swing/windows style simple panel caption

[hsm]

I need to simulate current swing UI using smartGWT with maximum precision.
Can anybody suggest me a solution on how to implement a simple panel caption which will looks like this:

┌ My cool panel ───────────┐
│                          │
│                          │
│                          │
│                          │
│                          │
└──────────────────────────┘

I'll have such panels nested in each other. Some panels will even have a comboBox in their caption. So HTML <legend> tag will not help.

Thanks before.

[Isomorphic]

Setting isGroup and groupLabel produces this appearance for any Canvas. However, a ComboBox version is one you'd have to build yourself right now, probably with a similar structure to what is used for isGroup - add margins and a border and "float" a widget over the border, possibly using snapTo positioning.