Change vtk3DWidget::SizeHandles() to a public method
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
At the moment, widgets resize their handles after they are transformed in the scene. If the user zooms in/out, the widget handles become disproportionately big or small compared to the viewport. If vtk3DWidget::SizeHandles() was changed to a public method it could be used as a callback, observing the renderer's StartEvent, so that widget handles are always correctly sized. This could be implemented in C++ inside the widgets themselves or left to the developer to do within their application. If implemented, this would probably make the SizeHandles() calls inside the *ButtonUp callbacks redundant.