mart at degeneration.co.uk
Tue Jun 6 10:56:45 PDT 2006
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
> 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
> 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
* 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
This allows for the browser to substitute other fonts while allowing the
canvas-based app to adapt the display to the characteristics of the
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