mutter/clutter/clutter-layout-manager.c

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/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2009 Intel Corporation.
*
* 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/>.
*
* Author:
* Emmanuele Bassi <ebassi@linux.intel.com>
*/
/**
* SECTION:clutter-layout-manager
* @short_description: Layout managers base class
*
* #ClutterLayoutManager is a base abstract class for layout managers. A
* layout manager implements the layouting policy for a composite or a
* container actor: it controls the preferred size of the actor to which
* it has been paired, and it controls the allocation of its children.
*
* Any composite or container #ClutterActor subclass can delegate the
* layouting of its children to a #ClutterLayoutManager. Clutter provides
* a generic container using #ClutterLayoutManager called #ClutterBox.
*
* Clutter provides some simple #ClutterLayoutManager sub-classes, like
* #ClutterFlowLayout and #ClutterBinLayout.
*
* <refsect2 id="ClutterLayoutManager-use-in-Actor">
* <title>Using a Layout Manager inside an Actor</title>
* <para>In order to use a #ClutterLayoutManager inside a #ClutterActor
* sub-class you should invoke clutter_layout_manager_get_preferred_width()
* inside the <structname>ClutterActor</structname>::get_preferred_width()
* virtual function and clutter_layout_manager_get_preferred_height()
* inside the <structname>ClutterActor</structname>::get_preferred_height()
* virtual function implementations. You should also call
* clutter_layout_manager_allocate() inside the implementation of the
* <structname>ClutterActor</structname>::allocate() virtual
* function.</para>
* <para>In order to receive notifications for changes in the layout
* manager policies you should also connect to the
* #ClutterLayoutManager::layout-changed signal and queue a relayout
* on your actor. The following code should be enough if the actor
* does not need to perform specific operations whenever a layout
* manager changes:</para>
* <informalexample><programlisting>
* g_signal_connect_swapped (layout_manager,
* "layout-changed",
* G_CALLBACK (clutter_actor_queue_relayout),
* actor);
* </programlisting></informalexample>
* </refsect2>
*
* <refsect2 id="ClutterLayoutManager-implementation">
* <title>Implementing a ClutterLayoutManager</title>
* <para>The implementation of a layout manager does not differ from
* the implementation of the size requisition and allocation bits of
* #ClutterActor, so you should read the relative documentation
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* <link linkend="clutter-subclassing-ClutterActor">for subclassing
* ClutterActor</link>.</para>
* <para>The layout manager implementation can hold a back pointer
* to the #ClutterContainer by implementing the
* <function>set_container()</function> virtual function. The layout manager
* should not hold a real reference (i.e. call g_object_ref()) on the
* container actor, to avoid reference cycles.</para>
* <para>If the layout manager has properties affecting the layout
* policies then it should emit the #ClutterLayoutManager::layout-changed
* signal on itself by using the clutter_layout_manager_layout_changed()
* function whenever one of these properties changes.</para>
* <para>If the layout manager has layout properties, that is properties that
* should exist only as the result of the presence of a specific (layout
* manager, container actor, child actor) combination, and it wishes to store
* those properties inside a #ClutterLayoutMeta then it should override the
* <structname>ClutterLayoutManager</structname>::get_child_meta_type()
* virtual function to return the #GType of the #ClutterLayoutMeta sub-class
* used to store the layout properties; optionally, the #ClutterLayoutManager
* sub-class might also override the
* <structname>ClutterLayoutManager</structname>::create_child_meta() virtual
* function to control how the #ClutterLayoutMeta instance is created,
* otherwise the default implementation will be equivalent to:</para>
* <informalexample><programlisting>
* ClutterLayoutManagerClass *klass;
* GType meta_type;
*
* klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
* meta_type = klass->get_child_meta_type (manager);
*
* return g_object_new (meta_type,
* "manager", manager,
* "container", container,
* "actor", actor,
* NULL);
* </programlisting></informalexample>
* <para>Where <varname>manager</varname> is the #ClutterLayoutManager,
* <varname>container</varname> is the #ClutterContainer using the
* #ClutterLayoutManager and <varname>actor</varname> is the #ClutterActor
* child of the #ClutterContainer.</para>
* </refsect2>
*
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
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* <refsect2 id="ClutterLayoutManager-animation">
* <title>Animating a ClutterLayoutManager</title>
* <para>A layout manager is used to let a #ClutterContainer take complete
* ownership over the layout (that is: the position and sizing) of its
* children; this means that using the Clutter animation API, like
