Tell if a user interaction is currently happening though a touch event in a view's window or something else – like an external keyboard or interaction in a different window (keyboard window). Example use: check if selection change was through touch or external keyboard.

MXSEventTrackingWindow.h

//
//  MXSEventTrackingWindow.h
//
//  Created by Max Seelemann on 01.09.16.
//  Copyright © 2016 The Soulmen. All rights reserved.
//

/*!
 @abstract Special window class used for advanced event processing.
 */
@interface MXSEventTrackingWindow : UIWindow
@end

/*!
 @abstract Convenience for getting infos about the current application state.
 */
@interface UIView (MXSEventTrackingWindow)

/*!
 @abstract Returns if the current event in the view's window is a touch event.
 @discussion Also returns NO when there is no current event in the window.
 */
@property(nonatomic, readonly) BOOL currentEventIsTouchEvent;

@end

MXSEventTrackingWindow.m

//
//  MXSEventTrackingWindow.m
//
//  Created by Max Seelemann on 01.09.16.
//  Copyright © 2016 The Soulmen. All rights reserved.
//

#import "MXSEventTrackingWindow.h"

@interface MXSEventTrackingWindow ()

@property(nonatomic, weak, readonly) UIEvent *currentEvent;

@end

@implementation MXSEventTrackingWindow

- (void)sendEvent:(UIEvent *)event
{
	_currentEvent = event;
	[super sendEvent: event];
	_currentEvent = nil;
}

@end

@implementation UIView (MXSEventTrackingWindow)

- (BOOL)currentEventIsTouchEvent
{
	if (![self.window isKindOfClass: MXSEventTrackingWindow.class])
		return NO;
	
	UIEvent *event = ((MXSEventTrackingWindow *)self.window).currentEvent;
	if (!event)
		return NO;
	
	return (event.type == UIEventTypeTouches || event.type == UIEventTypePresses);
}

@end

MyTextViewSubclass.m

@interface MyTextViewSubclass : UITextView
@end

@implementation MyTextViewSubclass

- (void)setSelectedTextRange:(UITextRange *)selectedTextRange
{
	NSLog(@"Selection changed by touch event: %d", self.currentEventIsTouchEvent);
	[super setSelectedTextRange: selectedTextRange];
}

@end