Re: [geometry] DOMMatrixInit dictionary

On Tue, 24 Mar 2015 22:36:17 +0100, Dirk Schulze <dschulze@adobe.com>  
wrote:

>
>> On Mar 24, 2015, at 10:27 PM, Simon Pieters <simonp@opera.com> wrote:
>>
>> Most interfaces in the Geometry spec have a dictionary type so you can  
>> use a direct JS object as an argument instead of requiring the object  
>> to implement the relevant interface. DOMMatrix doesn't have a  
>> dictionary though. It seems to me that it should.
>>
>> Since DOMMatrix has both a-f and m11-m44 attributes, the dictionary  
>> will have to support members for all those as well and accept objects  
>> where all are set.
>>
>> It probably makes sense to have a dictionary member for is2D, to  
>> preserve it being false even though the members indicate a 2d matrix.  
>> The constructor could throw TypeError if it was set to true but the  
>> other members indicate a 3d matrix.
>>
>> I don't see any reason to have a dictionary member for isIdentity.
>>
>> The a-f members and the corresponding mXX members can't have default  
>> values in the IDL, but can be defaulted in prose in the algorithm. If  
>> e.g. a and m11 are set to different values we could throw TypeError.
>>
>> dictionary DOMMatrixInit {
>>    unrestricted double a; // 1
>>    unrestricted double b; // 0
>>    unrestricted double c; // 0
>>    unrestricted double d; // 1
>>    unrestricted double e; // 0
>>    unrestricted double f; // 0
>>    unrestricted double m11; // 1
>>    unrestricted double m12; // 0
>>    unrestricted double m13 = 0;
>>    unrestricted double m14 = 0;
>>    unrestricted double m21; // 0
>>    unrestricted double m22; // 1
>>    unrestricted double m23 = 0;
>>    unrestricted double m24 = 0;
>>    unrestricted double m31 = 0;
>>    unrestricted double m32 = 0;
>>    unrestricted double m33 = 1;
>>    unrestricted double m34 = 0;
>>    unrestricted double m41; // 0
>>    unrestricted double m42; // 0
>>    unrestricted double m43 = 0;
>>    unrestricted double m44 = 1;
>>    boolean is2D;
>> };
>>
>> Does this seem reasonable?
>
> We didn’t want to add more things than there were requests for  
> initially. I think this is the only reason why we didn’t add it in the  
> first place.

OK, thanks. The current situation is inconsistent, which seems bad for Web  
developers.

-- 
Simon Pieters
Opera Software

Received on Wednesday, 25 March 2015 08:47:46 UTC