* clutter_actor_animate(), to animate the position and sizing of a child of
* a layout manager it is not going to work properly, as the animation will
* automatically override any setting done by the layout manager
* itself.</para>
* <para>It is possible for a #ClutterLayoutManager sub-class to animate its
* children layout by using the base class animation support. The
* #ClutterLayoutManager animation support consists of three virtual
* functions: <function>begin_animation()</function>,
* <function>get_animation_progress()</function> and
* <function>end_animation()</function>.</para>
* <variablelist>
* <varlistentry>
* <term><function>begin_animation (duration, easing)</function></term>
* <listitem><para>This virtual function is invoked when the layout
* manager should begin an animation. The implementation should set up
* the state for the animation and create the ancillary objects for
* animating the layout. The default implementation creates a
* #ClutterTimeline for the given duration and a #ClutterAlpha binding
* the timeline to the given easing mode. This function returns a
* #ClutterAlpha which should be used to control the animation from
* the caller perspective.</para></listitem>
* </varlistentry>
* <varlistentry>
* <term><function>get_animation_progress()</function></term>
* <listitem><para>This virtual function should be invoked when animating
* a layout manager. It returns the progress of the animation, using the
* same semantics as the #ClutterAlpha:alpha value.</para></listitem>
* </varlistentry>
* <varlistentry>
* <term><function>end_animation()</function></term>
* <listitem><para>This virtual function is invoked when the animation of
* a layout manager ends, and it is meant to be used for bookkeeping the
* objects created in the <function>begin_animation()</function>
* function. The default implementation will call it implicitly when the
* timeline is complete.</para></listitem>
* </varlistentry>
* </variablelist>
* <para>The simplest way to animate a layout is to create a #ClutterTimeline
* inside the <function>begin_animation()</function> virtual function, along
* with a #ClutterAlpha, and for each #ClutterTimeline::new-frame signal
* emission call clutter_layout_manager_layout_changed(), which will cause a
* relayout. The #ClutterTimeline::completed signal emission should cause
* clutter_layout_manager_end_animation() to be called. The default
* implementation provided internally by #ClutterLayoutManager does exactly
* this, so most sub-classes should either not override any animation-related
* virtual function or simply override <function>begin_animation()</function>
* and <function>end_animation()</function> to set up ad hoc state, and then
* chain up to the parent's implementation.</para>
* <example id="example-ClutterLayoutManager-animation">
* <title>Animation of a Layout Manager</title>
* <para>The code below shows how a #ClutterLayoutManager sub-class should
* provide animating the allocation of its children from within the
* <function>allocate()</function> virtual function implementation. The
* animation is computed between the last stable allocation performed
* before the animation started and the desired final allocation.</para>
* <para>The <varname>is_animating</varname> variable is stored inside the
* #ClutterLayoutManager sub-class and it is updated by overriding the
* <function>begin_animation()</function> and
* <function>end_animation()</function> virtual functions and chaining up
* to the base class implementation.</para>
* <para>The last stable allocation is stored within a #ClutterLayoutMeta
* sub-class used by the implementation.</para>
* <programlisting>
* static void
* my_layout_manager_allocate (ClutterLayoutManager *manager,
* ClutterContainer *container,
* const ClutterActorBox *allocation,
* ClutterAllocationFlags flags)
* {
* MyLayoutManager *self = MY_LAYOUT_MANAGER (manager);
* GList *children, *l;
*
* children = clutter_container_get_children (container);
*
* for (l = children; l != NULL; l = l-&gt;next)
* {
* ClutterActor *child = l->data;
* ClutterLayoutMeta *meta;
* MyLayoutMeta *my_meta;
*
* /&ast; retrieve the layout meta-object &ast;/
* meta = clutter_layout_manager_get_child_meta (manager,
* container,
* child);
* my_meta = MY_LAYOUT_META (meta);
*
* /&ast; compute the desired allocation for the child &ast;/
* compute_allocation (self, my_meta, child,
* allocation, flags,
* &amp;child_box);
*
* /&ast; this is the additional code that deals with the animation
* &ast; of the layout manager
* &ast;/
* if (!self-&gt;is_animating)
* {
* /&ast; store the last stable allocation for later use &ast;/
* my_meta-&gt;last_alloc = clutter_actor_box_copy (&amp;child_box);
* }
* else
* {
* ClutterActorBox end = { 0, };
* gdouble p;
*
* /&ast; get the progress of the animation &ast;/
* p = clutter_layout_manager_get_animation_progress (manager);
*
* if (my_meta-&gt;last_alloc != NULL)
* {
* /&ast; copy the desired allocation as the final state &ast;/
* end = child_box;
*
* /&ast; then interpolate the initial and final state
