Accessible

class Accessible(*args, **kwargs)

Implementations: AboutDialog, ActionBar, AppChooserButton, AppChooserDialog, AppChooserWidget, ApplicationWindow, AspectFrame, Assistant, Box, Button, Calendar, CellView, CenterBox, CheckButton, ColorButton, ColorChooserDialog, ColorChooserWidget, ColorDialogButton, ColumnView, ComboBox, ComboBoxText, Dialog, DragIcon, DrawingArea, DropDown, EditableLabel, EmojiChooser, Entry, Expander, FileChooserDialog, FileChooserWidget, Fixed, FlowBox, FlowBoxChild, FontButton, FontChooserDialog, FontChooserWidget, FontDialogButton, Frame, GLArea, GraphicsOffload, Grid, GridView, HeaderBar, IconView, Image, InfoBar, Inscription, Label, LevelBar, LinkButton, ListBase, ListBox, ListBoxRow, ListView, LockButton, MediaControls, MenuButton, MessageDialog, Notebook, Overlay, PageSetupUnixDialog, Paned, PasswordEntry, Picture, Popover, PopoverMenu, PopoverMenuBar, PrintUnixDialog, ProgressBar, Range, Revealer, Scale, ScaleButton, Scrollbar, ScrolledWindow, SearchBar, SearchEntry, Separator, ShortcutLabel, ShortcutsGroup, ShortcutsSection, ShortcutsShortcut, ShortcutsWindow, SpinButton, Spinner, Stack, StackPage, StackSidebar, StackSwitcher, Statusbar, Switch, Text, TextView, ToggleButton, TreeExpander, TreeView, Video, Viewport, VolumeButton, Widget, Window, WindowControls, WindowHandle

GtkAccessible is an interface for describing UI elements for Assistive Technologies.

Every accessible implementation has:

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 HIDDEN state will also change to reflect the 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 get_accessible_parent, get_first_accessible_child and 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 set_accessible_parent and updating the sibling by update_next_accessible_sibling.

Methods

class Accessible
announce(message: str, priority: AccessibleAnnouncementPriority) → 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.

Added in version 4.14.

Parameters:

  • message – the string to announce

  • priority – the priority of the announcement

get_accessible_parent() → Accessible | None

Retrieves the accessible parent for an accessible object.

This function returns NULL for top level widgets.

Added in version 4.10.

get_accessible_role() → AccessibleRole

Retrieves the accessible role of an accessible object.

get_at_context() → ATContext

Retrieves the accessible implementation for the given GtkAccessible.

Added in version 4.10.

get_bounds() → 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.

Added in version 4.10.

get_first_accessible_child() → Accessible | None

Retrieves the first accessible child of an accessible object.

Added in version 4.10.

get_next_accessible_sibling() → Accessible | None

Retrieves the next accessible sibling of an accessible object

Added in version 4.10.

get_platform_state(state: AccessiblePlatformState) → bool

Query a platform state, such as focus.

See gtk_accessible_platform_changed().

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.

Added in version 4.10.

Parameters:

state – platform state to query

reset_property(property: AccessibleProperty) → None

Resets the accessible property to its default value.

Parameters:

property – a GtkAccessibleProperty

reset_relation(relation: AccessibleRelation) → None

Resets the accessible relation to its default value.

Parameters:

relation – a GtkAccessibleRelation

reset_state(state: AccessibleState) → None

Resets the accessible state to its default value.

Parameters:

state – a GtkAccessibleState

set_accessible_parent(parent: Accessible | None = None, next_sibling: Accessible | None = 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.

Added in version 4.10.

Parameters:

  • parent – the parent accessible object

  • next_sibling – the sibling accessible object

update_next_accessible_sibling(new_sibling: Accessible | None = None) → None

Updates the next accessible sibling of self.

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

Added in version 4.10.

Parameters:

new_sibling – the new next accessible sibling to set

update_property(properties: Sequence[AccessibleProperty], values: Sequence[Any]) → None

Updates a list of accessible properties.

See the AccessibleProperty documentation for the value types of accessible properties.

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

Example:

value = gtk_adjustment_get_value (adjustment);
gtk_accessible_update_property (GTK_ACCESSIBLE (spin_button),
                                   GTK_ACCESSIBLE_PROPERTY_VALUE_NOW, value,
                                   -1);
Parameters:

  • properties

  • values

update_relation(relations: Sequence[AccessibleRelation], values: Sequence[Any]) → None

Updates a list of accessible relations.

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

If the AccessibleRelation requires a list of references, you should pass each reference individually, followed by None, e.g.

gtk_accessible_update_relation (accessible,
                                GTK_ACCESSIBLE_RELATION_CONTROLS,
                                  ref1, NULL,
                                GTK_ACCESSIBLE_RELATION_LABELLED_BY,
                                  ref1, ref2, ref3, NULL,
                                -1);
Parameters:

  • relations

  • values

update_state(states: Sequence[AccessibleState], values: Sequence[Any]) → None

Updates a list of accessible states. See the AccessibleState documentation for the value types of accessible states.

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

Example:

value = GTK_ACCESSIBLE_TRISTATE_MIXED;
gtk_accessible_update_state (GTK_ACCESSIBLE (check_button),
                             GTK_ACCESSIBLE_STATE_CHECKED, value,
                             -1);
Parameters:

  • states

  • values

Properties

class Accessible
props.accessible_role: AccessibleRole

The accessible role of the given GtkAccessible implementation.

The accessible role cannot be changed once set.

Virtual Methods

class Accessible
do_get_accessible_parent() → Accessible | None

Retrieves the accessible parent for an accessible object.

This function returns NULL for top level widgets.

Added in version 4.10.

do_get_at_context() → ATContext | None

Retrieves the accessible implementation for the given GtkAccessible.

Added in version 4.10.

do_get_bounds() → 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.

Added in version 4.10.

do_get_first_accessible_child() → Accessible | None

Retrieves the first accessible child of an accessible object.

Added in version 4.10.

do_get_next_accessible_sibling() → Accessible | None

Retrieves the next accessible sibling of an accessible object

Added in version 4.10.

do_get_platform_state(state: AccessiblePlatformState) → bool

Query a platform state, such as focus.

See gtk_accessible_platform_changed().

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.

Added in version 4.10.

Parameters:

state – platform state to query