click the key twice quickly on Keyboard , click event just fire once

[pppp0836]

Hi, I use pinch-zoom to show picture with Ionic framework,and that page have a small keyboard(some divs),When click the key twice quickly on Keyboard , click event just fire once ,This happens on mobile devices.If comment pinch-zoom tag in HTML file,It's OK.
To reduce this issue,Check out https://github.com/pppp0836/testimg.git

Thanks!