PixbufLoader

Incremental image loader.

GdkPixbufLoader provides a way for applications to drive the process of loading an image, by letting them send the image data directly to the loader instead of having the loader read the data from a file. Applications can use this functionality instead of gdk_pixbuf_new_from_file() or gdk_pixbuf_animation_new_from_file() when they need to parse image data in small chunks. For example, it should be used when reading an image from a (potentially) slow network connection, or when loading an extremely large file.

To use GdkPixbufLoader to load an image, create a new instance, and call [method@GdkPixbuf.PixbufLoader.write] to send the data to it. When done, [method@GdkPixbuf.PixbufLoader.close] should be called to end the stream and finalize everything.

The loader will emit three important signals throughout the process:

- [signal@GdkPixbuf.PixbufLoader::size-prepared] will be emitted as soon as the image has enough information to determine the size of the image to be used. If you want to scale the image while loading it, you can call [method@GdkPixbuf.PixbufLoader.set_size] in response to this signal. - [signal@GdkPixbuf.PixbufLoader::area-prepared] will be emitted as soon as the pixbuf of the desired has been allocated. You can obtain the GdkPixbuf instance by calling [method@GdkPixbuf.PixbufLoader.get_pixbuf]. If you want to use it, simply acquire a reference to it. You can also call gdk_pixbuf_loader_get_pixbuf() later to get the same pixbuf. - [signal@GdkPixbuf.PixbufLoader::area-updated] will be emitted every time a region is updated. This way you can update a partially completed image. Note that you do not know anything about the completeness of an image from the updated area. For example, in an interlaced image you will need to make several passes before the image is done loading.

Loading an animation

Loading an animation is almost as easy as loading an image. Once the first [signal@GdkPixbuf.PixbufLoader::area-prepared] signal has been emitted, you can call [method@GdkPixbuf.PixbufLoader.get_animation] to get the [class@GdkPixbuf.PixbufAnimation] instance, and then call and [method@GdkPixbuf.PixbufAnimation.get_iter] to get a [class@GdkPixbuf.PixbufAnimationIter] to retrieve the pixbuf for the desired time stamp.

Constructors

this
this(GdkPixbufLoader* gdkPixbufLoader, bool ownedRef)

Sets our main struct and passes it to the parent class.

this
this(string type, bool isMimeType)

Creates a new pixbuf loader object that always attempts to parse image data as if it were an image of type @image_type, instead of identifying the type automatically. Useful if you want an error if the image isn't the expected type, for loading image formats that can't be reliably identified by looking at the data, or if the user manually forces a specific type.

this
this()

Creates a new pixbuf loader object.

Members

Functions

addOnAreaPrepared
gulong addOnAreaPrepared(void delegate(PixbufLoader) dlg, ConnectFlags connectFlags)

This signal is emitted when the pixbuf loader has allocated the pixbuf in the desired size.

addOnAreaUpdated
gulong addOnAreaUpdated(void delegate(int, int, int, int, PixbufLoader) dlg, ConnectFlags connectFlags)

This signal is emitted when a significant area of the image being loaded has been updated.

addOnClosed
gulong addOnClosed(void delegate(PixbufLoader) dlg, ConnectFlags connectFlags)

This signal is emitted when gdk_pixbuf_loader_close() is called.

addOnSizePrepared
gulong addOnSizePrepared(void delegate(int, int, PixbufLoader) dlg, ConnectFlags connectFlags)

This signal is emitted when the pixbuf loader has been fed the initial amount of data that is required to figure out the size of the image that it will create.

close
bool close()

Informs a pixbuf loader that no further writes with gdk_pixbuf_loader_write() will occur, so that it can free its internal loading structures.

getAnimation
PixbufAnimation getAnimation()

Queries the #GdkPixbufAnimation that a pixbuf loader is currently creating.

getFormat
PixbufFormat getFormat()

Obtains the available information about the format of the currently loading image file.

getPixbuf
Pixbuf getPixbuf()

Queries the #GdkPixbuf that a pixbuf loader is currently creating.

getPixbufLoaderStruct
GdkPixbufLoader* getPixbufLoaderStruct(bool transferOwnership)

Get the main Gtk struct

getStruct
void* getStruct()

the main Gtk struct as a void*

setSize
void setSize(int width, int height)

Causes the image to be scaled while it is loaded.

write
bool write(char[] buf)

Parses the next count bytes in the given image buffer.

writeBytes
bool writeBytes(Bytes buffer)

Parses the next contents of the given image buffer.