* &ast; depending on the progress of the animation,
* &ast; and put the result inside the box we will use
* &ast; to allocate the child
* &ast;/
* clutter_actor_box_interpolate (my_meta-&gt;last_alloc,
* &amp;end,
* p,
* &amp;child_box);
* }
* else
* {
* /&ast; if there is no stable allocation then the child was
* &ast; added while animating; one possible course of action
* &ast; is to just bail out and fall through to the allocation
* &ast; to position the child directly at its final state
* &ast;/
* my_meta-&gt;last_alloc =
* clutter_actor_box_copy (&amp;child_box);
* }
* }
*
* /&ast; allocate the child &ast;/
* clutter_actor_allocate (child, &child_box, flags);
* }
*
* g_list_free (children);
* }
* </programlisting>
* </example>
* <para>Sub-classes of #ClutterLayoutManager that support animations of the
* layout changes should call clutter_layout_manager_begin_animation()
* whenever a layout property changes value, e.g.:</para>
* <informalexample>
* <programlisting>
* if (self->orientation != new_orientation)
* {
* ClutterLayoutManager *manager;
*
* self->orientation = new_orientation;
*
* manager = CLUTTER_LAYOUT_MANAGER (self);
* clutter_layout_manager_layout_changed (manager);
* clutter_layout_manager_begin_animation (manager, 500, CLUTTER_LINEAR);
*
* g_object_notify (G_OBJECT (self), "orientation");
* }
* </programlisting>
* </informalexample>
* <para>The code above will animate a change in the
* <varname>orientation</varname> layout property of a layout manager.</para>
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
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* </refsect2>
*
* #ClutterLayoutManager is available since Clutter 1.2
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <glib-object.h>
#include <gobject/gvaluecollector.h>
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
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#include "clutter-alpha.h"
#include "clutter-debug.h"
#include "clutter-layout-manager.h"
#include "clutter-layout-meta.h"
#include "clutter-marshal.h"
#include "clutter-private.h"
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
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#include "clutter-timeline.h"
#define LAYOUT_MANAGER_WARN_NOT_IMPLEMENTED(m,method) G_STMT_START { \
GObject *_obj = G_OBJECT (m); \
g_warning ("Layout managers of type %s do not implement " \
"the ClutterLayoutManager::%s method", \
G_OBJECT_TYPE_NAME (_obj), \
(method)); } G_STMT_END
enum
{
LAYOUT_CHANGED,
LAST_SIGNAL
};
G_DEFINE_ABSTRACT_TYPE (ClutterLayoutManager,
clutter_layout_manager,
G_TYPE_INITIALLY_UNOWNED);
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
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static GQuark quark_layout_meta = 0;
static GQuark quark_layout_alpha = 0;
static guint manager_signals[LAST_SIGNAL] = { 0, };
static void
layout_manager_freeze_layout_change (ClutterLayoutManager *manager)
{
gpointer is_frozen;
CLUTTER_NOTE (LAYOUT, "Freezing changes for manager '%s'[%p]",
G_OBJECT_TYPE_NAME (manager),
manager);
is_frozen = g_object_get_data (G_OBJECT (manager), "freeze-change");
if (is_frozen == NULL)
g_object_set_data (G_OBJECT (manager), "freeze-change",
GUINT_TO_POINTER (1));
else
{
guint level = GPOINTER_TO_UINT (is_frozen) + 1;
g_object_set_data (G_OBJECT (manager), "freeze-change",
GUINT_TO_POINTER (level));
}
}
static void
layout_manager_thaw_layout_change (ClutterLayoutManager *manager)
{
gpointer is_frozen;
is_frozen = g_object_get_data (G_OBJECT (manager), "freeze-change");
if (is_frozen == NULL)
g_critical (G_STRLOC ": Mismatched thaw; you have to call "
"clutter_layout_manager_freeze_layout_change() prior to "
"calling clutter_layout_manager_thaw_layout_change()");
else
{
guint level = GPOINTER_TO_UINT (is_frozen);
g_assert (level > 0);
CLUTTER_NOTE (LAYOUT, "Thawing changes for manager '%s'[%p]",
G_OBJECT_TYPE_NAME (manager),
manager);
level -= 1;
if (level == 0)
g_object_set_data (G_OBJECT (manager), "freeze-change", NULL);
else
g_object_set_data (G_OBJECT (manager), "freeze-change",
GUINT_TO_POINTER (level));
}
}
static void
layout_manager_real_get_preferred_width (ClutterLayoutManager *manager,
ClutterContainer *container,
gfloat for_height,
gfloat *min_width_p,
gfloat *nat_width_p)
{
LAYOUT_MANAGER_WARN_NOT_IMPLEMENTED (manager, "get_preferred_width");
if (min_width_p)
*min_width_p = 0.0;
if (nat_width_p)
*nat_width_p = 0.0;
}
static void
layout_manager_real_get_preferred_height (ClutterLayoutManager *manager,
ClutterContainer *container,
gfloat for_width,
gfloat *min_height_p,
gfloat *nat_height_p)
{
LAYOUT_MANAGER_WARN_NOT_IMPLEMENTED (manager, "get_preferred_height");
if (min_height_p)
*min_height_p = 0.0;
if (nat_height_p)
*nat_height_p = 0.0;
}
static void
layout_manager_real_allocate (ClutterLayoutManager *manager,
ClutterContainer *container,
const ClutterActorBox *allocation,
ClutterAllocationFlags flags)
{
LAYOUT_MANAGER_WARN_NOT_IMPLEMENTED (manager, "allocate");
}
static void
layout_manager_real_set_container (ClutterLayoutManager *manager,
