Re: order of layers

Otfried Cheong [2011.07.22 1411 +0200]:
> On 07/18/2011 09:43 AM, Olivier Devillers wrote:
> >The order of layers is changing in a strange way.
> >Is it on purpose ?
> 
> This feature was introduced in 7.0.13, I believe, since users
> complained that new layers were always added at the end.  The
> current behavior is that Ipe always resorts the layers in the order
> in which they appear in the view sequence.  This is updated whenever
> a change is made to any aspect of the layers.
> 
> What would be the right behavior?  Recompute the sequence only when
> moving to a new page?  Or whenever a layer is added or deleted?

My 2c are that I think that automatically changing the order of layers
automatically will always be confusing.  I would suspect that most of
the time the ordering of layers should represent some logical grouping
of concepts in adjacent layers, which may or may not correspond to the
ordering in which the layers are shown.  (I have a number of
presentations where this is the case.)  A better way to accommodate this
use of layers would be one or both of the following:

* Add layers at the end when they are created.  Allow users to drag the
  layers around in the layer list to obtain whatever ordering of layers
  they want.

* Always add the new layer after the currently active layer.  (How does
  one insert a new first layer then?)

In both cases, Ipe should not make any changes to the layer ordering
that wasn't explicitly initiated by the user.

Cheers,
Norbert