[whatwg] [2D Canvas] Do canvases in documents without a browsing context need to be rendered?

Ian Hickson ian at hixie.ch
Thu Mar 6 10:17:46 PST 2014

On Wed, 5 Mar 2014, Rik Cabanier wrote:
> Testing all browsers (except IE since 
> document.implementation.createHTMLDocument() doesn't work) they seem to 
> handle canvas contexts with no browsing context except when you use 
> text. Chrome crashes, firefox throws an exception and Safari draws the 
> text with a very small scale [1]

The spec actually defines what happens with fonts when you don't have a 
defined computed style:

# If the computed values are undefined for a particular case (e.g. because 
# the font style source object is not an element or is not being 
# rendered), then the relative keywords must be interpreted relative to 
# the normal-weight 10px sans-serif default.

This is needed for text rendering in Workers, if nothing else.

Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

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