UI.HandleBegin

static bool HandleBegin(string id, Pose& pose, Bounds handle, bool drawHandle, UIMove moveType)

   
string id Id of the handle group.
Pose& pose The pose state for the handle! The user will be able to grab this handle and move it around.
Bounds handle Size and location of the handle, relative to the pose.
bool drawHandle Should this function draw the handle visual for you, or will you draw that yourself?
UIMove moveType Describes how the handle will move when dragged around.
RETURNS: bool Returns true for every frame the user is grabbing the handle.

This begins a new UI group with its own layout! Much like a window, except with a more flexible handle, and no header. You can draw the handle, but it will have no text on it. Returns true for every frame the user is grabbing the handle.