Feature Request - Add WPF Accessibility Support

[RichiCoder1]

The Cef project just recently merged accessibility support of OSR (https://bitbucket.org/chromiumembedded/cef/pull-requests/99/issue-1217-cef3-accessibility-support/diff) and it would be terrific to see that supported in the next version of CefSharp.

[amaitland]

https://bitbucket.org/chromiumembedded/cef/commits/406867f293042006e9f5f1a1e5201db012e50adf

[RichiCoder1]

I might (maybe) be able to pick this up. Not overly familiar with either Cef or CefSharp though. It looks like it's a matter of forwarding accessibility events? (Which I have no idea how to do, but I can at least look into)

[amaitland]

IBrowserHost.SetAccessibilityState added in commit https://github.com/cefsharp/CefSharp/commit/921ea55fff0495c3e1895d7d4ba694e06163fca3

From a wrapper point of view CefAccessibilityHandler needs to be implemented and IAccessibilityHandler created (same as any of the other handlers)

[BenKeyFSI]

What is the status of this? Did commit 921ea55 resolve the issue? If so, why is the CefSharp.Wpf.Example application still inaccesible? Do I need to add a call to the SetAccessibilityState function somewhere?

[amaitland]

This issue relates to WPF.

See https://stackoverflow.com/questions/42163764/how-to-make-jaws-screen-reader-recognize-and-read-content-of-cefsharp-chromiumwe for an example of how to get the WinForms version working.

[BenKeyFSI]

I meant the CefSharp.Wpf.Example. The Windforms example currently works as is. Unfortunately, the WPF one does not. I have a key client that wants to use CEF in a WPF application with JAWS.

[amaitland]

Pull requests welcome

[BenKeyFSI]

I would be glad to work on this issue, if it is still open. However, my question regarding the status of this issue has yet to be answered. I have a key client who wants JAWS to be able to work in an application that uses CEF in a WPF application.

I found this search while doing a Google search. I am a little unclear on the status. The last comment before my first comment is a commit message that seems to be related. An yet the issue is still open. Is that because more work needs to be done?

Specifically, I do not understand the following comment.

"From a wrapper point of view CefAccessibilityHandler needs to be implemented and IAccessibilityHandler created (same as any of the other handlers)."

Is this meant to be a description of work that has yet to be done? If so, I will look into it. I cannot guarantee that I will be able to complete the work because I am not all that familiar with C#, but I am willing to try.

So please, amaitland, can you give a slightly more helpful response and answer the following question. Is there more work to be done and is the comment I quoted a description of that work.

[BenKeyFSI]

I figured it out. I think I can manage the remaining tasks. With a bit of luck, I may be finished by the end of next week.

[amaitland]

The issue is open as it still requres someone to put in a large chunk of time.

• [x] Add interface with xmldoc
• [x] Add VC++ wrapper class
• [x] Update ClientAdapter
• [x] Add the new handler to IRenderWebBrowser
• [x] Implement the WPF specifics ( I'm guessing a custom AutomationPeer, that's up to you to work out)

Probably a bunch of other steps that I cannot think of right now.

If you can get it implemented by next week then you will have done exceptionally well!

In future please just come straight out and ask what's required, if an issue is open on this issue tracker then it's open for a reason. Thanks!

[BenKeyFSI]

I had planed on fixing this. It proved to be more than I can manage at this time. In addition, we found another solution for our client. We suggested they use the WinForms version of CefSharp in their WPF application. This worked.

[amaitland]

Part implementation done in #2480

The WPF specifics are yet to be implemented.

[nnigam1]

Is there any way to enable accessibility in WpF with cefsharp and do UI automation

[amaitland]

Thanks to @justindarc there is now an experimental readonly implementation. There are obviously limitations as CEF only provides a readonly implementation.

Added in commits https://github.com/cefsharp/CefSharp/commit/e834d89518d3b56055f913a88d5cdbe22fa85c27 and https://github.com/cefsharp/CefSharp/commit/da8ad192a48c94b2076ad5c22fc3e8f8411c7f3b

Example of enabling

//Enable experimental Accessibility support 
browser.AccessibilityHandler = new AccessibilityHandler(browser);
browser.IsBrowserInitializedChanged += (sender, args) =>
{
    if ((bool)args.NewValue)
    {
        browser.GetBrowserHost().SetAccessibilityState(CefState.Enabled);
    }
};

The original commit from @justindarc used System.Drawing assembly to perform a calculation related to positioning when DPI scaling is enabled. We don't reference System.Drawing in the CefSharp.Wpf assembly and rather than include a reference I've used a similar calculation to other DPI scaling code we have internally. This hasn't been tested in the context of the accessibility handler. If you experience any positioning problems then please report back here.

Code change for reference is at https://github.com/cefsharp/CefSharp/commit/da8ad192a48c94b2076ad5c22fc3e8f8411c7f3b#diff-b137532b29cdc092534dc783dffc6a90L306

[schalla1]

Which version have this changes(WPF - Add basic UI Accessibility support. #2495) ? @amaitland if none, please add this feature in latest release @amaitland

[amaitland]

@schalla1 These changes will be in version 85. If you wish to test this out before 85 is released then you can use a build from https://www.myget.org/feed/cefsharp/package/nuget/CefSharp.Wpf

[vinuthamikkilineni]

@amaitland with latest version of CEF, although CEF with WPF elements are noticeable in inspect tool, NVDA/JAWs are not able to recognize them. Is there any pending bugs that needs to be addressed