ClutterContainer *container)
{
if (container != NULL)
g_object_set_data (G_OBJECT (container), "clutter-layout-manager", manager);
}
static ClutterLayoutMeta *
layout_manager_real_create_child_meta (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor)
{
ClutterLayoutManagerClass *klass;
GType meta_type;
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
meta_type = klass->get_child_meta_type (manager);
/* provide a default implementation to reduce common code */
if (meta_type != G_TYPE_INVALID)
{
g_assert (g_type_is_a (meta_type, CLUTTER_TYPE_LAYOUT_META));
return g_object_new (meta_type,
"manager", manager,
"container", container,
"actor", actor,
NULL);
}
return NULL;
}
static GType
layout_manager_real_get_child_meta_type (ClutterLayoutManager *manager)
{
return G_TYPE_INVALID;
}
static ClutterAlpha *
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
2009-12-12 00:02:43 +00:00
layout_manager_real_begin_animation (ClutterLayoutManager *manager,
guint duration,
gulong mode)
{
ClutterTimeline *timeline;
ClutterAlpha *alpha;
alpha = g_object_get_qdata (G_OBJECT (manager), quark_layout_alpha);
if (alpha != NULL)
{
clutter_alpha_set_mode (alpha, mode);
timeline = clutter_alpha_get_timeline (alpha);
clutter_timeline_set_duration (timeline, duration);
clutter_timeline_rewind (timeline);
return alpha;
};
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
2009-12-12 00:02:43 +00:00
timeline = clutter_timeline_new (duration);
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
2009-12-12 00:02:43 +00:00
alpha = clutter_alpha_new_full (timeline, mode);
/* let the alpha take ownership of the timeline */
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
2009-12-12 00:02:43 +00:00
g_object_unref (timeline);
g_signal_connect_swapped (timeline, "completed",
G_CALLBACK (clutter_layout_manager_end_animation),
manager);
g_signal_connect_swapped (timeline, "new-frame",
G_CALLBACK (clutter_layout_manager_layout_changed),
manager);
g_object_set_qdata_full (G_OBJECT (manager),
quark_layout_alpha, alpha,
(GDestroyNotify) g_object_unref);
clutter_timeline_start (timeline);
return alpha;
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
2009-12-12 00:02:43 +00:00
}
static gdouble
layout_manager_real_get_animation_progress (ClutterLayoutManager *manager)
{
ClutterAlpha *alpha;
alpha = g_object_get_qdata (G_OBJECT (manager), quark_layout_alpha);
if (alpha == NULL)
return 1.0;
return clutter_alpha_get_alpha (alpha);
}
static void
layout_manager_real_end_animation (ClutterLayoutManager *manager)
{
ClutterTimeline *timeline;
ClutterAlpha *alpha;
alpha = g_object_get_qdata (G_OBJECT (manager), quark_layout_alpha);
if (alpha == NULL)
return;
timeline = clutter_alpha_get_timeline (alpha);
g_assert (timeline != NULL);
if (clutter_timeline_is_playing (timeline))
clutter_timeline_stop (timeline);
g_signal_handlers_disconnect_by_func (timeline,
G_CALLBACK (clutter_layout_manager_end_animation),
manager);
g_signal_handlers_disconnect_by_func (timeline,
G_CALLBACK (clutter_layout_manager_layout_changed),
manager);
g_object_set_qdata (G_OBJECT (manager), quark_layout_alpha, NULL);
clutter_layout_manager_layout_changed (manager);
}
static void
clutter_layout_manager_class_init (ClutterLayoutManagerClass *klass)
{
quark_layout_meta =
g_quark_from_static_string ("clutter-layout-manager-child-meta");
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
2009-12-12 00:02:43 +00:00
quark_layout_alpha =
g_quark_from_static_string ("clutter-layout-manager-alpha");
klass->get_preferred_width = layout_manager_real_get_preferred_width;
klass->get_preferred_height = layout_manager_real_get_preferred_height;
klass->allocate = layout_manager_real_allocate;
klass->create_child_meta = layout_manager_real_create_child_meta;
klass->get_child_meta_type = layout_manager_real_get_child_meta_type;
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
2009-12-12 00:02:43 +00:00
klass->begin_animation = layout_manager_real_begin_animation;
klass->get_animation_progress = layout_manager_real_get_animation_progress;
klass->end_animation = layout_manager_real_end_animation;
klass->set_container = layout_manager_real_set_container;
/**
* ClutterLayoutManager::layout-changed:
* @manager: the #ClutterLayoutManager that emitted the signal
*
* The ::layout-changed signal is emitted each time a layout manager
* has been changed. Every #ClutterActor using the @manager instance
* as a layout manager should connect a handler to the ::layout-changed
* signal and queue a relayout on themselves:
*
* |[
* static void layout_changed (ClutterLayoutManager *manager,
* ClutterActor *self)
* {
* clutter_actor_queue_relayout (self);
* }
* ...
* self->manager = g_object_ref_sink (manager);
* g_signal_connect (self->manager, "layout-changed",
* G_CALLBACK (layout_changed),
* self);
* ]|
*
* Sub-classes of #ClutterLayoutManager that implement a layout that
* can be controlled or changed using parameters should emit the
* ::layout-changed signal whenever one of the parameters changes,
* by using clutter_layout_manager_layout_changed().
