Touchposé

Touchposé is a library for iOS that renders screen touches. Touchposé adds a transparent overlay to your app’s UI; all touch events cause semi-transparent circles to be rendered on the overlay--an essential tool when demoing an app with a projector or creating a demo video. By default, touches are only rendered when connected to a mirrored screen, but this be overridden.

Before deciding to using Touchposé, see the Caveats section below.

To use Touchposé with an app, indicate that TRTouchposeApplication should be used instead of UIApplication. This is done by specifying the application class in UIApplicationMain():

int main(int argc, char *argv[])
{
    @autoreleasepool
    {
        return UIApplicationMain(argc, argv,
                                 NSStringFromClass([TRTouchposeApplication class]),
                                 NSStringFromClass([MyAppDelegate class]));
    }
}

If you’re using Objective-C, that’s it; no other steps are needed. For Swift 3, keep reading.

Installation

CocoaPods

To use Touchposé with CocoaPods, add pod 'Touchpose', '~> 2.0' to you Podfile. For example:

source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '8.0'

use_frameworks! # required with Swift, optional with Objective-C

target 'TargetName' do
  pod 'Touchpose', '~> 2.0'
end

Using with Swift 3

Touchposé works with Swift 3, but requires a few additional steps to setup:

• Add main.swift to your project with the following content (replacing AppDelegate with the name of your application delegate class):

  import UIKit
  import Touchpose
  
  
  UIApplicationMain(CommandLine.argc,
                    UnsafeMutableRawPointer(CommandLine.unsafeArgv).bindMemory(to: UnsafeMutablePointer<Int8>.self, capacity: Int(CommandLine.argc)),
                    NSStringFromClass(TRTouchposeApplication.self),
                    NSStringFromClass(AppDelegate.self))

  (If anyone has a better way of passing CommandLine.unsafeArgv, I’d love to know what it is.)

• Remove the @UIApplicationMain attribute from your app delegate class.

• If you want to unconditionally enable Touchposé, add the following to your application( :didFinishLaunchingWithOptions) implementation should be something like this:

  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
      window?.makeKeyAndVisible()
      (application as! TRTouchposeApplication).showTouches = true
      // Override point for customization after application launch.
      return true
  }

Custom Touch Indicators

Instead of the default circle touch indicator, you can customize the view used for touches. To do this set the touchViewFactory property of TRTouchposeApplication to a custom factory class that implements the TRTouchposeTouchViewFactory protocol.

Touchposé includes an alternate touch view factory TRTouchposeImageTouchViewFactory that uses an image for the touch view. This can be configured like this:

TRTouchposeImageTouchViewFactory *touchViewFactory = [[TRTouchposeImageTouchViewFactory alloc] init];
touchViewFactory.touchImage = [UIImage imageNamed:@"Finger"];
touchViewFactory.offset = CGPointMake(52, 43);
touchposeApplication.touchViewFactory = touchViewFactory;

This setup produces a image of a hand with the pointer finger indicating the touch point. The offset property above provides the offset from the image’s origin (top-right corner) that represents the touch point.

Caveats

• Touchposé requires using a custom subclass of UIApplication. If your app already uses some other custom UIApplication subclass, you can’t use Touchposé.
• Touchposé uses method swizzling to intercept calls to -didAddSubview: and -becomeKeyWindow on UIWindow. Method swizzling is supported by the Objective-C runtime, but it’s usually considered a dangerous practice, especially when done on classes you don’t own. Furthermore, it only works if you’re the only one swizzling—if some other class is also swizzling methods on the same class, things may go amok.
• Touches are not always displayed in alert views and the keyboard.

My recommendation is to only use Touchposé in private builds when you want to demo your app to an audience on a projector.

License

Touchposé is licensed under the Apache License, Version 2.0.

Credits

The devices images in this README are from Robbie Pearce.