Class (GI Class)

Gtk-4.0GtkSnapshot

Assists in creating Gsk.RenderNodes for widgets.

It functions in a similar way to a cairo context, and maintains a stack of render nodes and their associated transformations.

The node at the top of the stack is the one that gtk_snapshot_append_…() functions operate on. Use the gtk_snapshot_push_…() functions and Snapshot.pop to change the current node.

The typical way to obtain a Gtk.Snapshot object is as an argument to the Gtk.Widget.snapshot vfunc. If you need to create your own Gtk.Snapshot, use Gtk.Snapshot.new.

Hierarchy (View Summary)

Index

Constructors

Properties

Compile-time signal type information.

This instance property is generated only for TypeScript type checking. It is not defined at runtime and should not be accessed in JS code.

$gtype: GType<Gtk.Snapshot>

Methods

  • Appends a stroked border rectangle inside the given outline.

    The four sides of the border can have different widths and colors.

    Parameters

    • outline: RoundedRect

      the outline of the border

    • border_width: number[]

      the stroke width of the border on the top, right, bottom and left side respectively.

    • border_color: Gdk.RGBA[]

      the color used on the top, right, bottom and left side.

    Returns void

  • Creates a new render node drawing the color into the given bounds and appends it to the current render node of snapshot.

    You should try to avoid calling this function if color is transparent.

    Parameters

    Returns void

  • Appends a conic gradient node with the given stops to snapshot.

    Parameters

    • bounds: Graphene.Rect

      the rectangle to render the gradient into

    • center: Graphene.Point

      the center point of the conic gradient

    • rotation: number

      the clockwise rotation in degrees of the starting angle. 0 means the starting angle is the top.

    • stops: ColorStop[]

      the color stops defining the gradient

    Returns void

  • Appends an inset shadow into the box given by outline.

    Parameters

    • outline: RoundedRect

      outline of the region surrounded by shadow

    • color: Gdk.RGBA

      color of the shadow

    • dx: number

      horizontal offset of shadow

    • dy: number

      vertical offset of shadow

    • spread: number

      how far the shadow spreads towards the inside

    • blur_radius: number

      how much blur to apply to the shadow

    Returns void

  • Creates render nodes for rendering layout in the given foregound color and appends them to the current node of snapshot without changing the current node. The current theme's foreground color for a widget can be obtained with Gtk.Widget.get_color.

    Note that if the layout does not produce any visible output, then nodes may not be added to the snapshot.

    Parameters

    Returns void

  • Appends an outset shadow node around the box given by outline.

    Parameters

    • outline: RoundedRect

      outline of the region surrounded by shadow

    • color: Gdk.RGBA

      color of the shadow

    • dx: number

      horizontal offset of shadow

    • dy: number

      vertical offset of shadow

    • spread: number

      how far the shadow spreads towards the outside

    • blur_radius: number

      how much blur to apply to the shadow

    Returns void

  • Appends a radial gradient node with the given stops to snapshot.

    Parameters

    • bounds: Graphene.Rect

      the rectangle to render the readial gradient into

    • center: Graphene.Point

      the center point for the radial gradient

    • hradius: number

      the horizontal radius

    • vradius: number

      the vertical radius

    • start: number

      the start position (on the horizontal axis)

    • end: number

      the end position (on the horizontal axis)

    • stops: ColorStop[]

      the color stops defining the gradient

    Returns void

  • Appends a repeating radial gradient node with the given stops to snapshot.

    Parameters

    • bounds: Graphene.Rect

      the rectangle to render the readial gradient into

    • center: Graphene.Point

      the center point for the radial gradient

    • hradius: number

      the horizontal radius

    • vradius: number

      the vertical radius

    • start: number

      the start position (on the horizontal axis)

    • end: number

      the end position (on the horizontal axis)

    • stops: ColorStop[]

      the color stops defining the gradient

    Returns void

  • Removes the top element from the stack of render nodes, and appends it to the node underneath it.

    Returns void

  • Blurs an image.

    The image is recorded until the next call to Gtk.Snapshot.pop.

    Parameters

    • radius: number

      the blur radius to use. Must be positive

    Returns void

  • Modifies the colors of an image by applying an affine transformation in RGB space.

