UI Automation Support for the Image Control Type

 
System_CAPS_ICON_note.jpg Note

This documentation is intended for .NET Framework developers who want to use the managed UI Automation classes defined in the System.Windows.Automation namespace. For the latest information about UI Automation, see Windows Automation API: UI Automation.

This topic provides information about UI Automation support for the Image 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.

Image controls used as icons, informational graphics, and charts will support the Image control type. Controls used as background or watermark images will not support the Image control type.

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

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

Control ViewContent View
ImageImage (Depends whether the image contains information (based on the value of IsContentElement property))

The following table lists the UI Automation properties whose value or definition is especially relevant to the Image control type. For more information about UI Automation properties, see UI Automation Properties for Clients.

UI Automation PropertyValueNotes
AutomationIdPropertySee notes.The value of this property needs to be unique across all controls in an application.
BoundingRectanglePropertySee notes.The outermost rectangle that contains the whole control.
ClickablePointPropertySee notes.The image control’s clickable point must be a point within the bounding rectangle of the image control.
IsKeyboardFocusablePropertySee notes.If the control can receive keyboard focus, it must support this property.
NamePropertySee notes.The Name property must be exposed for all image controls that contain information. Programmatic access to this information requires that a textual equivalent to the graphic be provided. If the image control is purely decorative, it must only show up in the control view of the UI Automation tree and is not required to have a name. UI frameworks must support an ALT or alternate text property on images that can be set from within their framework. This property will then map to the UI Automation Name property.
LabeledByPropertySee notes.If there is a static text label then this property must expose a reference to that control.
ControlTypePropertyImageThis value is the same for all UI frameworks.
LocalizedControlTypeProperty"image"Localized string corresponding to the Image control type.
IsContentElementPropertySee notes.The image control must be included in the content view of the UI Automation tree when it contains meaningful information not already exposed to the end user.
IsControlElementPropertyTrueThe image control is always included in the control view of the UI Automation tree.
HelpTextPropertySee notes.The HelpText property exposes a localized string which describes the actual visual appearance of the control (for example, a red square with a white ‘X’) or other tooltip information associated with the image.

This property must be supported when a long description is needed to convey more information about the image control. For example, a complicated chart or diagram. This property maps to the HTML LongDesc tag and the Scalable Vector Graphics (SVG) Desc tag. Developers working with image controls must support a property to allow the visual description to be set on the control. This property must be mapped to the UI Automation VisualDescription property.
ItemStatusPropertySee notes.If the image control represents state information about a particular item on the screen, the control should be contained within the item. When the image is contained within an item the item must support the status property and raise appropriate notifications when the status changes.

If an image is a standalone control and is conveying status this property must be supported.

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

Control PatternSupportNotes
IGridItemProviderDependsThe image control supports the Grid Item pattern if the control is within a grid container.
ITableItemProviderDependsThe image control supports the Table Item pattern if the control is within a container that has header controls.
IInvokeProviderNeverIf the image control contains a clickable image, the control should support a control type that supports the Invoke pattern, such as the Button control type.
ISelectionItemProviderNeverImage controls should not support the Selection Item pattern.

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

UI Automation EventSupportNotes
InvokedEventNeverNone
ElementAddedToSelectionEventNeverNone
ElementRemovedFromSelectionEventNeverNone
ElementSelectedEventNeverNone
BoundingRectangleProperty property-changed event.RequiredNone
IsOffscreenProperty property-changed event.RequiredNone
IsEnabledProperty property-changed event.RequiredNone
NameProperty property-changed event.RequiredNone
AutomationFocusChangedEventRequiredNone
StructureChangedEventRequiredNone

Image
UI Automation Control Types Overview
UI Automation Overview

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