UI Automation Support for the Tree Item Control Type

This topic provides information about UI Automation support for the Tree Item control type. In UI Automation, a control type is a set of conditions that a control must meet in order to use the ControlTypeProperty property. The conditions include specific guidelines for UI Automation tree structure, UI Automation property values and control patterns.

The Tree Item control type represents a node within a tree container. Each node might contain other nodes, called child nodes. Parent nodes, or nodes that contain child nodes, can be displayed as expanded or collapsed.

The following sections define the required UI Automation tree structure, properties, control patterns, and events for the Tree Item control type. The UI Automation requirements apply to all tree item controls, whether Windows Presentation Foundation (WPF), Win32, or Windows Forms.

This topic contains the following sections.

• Required UI Automation Tree Structure
• Required UI Automation Properties
• Required UI Automation Control Patterns
• Required UI Automation Events
• Related Topics

Required UI Automation Tree Structure

The following table depicts the control view and the content view of the UI Automation tree that pertains to tree item controls and describes what can be contained in each view. For more information on the UI Automation tree, see UI Automation Tree Overview.

Control View	Content View
Tree Item CheckBox (0 or 1) Image (0 or 1) Button (0 or 1) TreeItem (0 or more)	TreeItem TreeItem (0 or more)

Tree item controls can have zero or more tree item children in the content view of the UI Automation tree. If the tree item control has functionality beyond what is exposed in the control patterns listed below, then the control should be based on the Data Item control type.

Collapsed tree items will not display in the control view or content view until they become expanded and visible (or, can be scrolled into view).

Tree items that are scrolled off the screen will appear in both the control and content views of the UI Automation tree and should have the IsOffscreenProperty set to true.

Required UI Automation Properties

The following table lists the UI Automation properties whose value or definition is especially relevant to list controls. For more information on UI Automation properties, see UI Automation Properties for Clients.

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UI Automation Property	Value	Notes
AutomationIdProperty	See notes.	The value of this property needs to be unique across all controls in an application.
BoundingRectangleProperty	See notes.	The outermost rectangle that contains the whole control.
ClickablePointProperty	See notes.	This property must return a location of the item that will cause the item to change selection state or become focused.
ControlTypeProperty	TreeItem	This value is the same for all UI frameworks.
IsContentElementProperty	True	The list control is always included in the content view of the UI Automation tree.
IsControlElementProperty	True	The list control is always included in the control view of the UI Automation tree.
IsOffscreenProperty	See notes.	This property is set to indicate when a tree item control is scrolled off the screen.
IsKeyboardFocusableProperty	See notes.	If the control can receive keyboard focus, it must support this property.
ItemTypeProperty	See notes.	If the tree item control uses a visual icon to indicate that is a particular type of object, then this property must be supported and indicate what the object is.
LabeledByProperty	Null	Tree item controls are self-labeling.
LocalizedControlTypeProperty	"tree item"	Localized string corresponding to the List control type.
NameProperty	See notes.	This property exposes the text displayed for each tree item control.

Required UI Automation Control Patterns

The following table lists the UI Automation control patterns required to be supported by list controls. For more information on control patterns, see UI Automation Control Patterns Overview.

Control Pattern/Pattern Property	Support/Value	Notes
IInvokeProvider	Depends	Implement this control pattern if the tree item has a separate, actionable command.
IExpandCollapseProvider	Yes	All tree items can be expanded or collapsed.
ExpandCollapseState	Expanded, Collapsed, or Leaf Node	Tree items will be leaf nodes when they are not expanded or collapsed.
IScrollItemProvider	Depends	Implement this control pattern if the tree container supports the Scroll control pattern.
ISelectionItemProvider	Depends	Implement this control pattern if it is possible to have an active selection that is maintained when the user returns to the tree container.
SelectionContainer	Yes	This property will expose the same container for all items within the container.

Required UI Automation Events

The following table lists the UI Automation events required to be supported by all tree item controls. For more information about events, see UI Automation Events Overview.

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UI Automation Event	Support	Notes
AutomationFocusChangedEvent	Required	None
BoundingRectangleProperty property-changed event.	Required	None
IsEnabledProperty property-changed event.	Required	None
IsOffscreenProperty property-changed event.	Required	None
ItemStatusProperty property-changed event.	Depends	None
NameProperty property-changed event.	Required	None
StructureChangedEvent	Required	None
ExpandCollapseStateProperty property-changed event.	Required	None
InvokedEvent	Depends	None
CurrentViewProperty property-changed event.	Depends	None
ElementAddedToSelectionEvent	Depends	None
ElementRemovedFromSelectionEvent	Depends	None
ElementSelectedEvent	Depends	None
ToggleStateProperty property-changed event.	Depends	None
ValueProperty property-changed event.	Depends	None

See Also

Reference

TreeItem

Concepts

UI Automation Control Types Overview
UI Automation Overview