    In particular, the colors will be transformed by applying

    pixel = transpose(color_matrix) * pixel + color_offset
    

    for every pixel. The transformation operates on unpremultiplied colors, with color components ordered R, G, B, A.

    The image is recorded until the next call to Gtk.Snapshot.pop.

    Parameters

    • color_matrix: Graphene.Matrix

      the color matrix to use

    • color_offset: Vec4

      the color offset to use

    Returns void

  • Modifies the colors of an image by applying a transfer function for each component.

    The transfer functions operate on unpremultiplied colors.

    The image is recorded until the next call to Gtk.Snapshot.pop.

    Parameters

    • red: never

      the transfer for the red component

    • green: never

      the transfer for the green component

    • blue: never

      the transfer for the blue component

    • alpha: never

      the transfer for the alpha component

    Returns void

  • Snapshots a cross-fade operation between two images with the given progress.

    Until the first call to Gtk.Snapshot.pop, the start image will be snapshot. After that call, the end image will be recorded until the second call to Gtk.Snapshot.pop.

    Calling this function requires two subsequent calls to Gtk.Snapshot.pop.

    Parameters

    • progress: number

      progress between 0.0 and 1.0

    Returns void

  • Push a Gsk.GLShaderNode.

    The node uses the given Gsk.GLShader and uniform values Additionally this takes a list of n_children other nodes which will be passed to the Gsk.GLShaderNode.

    The take_args argument is a block of data to use for uniform arguments, as per types and offsets defined by the shader. Normally this is generated by Gsk.GLShader.format_args or Gsk.ShaderArgsBuilder.

    The snapshotter takes ownership of take_args, so the caller should not free it after this.

    If the renderer doesn't support GL shaders, or if there is any problem when compiling the shader, then the node will draw pink. You should use Gsk.GLShader.compile to ensure the shader will work for the renderer before using it.

    If the shader requires textures (see Gsk.GLShader.get_n_textures), then it is expected that you call Gtk.Snapshot.gl_shader_pop_texture the number of times that are required. Each of these calls will generate a node that is added as a child to the Gsk.GLShaderNode, which in turn will render these offscreen and pass as a texture to the shader.

    Once all textures (if any) are pop:ed, you must call the regular Gtk.Snapshot.pop.

    If you want to use pre-existing textures as input to the shader rather than rendering new ones, use Gtk.Snapshot.append_texture to push a texture node. These will be used directly rather than being re-rendered.

    For details on how to write shaders, see Gsk.GLShader.

    Parameters

    • shader: Gsk.GLShader

      The code to run

    • bounds: Graphene.Rect

      the rectangle to render into

    • take_args: GLib.Bytes | Uint8Array<ArrayBufferLike>

      Data block with arguments for the shader.

    Returns void

  • Until the first call to Gtk.Snapshot.pop, the mask image for the mask operation will be recorded.

    After that call, the source image will be recorded until the second call to Gtk.Snapshot.pop.

    Calling this function requires 2 subsequent calls to gtk_snapshot_pop().

    Parameters

    Returns void

  • Modifies the opacity of an image.

    The image is recorded until the next call to Gtk.Snapshot.pop.

    Parameters

    • opacity: number

      the opacity to use

    Returns void

  • Strokes the given path with the attributes given by stroke and an image.

    The image is recorded until the next call to Gtk.Snapshot.pop.

    Note that the strokes are subject to the same transformation as everything else, so uneven scaling will cause horizontal and vertical strokes to have different widths.

    If you want to stroke the path with a color, Gtk.Snapshot.append_stroke may be more convenient.

    Parameters

    • path: Gsk.Path

      The path to stroke

    • stroke: Stroke

      The stroke attributes

    Returns void

  • Creates a render node for the CSS background according to context, and appends it to the current node of snapshot, without changing the current node.

    Parameters

    • context: Gtk.StyleContext

      the style context that defines the background

    • x: number

      X origin of the rectangle

    • y: number

      Y origin of the rectangle

    • width: number

      rectangle width

    • height: number

      rectangle height

    Returns void

  • Creates a render node for the focus outline according to context, and appends it to the current node of snapshot, without changing the current node.

