2004

180 | Chapter 14 Control the Properties of Objects
Change Layer Settings and Layer Properties
Because everything in your drawing is associated with a layer, it's likely that
in the course of planning and creating a drawing, you'll need to change what
you place on a layer or how you view the layers in combination. You can
■ Reassign objects from one layer to another
■ Change the name of a layer
■ Change the default color, linetype, or other properties of the layer
Reassigning an object to a different layer is useful if you create an object on
the wrong layer or decide to change your layer organization. Unless the color,
linetype, or other properties of the object have been set explicitly, an object
that you reassign to a different layer will acquire the properties of that layer.
You can change layer properties in the Layer Properties Manager and in the
Layer control. Click the icons to change settings. Layer names and colors can
be changed only in the Layer Properties Manager, not the Layer control.
Undo Changes to Layer Settings
You can use Layer Previous to undo changes you make to layer settings. For
example, if you freeze several layers and change some of the geometry in a
drawing, and then want to thaw the frozen layers, you can do this with a
single command, without affecting the geometry changes. In another
example, if you changed the color and linetype of several layers but later
decide you prefer the old properties, you can use Layer Previous to undo the
changes and restore the original layer settings.
When you use Layer Previous, it undoes the most recent change or set of
changes made using either the Layer control or the Layer Properties Manager.
Every change you make to layer settings is tracked and can be undone with
Layer Previous. You can use
LAYERPMODE to suspend layer property tracking
when you don’t need it, such as when you run large scripts. There is a modest
performance gain in turning off Layer Previous tracking.
Layer Previous does not undo the following changes:
■ Renamed layers. If you rename a layer and change its properties, Layer
Previous restores the original properties but not the original layer name.
■ Deleted layers. If you delete or purge a layer, using Layer Previous does
not restore it.
■ Added layers. If you add a new layer to a drawing, using Layer Previous
does not remove it.