# :: Reference :: Bounded Sizes :: Bounded sizes are used to restrict a layout element's initial size. They add context related layout information that the element does not or cannot provide. To use a bounded size, you typically combine a component size (min, pref or default) with a constant size as lower or upper bound. For example, a well designed command button honors the button's label and icon size, but also uses a minimum width. The latter increases the design consistency and often makes it easier to click on buttons with short labels. A Swing `JButton` is used in different contexts: form, button bar, button stack, toolbar with icons, toolbar with texts, toolbar in large button mode, etc. Since the JButton (or the ButtonUI) can only provide a single `preferredSize` that often lacks the context. And so, the button lacks information about context-related layout requirements. ## String Representations String representations for bounded sizes are used in the FormLayout constructors as well as in classes `ColumnSpec`, `RowSpec` and `Border`. The string encodings allow to set only a lower or upper bound, where the related Java objects allow to set both bounds at the same time, which is needed rarely.
    boundedSize ::=   [constantSize,componentSize]               // lower bound
                    | [componentSize,constantSize]               // upper bound
                    | [constantSize,componentSize,constantSize]  // lower and upper

                    | MAX(constantSize;componentSize)            // lower bound (old)
                    | MIN(constantSize;componentSize)            // upper bound (old)
## Examples
    new ColumnSpec("[50dlu,pref]");     //  pref size with lower bound 50dlu

    new RowSpec("[pref,80dlu]");        //  pref size with upper bound 80dlu

    new FormLayout("[50dlu,pref], 4dlu, [100dlu,min]",
                   "p, 3dlu, p, 3dlu, [200dlu,p]:grow");
(c) 2009 JGoodies |  |