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Re: Canvas

From: Laurens Holst <lholst@students.cs.uu.nl>
Date: Sun, 08 Apr 2007 15:32:24 +0900
Message-ID: <46188C78.9040200@students.cs.uu.nl>
To: Andrew Fedoniouk <news@terrainformatica.com>
CC: public-html@w3.org, David Hyatt <hyatt@apple.com>
Laurens Holst schreef:
> Andrew Fedoniouk schreef:
>>> <canvas> is a dynamic image that can be generated on the fly via JS. 
>>> There is usefulness to this model, since it allows you to build the 
>>> bitmap once and then treat it like an image from that point on.
>> If it is just an image then what was/is wrong with existing Image object
>> and <img> that are there from the primordial Navigator?
>> <img id="canvas" src="placeholder.gif" />
>> <script>
>>   var img = $("#canvas");
>>   var gfx = img.graphics( 300,300, "white" );
>>   gfx.line(...);
>> </script>
>> or so.
> Ah, yes, I think this is a very good idea! ‘1+’, so to say :).
> The reference to ‘placeholder.gif’ even seems excessive; only if you 
> want to have a fallback image. The default form would be simply 
> <img/>. It would basically mean slapping on the <canvas> API to <img>. 

Ah, no, never mind, this wouldn’t work.

The problem is the fallback behaviour of <img>. If the source file 
doesn’t load, or is not present, it falls back to the alternate content, 
and there is no longer a canvas present to draw on.  <canvas> in the 
contrary always creates the canvas, unless it’s not supported by the 


Ushiko-san! Kimi wa doushite, Ushiko-san nan da!!
Laurens Holst, student, university of Utrecht, the Netherlands.
Website: www.grauw.nl. Backbase employee; www.backbase.com.

Received on Sunday, 8 April 2007 06:34:15 UTC

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