-- File:	Transfer_Finder.cdl
-- Created:	Fri Nov  4 10:59:26 1994
-- Author:	Christian CAILLET
--		<cky@anion>
---Copyright:	 Matra Datavision 1994


deferred class Finder  from Transfer  inherits TShared

    ---Purpose : a Finder allows to map any kind of object as a Key for a Map.
    --           This works by defining, for a Hash Code, that of the real Key,
    --           not of the Finder which acts only as an intermediate.
    --           When a Map asks for the HashCode of a Finder, this one returns
    --           the code it has determined at creation time

uses CString, Type, Transient,
     DictionaryOfTransient from Dico, ParamType from Interface

is

    SetHashCode (me : mutable; code : Integer)  is static protected;
    ---Purpose : Stores the HashCode which corresponds to the Value given to
    --           create the Mapper

    GetHashCode (me) returns Integer  is static;
    ---Purpose : Returns the HashCode which has been stored by SetHashCode
    --           (remark that HashCode could be deferred then be defined by
    --            sub-classes, the result is the same)

    Equates (me; other : Finder) returns Boolean  is deferred;
    ---Purpose : Specific testof equallity : to be defined by each sub-class,
    --           must be False if Finders have not the same true Type, else
    --           their contents must be compared

    ValueType    (me) returns Type  is virtual;
    ---Purpose : Returns the Type of the Value. By default, returns the
    --           DynamicType of <me>, but can be redefined

    ValueTypeName (me) returns CString  is virtual;
    ---Purpose : Returns the name of the Type of the Value. Default is name
    --           of ValueType, unless it is for a non-handled object

    	-- --    Attributes


    SetAttribute (me : mutable; name : CString; val : Transient);
    ---Purpose : Adds an attribute with a given name (replaces the former one
    --           with the same name if already exists)

    RemoveAttribute (me : mutable; name : CString) returns Boolean;
    ---Purpose : Removes an attribute
    --           Returns True when done, False if this attribute did not exist

    GetAttribute (me; name : CString; type : Type from Standard;
    	    	  val : out mutable Transient)  returns Boolean;
    ---Purpose : Returns an attribute from its name, filtered by a type
    --           If no attribute has this name, or if it is not kind of this
    --           type, <val> is Null and returned value is False
    --           Else, it is True

    Attribute    (me; name : CString) returns Transient;
    ---Purpose : Returns an attribute from its name. Null Handle if not recorded
    --           (whatever Transient, Integer, Real ...)

    AttributeType (me; name : CString) returns ParamType from Interface;
    ---Purpose : Returns the type of an attribute :
    --           ParamInt , ParamReal , ParamText (String) , ParamIdent (any)
    --           or ParamVoid (not recorded)


    SetIntegerAttribute (me : mutable; name : CString; val : Integer);
    ---Purpose : Adds an integer value for an attribute

    GetIntegerAttribute (me; name : CString; val : out Integer) returns Boolean;
    ---Purpose : Returns an attribute from its name, as integer
    --           If no attribute has this name, or not an integer,
    --           <val> is 0 and returned value is False
    --           Else, it is True

    IntegerAttribute (me; name : CString) returns Integer;
    ---Purpose : Returns an integer attribute from its name. 0 if not recorded

    SetRealAttribute    (me : mutable; name : CString; val : Real);
    ---Purpose : Adds a real value for an attribute

    GetRealAttribute    (me; name : CString; val : out Real) returns Boolean;
    ---Purpose : Returns an attribute from its name, as real
    --           If no attribute has this name, or not a real
    --           <val> is 0.0 and returned value is False
    --           Else, it is True

    RealAttribute       (me; name : CString) returns Real;
    ---Purpose : Returns a real attribute from its name. 0.0 if not recorded

    SetStringAttribute  (me : mutable; name : CString; val : CString);
    ---Purpose : Adds a String value for an attribute

    GetStringAttribute  (me; name : CString; val : out CString) returns Boolean;
    ---Purpose : Returns an attribute from its name, as String
    --           If no attribute has this name, or not a String
    --           <val> is 0.0 and returned value is False
    --           Else, it is True

    StringAttribute     (me; name : CString) returns CString;
    ---Purpose : Returns a String attribute from its name. "" if not recorded

    AttrList     (me) returns DictionaryOfTransient;
    ---Purpose : Returns the exhaustive list of attributes

    SameAttributes (me : mutable; other : Finder);
    ---Purpose : Gets the list of attributes from <other>, as such, i.e.
    --           not copied : attributes are shared, any attribute edited,
    --           added, or removed in <other> is also in <me> and vice versa
    --           The former list of attributes of <me> is dropped

    GetAttributes  (me : mutable; other : Finder;
    	    	    fromname : CString = ""; copied : Boolean = Standard_True);
    ---Purpose : Gets the list of attributes from <other>, by copying it
    --           By default, considers all the attributes from <other>
    --           If <fromname> is given, considers only the attributes with
    --           name beginning by <fromname>
    --           
    --           For each attribute, if <copied> is True (D), its value is also
    --           copied if it is a basic type (Integer,Real,String), else it
    --           remains shared between <other> and <me>
    --           
    --           These new attributes are added to the existing ones in <me>,
    --           in case of same name, they replace the existing ones

fields

    thecode : Integer;
    theattrib : DictionaryOfTransient;

end Finder;