*
* Since: 1.2
*/
manager_signals[LAYOUT_CHANGED] =
g_signal_new (I_("layout-changed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterLayoutManagerClass,
layout_changed),
NULL, NULL,
_clutter_marshal_VOID__VOID,
G_TYPE_NONE, 0);
}
static void
clutter_layout_manager_init (ClutterLayoutManager *manager)
{
}
/**
* clutter_layout_manager_get_preferred_width:
* @manager: a #ClutterLayoutManager
* @container: the #ClutterContainer using @manager
* @for_height: the height for which the width should be computed, or -1
* @min_width_p: (out) (allow-none): return location for the minimum width
* of the layout, or %NULL
* @nat_width_p: (out) (allow-none): return location for the natural width
* of the layout, or %NULL
*
* Computes the minimum and natural widths of the @container according
* to @manager.
*
* See also clutter_actor_get_preferred_width()
*
* Since: 1.2
*/
void
clutter_layout_manager_get_preferred_width (ClutterLayoutManager *manager,
ClutterContainer *container,
gfloat for_height,
gfloat *min_width_p,
gfloat *nat_width_p)
{
ClutterLayoutManagerClass *klass;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
klass->get_preferred_width (manager, container, for_height,
min_width_p,
nat_width_p);
}
/**
* clutter_layout_manager_get_preferred_height:
* @manager: a #ClutterLayoutManager
* @container: the #ClutterContainer using @manager
* @for_width: the width for which the height should be computed, or -1
* @min_height_p: (out) (allow-none): return location for the minimum height
* of the layout, or %NULL
* @nat_height_p: (out) (allow-none): return location for the natural height
* of the layout, or %NULL
*
* Computes the minimum and natural heights of the @container according
* to @manager.
*
* See also clutter_actor_get_preferred_height()
*
* Since: 1.2
*/
void
clutter_layout_manager_get_preferred_height (ClutterLayoutManager *manager,
ClutterContainer *container,
gfloat for_width,
gfloat *min_height_p,
gfloat *nat_height_p)
{
ClutterLayoutManagerClass *klass;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
klass->get_preferred_height (manager, container, for_width,
min_height_p,
nat_height_p);
}
/**
* clutter_layout_manager_allocate:
* @manager: a #ClutterLayoutManager
* @container: the #ClutterContainer using @manager
* @allocation: the #ClutterActorBox containing the allocated area
* of @container
* @flags: the allocation flags
*
* Allocates the children of @container given an area
*
* See also clutter_actor_allocate()
*
* Since: 1.2
*/
void
clutter_layout_manager_allocate (ClutterLayoutManager *manager,
ClutterContainer *container,
const ClutterActorBox *allocation,
ClutterAllocationFlags flags)
{
ClutterLayoutManagerClass *klass;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
g_return_if_fail (allocation != NULL);
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
klass->allocate (manager, container, allocation, flags);
}
/**
* clutter_layout_manager_layout_changed:
* @manager: a #ClutterLayoutManager
*
* Emits the #ClutterLayoutManager::layout-changed signal on @manager
*
* This function should only be called by implementations of the
* #ClutterLayoutManager class
*
* Since: 1.2
*/
void
clutter_layout_manager_layout_changed (ClutterLayoutManager *manager)
{
gpointer is_frozen;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
is_frozen = g_object_get_data (G_OBJECT (manager), "freeze-change");
if (is_frozen == NULL)
g_signal_emit (manager, manager_signals[LAYOUT_CHANGED], 0);
else
CLUTTER_NOTE (LAYOUT, "Layout manager '%s'[%p] has been frozen",
G_OBJECT_TYPE_NAME (manager),
manager);
}
/**
* clutter_layout_manager_set_container:
* @manager: a #ClutterLayoutManager
* @container: (allow-none): a #ClutterContainer using @manager
*
* If the #ClutterLayoutManager sub-class allows it, allow
* adding a weak reference of the @container using @manager
* from within the layout manager
*
* The layout manager should not increase the reference
* count of the @container
*
* Since: 1.2
*/
void
clutter_layout_manager_set_container (ClutterLayoutManager *manager,
ClutterContainer *container)
{
ClutterLayoutManagerClass *klass;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (container == NULL || CLUTTER_IS_CONTAINER (container));
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
if (klass->set_container)
klass->set_container (manager, container);
}
GType
_clutter_layout_manager_get_child_meta_type (ClutterLayoutManager *manager)
{
return CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager)->get_child_meta_type (manager);
}
static inline ClutterLayoutMeta *
create_child_meta (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor)
{
ClutterLayoutManagerClass *klass;
ClutterLayoutMeta *meta = NULL;
layout_manager_freeze_layout_change (manager);
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
if (klass->get_child_meta_type (manager) != G_TYPE_INVALID)
meta = klass->create_child_meta (manager, container, actor);
layout_manager_thaw_layout_change (manager);
return meta;
}
static inline ClutterLayoutMeta *
get_child_meta (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor)
