ViewBridgeAuxiliary and targeting synthesized keystrokes

[Greg Scown]

Dear NSPasteboard Crew:

El Capitan appears to have introduced a new process: ViewBridgeAuxiliary. This process appears to serve as an intermediary for keyboard events for the file dialog in sandboxed applications. When one presses command-V in a sandboxed file dialog, the event first transits the ViewBridgeAuxiliary process then the "power box" (com.apple.appkit.xpc.openAndSavePanelService) process. Events do not transit ViewBridgeAuxiliary for non-sandboxed applications.

It used to be that one could send a synthesized command-V to the "power box" (com.apple.appkit.xpc.openAndSavePanelService) process using CGEventPostToPSN(). Events synthesized in this manner appear to be ignored on El Capitan.

I did try to mimic the system behavior by first targeting the synthesized event at ViewBridgeAuxiliary, but when the event comes through it does not have ViewBridgeAuxiliary's PID. Instead, it has the "power box" PID. This worries me, because it suggests the purpose of ViewBridgeAuxiliary may be to prevent synthesized keystrokes in sandboxed file dialogs.

I'm planning to dig into this, as we don't want TextExpander users to be unable to expand snippets in the file dialogs of sandboxed apps.

Has anyone noticed this in their work? Have you tried any clever workarounds with success?

I'll share what I find, but I expect it will be at least several days before I have more to share.

Thanks!

Greg Scown

Smile Founder

Twitter: @macgreg