I added Docking to GMod a while ago. GWEN uses it too. I don’t think many people designing GUI layouts in GMod know about it (probably because I only added it in the last 6 months and they’re learning from older code).
I always feel like I learn better by looking at images rather than text. So here goes (this is in GWEN but it’s the same principle in GMod)
New Button called Bart
Dock Bart ‘Left’
New Button Homer – Dock ‘Fill’
Dock Bart ‘Bottom’
Dock Homer ‘Left’
Send Homer To The Back
Reduce Homer’s Width
Add Marge – Dock ‘Fill’
Change Homer’s Margin (0,0,4,0) (l,u,r,d)
Create Button ‘:D’ on Homer, Dock ‘Bottom’
Change :D margin to (4,4,4,4)
As you can see it makes laying out your controls set and forget. Previously you’d be setting the layout in something like PerformLayout – manually working out pixels, subtracting from the width of the parent. It gets messy.
Docking isn’t appropriate for everything but it works for a lot of stuff. It also has the advantage that it automatically scales when stuff gets resized.