Layer

Scope

• Book Page content object > Book Page object > Size and Position > Layer property

Purpose

This property specifies the 'layer' on the page of the parent object. This determines which objects are shown on top of (or in front of) other objects on the page. Think of each object as being drawn on its own transparent sheet of paper, and then all of these sheets of paper stacked on top of one another. The sheet on the bottom is 'Layer 1', the one on top of that is 'Layer 2', and so on. If you then look at the stack from the top, you will see that some objects are on top of other objects, possibly obscuring the lower objects.

Objects are automatically assigned to layers in the order you create them on the page (so the most recent ones are on the top). You can change the order of objects in one of the following ways:

• By dragging an object to a new position within the Objects pane - the further up the list, the higher the level number
• By using the following options on the Change Layer button:
  • In the Foreground: Move the object to the top
  • Forward One Level: Move the object up one level
  • Backward One Level Move the object down one level
  • In the Background: Move the object to the bottom
• By manually entering the required level number in the Layer property's input field

Normally, each object should be on a unique level, but it is possible to place multiple objects on the same level by entering the same number in the Layer field. However, as soon as you move any object via one of the other methods, Enable Now will automatically renumber them all, to be unique (so being able to assign objects to the same level is probably a bug).

For some object types, the Layer is irrelevant, and only exists because every object has a Layer property. This includes all of the 'Action' objects - including Time Control, Counter, Collection, Animation, and Object Visibility.