Note: Layout containers are a new feature, it's currently in the stable svn branch (v0-7). It will most likely be released with CEGUI 0.7.2
This introduces the concept of widgets that automatically layout their child widgets. Without these layout containers, doing dynamic complex UI was really hard and you had to do a lot of custom code.
Layout containers are simply widgets that have no visuals to them, they don't render anything, they also usually don't react to any input (this isn't really required but the 3 existing stock layout containers don't react to input themselves). They simply just set their child windows positions in a certain way (depending on the container). When child windows are resized, added or removed, the layout containers relayouts them to match the arrangement.
Inbuilt layout containers
Vertical Layout Container
Arranges child windows one after each other vertically.
CEGUI::VerticalLayoutContainer* layout = static_cast<CEGUI::VerticalLayoutContainer*>(CEGUI::WindowManager::getSingleton().createWindow("VerticalLayoutContainer"));
// add windows to the layout layout->addChildWindow(wnd1); layout->addChildWIndow(wnd2);
Horizontal Layout Container
Arranges child windows one after each other horizontally.
Horizontal layout container is used exactly the same as vertical layout container.
Grid Layout Container
Arranges child windows into a grid. You have to set grid dimensions before you add any windows to the container.