Splitter Tracker

Docking Pane allows you to change what your docking panes look like when they are resized.  You can use a splitter tracker that will draw an outline to depict the new size of your docking pane window or you can resize your docking panes in "real-time," instantly seeing how your new docking pane will look.

Splitter tracker enabled
Splitter tracker enabled

Splitter tracker disabled
Splitter tracker disabled