Detect text is entered using dictation on iOS 16 - ios

Question

How do I detect that text is entered into UITextField using dictation on iOS 16?

Answer 1

Before iOS 16, we could detect the user is using dictation to enter text by checking primaryLanguage variable of the textInputMode being dictation. Simple enough. But this method doesn't work no more. In iOS 16, primaryLanguage is the language selected for dictation.
In my Remote Mouse & Keyboard for Mac / PC app (https://remote4mac.app), I need to detect whether the user is using dictation to wait for the whole phrase before sending it to the computer. So I started looking for alternative methods and spent a good couple of hours to no avail. But then I remembered method swizzling. iOS using UIDictationController to control dictation interactions, but it's a private class. So I had to figure out how to swizzle its methods, and fortunately, you can do that by adding a category and using category methods for it like this
#interface NSObject(PrivateSwizzleCategory)
- (void)swizzled_setupForDictationStart;
- (void)swizzled_stopDictation;
#end
#implementation NSObject(PrivateSwizzleCategory)
- (void)swizzled_setupForDictationStart {
[(NSObject *)self swizzled_setupForDictationStart];
[[NSNotificationCenter defaultCenter] postNotificationName:#"UIDictationControllerWillStart" object:nil];
}
- (void)swizzled_stopDictation {
[(NSObject *)self swizzled_stopDictation];
[[NSNotificationCenter defaultCenter] postNotificationName:#"UIDictationControllerDidStop" object:nil];
}
#end
Then you just need to run a code that will swizzle those methods with the UIDictationController like this
Method original, swizzled;
original = class_getInstanceMethod(objc_getClass("UIDictationController"), NSSelectorFromString(#"setupForDictationStart"));
swizzled = class_getInstanceMethod(objc_getClass("NSObject"), #selector(swizzled_setupForDictationStart));
method_exchangeImplementations(original, swizzled);
original = class_getInstanceMethod(objc_getClass("UIDictationController"), NSSelectorFromString(#"stopDictation"));
swizzled = class_getInstanceMethod(objc_getClass("NSObject"), #selector(swizzled_stopDictation));
method_exchangeImplementations(original, swizzled);
and you are done. Just listen to the new notifications and act accordingly in your code.
So now its time for me to see if the app will pass Apple review.