Re: [whatwg] Question about gradient stops in canvas and parsing as CSS colors
On Wed, 22 Sep 2010, Boris Zbarsky wrote: Consider this code: gradient.addColorStop(1.0,rgba( 0, 0, 0, 0); where |gradient| is a canvas radial gradient. Note the lack of ')' at the end of the rgba string there. What's the correct behavior? The spec says: If the color cannot be parsed as a CSS color, then a SYNTAX_ERR exception must be raised. However an actual CSS parser parsing that string as a color would infer the closing ')' per CSS 2.1 section 4.2 the item about unexpected EOF. Note that this is a tokenization-level requirement, as far as I can tell, so this happens before the syntax rules for productions like color are applied. Observed behavior in UAs is: * Webkit simply doesn't implement CSS 2.1 section 4.2 correctly * Opera throws an exception from the addColorStop call above, but shows lime text if loading this: data:text/html,span style=color: rgb(0, 255, 0Lime/span * Gecko shows lime text in the HTML testcase and treats the color stop above as valid rgba(0, 0, 0, 0). Clearly I happen to think Gecko's behavior is the sane one here, but there's a clear interoperability problem either way. Certainly Opera and Gecko interpreted the spec differently. Your interpretation is correct. I've fixed one point in the HTML spec that was phrased in terms of validity rather than in terms of successful parsing, and added a paragraph and example clarifying this, along with cross-references to this paragraph where relevant. -- Ian Hickson U+1047E)\._.,--,'``.fL http://ln.hixie.ch/ U+263A/, _.. \ _\ ;`._ ,. Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
Re: [whatwg] Question about gradient stops in canvas and parsing as CSS colors
On 12/29/10 3:07 PM, Ian Hickson wrote: * Webkit simply doesn't implement CSS 2.1 section 4.2 correctly * Opera throws an exception from the addColorStop call above, but shows lime text if loading this: data:text/html,span style=color: rgb(0, 255, 0Lime/span * Gecko shows lime text in the HTML testcase and treats the color stop above as valid rgba(0, 0, 0, 0). Clearly I happen to think Gecko's behavior is the sane one here, but there's a clear interoperability problem either way. Certainly Opera and Gecko interpreted the spec differently. Your interpretation is correct. I've fixed one point in the HTML spec that was phrased in terms of validity rather than in terms of successful parsing, and added a paragraph and example clarifying this, along with cross-references to this paragraph where relevant. Sounds good. Assuming the new text is in the CSS Modules section, there's a minor typo: the text as it closing the open construct should not have it there. -Boris
Re: [whatwg] Question about gradient stops in canvas and parsing as CSS colors
On Wed, Sep 22, 2010 at 3:49 PM, Anne van Kesteren ann...@opera.com wrote: On Wed, 22 Sep 2010 16:47:02 +0200, Boris Zbarsky bzbar...@mit.edu wrote: Clearly I happen to think Gecko's behavior is the sane one here, but there's a clear interoperability problem either way. Certainly Opera and Gecko interpreted the spec differently. Might be the way we invoke the CSS code. I think the Gecko behavior makes sense. Philip, can your test suite cover this? Added with the Gecko behaviour (and added a few other cases - Opera 10.61 fails some like rgba-solid-3): http://dvcs.w3.org/hg/html/diff/5a95d6481bac/tests/submission/PhilipTaylor/tools/canvas/tests2d.yaml Run the tests from http://test.w3.org/html/tests/submission/PhilipTaylor/canvas/index.2d.fillStyle.parse.html or (if that's down) http://dvcs.w3.org/hg/html/raw-file/tip/tests/submission/PhilipTaylor/canvas/index.2d.fillStyle.parse.html -- Philip Taylor exc...@gmail.com
[whatwg] Question about gradient stops in canvas and parsing as CSS colors
Consider this code: gradient.addColorStop(1.0,rgba( 0, 0, 0, 0); where |gradient| is a canvas radial gradient. Note the lack of ')' at the end of the rgba string there. What's the correct behavior? The spec says: If the color cannot be parsed as a CSS color, then a SYNTAX_ERR exception must be raised. However an actual CSS parser parsing that string as a color would infer the closing ')' per CSS 2.1 section 4.2 the item about unexpected EOF. Note that this is a tokenization-level requirement, as far as I can tell, so this happens before the syntax rules for productions like color are applied. Observed behavior in UAs is: * Webkit simply doesn't implement CSS 2.1 section 4.2 correctly * Opera throws an exception from the addColorStop call above, but shows lime text if loading this: data:text/html,span style=color: rgb(0, 255, 0Lime/span * Gecko shows lime text in the HTML testcase and treats the color stop above as valid rgba(0, 0, 0, 0). Clearly I happen to think Gecko's behavior is the sane one here, but there's a clear interoperability problem either way. Certainly Opera and Gecko interpreted the spec differently. -Boris
Re: [whatwg] Question about gradient stops in canvas and parsing as CSS colors
On Wed, 22 Sep 2010 16:47:02 +0200, Boris Zbarsky bzbar...@mit.edu wrote: Clearly I happen to think Gecko's behavior is the sane one here, but there's a clear interoperability problem either way. Certainly Opera and Gecko interpreted the spec differently. Might be the way we invoke the CSS code. I think the Gecko behavior makes sense. Philip, can your test suite cover this? -- Anne van Kesteren http://annevankesteren.nl/
