WARNING: This is old code

Feel free to look to this code for inspiration, but do not expect it to run. The basic approach may still work, but it has not been tested in years.

---

SKUTouchPresenter

SKUTouchPresenter allows you to demo your app to an audience and have them follow your touches. It displays a dot (or multiple dots) wherever the screen is touched. You can configure the dot's color and opacity, and you can also have the dot(s) appear only when the device is mirroring to a second display via AirPlay or an adapter cable.

A sample app is included, which allows you to turn dots on & off and customize the color/opacity:

Integration

With Cocoapods:

1. Add SKUTouchPresenter to your Podfile, and run pod install.

Manually (without Cocoapods):

1. Add the SKUTouchPresenter.h & SKUTouchPresenter.m files to your project.
2. Add the QuartzCore system framework to your project.

Important: if you already use a custom subclass of UIApplication, then you should edit SKUTouchPresenter.h and change the superclass from UIApplication to the name of your custom subclass (so the inheritance chain is UIApplication -> YourApplicationSubclass -> SKUTouchPresenter).

Usage

Call showTouchesWithColor: or showTouchesWhenMirroringWithColor: in your application delegate, or whenever you want to start showing touches.

+ (void) showTouchesWithColor: (UIColor *)color

Enables (or disables) showing dots wherever the screen is touched. Pass nil to disable.

+ (void) showTouchesWhenMirroringWithColor: (UIColor *)color

Enables (or disables) showing dots wherever the screen is touched, but only when the device is mirroring to a second display.

+ (void) setTouchRadius: (CGFloat)radius

Sets the radius of the dot in pixels. The default is 20 pixels.

The SKUTouchPresenter class works with or without ARC.

Implementation Details

When enabled, the class intercepts touch events via UIApplication sendEvents:, displaying a dot wherever a touch occurs. Events are passed onward, so this shouldn't affect your app's behavior.

In order to intercept events via UIApplication sendEvents:, you typically subclass UIAppliation. By default, the code uses dynamic subclassing to do this automatically the first time you call showTouchesWithColor: or showTouchesWhenMirroringWithColor. This enables you to wrap these calls with #define blocks and only include the functionality for particular builds.

SKUTouchPresenter does not use any private APIs and should be fine for App Store approval. However, you can set it up manually without the dynamic subclassing: you just need to add SKUTouchPresenter as a custom subclass of UIApplication. Here's how to do that:

1. Follow the integration steps above.
2. Edit main.m to add @"SKUTouchPresenter" as the third argument to UIApplicationMain.
3. If your app already uses a custom subclass of UIApplication then please see the notes about custom subclasses in the Usage section.
4. If you want to delete the dynamic subclassing code to be extra paranoid, open SKUTouchPresenter.m and delete the two blocks of code that say "Can delete if subclassing...".

License

Copyright 2011-2014 Scott Guelich. May be distributed in accordance with the MIT license.