CoolBar class 

CoolBar controls act as containers for child windows. An application assigns child windows, which are often other controls, to a CoolBar control band. CoolBar controls contain one or more bands, and each band can have any combination of a gripper bar, a bitmap, a text label, and a child window. However, bands cannot contain more than one child window. 

A CoolBar control displays the child window over a specified background bitmap. As you dynamically reposition a CoolBar 
control band, the CoolBar control manages the size and position of the child window assigned to that band. 

All CoolBar control bands can be resized, except those that use the RBBS_FIXEDSIZE style. To resize or change the order of bands within the control, click and drag a band's gripper bar. The CoolBar control automatically resizes and repositions child windows assigned to its bands. Additionally, you can toggle the size of a band by clicking on the band text, if there is any.