gstreamer/ges/ges-extractable.h
2020-03-05 17:04:51 -03:00

154 lines
6.7 KiB
C

/* GStreamer Editing Services
*
* Copyright (C) 2012 Thibault Saunier <thibault.saunier@collabora.com>
* Copyright (C) 2012 Volodymyr Rudyi <vladimir.rudoy@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef _GES_EXTRACTABLE_
#define _GES_EXTRACTABLE_
typedef struct _GESExtractable GESExtractable;
#include <glib-object.h>
#include <gio/gio.h>
#include <gst/gst.h>
#include <ges/ges-types.h>
#include <ges/ges-asset.h>
G_BEGIN_DECLS
/* GESExtractable interface declarations */
#define GES_TYPE_EXTRACTABLE (ges_extractable_get_type ())
#define GES_EXTRACTABLE(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GES_TYPE_EXTRACTABLE, GESExtractable))
#define GES_IS_EXTRACTABLE(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GES_TYPE_EXTRACTABLE))
#define GES_EXTRACTABLE_GET_INTERFACE(inst) (G_TYPE_INSTANCE_GET_INTERFACE ((inst), GES_TYPE_EXTRACTABLE, GESExtractableInterface))
GES_API
GType ges_extractable_get_type (void);
/**
* GESExtractableCheckId:
* @type: The #GESExtractable type to check @id for
* @id: The ID to check
* @error: An error that can be set if needed
*
* Method for checking that an ID is valid for the given #GESExtractable
* type. If the given ID is considered valid, it can be adjusted into some
* standard and returned to prevent the creation of separate #GESAsset-s,
* with different #GESAsset:id, that would otherwise act the same.
*
* Returns (transfer full) (nullable): The actual #GESAsset:id to set on
* any corresponding assets, based on @id, or %NULL if @id is not valid.
*/
typedef gchar* (*GESExtractableCheckId) (GType type, const gchar *id,
GError **error);
/**
* GESExtractableInterface:
* @asset_type: The subclass type of #GESAsset that should be created when
* an asset with the corresponding #GESAsset:extractable-type is
* requested.
* @check_id: The method to call to check whether a given ID is valid as
* an asset #GESAsset:id for the given #GESAsset:extractable-type. The
* returned ID is the actual #GESAsset:id that is set on the asset. The
* default implementation will simply always return the type name of the
* #GESAsset:extractable-type, even if the received ID is %NULL. As such,
* any given ID is considered valid (or is ignored), but only one is
* actually ever set on an asset, which means the given
* #GESAsset:extractable-type can only have one associated asset.
* @can_update_asset: Whether an object of this class can have its
* #GESAsset change over its lifetime. This should be set to %TRUE if one
* of the object's parameters that is associated with its ID can change
* after construction, which would require an asset with a new ID. Note
* that the subclass is required to handle the requesting and setting of
* the new asset on the object.
* @set_asset: This method is called after the #GESAsset of an object is
* set. If your class supports the asset of an object changing, then you
* can use this method to change the parameters of the object to match the
* new asset #GESAsset:id. If setting the asset should be able to fail,
* you should implement @set_asset_full instead.
* @set_asset_full: Like @set_asset, but also allows you to return %FALSE
* to indicate a failure to change the object in response to a change in
* its asset.
* @get_parameters_from_id: The method to call to get the object
* properties corresponding to a given asset #GESAsset:id. The default
* implementation will simply return no parameters. The default #GESAsset
* will call this to set the returned properties on the extracted object,
* but other subclasses may ignore this method.
* @get_id: The method to fetch the #GESAsset:id of some associated asset.
* Note that it may be the case that the object does not have its asset
* set, or even that an asset with such an #GESAsset:id does not exist in
* the GES cache. Instead, this should return the #GESAsset:id that is
* _compatible_ with the current state of the object. The default
* implementation simply returns the type name of the object, which is
* what is used as the #GESAsset:id by default.
* @get_real_extractable_type: The method to call to get the actual
* #GESAsset:extractable-type an asset should have set, given the
* requested #GESAsset:id. The default implementation simply returns the
* same type as given. You can overwrite this if it is more appropriate
* to extract the object from a subclass, depending on the requested
* #GESAsset:id. Note that when an asset is requested, this method will be
* called before the other class methods. In particular, this means that
* the @check_id and @get_parameters_from_id class methods of the returned
* type will be used (instead of our own).
* @register_metas: The method to set metadata on an asset. This is called
* on initiation of the asset, but before it begins to load its state.
*/
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
struct _GESExtractableInterface
{
GTypeInterface parent;
GType asset_type;
GESExtractableCheckId check_id;
gboolean can_update_asset;
void (*set_asset) (GESExtractable *self,
GESAsset *asset);
gboolean (*set_asset_full) (GESExtractable *self,
GESAsset *asset);
GParameter *(*get_parameters_from_id) (const gchar *id,
guint *n_params);
gchar * (*get_id) (GESExtractable *self);
GType (*get_real_extractable_type) (GType wanted_type,
const gchar *id);
gboolean (*register_metas) (GESExtractableInterface *self,
GObjectClass *klass,
GESAsset *asset);
gpointer _ges_reserved[GES_PADDING];
};
G_GNUC_END_IGNORE_DEPRECATIONS
GES_API
GESAsset* ges_extractable_get_asset (GESExtractable *self);
GES_API
gboolean ges_extractable_set_asset (GESExtractable *self,
GESAsset *asset);
GES_API
gchar * ges_extractable_get_id (GESExtractable *self);
G_END_DECLS
#endif /* _GES_EXTRACTABLE_ */