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Accessibility Support

This topic describes technologies that VCL controls use to support accessibility features.

Microsoft Active Accessibility

Microsoft Active Accessibility (MSAA) is a COM-based technology that uses applications for Microsoft Windows to improve the accessibility aids. This technology is available for controls in the following VCL libraries:

Each control in these libraries creates MSAA tree nodes that expose the UI structure and other information to third-party accessibility applications. A screen-reading app (for example, Microsoft Narrator) reads information from these nodes when a user navigates between UI elements.

Microsoft UI Automation

Microsoft UI Automation (UIA) is an accessibility framework designed to exchange information between UI elements and third-party accessibility tools. This framework is available in controls from the ExpressEditors library. These controls create UIA tree nodes that allow third-party accessibility applications (such as Microsoft Narrator) to obtain UI information for users and interact with UI elements programmatically.