47 lines
1.6 KiB
Text
47 lines
1.6 KiB
Text
Windows Accessibility Bridge.
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This code provides a bridge between our internal Accessibility
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interfaces (implemented on all visible 'things' in the suite: eg.
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windows, buttons, entry boxes etc.) - and the Windows MSAA /
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IAccessible2 COM interfaces that are familiar to windows users and
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Accessible Technologies (ATs) such as the NVDA screen reader.
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The code breaks into three bits:
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source/service/
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+ the UNO service providing the accessibility bridge.
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It essentially listens to events from the LibreOffice
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core and creates and synchronises COM peers for our
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internal accessibilty objects when events arrive.
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source/UAccCom/
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+ implementations of the MSAA / IAccessible2 interfaces
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to provide native peers for the accessbility code.
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source/UAccCOMIDL/
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+ COM Interface Definition Language (IDL) for UAccCom.
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Here is one way of visualising the code / control flow
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VCL <-> UNO toolkit <-> UNO a11y <-> win a11y <-> COM / IAccessible2
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vcl/ <-> toolkit/ <-> accessibility/ <-> winaccessibility/ <-> UAccCom/
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Debugging / playing with winaccessibility
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First you need to ensure that UAccCOM.dll is registered, if this did
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not happen at install time use:
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regsvr32 /absolute/path/to/program/UAccCOM.dll
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Next you need to enable 'experiemental mode' in Tools->Options. After
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that NVDA should work as expected. In order to use 'accprobe' to debug
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it is necessary to override the check for whether an AT (like NVDA) is
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running; to do that use:
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SAL_FORCE_IACCESSIBLE2=1 soffice.exe -writer
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Then you can use accprobe to introspect the accessibility hierarchy
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remotely, checkout:
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http://accessibility.linuxfoundation.org/a11yweb/util/accprobe/
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