How to maximize a video player on screen?

[BosseB]

I would like to know if there is some advice on how one can maximize a player object to fill the whole screen and have user controls "sneak up" when the mouse moves close to the bottom edge.
Many players have this built-in and I would really like to be able to do it also in my own player.
I.e. if I click the Max button the player should zoom out to fill the screen and still operate as before.
Then if I hit Esc it shall return to the previous state.
Mouse moves in a special zone shall bring up a panel with user controls where the return to normal should also be found.

I have tried several ways but the result is always a black screen and nothing more...
The player I use is a TPasLibVlcPlayer object, and it is located on the main form above a panel (bottom aligned) holding all the manual controls. The player is aligned client.