    Parameters

    • context: Gtk.StyleContext

      the style context that defines the focus ring

    • x: number

      X origin of the rectangle

    • y: number

      Y origin of the rectangle

    • width: number

      rectangle width

    • height: number

      rectangle height

    Returns void

  • Creates a render node for the CSS border according to context, and appends it to the current node of snapshot, without changing the current node.

    Parameters

    • context: Gtk.StyleContext

      the style context that defines the frame

    • x: number

      X origin of the rectangle

    • y: number

      Y origin of the rectangle

    • width: number

      rectangle width

    • height: number

      rectangle height

    Returns void

  • Creates a render node for rendering layout according to the style information in context, and appends it to the current node of snapshot, without changing the current node.

    Parameters

    Returns void

  • Rotates @snapshot's coordinate system by angle degrees in 2D space - or in 3D speak, rotates around the Z axis. The rotation happens around the origin point of (0, 0) in the snapshot's current coordinate system.

    To rotate around axes other than the Z axis, use Gsk.Transform.rotate_3d.

    Parameters

    • angle: number

      the rotation angle, in degrees (clockwise)

    Returns void

  • Rotates snapshot's coordinate system by angle degrees around axis.

    For a rotation in 2D space, use Gsk.Transform.rotate.

    Parameters

    • angle: number

      the rotation angle, in degrees (clockwise)

    • axis: Vec3

      The rotation axis

    Returns void

  • Makes a copy of the current state of snapshot and saves it on an internal stack.

    When Gtk.Snapshot.restore is called, snapshot will be restored to the saved state.

    Multiple calls to Gtk.Snapshot.save and Gtk.Snapshot.restore can be nested; each call to gtk_snapshot_restore() restores the state from the matching paired gtk_snapshot_save().

    It is necessary to clear all saved states with corresponding calls to gtk_snapshot_restore().

    Returns void

  • Scales snapshot's coordinate system in 2-dimensional space by the given factors.

    Use Gtk.Snapshot.scale_3d to scale in all 3 dimensions.

    Parameters

    • factor_x: number

      scaling factor on the X axis

    • factor_y: number

      scaling factor on the Y axis

    Returns void

  • Scales snapshot's coordinate system by the given factors.

    Parameters

    • factor_x: number

      scaling factor on the X axis

    • factor_y: number

      scaling factor on the Y axis

    • factor_z: number

      scaling factor on the Z axis

    Returns void

  • Returns the render node that was constructed by snapshot.

    Note that this function may return null if nothing has been added to the snapshot or if its content does not produce pixels to be rendered.

    After calling this function, it is no longer possible to add more nodes to snapshot. The only function that should be called after this is GObject.Object.unref.

    Returns Gsk.RenderNode

    the constructed Gsk.RenderNode or null if there are no nodes to render.

  • Returns a paintable encapsulating the render node that was constructed by snapshot.

    After calling this function, it is no longer possible to add more nodes to snapshot. The only function that should be called after this is GObject.Object.unref.

    Parameters

    • Optionalsize: Size

      The size of the resulting paintable or null to use the bounds of the snapshot

    Returns Gdk.Paintable

    a new Gdk.Paintable

Methods - Inherited from Gdk

  • 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:

      g_object_bind_property (action, "active", widget, "sensitive", 0);
    

    Will result in the "sensitive" property of the widget GObject.Object instance to be updated with the same value of the "active" property of the action GObject.Object instance.

    If flags contains GObject.BindingFlags.BIDIRECTIONAL then the binding will be mutual: if target_property on target changes then the source_property on source will be updated as well.

    The binding will automatically be removed when either the source or the target instances are finalized. To remove the binding without affecting the source and the target you can just call g_object_unref() on the returned GObject.Binding instance.

    Removing the binding by calling g_object_unref() on it must only be done if the binding, source and target are only used from a single thread and it is clear that both source and target outlive the binding. Especially it is not safe to rely on this if the binding, source or target can be finalized from different threads. Keep another reference to the binding and use g_binding_unbind() instead to be on the safe side.

    A GObject.Object can have multiple bindings.

    Parameters

    Returns GObject.Binding

    the GObject.Binding instance representing the binding between the two GObject.Object instances. The binding is released whenever the GObject.Binding reference count reaches zero.

