clutter_backend_add_options (ClutterBackend *backend,
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GOptionGroup *group)
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{
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ClutterBackendClass *klass;
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g_return_if_fail (CLUTTER_IS_BACKEND (backend));
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klass = CLUTTER_BACKEND_GET_CLASS (backend);
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if (klass->add_options)
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klass->add_options (backend, group);
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}
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gboolean
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_clutter_backend_pre_parse (ClutterBackend *backend,
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GError **error)
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{
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ClutterBackendClass *klass;
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g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), FALSE);
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klass = CLUTTER_BACKEND_GET_CLASS (backend);
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if (klass->pre_parse)
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return klass->pre_parse (backend, error);
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return TRUE;
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}
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gboolean
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_clutter_backend_post_parse (ClutterBackend *backend,
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GError **error)
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{
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ClutterBackendClass *klass;
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g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), FALSE);
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klass = CLUTTER_BACKEND_GET_CLASS (backend);
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if (klass->post_parse)
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return klass->post_parse (backend, error);
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return TRUE;
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}
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ClutterActor *
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_clutter_backend_create_stage (ClutterBackend *backend,
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ClutterStage *wrapper,
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GError **error)
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{
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ClutterMainContext *context;
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ClutterBackendClass *klass;
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ClutterActor *stage = NULL;
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g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), FALSE);
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g_return_val_if_fail (CLUTTER_IS_STAGE (wrapper), FALSE);
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context = clutter_context_get_default ();
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if (!context->stage_manager)
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context->stage_manager = clutter_stage_manager_get_default ();
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klass = CLUTTER_BACKEND_GET_CLASS (backend);
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if (klass->create_stage)
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stage = klass->create_stage (backend, wrapper, error);
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if (!stage)
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return NULL;
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g_assert (CLUTTER_IS_STAGE_WINDOW (stage));
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_clutter_stage_set_window (wrapper, CLUTTER_STAGE_WINDOW (stage));
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_clutter_stage_manager_add_stage (context->stage_manager, wrapper);
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return stage;
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}
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void
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_clutter_backend_redraw (ClutterBackend *backend,
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ClutterStage *stage)
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{
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ClutterBackendClass *klass;
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klass = CLUTTER_BACKEND_GET_CLASS (backend);
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if (G_LIKELY (klass->redraw))
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klass->redraw (backend, stage);
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}
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void
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_clutter_backend_ensure_context (ClutterBackend *backend,
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ClutterStage *stage)
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{
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ClutterBackendClass *klass;
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static ClutterStage *current_context_stage = NULL;
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g_return_if_fail (CLUTTER_IS_BACKEND (backend));
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g_return_if_fail (CLUTTER_IS_STAGE (stage));
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if (current_context_stage != stage || !CLUTTER_ACTOR_IS_REALIZED (stage))
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{
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if (!CLUTTER_ACTOR_IS_REALIZED (stage))
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{
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CLUTTER_NOTE (MULTISTAGE, "Stage is not realized, unsetting");
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stage = NULL;
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}
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else
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CLUTTER_NOTE (MULTISTAGE, "Setting the new stage [%p]", stage);
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klass = CLUTTER_BACKEND_GET_CLASS (backend);
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if (G_LIKELY (klass->ensure_context))
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klass->ensure_context (backend, stage);
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/* FIXME: With a NULL stage and thus no active context it may make more
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* sense to clean the context but then re call with the default stage
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* so at least there is some kind of context in place (as to avoid
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* potential issue of GL calls with no context)
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*/
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current_context_stage = stage;
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}
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else
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CLUTTER_NOTE (MULTISTAGE, "Stage is the same");
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}
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ClutterFeatureFlags
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_clutter_backend_get_features (ClutterBackend *backend)
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{
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ClutterBackendClass *klass;
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g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), 0);
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klass = CLUTTER_BACKEND_GET_CLASS (backend);
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if (klass->get_features)
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return klass->get_features (backend);
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return 0;
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}
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void
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_clutter_backend_init_events (ClutterBackend *backend)
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{
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ClutterBackendClass *klass;
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ClutterMainContext *clutter_context;
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clutter_context = clutter_context_get_default ();
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g_return_if_fail (CLUTTER_IS_BACKEND (backend));
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g_return_if_fail (clutter_context != NULL);
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clutter_context->events_queue = g_queue_new ();
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klass = CLUTTER_BACKEND_GET_CLASS (backend);
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if (klass->init_events)
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klass->init_events (backend);
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}
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ClutterUnit
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_clutter_backend_get_units_per_em (ClutterBackend *backend)
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{
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ClutterBackendPrivate *priv;
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g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), 0);
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priv = backend->priv;
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if (G_UNLIKELY (priv->units_per_em < 0))
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update_units_per_em (backend);
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return priv->units_per_em;
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}
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/**
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* clutter_get_default_backend:
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*
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* Retrieves the default #ClutterBackend used by Clutter. The
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* #ClutterBackend holds backend-specific configuration options.
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*
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* Return value: the default backend. You should not ref or
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* unref the returned object. Applications should rarely need
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* to use this.
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*
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* Since: 0.4
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*/
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ClutterBackend *
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clutter_get_default_backend (void)
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{
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ClutterMainContext *clutter_context;
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clutter_context = clutter_context_get_default ();
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return clutter_context->backend;
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}
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/* FIXME: below should probably be moved into clutter_main */
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/**
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* clutter_backend_set_double_click_time:
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* @backend: a #ClutterBackend
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* @msec: milliseconds between two button press events
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*
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* Sets the maximum time between two button press events, used to
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* verify whether it's a double click event or not.
