[Drawkit] x-axis zooming?

[Graham Cox]

I suspect that you probably don't want to simply zoom the graphics in  
the x direction only. That would cause everything to stretch out and  
become very distorted.

Instead what will change is your time <--> x position ratio. I'm far  
from familiar with music notation but let's say you had a system where  
each time value (1/16th note, say) took  up 10 points. Somewhere you  
will be doing calculations to place notes (and everything else, like  
bar lines) at a certain position using this ratio. By changing that  
ratio you will  allow "zooming" in the x direction but without the  
graphics themselves changing size.

 From this is should be clear that you'll have to handle this  
yourself. If you plan for it in your code that decides where to place  
notes, it should be straightforward, but other than that I can't  
really give very concrete advice.

To implement graphical zooming which differs in x and y, you'd need to  
subclass the DKDrawingView class but I really doubt that's what you  
want.

cheers, Graham


On 28 Jun 2008, at 7:02 am, James Maxwell wrote:

> Hello All,
>
> Anybody have any thoughts on implementing an x-axis only zoom?
> I'm working on a music app interface, and this is a common  
> requirement - "piano scroll" editors do this all the time, in order  
> to clearly view notes in rapid passages, so everything won't be too  
> tightly clumped together.
>
> thanks,
>
> J.