  • Complete version of g_object_bind_property().

    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.

    If flags contains GObject.BindingFlags.BIDIRECTIONAL then the binding will be mutual: if target_property on target changes then the source_property on source will be updated as well. The transform_from function is only used in case of bidirectional bindings, otherwise it will be ignored

    The binding will automatically be removed when either the source or the target instances are finalized. This will release the reference that is being held on the GObject.Binding instance; if you want to hold on to the GObject.Binding instance, you will need to hold a reference to it.

    To remove the binding, call g_binding_unbind().

    A GObject.Object can have multiple bindings.

    The same user_data parameter will be used for both transform_to and transform_from transformation functions; the notify function will be called once, when the binding is removed. If you need different data for each transformation function, please use g_object_bind_property_with_closures() instead.

    Parameters

    • source_property: string

      the property on source to bind

    • target: GObject.Object

      the target GObject.Object

    • target_property: string

      the property on target to bind

    • flags: GObject.BindingFlags

      flags to pass to GObject.Binding

    • Optionaltransform_to: BindingTransformFunc

      the transformation function from the source to the target, or null to use the default

    • Optionaltransform_from: BindingTransformFunc

      the transformation function from the target to the source, or null to use the default

    • Optionalnotify: DestroyNotify

      a function to call when disposing the binding, to free resources used by the transformation functions, or null if not required

    Returns GObject.Binding

    the GObject.Binding instance representing the binding between the two GObject.Object instances. The binding is released whenever the GObject.Binding reference count reaches zero.

  • 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.

    This function is the language bindings friendly version of g_object_bind_property_full(), using GClosures instead of function pointers.

    Parameters

    Returns GObject.Binding

    the GObject.Binding instance representing the binding between the two GObject.Object instances. The binding is released whenever the GObject.Binding reference count reaches zero.

  • Disconnects a handler from an instance so it will not be called during any future or currently ongoing emissions of the signal it has been connected to.

    Parameters

    • id: number

      Handler ID of the handler to be disconnected

    Returns void

  • This function is intended for GObject.Object 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().

    Returns void

  • 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.Object::notify signal is emitted for each property modified while the object is frozen.

    This is necessary for accessors that modify multiple properties to prevent premature notification while the object is still being modified.

    Returns void

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

    Parameters

    • key: string

      name of the key for that association

    Returns any

    the data if found, or null if no such data exists.

  • Gets a property of an object.

    The value can be:

    • an empty GObject.Value initialized by G_VALUE_INIT, which will be automatically initialized with the expected type of the property (since GLib 2.60)
    • a GObject.Value initialized with the expected type of the property
    • a GObject.Value initialized with a type to which the expected type of the property can be transformed

    In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling GObject.Value.unset.

    Note that GObject.Object.get_property is really intended for language bindings, GObject.Object.get is much more convenient for C programming.

    Parameters

    • property_name: string

      The name of the property to get

    • value: any

      Return location for the property value. Can be an empty GObject.Value initialized by G_VALUE_INIT (auto-initialized with expected type since GLib 2.60), a GObject.Value initialized with the expected property type, or a GObject.Value initialized with a transformable type

    Returns any

  • 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.

    Parameters

    • names: string[]

      the names of each property to get

    • values: any[]

      the values of each property to get

    Returns void

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

    When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.

    Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.

    Parameters

    • property_name: string

      the name of a property installed on the class of object.

    Returns void

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

    This function omits the property name lookup, hence it is faster than g_object_notify().

    One way to avoid using g_object_notify() from within the class that registered the properties, and using g_object_notify_by_pspec() instead, is to store the GParamSpec used with g_object_class_install_property() inside a static array, e.g.:

      typedef enum
    {
    PROP_FOO = 1,
    PROP_LAST
    } MyObjectProperty;

    static GParamSpec *properties[PROP_LAST];

    static void
    my_object_class_init (MyObjectClass *klass)
    {
    properties[PROP_FOO] = g_param_spec_int ("foo", NULL, NULL,
    0, 100,
    50,
    G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
    g_object_class_install_property (gobject_class,
    PROP_FOO,
    properties[PROP_FOO]);
    }

    and then notify a change on the "foo" property with:

      g_object_notify_by_pspec (self, properties[PROP_FOO]);
    

    Parameters

    Returns void

  • Increases the reference count of object.

