9.5 Borders

Both block and inline areas can have their borders visible using a non-zero border width.

• There are properties specified separately on each of the before, after, start, and end sides.

• The *-width properties are used to specify border width (precedence is given to wider widths in coincident table borders).

  • In table borders, wider widths take precedence over narrower widths.

  • A compound value can be specified through individual component settings

    • *-width.length=" length " ,

    • *-width. conditionality =" conditionality ";

      • the values of " discard " or " retain " apply to the border of split areas, i.e.

        • column and page reference areas for block areas (including table cells ),

        • line reference areas for inline areas;

  • a simple *-width=" length " length value:

    • implies *-width.conditionality="discard" ,

    • allows user -agent dependent values of " thin ", " medium ", and " thick ".

• The *-style properties are used to specify border style (listed in the order of precedence when width is equal for coincident table borders)

  • "hidden" :

    • forces *-width="0pt" ,

    • is a special case for table borders, in that " hidden " has higher precedence than any other coincident border specification, so the border is never seen,

  • "double" (with both lines and intervening space equal to the width),

  • "solid" ,

  • "dashed" ,

  • " dotted " ,

  • "ridge" ,

  • "outset" ,

  • "groove" ,

  • "inset" ,

  • "none" :

    • forces *-width="0pt" ,

    • is a special case for table borders, in that " none " has lower precedence than any other coincident border specification, so the border may still be seen.

• The *- color properties are used to specify border color (the precedence is to construct nesting in coincident table borders of equal width and style).

  • Any valid color specification can be used.

  • The order of precedence (highest to lowest ) is cell , row, row group, column, column group , then table.

• The region areas are fixed at a border width of 0pt and a padding of 0pt .

Borders with a conditionality of " discard " (the default) will have borders along split reference area edges discarded, as shown in Figure 9-7.

• A retained border will be drawn along the reference area's edge.

Figure 9-7. An illustration of border conditionality

Note the following about the example:

• each test includes a test of both block and inline level bordered areas;

• the split areas have, respectively, open and closed edges along the splits in the first and second tests, implementing each of the " discard " and " retain " property values;

• the presence of the retained border in the inline test changes the amount of text that fits on the third line.