GWT DnD: Keep draggable within an AbsolutePanel

Answer 1

I've used dragController.setConstrainWidgetToBoundaryPanel(true), and I think dragController.setBehaviorConstrainedToBoundaryPanel(true) does the same thing. For more information, check out the javadoc for your version.

Answer 2

The method you're looking for is defined in AbstractDragController with this signature; void setBehaviorConstrainedToBoundaryPanel(boolean constrainedToBoundaryPanel);

The boundary panel (often passed in in the first parameter to the drag controller constructor) in this case should be an AbsolutePanel which wraps the slider.

It may also be helpful to visualize the absolute panel if things are not working as expected: absolutePanel.getElement().getStyle().setProperty("border", "1px dashed red");