How to use Accessibility with sandboxed app?

Question

OS X have a nice feature such as Accessibility API, which allow to control some system elements and another applications from your app code. But it stops working after turning on Sandbox. To submit an app to the store is mandatory to turn on sandboxing.

That`s what Apple say:

With App Sandbox, you can and should enable your app for accessibility, as described in this document. However, you cannot sandbox an assistive app such as a screen reader, and you cannot sandbox an app that controls another app.

But App Store has a few applications that use Accessibility API:

• Cinch – resize Windows
• BetterSnapTool - same
• PopClip – gets the selected text

So it means that it is possible to use Sandbox/Accessibility API/App Store together, but how?

Answer 1

As of a couple of years ago, Accessibility APIs were not available from within the OS X sandbox, but that might have changed. It is more likely, however, that those apps managed to get a special exception from Apple, and that they have additional sandboxing entitlements that partially break them out of the sandbox just enough to let them use the accessibility APIs.

What you should do is first file a bug via bugreporter.apple.com, telling what you're trying to do with accessibility and why, and asking them to give you a sandboxing exception. If they approve the exception, they will probably give you a custom bit of sandbox profile language code that makes it possible to call the accessibility APIs from within the (somewhat weakened) sandbox.

With that said, depending on what you're doing, don't be surprised if Apple says, "Sorry, that app doesn't fit the app store model. Please sign your app using Developer ID with sandboxing disabled, and distribute it outside the store."

Answer 2

All these apps got on the App Store before sandboxing was enforced in 2012. My own HazeOver app is the same story. It can use accessibility only because it's still not sandboxed. Apple allows updating these apps, but they won't accept any new apps without a sandbox.

Answer 3

About getting selected text. There is two methods to get selected text:

#1: You can imitate CMD+C and then read pasteboard contents.

#2: You can write a service, and the system will pass selected text to your app.

https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/SysServices/introduction.html#//apple_ref/doc/uid/10000101-SW1

If you need to be notified when text was selected, you can listen to keyboard and mouse events: mouse draged, Shift+arrows pressed.