-- file EntityEditor.mesa
-- created by Donahue, October 18, 1982 1:48 pm
-- last edited by: Donahue December 29, 1982 11:57 am

DIRECTORY
  DB: TYPE USING[ Entity, Segment ],
  ViewerClasses: TYPE USING[ Viewer ],
  VTables: TYPE USING[ VTable ];

EntityEditor: DEFINITIONS IMPORTS DB =

  BEGIN  OPEN DB, ViewerClasses, VTables;
  
  SaveFailed: ERROR;
    
  DisplayEntities: PROC[ of: Entity, parent: Viewer, in: DB.Segment,
                               noEdits: BOOLEAN _ FALSE ] RETURNS[ viewer: VTable ];
  -- make a nested viewer (a VTable) that has all of the tuples for the "*" relation, using the
  -- entity provided as the "of" field
  -- if noEdits is true then the table produced cannot be changed
  -- the viewer produced is NOT painted
  -- the entities are displayed in iconic form (yellow-bugging them "opens" them, blue-bugging
  -- deletes them from the display) 
  
  NewEntry: PROC[ is: Entity, table: VTable ];
  -- add a new entry to the table
  -- The table will be expanded as necessary to contain the new icon (duplicates are not stored)
  -- Again, the table is not painted and no updates are actually made to the database
  
  SaveEntities: PROC[ viewer: Viewer, in: DB.Segment, newOf: Entity _ NIL ];
  -- given a table set up by DisplayEntities, add all of its contents to the database
  -- if a newOf is provided, then it will be used to create new relationships with all of the
  -- entities that are displayed in the table; otherwise all of the existing relationships for the
  -- entity provided when the table was created will be updated
  -- if a log is provided, then all changes will be logged
    
  END.