Re: Minimum requirements for a NSAccessibility object?
Re: Minimum requirements for a NSAccessibility object?
- Subject: Re: Minimum requirements for a NSAccessibility object?
- From: Mike Engber <email@hidden>
- Date: Thu, 24 Aug 2006 09:34:46 -0700
We've covered this before on the list. So you might want to go back
and re-read some of my previous emails.
When the NSApp's accessibilityHitTest is going to find the window at
the specified point then call accessibilityHitTest on that window
which will use NSView's hitTest method to find the view at the
specified point.
The call to NSView's hitTest will defeat you. It will poke into your
view hierarchy.
You would normally prevent this by overriding accessibilityHitTest on
the window containing your view. But, I don't see how you can do this
as an imbedded view without resorting to some major hackery.
Alternatively, accessibilityHitTest will ultimately be called on the
view the window finds. So, if you override accessibilityHitTest for
_every_ view in your view hierarchy you could take control that way.
I.e. the view can return some other ui element from its
accessibilityHitTest method. But, obviously, this requires you to use
custom subclasses for _everything_ in your view hierarchy. This might
be impossible if some of the views in there are not created by you.
E.g. an NSBrowser will create subviews.
This is the first issue that comes to mind, but there may be other
problems as well depending on the details of your actual view
hierarchy vs the accessibility hierarchy you want to present.
-ME
On Aug 24, 2006, at 9:08 AM, Håkan Waara wrote:
24 aug 2006 kl. 18.04 skrev Mike Engber:
On Aug 24, 2006, at 5:41 AM, Håkan Waara wrote:
So I'm a bit worried that 3rd party accessible apps peek at the
NSView hierarchy to traverse the accessibility hierarchy. In my
case that would be fatal, because the view hierarchy is *not*
ordered in any sensible way, according to how the actual UI works.
3rd party apps that use the accessibility APIs have no ability to
peak at the NSView hierarchy. They only see the accessibility
hierarchy you present. So if you've taken (enough) control over
what NSApp presents they'll only see what you want them to see.
Unfortunately, since we're (at least aiming to be) an embeddable
NSView, I can't have any control over the NSWindow or the NSApp.
All I can control is the topmost NSView, and everything below it.
Is that sufficient?
/Håkan
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Accessibility-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden