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Re: [geometry] DOMMatrixInit dictionary

From: Dirk Schulze <dschulze@adobe.com>
Date: Wed, 25 Mar 2015 12:03:56 +0000
To: Simon Pieters <simonp@opera.com>
CC: "public-fx@w3.org" <public-fx@w3.org>
Message-ID: <2AC95CC9-CCB0-446E-B77B-C0D90A508B65@adobe.com>

On Mar 25, 2015, at 9:47 AM, Simon Pieters <simonp@opera.com<mailto:simonp@opera.com>> wrote:

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


On Mar 24, 2015, at 10:27 PM, Simon Pieters <simonp@opera.com<mailto: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.

I admit that I can see confusion here.

Greetings,
Dirk


--
Simon Pieters
Opera Software

Received on Wednesday, 25 March 2015 12:04:30 UTC

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