Support Mouse wheel in firefox from version 69

[eTouchard]

GWT version: 2.8.2
Browser (with version): firefox 69.0.2
Operating System: All

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Description

Mouse wheel is no longer taken into account in firefox

Steps to reproduce

Create an MouseWheelHandler and add it to a widget using addDomHandler(handler, MouseDownEvent.getType());

when turning the wheel the handler is not called

[rdeangelis83]

com.google.gwt.user.client.ui.Widget#addDomHandler(handler, MouseWheelEvent.getType()) works correctly also in Firefox.
Can you provide simple example project how to reproduce this issue?

[zbynek]

Technically the wheel events fire, but implementing a handler that checks if it's scrolling up or down is impossible, because

gwt/user/src/com/google/gwt/dom/client/DOMImplStandardBase.java

Line 205 in ebc32a0

public native int eventGetMouseWheelVelocityY(NativeEvent evt) /*-{

rounds the delta to zero for many input devices and if you try to circumvent that by extracting wheelDelta directly, you run into problems with GWT using two different event types

• https://developer.mozilla.org/en-US/docs/Web/API/Element/DOMMouseScroll_event for Gecko
• https://developer.mozilla.org/en-US/docs/Web/API/Element/mousewheel_event for Blink
  Both of them are deprecated.