Hi Tao,
I don't think there is such a feature in the "official" version.
But as you can see in a previous post of mine, I implemented this feature a while ago in a specific version visible on my github.
Here is the link to the post mentionning it:
https://groups.google.com/forum/#!topic/vldocking/Kgm0ekkbCO8And here is the diff to what I modified:
https://github.com/fmarot/vldocking/compare/lockUnlock-featureIt is not a stable version but shows a way to do what you are looking for.
Basiacally, I made the components extend a new class called "LockableUnlockableHeaderPanel" and there is a way to notify those components to hide their header.
Hope this helps
Francois Marot