spacing  spacing
spacing               /                \           spacing
        \     port                         port   /
        |  | width  |  |              | | width |  |
        0
      0_|_________________________________________    ___
        /                                         \   ___  spacing
        |                                         |
        |                 Caption                 |        caption height
        |             ________________            |   ___
        |             |               |           |   ___   spacing
        |             |               |           |
        O In Name     |               |  Out Name O        entry
        |             |               |           |   ___
        |             |               |           |   ___  spacing
        |             |               |           |
        O Another In  |               |  Out Name O
        |             |               |           |
        |             |               |           |
        |             |               |           |
        O             |               |           O
        |             |               |           |
        |             |_______________|           |
        |                                         |
        O                                         |
        |                                         |
        \_________________________________________/

Node's size must be recalculated in following cases:

1. After construction.
2. Embedding the widget.
3. After resizing.
4. Before painting (conditional, depends on whether the font metrics was changed).
5. When incoming data changed (could trigger size changes, maybe in captions).
6. When embedded widget changes its size.