hldj.org

Many of you may be familiar with command menus already: they are the menus that pop-up on screen in HL1 games and show options to say/do various things such as change teams, drop a weapon, say a command etc. But what you may not have known is that you can make your own custom command menus that include your own commands. Here is how to make one for HLDJ for an HL1 game (example screenshot):



Create a text file named "commandmenu.txt" and place it in your game directory (if one already exists, you can rename it or edit it and add menus to it, see below).
Now you can create your own menus and items in it using the following format for menu items: and this one for submenus: Where <key> is the key used to activate that menu item, <label> is the display name of the item and <command> is the command(s) that are executed when that item is selected.
Here's an example of a simple HLDJ custom command menu: Now just bind a key to "+commandmenu" in-game, and you have a quick way of accessing all HLDJ commands from a menu.
Here's the commandmenu.txt file for downloading.

You can place this file into your custom folder instead, to have it loaded every time you start a game with HLDJ.

Can this be done on a source engine game, like tf2?

This is an HL1-only feature, some Source games feature tweakable UI/dialogs, but unfortunately there's no generic/easy interface to do something like this for Source.

but do you KNOW how to do that for CSS ?

I played around with custom UI's in CSS early in development, at the time there was nothing useful to be gained from them.