{
ClutterLayoutMeta *layout = NULL;
layout = g_object_get_qdata (G_OBJECT (actor), quark_layout_meta);
if (layout != NULL)
{
ClutterChildMeta *child = CLUTTER_CHILD_META (layout);
if (layout->manager == manager &&
child->container == container &&
child->actor == actor)
return layout;
/* if the LayoutMeta referenced is not attached to the
* layout manager then we simply ask the layout manager
* to replace it with the right one
*/
}
layout = create_child_meta (manager, container, actor);
if (layout != NULL)
{
g_assert (CLUTTER_IS_LAYOUT_META (layout));
g_object_set_qdata_full (G_OBJECT (actor), quark_layout_meta,
layout,
(GDestroyNotify) g_object_unref);
return layout;
}
return NULL;
}
/**
* clutter_layout_manager_get_child_meta:
* @manager: a #ClutterLayoutManager
* @container: a #ClutterContainer using @manager
* @actor: a #ClutterActor child of @container
*
* Retrieves the #ClutterLayoutMeta that the layout @manager associated
* to the @actor child of @container, eventually by creating one if the
* #ClutterLayoutManager supports layout properties
*
* Return value: (transfer none): a #ClutterLayoutMeta, or %NULL if the
* #ClutterLayoutManager does not have layout properties. The returned
* layout meta instance is owned by the #ClutterLayoutManager and it
* should not be unreferenced
*
* Since: 1.0
*/
ClutterLayoutMeta *
clutter_layout_manager_get_child_meta (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor)
{
g_return_val_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager), NULL);
g_return_val_if_fail (CLUTTER_IS_CONTAINER (container), NULL);
g_return_val_if_fail (CLUTTER_IS_ACTOR (actor), NULL);
return get_child_meta (manager, container, actor);
}
static inline gboolean
layout_set_property_internal (ClutterLayoutManager *manager,
GObject *gobject,
GParamSpec *pspec,
const GValue *value)
{
if (pspec->flags & G_PARAM_CONSTRUCT_ONLY)
{
g_warning ("%s: Child property '%s' of the layout manager of "
"type '%s' is constructor-only",
G_STRLOC, pspec->name, G_OBJECT_TYPE_NAME (manager));
return FALSE;
}
if (!(pspec->flags & G_PARAM_WRITABLE))
{
g_warning ("%s: Child property '%s' of the layout manager of "
"type '%s' is not writable",
G_STRLOC, pspec->name, G_OBJECT_TYPE_NAME (manager));
return FALSE;
}
g_object_set_property (gobject, pspec->name, value);
return TRUE;
}
static inline gboolean
layout_get_property_internal (ClutterLayoutManager *manager,
GObject *gobject,
GParamSpec *pspec,
GValue *value)
{
if (!(pspec->flags & G_PARAM_READABLE))
{
g_warning ("%s: Child property '%s' of the layout manager of "
"type '%s' is not readable",
G_STRLOC, pspec->name, G_OBJECT_TYPE_NAME (manager));
return FALSE;
}
g_object_get_property (gobject, pspec->name, value);
return TRUE;
}
/**
* clutter_layout_manager_child_set:
* @manager: a #ClutterLayoutManager
* @container: a #ClutterContainer using @manager
* @actor: a #ClutterActor child of @container
* @first_property: the first property name
* @Varargs: a list of property name and value pairs
*
* Sets a list of properties and their values on the #ClutterLayoutMeta
* associated by @manager to a child of @container
*
* Languages bindings should use clutter_layout_manager_child_set_property()
* instead
*
* Since: 1.2
*/
void
clutter_layout_manager_child_set (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor,
const gchar *first_property,
...)
{
ClutterLayoutMeta *meta;
GObjectClass *klass;
const gchar *pname;
va_list var_args;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
g_return_if_fail (CLUTTER_IS_ACTOR (actor));
g_return_if_fail (first_property != NULL);
meta = get_child_meta (manager, container, actor);
if (meta == NULL)
{
g_warning ("Layout managers of type '%s' do not support "
"layout metadata",
g_type_name (G_OBJECT_TYPE (manager)));
return;
}
klass = G_OBJECT_GET_CLASS (meta);
va_start (var_args, first_property);
pname = first_property;
while (pname)
{
GValue value = { 0, };
GParamSpec *pspec;
gchar *error;
gboolean res;
pspec = g_object_class_find_property (klass, pname);
if (pspec == NULL)
{
g_warning ("%s: Layout managers of type '%s' have no layout "
"property named '%s'",
G_STRLOC, G_OBJECT_TYPE_NAME (manager), pname);
break;
}
G_VALUE_COLLECT_INIT (&value, G_PARAM_SPEC_VALUE_TYPE (pspec),
var_args, 0,
&error);
if (error)
{
g_warning ("%s: %s", G_STRLOC, error);
g_free (error);
break;
}
res = layout_set_property_internal (manager, G_OBJECT (meta),
pspec,
&value);
g_value_unset (&value);
if (!res)
break;
pname = va_arg (var_args, gchar*);
}
va_end (var_args);
}
/**
* clutter_layout_manager_child_set_property:
* @manager: a #ClutterLayoutManager
* @container: a #ClutterContainer using @manager
* @actor: a #ClutterActor child of @container
* @property_name: the name of the property to set
* @value: a #GValue with the value of the property to set
*
* Sets a property on the #ClutterLayoutMeta created by @manager and
* attached to a child of @container
*
* Since: 1.2
*/
void
clutter_layout_manager_child_set_property (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor,
const gchar *property_name,
const GValue *value)
