When resizing SplitPane will be good to have the affected panes size information in it.

[tancyew]

Is your feature request related to a problem? Please describe.

Right now there are existing events to listen for splitter resize event such as splitterResizeStart and splitterResizeEnd. The information right now only contain one of the two panes that is being affected.

Describe the solution you'd like

The event args being return at the moment for both events mentioned above only return one pane information. (e.g. if there is two panes split horizontally and it is being resized left and right. only the width and height of the right pane is being returned.

Describe alternatives you've considered

Additional context