Bugs out in safari on iPhone about pinch-zoom

[Todd1561]

I've run into this, too. Specifically, what's happening is when you drag your finger outside the pinch-zoom box and release when you're outside the box pinch-zoom seem to get stuck in a limbo state where it thinks your finger is still on the screen (probably at the edge of the box) when it isn't. At this point you can no longer pan as it thinks you have 2 fingers on the screen, so you're stuck in this limbo state of zooming.

Unfortunately, I don't have a solution, I just wanted to include some more detailed into as to what's happening. Only "workaround" I've come up with is to use this project only when it consumes the entirety of your device screen so this situation can't arise to begin with.

[Todd1561]

After messing with this more I determined the issue is the "pointerup" event does not fire if your finger releases when not within the pinch-zoom box. Without this event firing it leaves pinch-zoom in a limbo state. The fix was actually pretty simple, rather than binding the "pointerup" event just to the pinch-zoom box I bound it to the entire document. That way no matter where the user releases it'll fire the event and return pinch-zoom to a normal state. All that needs to be changed is one line of code (line 105):

From this:
this._element.addEventListener('pointerup', this._pointerEnd);
To this:
document.addEventListener('pointerup', this._pointerEnd);

[edman007]

The pointerup event probably isn't firing because it was canceled. The version of pointertracker used by pinch-zoom doesn't listen for it so that's why the event is missing. Updating pointertracker fixes it. I have a pull request ( #26 ) that fixes it and adds some other things.