Registering MouseEnter and MouseMove Events in PopupCloser

[amartya4256]

We have an issue with Edge Browser here: eclipse-platform/eclipse.platform.swt#2072

The reason:
SWT cannot recieve the MouseUp or MouseDown event from the tooltip as the tooltip is running a webview instance (Edge browser) inside and when you click on the javadoc, the click is registered by Webview and not SWT. This is a problem since, there's no known way to directly get this mouseclick event out of Webview to SWT unlike IE. Hence, how we did it in eclipse-platform/eclipse.platform.swt#1551, we rather need to rely on mouseEnter and mouseMove instead.

The problem is that the toolTip is created using AdditionalInformationController where PopupCloser is resposible from replacing the tooltip control with the one with a scrollbar, but it doesn't handle any MouseEnter and MouseMove event unlike AbstarctHoverControlManager:Closer which is responsible for replacing the tooltip control in case of eclipse-platform/eclipse.platform.swt#1551.

Hence, we need it to also register listeners for MouseEnter and MouseMove as done in the PR #2977. Although, this addition of extra events doesn't have any visual effects on other widgets (as far as I have tested), but it can indeed trigger replaceInformationControl on there 2 extra events too for all the consumers using a popupCloser.

We can rather accept this solution as a feature to the widgets reacting to "mouseHover" for replacing the information control or figure out how edge can send a mouseUp event (which doesn't seem to be quite straight forward or maybe even not possible)

Refer PR:
#2977

[amartya4256]

@fedejeanne @HeikoKlare What do you think?

[fedejeanne]

As discussed before: I'm fine with merging #2977 in M1.

Thank you for the analysis, Marty!

[HeikoKlare]

As we have no idea yet how to properly capture the relevant mouse events in Edge without JavaScript being enabled, I think the proposed change makes sense to resolve the degraded user experience of the PopupCloser.
I have posted some further thoughts/concerns on the proposal in the according PR: #2977 (review)

@sratz since you are deeply involved into Edge development as well, it would be nice to have your opinion on this as well.