Multitouch (two or more 'fingers') during pan creates flickering effect

Bug report

Expected behaviour

When multitouch is performed, the expected behaviour is that only the first ‘finger’ is used for panning. All other touches are ignored. The panning is smooth and creates not flickering effect (switching very quickly between two or more pannings).

Actual behaviour

When multitouch is performed, the actual behaviour is that all touches are processed and a panning for each touch is performed very quickly behind each other. This creates a flickering effect (switching very quickly between two or more pannings).

Steps to reproduce the behaviour

1. Open any demo where panning is allowed on a device that supports touch events
2. Pan an svg-element with two fingers

Configuration

• svg-pan-zoom version: The latest version from github
• Browser(s): all
• Operating system(s): all

Feature Request

• Add an option to disable multitouch
• Default behaviour should not be affected. So standard multitouch is enabled but an option to disable it would be super.
• No, as the default behaviour is not affected

[Kookpot]

Hi @bumbu ,

First of all thanks for making this awesome library and second thanks for helping me fix the bug! I really appreciate it. Keep up the good work!

Cheers, Koen.

[bumbu]

Hi @KoenkookpotPlasmans,

You’re changes are now in master. You can see that I closed that PR as I had so separate source code changes and build into separate commits.

I also published a new version on npm. I added you to the list of contributors, but if you don’t want to be there, let me know or create a PR with that line removed.

Thank you for all your time and effort!