Can't scroll page after interacting with canvas on touch screen.

[samuelkilada]

Version

1.7.6

Test Case

Kind of hard to duplicate as it happens in Cordova.

Steps to reproduce

I have a cordova app, and updated to Fabric version 1.7.6 in order to fix the bug caused by #3690. Though that did the trick, now as soon as you touch the canvas on a touch screen device, the rest of the page cannot scroll anymore, even when the canvas is hidden. You have to leave the page entirely to reset it.

Expected Behavior

You should be able to scroll a page regardless of whether you have edited / touched a canvas.

Actual Behavior

Cannot scroll after editing / touching a canvas.

[asturur]

if it happens in cordova and can't be replicate in an html page alone i cannot take care of it.

[samuelkilada]

That makes sense. Any ideas that might point me in the right direction? The only thing I changed in my app was the fabric version, and so that is causing the problem somehow. If you are aware of anything I would greatly appreciate it. Either way, thank you for the time!

[asturur]

can you open the app in a normal browser? if yes inspect the canvas element, search for the style.l property touch-action and remove it

other than that check the file in the repo canvas.events.mixin.js

if the touch events are appended to window, that may cause problems?

[samuelkilada]

Interesting thoughts, thank you. I don't exactly know what's going on, but somehow upon editing the Fabric canvas the touch events are stripped from the rest of the document. This is occurring on both Android and Windows Phone. The only element that does continue to allow scrolling is the very background of the page, so you have to carefully place your finger right on the background (most of it is covered in my app) in order to be able to scroll.

Perhaps your hunch that the events are being appended to the window is correct, because only the window itself is receiving the events. Just trying to figure out what to do about it.

[guari]

See bug #3756, it seems to happen on many IOS Safari versions, with a simple free-drawing setting, tested on latest release.

[khmyznikov]

@samuelkilada try to use canvas.discardActiveObject() then you hide/leave canvas

[asturur]

to be handled in #3869