{
ClutterLayoutMeta *meta;
GObjectClass *klass;
GParamSpec *pspec;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
g_return_if_fail (CLUTTER_IS_ACTOR (actor));
g_return_if_fail (property_name != NULL);
g_return_if_fail (value != NULL);
meta = get_child_meta (manager, container, actor);
if (meta == NULL)
{
g_warning ("Layout managers of type '%s' do not support "
"layout metadata",
g_type_name (G_OBJECT_TYPE (manager)));
return;
}
klass = G_OBJECT_GET_CLASS (meta);
pspec = g_object_class_find_property (klass, property_name);
if (pspec == NULL)
{
g_warning ("%s: Layout managers of type '%s' have no layout "
"property named '%s'",
G_STRLOC, G_OBJECT_TYPE_NAME (manager), property_name);
return;
}
layout_set_property_internal (manager, G_OBJECT (meta), pspec, value);
}
/**
* clutter_layout_manager_child_get:
* @manager: a #ClutterLayoutManager
* @container: a #ClutterContainer using @manager
* @actor: a #ClutterActor child of @container
* @first_property: the name of the first property
* @Varargs: a list of property name and return location for the value pairs
*
* Retrieves the values for a list of properties out of the
* #ClutterLayoutMeta created by @manager and attached to the
* child of a @container
*
* Since: 1.2
*/
void
clutter_layout_manager_child_get (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor,
const gchar *first_property,
...)
{
ClutterLayoutMeta *meta;
GObjectClass *klass;
const gchar *pname;
va_list var_args;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
g_return_if_fail (CLUTTER_IS_ACTOR (actor));
g_return_if_fail (first_property != NULL);
meta = get_child_meta (manager, container, actor);
if (meta == NULL)
{
g_warning ("Layout managers of type '%s' do not support "
"layout metadata",
g_type_name (G_OBJECT_TYPE (manager)));
return;
}
klass = G_OBJECT_GET_CLASS (meta);
va_start (var_args, first_property);
pname = first_property;
while (pname)
{
GValue value = { 0, };
GParamSpec *pspec;
gchar *error;
gboolean res;
pspec = g_object_class_find_property (klass, pname);
if (pspec == NULL)
{
g_warning ("%s: Layout managers of type '%s' have no layout "
"property named '%s'",
G_STRLOC, G_OBJECT_TYPE_NAME (manager), pname);
break;
}
g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (pspec));
res = layout_get_property_internal (manager, G_OBJECT (meta),
pspec,
&value);
if (!res)
{
g_value_unset (&value);
break;
}
G_VALUE_LCOPY (&value, var_args, 0, &error);
if (error)
{
g_warning ("%s: %s", G_STRLOC, error);
g_free (error);
g_value_unset (&value);
break;
}
g_value_unset (&value);
pname = va_arg (var_args, gchar*);
}
va_end (var_args);
}
/**
* clutter_layout_manager_child_get_property:
* @manager: a #ClutterLayoutManager
* @container: a #ClutterContainer using @manager
* @actor: a #ClutterActor child of @container
* @property_name: the name of the property to get
* @value: a #GValue with the value of the property to get
*
* Gets a property on the #ClutterLayoutMeta created by @manager and
* attached to a child of @container
*
* The #GValue must already be initialized to the type of the property
* and has to be unset with g_value_unset() after extracting the real
* value out of it
*
* Since: 1.2
*/
void
clutter_layout_manager_child_get_property (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor,
const gchar *property_name,
GValue *value)
{
ClutterLayoutMeta *meta;
GObjectClass *klass;
GParamSpec *pspec;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
g_return_if_fail (CLUTTER_IS_ACTOR (actor));
g_return_if_fail (property_name != NULL);
g_return_if_fail (value != NULL);
meta = get_child_meta (manager, container, actor);
if (meta == NULL)
{
g_warning ("Layout managers of type %s do not support "
"layout metadata",
g_type_name (G_OBJECT_TYPE (manager)));
return;
}
klass = G_OBJECT_GET_CLASS (meta);
pspec = g_object_class_find_property (klass, property_name);
if (pspec == NULL)
{
g_warning ("%s: Layout managers of type '%s' have no layout "
"property named '%s'",
G_STRLOC, G_OBJECT_TYPE_NAME (manager), property_name);
return;
}
layout_get_property_internal (manager, G_OBJECT (meta), pspec, value);
}
/**
* clutter_layout_manager_find_child_property:
* @manager: a #ClutterLayoutManager
* @name: the name of the property
*
* Retrieves the #GParamSpec for the layout property @name inside
* the #ClutterLayoutMeta sub-class used by @manager
*
* Return value: (transfer none): a #GParamSpec describing the property,
* or %NULL if no property with that name exists. The returned
* #GParamSpec is owned by the layout manager and should not be
* modified or freed
*
* Since: 1.2
*/
GParamSpec *
clutter_layout_manager_find_child_property (ClutterLayoutManager *manager,
const gchar *name)
{
ClutterLayoutManagerClass *klass;
GObjectClass *meta_klass;
GParamSpec *pspec;
GType meta_type;
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
meta_type = klass->get_child_meta_type (manager);
if (meta_type == G_TYPE_INVALID)
return NULL;
meta_klass = g_type_class_ref (meta_type);
pspec = g_object_class_find_property (meta_klass, name);
g_type_class_unref (meta_klass);
return pspec;
}
/**
