Hi Jason,
Zoom should first be driven by hit testing in the browser. If you have a
point within an object the zoom event should be generated at the object hit
and then the object should manage the zoom from that point. The application
needs to make the decision how it zooms once the event is received. This
will be particularly important, for example, if you have something like a
flow chart and your browser deems the hit to be within a line. The
application may find the point toward the end of the line and want to zoom
around that point. We will need these concepts when we apply zooming to SVG
and HTML5 Canvas.
So, the x,y coordinates are essential. There may be some instances, such as
text, or UI controls the app. may wish to zoom off center of the x,y
coordinate.
Rich
Rich Schwerdtfeger Th
From: Jason White <jason@jasonjgw.net>
To: public-indie-ui@w3.org,
Date: 03/11/2013 05:44 PM
Subject: Re: pan, rotation, move and zoom request events
James Craig <jcraig@apple.com> wrote:
> I think that depends on the application. In most cases, I would expect
the
> zoom event to be centered on the x/y coordinates if they were provided.
If
> origin coordinates are not provided, zoom would probably be centered in
the
> middle of the current view.
That's reasonable. Could you perhaps clarify it in the text without
unduly limiting what applications do?
