@Override
        public void onBrowserEvent(final Event event) {
            switch (event.getTypeInt()) {
                case Event.ONMOUSEDOWN:
                    mouseDown = true;
                    offset = getEventPosition(event) - getAbsolutePosition();
                    Event.setCapture(getElement());
                    event.preventDefault();

                    setDragging(true);
                    startResizing(vertical);
                    break;

                case Event.ONMOUSEUP:
                    mouseDown = false;
                    Event.releaseCapture(getElement());
                    event.preventDefault();

                    setDragging(false);
                    stopResizing();
                    break;

                case Event.ONMOUSEMOVE:
                    if (mouseDown) {
                        handleMouseDrag(event);
                    }
                    break;
            }
        }
Sets the minimum allowable size for the given widget.
<p>
<p>
Its associated splitter cannot be dragged to a position that would make
it smaller than this size. This method has no effect for the
{@link DockLayoutPanel.Direction#CENTER} widget.
</p>

@param child   the child whose minimum size will be set
@param minSize the minimum size for this widget
stroom-core-client-widget/src/main/java/com/google/gwt/user/client/ui/MySplitLayoutPanel.java