Static functions

getType
GType getType()

Variables

gdkPixbufLoader
GdkPixbufLoader* gdkPixbufLoader;

the main Gtk struct

Inherited Members

From ObjectG

gObject
GObject* gObject;

the main Gtk struct

ownedRef
bool ownedRef;
Undocumented in source.
getObjectGStruct
GObject* getObjectGStruct(bool transferOwnership)

Get the main Gtk struct

getStruct
void* getStruct()

the main Gtk struct as a void*

isGcRoot
bool isGcRoot;
Undocumented in source.
signals
DClosure[gulong] signals;
Undocumented in source.
destroyNotify
void destroyNotify(ObjectG obj)
Undocumented in source. Be warned that the author may not have intended to support it.
toggleNotify
void toggleNotify(ObjectG obj, GObject* object, int isLastRef)
Undocumented in source. Be warned that the author may not have intended to support it.
~this
~this()
Undocumented in source.
opCast
T opCast()
getDObject
RT getDObject(U obj, bool ownedRef)

Gets a D Object from the objects table of associations.

removeGcRoot
void removeGcRoot()
Undocumented in source. Be warned that the author may not have intended to support it.
setProperty
void setProperty(string propertyName, T value)
unref
deprecated void unref(ObjectG obj)
Undocumented in source. Be warned that the author may not have intended to support it.
doref
deprecated ObjectG doref(ObjectG obj)
Undocumented in source. Be warned that the author may not have intended to support it.
addOnNotify
gulong addOnNotify(void delegate(ParamSpec, ObjectG) dlg, string property, ConnectFlags connectFlags)

The notify signal is emitted on an object when one of its properties has been changed. Note that getting this signal doesn't guarantee that the value of the property has actually changed, it may also be emitted when the setter for the property is called to reinstate the previous value.

getType
GType getType()
compatControl
size_t compatControl(size_t what, void* data)
interfaceFindProperty
ParamSpec interfaceFindProperty(TypeInterface gIface, string propertyName)

Find the #GParamSpec with the given name for an interface. Generally, the interface vtable passed in as @g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek().

interfaceInstallProperty
void interfaceInstallProperty(TypeInterface gIface, ParamSpec pspec)

Add a property to an interface; this is only useful for interfaces that are added to GObject-derived types. Adding a property to an interface forces all objects classes with that interface to have a compatible property. The compatible property could be a newly created #GParamSpec, but normally g_object_class_override_property() will be used so that the object class only needs to provide an implementation and inherits the property description, default value, bounds, and so forth from the interface property.

interfaceListProperties
ParamSpec[] interfaceListProperties(TypeInterface gIface)

Lists the properties of an interface.Generally, the interface vtable passed in as @g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek().

addToggleRef
void addToggleRef(GToggleNotify notify, void* data)

Increases the reference count of the object by one and sets a callback to be called when all other references to the object are dropped, or when this is already the last reference to the object and another reference is established.

addWeakPointer
void addWeakPointer(void* weakPointerLocation)

Adds a weak reference from weak_pointer to @object to indicate that the pointer located at @weak_pointer_location is only valid during the lifetime of @object. When the @object is finalized, @weak_pointer will be set to %NULL.

bindProperty
Binding bindProperty(string sourceProperty, ObjectG target, string targetProperty, GBindingFlags flags)

Creates a binding between @source_property on @source and @target_property on @target. Whenever the @source_property is changed the @target_property is updated using the same value. For instance:

bindPropertyFull
Binding bindPropertyFull(string sourceProperty, ObjectG target, string targetProperty, GBindingFlags flags, GBindingTransformFunc transformTo, GBindingTransformFunc transformFrom, void* userData, GDestroyNotify notify)

Complete version of g_object_bind_property().

bindPropertyWithClosures
Binding bindPropertyWithClosures(string sourceProperty, ObjectG target, string targetProperty, GBindingFlags flags, Closure transformTo, Closure transformFrom)

Creates a binding between @source_property on @source and @target_property on @target, allowing you to set the transformation functions to be used by the binding.

dupData
void* dupData(string key, GDuplicateFunc dupFunc, void* userData)

This is a variant of g_object_get_data() which returns a 'duplicate' of the value. @dup_func defines the meaning of 'duplicate' in this context, it could e.g. take a reference on a ref-counted object.

dupQdata
void* dupQdata(GQuark quark, GDuplicateFunc dupFunc, void* userData)

This is a variant of g_object_get_qdata() which returns a 'duplicate' of the value. @dup_func defines the meaning of 'duplicate' in this context, it could e.g. take a reference on a ref-counted object.

forceFloating
void forceFloating()

This function is intended for #GObject implementations to re-enforce a floating[floating-ref] object reference. Doing this is seldom required: all #GInitiallyUnowneds are created with a floating reference which usually just needs to be sunken by calling g_object_ref_sink().

freezeNotify
void freezeNotify()

Increases the freeze count on @object. If the freeze count is non-zero, the emission of "notify" signals on @object is stopped. The signals are queued until the freeze count is decreased to zero. Duplicate notifications are squashed so that at most one #GObject::notify signal is emitted for each property modified while the object is frozen.

getData
void* getData(string key)

Gets a named field from the objects table of associations (see g_object_set_data()).

getProperty
void getProperty(string propertyName, Value value)

Gets a property of an object.

getQdata
void* getQdata(GQuark quark)

This function gets back user data pointers stored via g_object_set_qdata().

getValist
void getValist(string firstPropertyName, void* varArgs)

