HTML and CSS Reference
In-Depth Information
the browser must provide some way to tell the user which cell it is read-
ing.
The
speak-header
property provides two ways for a browser to identify a
cell or collection of cells in the table. If
once
(the default) is specified, the
browser reads the contents of a header cell only once before proceeding
to read the contents of each associated data cell. This way, a user mov-
ing across a row of cells would hear the row header and column header
of the first cell in the row, but would hear the changing column headers
only as she moved to subsequent cells in the row.
If you set the
speak-header
property to
always
, the browser prefaces the
reading of each cell's contents with a reading of its associated header.
This may prove more useful with complex tables or where the header
values make it easier to understand the table contentsespecially when a
table contains only numbers.
Note that headers are spoken only when the browser knows which head-
er cells are associated with which data cells. Conscientious authors al-
ways use the
header
attribute with their table cells, to specify the header
cells related to each data cell in their tables.
8.4.9.4. The table-layout property
Table layout is a tough task for any browser. To create an attractive
table, the browser must find the widest cell in each column, adjust that
column to accommodate the width, and then adjust the overall table to
accommodate all of its columns. For large tables, document rendering
can be noticeably slowed as the browser makes several passes over the
table, trying to get things just right.
To help in this process, use the
table-layout
property. If you set the
property to
fixed
, the browser determines column widths based on the
widths of cells in the first row of the table. If you explicitly set the
column widths, setting the table's
table-layout
property to
fixed
makes
the table-rendering process even faster, enhancing the readers' experi-
ence as they view your document.
