Gtk.Accessible¶

interface

An interface for describing UI elements for Assistive Technologies.

Every accessible implementation has:

a “role”, represented by a value of the AccessibleRole enumeration
“attributes”, represented by a set of AccessibleState, AccessibleProperty and AccessibleRelation values

The role cannot be changed after instantiating a GtkAccessible implementation.

The attributes are updated every time a UI element's state changes in a way that should be reflected by assistive technologies. For instance, if a GtkWidget visibility changes, the AccessibleState.HIDDEN state will also change to reflect the Widget.visible property.

Every accessible implementation is part of a tree of accessible objects. Normally, this tree corresponds to the widget tree, but can be customized by reimplementing the Accessible.get_accessible_parent, Accessible.get_first_accessible_child and Accessible.get_next_accessible_sibling virtual functions.

Note that you can not create a top-level accessible object as of now, which means that you must always have a parent accessible object.

Also note that when an accessible object does not correspond to a widget, and it has children, whose implementation you don't control, it is necessary to ensure the correct shape of the a11y tree by calling Accessible.set_accessible_parent and updating the sibling by Accessible.update_next_accessible_sibling.

Methods¶

announce¶

def announce(self, message: str, priority: AccessibleAnnouncementPriority | int) -> None

Requests the user's screen reader to announce the given message.

This kind of notification is useful for messages that either have only a visual representation or that are not exposed visually at all, e.g. a notification about a successful operation.

Also, by using this API, you can ensure that the message does not interrupts the user's current screen reader output.

Parameters:

message — the string to announce
priority — the priority of the announcement

get_accessible_id¶

def get_accessible_id(self) -> str | None

Retrieves the accessible identifier for the accessible object.

This functionality can be overridden by GtkAccessible implementations.

It is left to the accessible implementation to define the scope and uniqueness of the identifier.

get_accessible_parent¶

def get_accessible_parent(self) -> Accessible | None

Retrieves the accessible parent for an accessible object.

This function returns NULL for top level widgets.

get_accessible_role¶

def get_accessible_role(self) -> AccessibleRole

Retrieves the accessible role of an accessible object.

get_at_context¶

def get_at_context(self) -> ATContext

Retrieves the implementation for the given accessible object.

get_bounds¶

def get_bounds(self) -> tuple[bool, int, int, int, int]

Queries the coordinates and dimensions of this accessible

This functionality can be overridden by GtkAccessible implementations, e.g. to get the bounds from an ignored child widget.

get_first_accessible_child¶

def get_first_accessible_child(self) -> Accessible | None

Retrieves the first accessible child of an accessible object.

get_next_accessible_sibling¶

def get_next_accessible_sibling(self) -> Accessible | None

Retrieves the next accessible sibling of an accessible object

get_platform_state¶

def get_platform_state(self, state: AccessiblePlatformState | int) -> bool

Queries a platform state, such as focus.

This functionality can be overridden by GtkAccessible implementations, e.g. to get platform state from an ignored child widget, as is the case for GtkText wrappers.

Parameters:

state — platform state to query

reset_property¶

def reset_property(self, property: AccessibleProperty | int) -> None

Resets the accessible property to its default value.

Parameters:

property — the accessible property

reset_relation¶

def reset_relation(self, relation: AccessibleRelation | int) -> None

Resets the accessible relation to its default value.

Parameters:

relation — the accessible relation

reset_state¶

def reset_state(self, state: AccessibleState | int) -> None

Resets the accessible state to its default value.

Parameters:

state — the accessible state

set_accessible_parent¶

def set_accessible_parent(self, parent: Accessible | None = ..., next_sibling: Accessible | None = ...) -> None

Sets the parent and sibling of an accessible object.

This function is meant to be used by accessible implementations that are not part of the widget hierarchy, and but act as a logical bridge between widgets. For instance, if a widget creates an object that holds metadata for each child, and you want that object to implement the GtkAccessible interface, you will use this function to ensure that the parent of each child widget is the metadata object, and the parent of each metadata object is the container widget.

Parameters:

parent — the parent accessible object
next_sibling — the sibling accessible object

update_next_accessible_sibling¶

def update_next_accessible_sibling(self, new_sibling: Accessible | None = ...) -> None

Updates the next accessible sibling.

That might be useful when a new child of a custom accessible is created, and it needs to be linked to a previous child.

Parameters:

new_sibling — the new next accessible sibling to set

update_platform_state¶

def update_platform_state(self, state: AccessiblePlatformState | int) -> None

Informs ATs that the platform state has changed.

This function should be used by GtkAccessible implementations that have a platform state but are not widgets. Widgets handle platform states automatically.

Parameters:

state — the platform state to update

update_property¶

def update_property(self, properties: list[AccessibleProperty | int], values: list[GObject.Value]) -> None

Updates an array of accessible properties.

This function should be called by GtkWidget types whenever an accessible property change must be communicated to assistive technologies.

This function is meant to be used by language bindings.

Parameters:

properties — an array of accessible properties
values — an array of GValues, one for each property

update_relation¶

def update_relation(self, relations: list[AccessibleRelation | int], values: list[GObject.Value]) -> None

Updates an array of accessible relations.

This function should be called by GtkWidget types whenever an accessible relation change must be communicated to assistive technologies.

This function is meant to be used by language bindings.

Parameters:

relations — an array of accessible relations
values — an array of GValues, one for each relation

update_state¶

def update_state(self, states: list[AccessibleState | int], values: list[GObject.Value]) -> None

Updates an array of accessible states.

This function should be called by GtkWidget types whenever an accessible state change must be communicated to assistive technologies.

This function is meant to be used by language bindings.

Parameters:

states — an array of accessible states
values — an array of GValues, one for each state

Virtual methods¶

do_get_accessible_id¶

def do_get_accessible_id(self) -> str | None

Retrieves the accessible identifier for the accessible object.

This functionality can be overridden by GtkAccessible implementations.

It is left to the accessible implementation to define the scope and uniqueness of the identifier.

do_get_accessible_parent¶

def do_get_accessible_parent(self) -> Accessible | None

Retrieves the accessible parent for an accessible object.

This function returns NULL for top level widgets.

do_get_at_context¶

def do_get_at_context(self) -> ATContext | None

Retrieves the implementation for the given accessible object.

do_get_bounds¶

def do_get_bounds(self) -> tuple[bool, int, int, int, int]

Queries the coordinates and dimensions of this accessible

This functionality can be overridden by GtkAccessible implementations, e.g. to get the bounds from an ignored child widget.

do_get_first_accessible_child¶

def do_get_first_accessible_child(self) -> Accessible | None

Retrieves the first accessible child of an accessible object.

do_get_next_accessible_sibling¶

def do_get_next_accessible_sibling(self) -> Accessible | None

Retrieves the next accessible sibling of an accessible object

do_get_platform_state¶

def do_get_platform_state(self, state: AccessiblePlatformState | int) -> bool

Queries a platform state, such as focus.

This functionality can be overridden by GtkAccessible implementations, e.g. to get platform state from an ignored child widget, as is the case for GtkText wrappers.

Parameters:

state — platform state to query

Properties¶

accessible_role¶

accessible_role: AccessibleRole | int  # read/write

The accessible role of the given GtkAccessible implementation.

The accessible role cannot be changed once set.