* clutter_layout_manager_list_child_properties:
* @manager: a #ClutterLayoutManager
* @n_pspecs: (out): return location for the number of returned
* #GParamSpec<!-- -->s
*
* Retrieves all the #GParamSpec<!-- -->s for the layout properties
* stored inside the #ClutterLayoutMeta sub-class used by @manager
*
2010-09-08 15:41:47 +00:00
* Return value: (transfer full) (array length=n_pspecs): the newly-allocated,
* %NULL-terminated array of #GParamSpec<!-- -->s. Use g_free() to free the
* resources allocated for the array
*
* Since: 1.2
*/
GParamSpec **
clutter_layout_manager_list_child_properties (ClutterLayoutManager *manager,
guint *n_pspecs)
{
ClutterLayoutManagerClass *klass;
GObjectClass *meta_klass;
GParamSpec **pspecs;
GType meta_type;
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
meta_type = klass->get_child_meta_type (manager);
if (meta_type == G_TYPE_INVALID)
return NULL;
meta_klass = g_type_class_ref (meta_type);
pspecs = g_object_class_list_properties (meta_klass, n_pspecs);
g_type_class_unref (meta_klass);
return pspecs;
}
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
2009-12-12 00:02:43 +00:00
/**
* clutter_layout_manager_begin_animation:
* @manager: a #ClutterLayoutManager
* @duration: the duration of the animation, in milliseconds
* @mode: the easing mode of the animation
*
* Begins an animation of @duration milliseconds, using the provided
* easing @mode
*
* The easing mode can be specified either as a #ClutterAnimationMode
* or as a logical id returned by clutter_alpha_register_func()
*
* The result of this function depends on the @manager implementation
*
* Return value: (transfer none): The #ClutterAlpha created by the
* layout manager; the returned instance is owned by the layout
* manager and should not be unreferenced
*
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
2009-12-12 00:02:43 +00:00
* Since: 1.2
*/
ClutterAlpha *
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
2009-12-12 00:02:43 +00:00
clutter_layout_manager_begin_animation (ClutterLayoutManager *manager,
guint duration,
gulong mode)
{
ClutterLayoutManagerClass *klass;
g_return_val_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager), NULL);
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
2009-12-12 00:02:43 +00:00
return klass->begin_animation (manager, duration, mode);
layout: Add animation support to LayoutManager In order to animate a fluid layout we cannot use the common animation code paths as they will override the size request and allocation paths that are handled by the layout manager itself. One way to introduce animations in the allocation sequence is to use a Timeline and an Alpha to compute a progress value and then use that value to interpolate an ActorBox between the initial and final states of the animation - with the initial state being the last allocation of the child prior to the animation start, and the final state the allocation of the child at the end; for every frame of the Timeline we then queue a relayout on the layout manager's container, which will result in an animation. ClutterLayoutManager is the most likely place to add a generic API for beginning and ending an animation, as well as the place to provide a default code path to create the ancillary Timeline and Alpha instances needed to drive the animation. A LayoutManager sub-class will need to: • call clutter_layout_manager_begin_animation() whenever it should animate between two states, for instance: whenever a layout property changes value; • eventually override begin_animation() and end_animation() in case further state needs to be set up, and then chain up to the default implementation provided by LayoutManager; • if a completely different implementation is required, the layout manager sub-class should override begin_animation(), end_animation() and get_animation_progress(). Inside the allocate() implementation the sub-class should also interpolate between the last known allocation of a child and the newly computed allocation.
2009-12-12 00:02:43 +00:00
}
/**
* clutter_layout_manager_end_animation:
* @manager: a #ClutterLayoutManager
*
* Ends an animation started by clutter_layout_manager_begin_animation()
*
* The result of this call depends on the @manager implementation
*
* Since: 1.2
*/
void
clutter_layout_manager_end_animation (ClutterLayoutManager *manager)
{
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager)->end_animation (manager);
}
/**
* clutter_layout_manager_get_animation_progress:
* @manager: a #ClutterLayoutManager
*
* Retrieves the progress of the animation, if one has been started by
* clutter_layout_manager_begin_animation()
*
* The returned value has the same semantics of the #ClutterAlpha:alpha
* value
*
* Return value: the progress of the animation
*
* Since: 1.2
*/
gdouble
clutter_layout_manager_get_animation_progress (ClutterLayoutManager *manager)
{
ClutterLayoutManagerClass *klass;
g_return_val_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager), 1.0);
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
return klass->get_animation_progress (manager);
}