Left Setting View Moving Effect

link : https://github.com/swamful/leftSettingEffect

Currently, hidden left extra view is a fashion. 
So I decided to make it with more sensitive showing way. 

At first when app is launched, just gray MainView would be shown. That view is just normal view. Hidden left view is still not shown. But if you drag a MainView to right, a MainView would open like a half opened door and hidden left view begin to show. Finally a MainView stays half opened status and left lists will be shown with appearing animation. 

Below video is recorded a simulator on my MacBook . 
In fact, my device is too old. MacBookPro 2010 mid. Simulator in video show a moving seem to be rough. But if you try on own your iPhone, the moving would be very smooth.