Gets properties of an object.

getv
void getv(string[] names, Value[] values)

Gets @n_properties properties for an @object. Obtained properties will be set to @values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.

isFloating
bool isFloating()

Checks whether @object has a floating[floating-ref] reference.

notify
void notify(string propertyName)

Emits a "notify" signal for the property @property_name on @object.

notifyByPspec
void notifyByPspec(ParamSpec pspec)

Emits a "notify" signal for the property specified by @pspec on @object.

doref
alias doref = ref_
Undocumented in source.
ref_
ObjectG ref_()

Increases the reference count of @object.

refSink
ObjectG refSink()

Increase the reference count of @object, and possibly remove the floating[floating-ref] reference, if @object has a floating reference.

removeToggleRef
void removeToggleRef(GToggleNotify notify, void* data)

Removes a reference added with g_object_add_toggle_ref(). The reference count of the object is decreased by one.

removeWeakPointer
void removeWeakPointer(void* weakPointerLocation)

Removes a weak reference from @object that was previously added using g_object_add_weak_pointer(). The @weak_pointer_location has to match the one used with g_object_add_weak_pointer().

replaceData
bool replaceData(string key, void* oldval, void* newval, GDestroyNotify destroy, GDestroyNotify oldDestroy)

Compares the user data for the key @key on @object with @oldval, and if they are the same, replaces @oldval with @newval.

replaceQdata
bool replaceQdata(GQuark quark, void* oldval, void* newval, GDestroyNotify destroy, GDestroyNotify oldDestroy)

Compares the user data for the key @quark on @object with @oldval, and if they are the same, replaces @oldval with @newval.

runDispose
void runDispose()

Releases all references to other objects. This can be used to break reference cycles.

setData
void setData(string key, void* data)

Each object carries around a table of associations from strings to pointers. This function lets you set an association.

setDataFull
void setDataFull(string key, void* data, GDestroyNotify destroy)

Like g_object_set_data() except it adds notification for when the association is destroyed, either by setting it to a different value or when the object is destroyed.

setProperty
void setProperty(string propertyName, Value value)

Sets a property on an object.

setQdata
void setQdata(GQuark quark, void* data)

This sets an opaque, named pointer on an object. The name is specified through a #GQuark (retrieved e.g. via g_quark_from_static_string()), and the pointer can be gotten back from the @object with g_object_get_qdata() until the @object is finalized. Setting a previously set user data pointer, overrides (frees) the old pointer set, using #NULL as pointer essentially removes the data stored.

setQdataFull
void setQdataFull(GQuark quark, void* data, GDestroyNotify destroy)

This function works like g_object_set_qdata(), but in addition, a void (*destroy) (gpointer) function may be specified which is called with @data as argument when the @object is finalized, or the data is being overwritten by a call to g_object_set_qdata() with the same @quark.

setValist
void setValist(string firstPropertyName, void* varArgs)

Sets properties on an object.

setv
void setv(string[] names, Value[] values)

Sets @n_properties properties for an @object. Properties to be set will be taken from @values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.

stealData
void* stealData(string key)

Remove a specified datum from the object's data associations, without invoking the association's destroy handler.

stealQdata
void* stealQdata(GQuark quark)

This function gets back user data pointers stored via g_object_set_qdata() and removes the @data from object without invoking its destroy() function (if any was set). Usually, calling this function is only required to update user data pointers with a destroy notifier, for example: |[<!-- language="C" --> void object_add_to_user_list (GObject *object, const gchar *new_string) { // the quark, naming the object data GQuark quark_string_list = g_quark_from_static_string ("my-string-list"); // retrieve the old string list GList *list = g_object_steal_qdata (object, quark_string_list);

thawNotify
void thawNotify()

Reverts the effect of a previous call to g_object_freeze_notify(). The freeze count is decreased on @object and when it reaches zero, queued "notify" signals are emitted.

unref
void unref()

Decreases the reference count of @object. When its reference count drops to 0, the object is finalized (i.e. its memory is freed).

watchClosure
void watchClosure(Closure closure)

This function essentially limits the life time of the @closure to the life time of the object. That is, when the object is finalized, the @closure is invalidated by calling g_closure_invalidate() on it, in order to prevent invocations of the closure with a finalized (nonexisting) object. Also, g_object_ref() and g_object_unref() are added as marshal guards to the @closure, to ensure that an extra reference count is held on @object during invocation of the @closure. Usually, this function will be called on closures that use this @object as closure data.

weakRef
void weakRef(GWeakNotify notify, void* data)

Adds a weak reference callback to an object. Weak references are used for notification when an object is disposed. They are called "weak references" because they allow you to safely hold a pointer to an object without calling g_object_ref() (g_object_ref() adds a strong reference, that is, forces the object to stay alive).

weakUnref
void weakUnref(GWeakNotify notify, void* data)

Removes a weak reference callback to an object.

clearObject
void clearObject(ObjectG objectPtr)

Clears a reference to a #GObject.

Meta