Issue 308 - svgweb - Implement currentTranslate and currentScale and have it be a fast path

Issue 308:	Implement currentTranslate and currentScale and have it be a fast path
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Status:	Fixed
Owner:	bradneuberg
Closed:	Sep 18
Type-Defect
Priority-Medium

Reported by bradneuberg, Sep 17, 2009

Implement currentTranslate and currentScale and have them be a 'fast path'
for faster zooming and panning of the entire root without having to go
through the full viewBox parsing and algorithm. We will have to modify the
currentTranslate API to take formal getters and setters due to limitations
on IE:

root.currentTranslate.setX(5);
alert(root.currentTranslate.getX());

Comment 1 by bradneuberg, Sep 18, 2009

Implemented; helps a very small amount for performance but makes the code easier to
comprehend and helps others do zooming and panning much easier than having to mess
with the viewBox.

Comment 2 by bradneuberg, Sep 18, 2009

This issue was closed by revision r877.

Status: Fixed

Comment 3 by helder.magalhaes, Oct 04, 2009

Oh, this is way cool! :-)

I've been preparing a couple examples [1] (same using SVG Web [2]) [3] using these
DOM APIs for zoom and pan: this allows, for example, for an easy implementation of
zoom/pan controls (pretty related with issue 291).

I've just finished re-factoring them in order to be compatible with SVG Web, but I
didn't quite understand the IE limitations which don't allow to manipulate the
currentScale and currentTranslate directly, i.e., the standard way (is that an HTC
limitation?).


Nit for revision 877:

(UserManual.html, line 956)
+ <p id="known_issues25">* <code>currentTranslate</code> is supported on the SVG root
tag (see the section <a href="#zoomAndPan">"Zooming and Panning with currentTranslate
and currentScale"</a> for details). However, due to limitations in Internet Explorer
the way to work with this is slightly different when using SVG Web than the SVG 1.1
standard. See the <a href="#zoomAndPan">section</a> for

Missing end of last sentence. Suggested:

See the <a href="#zoomAndPan">section</a> for details.


Finally, I'd vote for a rename of this issue: something like "Support
currentTranslate and currentScale (for zoom/pan, drag&drop and more)" (I'm not sure
if the original title was too long and therefore truncated).


[1] http://heldermagalhaes.com/stuff/svg/demos/ZoomAndPan-Demo.svg
[2] http://heldermagalhaes.com/stuff/svg/demos/ZoomAndPan-Demo-SVGWeb.html
[3] http://heldermagalhaes.com/stuff/svg/demos/SVGObject-HTMLCanvasInteractors/
[4] http://code.google.com/p/svgweb/