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*
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* Since: 0.4
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*/
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void
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clutter_backend_set_double_click_time (ClutterBackend *backend,
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guint msec)
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{
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g_return_if_fail (CLUTTER_IS_BACKEND (backend));
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backend->priv->double_click_time = msec;
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}
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/**
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* clutter_backend_get_double_click_time:
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* @backend: a #ClutterBackend
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*
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* Gets the maximum time between two button press events, as set
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* by clutter_backend_set_double_click_time().
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*
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* Return value: a time in milliseconds
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*
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* Since: 0.4
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*/
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guint
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clutter_backend_get_double_click_time (ClutterBackend *backend)
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{
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g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), 0);
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return backend->priv->double_click_time;
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}
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/**
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* clutter_backend_set_double_click_distance:
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* @backend: a #ClutterBackend
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* @distance: a distance, in pixels
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*
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* Sets the maximum distance used to verify a double click event.
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*
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* Since: 0.4
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*/
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void
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clutter_backend_set_double_click_distance (ClutterBackend *backend,
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guint distance)
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{
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g_return_if_fail (CLUTTER_IS_BACKEND (backend));
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backend->priv->double_click_distance = distance;
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}
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/**
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* clutter_backend_get_double_click_distance:
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* @backend: a #ClutterBackend
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*
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* Retrieves the distance used to verify a double click event
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*
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* Return value: a distance, in pixels.
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*
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* Since: 0.4
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*/
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guint
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clutter_backend_get_double_click_distance (ClutterBackend *backend)
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{
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g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), 0);
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return backend->priv->double_click_distance;
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}
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/**
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* clutter_backend_set_resolution:
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* @backend: a #ClutterBackend
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* @dpi: the resolution in "dots per inch" (Physical inches aren't
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* actually involved; the terminology is conventional).
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*
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* Sets the resolution for font handling on the screen. This is a
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* scale factor between points specified in a #PangoFontDescription
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* and cairo units. The default value is 96, meaning that a 10 point
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* font will be 13 units high. (10 * 96. / 72. = 13.3).
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*
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* Applications should never need to call this function.
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*
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* Since: 0.4
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*/
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void
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clutter_backend_set_resolution (ClutterBackend *backend,
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gdouble dpi)
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{
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ClutterBackendPrivate *priv;
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g_return_if_fail (CLUTTER_IS_BACKEND (backend));
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priv = backend->priv;
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if (dpi < 0)
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dpi = -1.0;
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priv->resolution = dpi;
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if (CLUTTER_CONTEXT ()->font_map)
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cogl_pango_font_map_set_resolution (CLUTTER_CONTEXT ()->font_map, dpi);
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g_signal_emit (backend, backend_signals[RESOLUTION_CHANGED], 0);
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}
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/**
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* clutter_backend_get_resolution:
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* @backend: a #ClutterBackend
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*
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* Gets the resolution for font handling on the screen; see
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* clutter_backend_set_resolution() for full details.
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*
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* Return value: the current resolution, or -1 if no resolution
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* has been set.
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*
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* Since: 0.4
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*/
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gdouble
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clutter_backend_get_resolution (ClutterBackend *backend)
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{
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g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), -1.0);
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return backend->priv->resolution;
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}
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/**
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* clutter_backend_set_font_options:
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* @backend: a #ClutterBackend
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* @options: Cairo font options for the backend, or %NULL
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*
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* Sets the new font options for @backend. If @options is %NULL,
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* the first following call to clutter_backend_get_font_options()
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* will return the default font options for @backend.
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*
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* This function is intended for actors creating a Pango layout
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* using the PangoCairo API.
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*
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* Since: 0.8
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*/
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void
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clutter_backend_set_font_options (ClutterBackend *backend,
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cairo_font_options_t *options)
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{
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ClutterBackendPrivate *priv;
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g_return_if_fail (CLUTTER_IS_BACKEND (backend));
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priv = backend->priv;
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if (priv->font_options != options)
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{
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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;
|
|
}
|
|
|
|
/**
|
|
* 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
|
|
*/
|
|
void
|
|
clutter_backend_set_font_name (ClutterBackend *backend,
|
|
const gchar *font_name)
|
|
{
|
|
ClutterBackendPrivate *priv;
|
|
|
|
g_return_if_fail (CLUTTER_IS_BACKEND (backend));
|
|
|
|
priv = backend->priv;
|
|
|
|
g_free (priv->font_name);
|
|
|
|
if (font_name == NULL || *font_name == '\0')
|
|
priv->font_name = g_strdup (DEFAULT_FONT_NAME);
|
|
else
|
|
priv->font_name = g_strdup (font_name);
|
|
|
|
g_signal_emit (backend, backend_signals[FONT_CHANGED], 0);
|
|
}
|
|
|
|
/**
|
|
* 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
|
|
*/
|
|
G_CONST_RETURN gchar *
|
|
clutter_backend_get_font_name (ClutterBackend *backend)
|
|
{
|
|
ClutterBackendPrivate *priv;
|
|
|
|
g_return_val_if_fail (CLUTTER_IS_BACKEND (backend), NULL);
|
|
|
|
priv = backend->priv;
|
|
|
|
if (G_LIKELY (priv->font_name))
|
|
return priv->font_name;
|
|
|
|
priv->font_name = g_strdup (DEFAULT_FONT_NAME);
|
|
|
|
return priv->font_name;
|
|
}
|