RFR: 8206253: No/Wrong scroll events from touch input in window mode

[Jose Pereda]

On Mon, 8 Mar 2021 23:47:32 GMT, Kevin Rushforth <kcr at openjdk.org> wrote:

>> This PR changes the parameter names to accommodate class calculations related to screen event coordinates (AbsX, AbsY).
>> 
>> As [discussed](https://bugs.openjdk.java.net/browse/JDK-8206253?focusedCommentId=14405707&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14405707), the sendScrollXXXEvent methods are currently passing the screen coordinates (AbsX, AbsY) to the local ones, but they shouldn't modify those, but the screen ones.
>> 
>> Tested successfully on Android with ComboBox controls in different positions.
>
> Since this touches shared code, what testing have you done to ensure that it works as expected on other platforms?

I've tested Mac (via touchPad), but even setting `com.sun.javafx.gestures.scroll` to true, `ScrollGestureRecognizer` doesn't get called (via `GlassViewEventHandler::handleEndTouchEvent`), as the flow of scroll events goes through `GlassViewEventHandler::handleScrollGestureEvent`.

Same on Linux and Windows (via touchPad), where the flow of scroll events goes through `GlassViewEventHandler::handleScrollEvent`.

I've also tested on Windows with a touch enabled display (and `com.sun.javafx.gestures.scroll` set to true). 
In this case, scroll events are handled mostly via `GlassViewEventHandler::handleScrollGestureEvent`, but also by `ScrollGestureRecognizer`. Before this PR, the latter added wrong coordinates to the gesture, causing the scroll to stop. With the changes, there are a few events, but they are now exactly the same as those from handleScrollGestureEvent (so there are duplicated calls to `scene.sceneListener.scrollEvent`), and the scroll is more fluid, doesn't stop. 
(Anyway, I don't think it is expected to set `com.sun.javafx.gestures.scroll` in this platform)

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PR: https://git.openjdk.java.net/jfx/pull/420