    Since GLib 2.56, if GLIB_VERSION_MAX_ALLOWED is 2.56 or greater, the type of object will be propagated to the return type (using the GCC typeof() extension), so any casting the caller needs to do on the return type must be explicit.

    Returns GObject.Object

    the same object

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

    In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.

    Since GLib 2.56, the type of object will be propagated to the return type under the same conditions as for g_object_ref().

    Returns GObject.Object

    object

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

    This function should only be called from object system implementations.

    Returns void

  • Sets multiple properties of an object at once. The properties argument should be a dictionary mapping property names to values.

    Parameters

    • properties: { [key: string]: any }

      Object containing the properties to set

    Returns void

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

    If the object already had an association with that name, the old association will be destroyed.

    Internally, the key is converted to a GLib.Quark using g_quark_from_string(). This means a copy of key is kept permanently (even after object has been finalized) — so it is recommended to only use a small, bounded set of values for key in your program, to avoid the GLib.Quark storage growing unbounded.

    Parameters

    • key: string

      name of the key

    • Optionaldata: any

      data to associate with that key

    Returns void

  • Sets a property on an object.

    Parameters

    • property_name: string

      The name of the property to set

    • value: any

      The value to set the property to

    Returns void

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

    Parameters

    • key: string

      name of the key

    Returns any

    the data if found, or null if no such data exists.

  • 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:

    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);

    // prepend new string
    list = g_list_prepend (list, g_strdup (new_string));
    // this changed 'list', so we need to set it again
    g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
    }
    static void
    free_string_list (gpointer data)
    {
    GList *node, *list = data;

    for (node = list; node; node = node->next)
    g_free (node->data);
    g_list_free (list);
    }

    Using g_object_get_qdata() in the above example, instead of g_object_steal_qdata() would have left the destroy function set, and thus the partial string list would have been freed upon g_object_set_qdata_full().

    Parameters

    • quark: number

      A GLib.Quark, naming the user data pointer

    Returns any

    The user data pointer set, or null

  • Stops a signal's emission by the given signal name. This will prevent the default handler and any subsequent signal handlers from being invoked.

    Parameters

    • detailedName: string

      Name of the signal to stop emission of

    Returns void

  • 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.

    Duplicate notifications for each property are squashed so that at most one GObject.Object::notify signal is emitted for each property, in the reverse order in which they have been queued.

    It is an error to call this function when the freeze count is zero.

    Returns void

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

    If the pointer to the GObject.Object may be reused in future (for example, if it is an instance variable of another object), it is recommended to clear the pointer to null rather than retain a dangling pointer to a potentially invalid GObject.Object instance. Use g_clear_object() for this.

    Returns void

  • the constructed function is called by g_object_new() as the final step of the object creation process. At the point of the call, all construction properties have been set on the object. The purpose of this call is to allow for object initialisation steps that can only be performed after construction properties have been set. constructed implementors should chain up to the constructed call of their parent class to allow it to complete its initialisation.

    Returns void

  • the dispose function is supposed to drop all references to other objects, but keep the instance otherwise intact, so that client method invocations still work. It may be run multiple times (due to reference loops). Before returning, dispose should chain up to the dispose method of the parent class.

    Returns void

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

    When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.

    Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.

    Parameters

    Returns void

  • the generic setter for all properties of this type. Should be overridden for every type with properties. If implementations of set_property don't emit property change notification explicitly, this will be done implicitly by the type system. However, if the notify signal is emitted explicitly, the type system will not emit it a second time.

    Parameters

    Returns void

  • 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.

    Parameters

    Returns void

  • 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 GObject.ParamSpec, 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.

    This function is meant to be called from the interface's default vtable initialization function (the class_init member of GObject.TypeInfo.) It must not be called after after class_init has been called for any object types implementing this interface.

    If pspec is a floating reference, it will be consumed.

    Parameters

    Returns void

  • Parameters

    • property_id: number

      the new property ID

    • name: string

      the name of a property registered in a parent class or in an interface of this class.

    Returns void

Interfaces

ConstructorProps
SignalSignatures