STATE: n/a
TYPE: overlay
SIZE: 7x pixels wide x 8
PALETTE: Eclipse 183 colour palette

Overlay 
-------

Maximum 7 pixels wide x 8 pixels high, always centered.

Icon should have a white outside keyline around it to separate it from the icon it is being appended to. 
Position of overlay based on what kind of information is being communicated.

Nature Overlay:

  Overlay indicating the "nature" of the object.
  
  +--+   Top right of 16x16 icon
  | A|
  |  |
  +--+
  
   
  Only a few project nature overlay icons should be used to prevent crowding in the interface.
  Quickly identify the type object.
  
  The white keyline border is applied around the image to enhance legibility (may use 70% white)

  Example: background layer.

Auxillary Overlay:
  The auxiliary overlay quickly identifies the status of an object (displayed in all tree views).
  
  +--+  Bottom Left of 16x16 icon
  |  |
  |A |
  +--+

  Examples of auxiliary overlays are connected, waiting, warning, error, failure, and success.
  
Layer Overlay:
  Overlays are displayed in the Layer, Info and Document view to identify attributes of an object.
  
  +--+    Extend the base 16x16 icon offering positions A, B and C.
  |  A B
  |   C
  +--+
  
  It is important to make sure the base object icon can support the addition of overlays without compromising readability.
  
  Slots A and B are used to communicate attributes.
  Slot C is used to communicate double-click "interaction".
  
  Example: Document marked with "paperclip" attachment in position A, and "T" in position B to indicate a template
  and a "+" in position "C" to indicate a new document will be created if they double click.

Session Overlay:
  Communicate session information (local modifications, status of the current commit and so on). Anything
  around the possibility of losing work.
  
  When displayed in the catalog view position A can be used to how session interaction is handled.
  
  Example: mark "dirty" temporary resources that will need to be written out when the application closes.
  Example: mark "sync" if resource acts in auto-commit mode (and ignores the current transaction)
  
  +--+
  |  |
  | A|
  +--+
  
  When displayed in the context of a transaction (such as an open Map) the overlay extends the base 16x16 icon.
  Position A remains dedicated to big picture changes (temporary layers, involved in the current transaction).
  Position B can get more specific about the nature of the outstanding change.
  
  +--+
  |  B
  |  A
  +--+
  
  Examples are "added", "deleted", "changed" (or "dirty")
    
Underlay
--------

  Suggested to communicate interaction status.
  
  Example: Highlight layers that interact with the current tool.
  