How to get my finger or mouse position to drag IMGUIContainer ?

I found that its better to use RagisterCallback function to detect touches and clicks in uiTool kit

myIMGUIContainer.RegisterCallback(ev => SelectStatement(ev));

but how i can detect my finger or mouse position while it moves throught my game screen so that myIMGUIContainer element will follow it? i think there is no function in event to get that . any help ?

No answer ? So uitool kit isnt ready ? No clear complete documentation ?