Lars Schöning wrote:
May I suggest the addition of a
drawString method with parameters for font type, size and string.
In order to achieve usability canvas really requires an equivalent
prototype
method, however the established prototype functions take immense amounts of
clocktime and significantly (and unnessessarily) slow down the canvas. The
current lack of standard in canvas makes it possible to include a
drawString
method before it is too late, thus adding new possibilities to the object.
You can't really implement drawString as a single call, since there's no
guarantee that the font you requested will be available so you need to
be ready to deal with that eventuality.
A process which might work is:
* Make a request to prepare some text with an ordered list of preferred
fonts, CSS-style.
* Get back some kind of descriptor which allows you to discover various
characteristics of the dimensions of the text as it will be rendered.
* At some later point, ask the canvas to "draw" the descriptor at a
given location.
This allows for the browser to substitute other fonts while allowing the
canvas-based app to adapt the display to the characteristics of the
selected font.