    indexing
    	description: "SToraGe Mode flags"
    	legal: "See notice at end of class."
    	info: "Priority mode not supported"
    	status: "See notice at end of class."
    	date: "$Date: 2006-08-17 13:49:39 -0700 (Thu, 17 Aug 2006) $"
    	revision: "$Revision: 62697 $"

    class interface
    	ECOM_STGM

    create
    	default_create
    			-- Process instances of classes with no creation clause.
    			-- (Default: do nothing.)
    			-- (from ANY)

    feature -- Access

    	generating_type: STRING_8
    			-- Name of current object's generating type
    			-- (type of which it is a direct instance)
    			-- (from ANY)

    	generator: STRING_8
    			-- Name of current object's generating class
    			-- (base class of the type of which it is a direct instance)
    			-- (from ANY)

    	is_valid_stgm (stgm: INTEGER_32): BOOLEAN
    			-- Is `stgm' a valid storage mode flag?

    	stgm_convert: INTEGER_32
    			-- This flag is applicable only to the creation of IStorage objects.
    			-- Stgm_convert allows the creation to proceed while preserving
    			-- existing data. The old data is saved to a stream named CONTENTS
    			-- containing the same data that was in the old IStorage or IStream
    			-- instance. In the IStorage case, the data is flattened to a
    			-- stream regardless of whether the existing file currently contains
    			-- a layered storage object.

    	stgm_create: INTEGER_32
    			-- Stgm_create indicates an existing IStorage or IStream object
    			-- should be removed before the new one replaces it. A new object
    			-- is created when this flag is specified only if the existing
    			-- IStorage or IStream has been successfully removed.

    	stgm_deleteonrelease: INTEGER_32
    			-- The Stgm_deleteonrelease flag indicates that the underlying
    			-- file is to be automatically destroyed when the root IStorage
    			-- object is released. This capability is most useful for
    			-- creating temporary files.

    	stgm_direct: INTEGER_32
    			-- Stgm_DIrect is always specified for IStream objects.
    			-- Stgm_transacted is not supported in the compound file
    			-- implementation of IStream. Other implementations can choose
    			-- to support it.

    	stgm_failifthere: INTEGER_32
    			-- Stgm_failifthere causes the create operation to fail if an
    			-- existing object with the specified name exists. In this case,
    			-- Stg_e_filealreadyexists is returned. Stgm_failifthere
    			-- applies to both IStorage and IStream objects.

    	stgm_priority: INTEGER_32
    			-- The Stgm_priority flag allows an IStorage object to be opened
    			-- so that a subsequent copy operation can be done at reduced cost.
    			-- Stgm_priority allows an application to read certain streams
    			-- from storage before opening the storage object in a mode that would
    			-- require a snapshot copy to be made. Priority mode has exclusive
    			-- access to the committed version of the IStorage object.
    			-- While a compound file is open in priority mode, no other opening
    			-- of the compound file can commit changes even one that was opened
    			-- before the priority mode opening. Therefore, applications should
    			-- keep IStorage objects open in priority mode for as short a time
    			-- as possible.

    	stgm_read: INTEGER_32
    			-- When applied to an IStream object, Stgm_READ enables
    			-- applications to successfully call IStream.Read. If Stgm_read
    			-- is omitted, IStream.Read will return an error. When applied to an
    			-- IStorage, Stgm_READ allows the enumeration of the storage
    			-- object's elements and enables applications to open these elements
    			-- in read mode. Parents of storage objects to be opened in read mode
    			-- must also have been opened in read mode otherwise, an error is
    			-- returned.

    	stgm_readwrite: INTEGER_32
    			-- Stgm_readwrite is the logical combination of the
    			-- Stgm_read and Stgm_write. However, the defined value
    			-- of Stgm_readwrite is not equal to
    			-- (Stgm_read or Stgm_write).

    	stgm_share_deny_none: INTEGER_32
    			-- 0x00000040L
    			-- Stgm_SHARE_DENY_NONE indicates that neither read access nor
    			-- write access should be denied to subsequent openings. This is the
    			-- default sharing mode and if no Stgm_SHARE_* flag is explicitly
    			-- given, Stgm_SHARE_DENY_NONE is implied.

    	stgm_share_deny_read: INTEGER_32
    			-- 0x00000030L
    			-- When successfully applied to a root IStorage, the
    			-- Stgm_SHARE_DENY_READ flag prevents others from opening the
    			-- object in read mode. The open call fails and returns an error if
    			-- the object is presently open in deny-read mode.
    			-- Stgm_SHARE_DENY_READ is most useful when opening root storage
    			-- objects. Deny modes on inner elements are still useful if some
    			-- component is coordinating the opening of these inner elements, as
    			-- might happen in a Copy/Paste operation. However, inner elements
    			-- always require Stgm_SHARE_EXCLUSIVE. Opening a parent storage
    			-- object with Stgm_SHARE_DENY_READ applies only to that opening,
    			-- not the network-wide set of openings of the parent.

    	stgm_share_deny_write: INTEGER_32
    			-- When successfully applied the Stgm_share_deny_write flag
    			-- prevents subsequent openings of either a storage or a stream from
    			-- specifying write mode. The open call fails and returns an error
    			-- if the storage or stream is presently open in write mode.
    			-- For information about the interaction of this flag with nested
    			-- openings, see the earlier discussion about Stgm_share_deny_read.

    	stgm_share_exclusive: INTEGER_32
    			-- The compound files implementation requires that all inner elements
    			-- be opened Stgm_share_exclusive. It is the logical combination
    			-- of the Stgm_share_deny_read and Stgm_share_deny_write.
    			-- All root storage objects, as well as child storage and stream
    			-- objects must be opened with Stgm_share_exclusive.

    	stgm_transacted: INTEGER_32
    			-- The transaction for each open object is nested in the transaction
    			-- for its parent storage object. Therefore, committing changes at the
    			-- child level is dependent on committing changes in the parent and
    			-- a commit of the root storage object (top-level parent) is necessary
    			-- before changes to an object are actually written to disk.
    			-- The changes percolate upward: inner objects publish changes to the
    			-- transaction of the next object outwards. Outermost objects publish
    			-- changes permanently into the file system. Transacted mode is not
    			-- required on the parent storage object in order to use transacted
    			-- mode on a contained object.The scope of changes that are buffered
    			-- in transacted mode is very broad. A storage or stream object can
    			-- be opened, have arbitrary changes made to it, and then have the
    			-- changes reverted, preserving the object as it was when it was
    			-- first opened. The creation and destruction of elements within a
    			-- storage object are scoped by its transaction.

    	stgm_write: INTEGER_32
    			-- Stgm_write lets an object commit changes to the storage.
    			-- Specifically, unless this flag has been given, IStorage.Commit
    			-- and IStream.Commit will fail. An open object whose changes cannot
    			-- be committed can save its changes by copying the storage or stream
    			-- with IStorage.CopyTo or IStream.CopyTo. In direct mode,
    			-- changes are committed after every change operation. Thus, write
    			-- permissions are needed to call any function that causes a change.
    			-- On streams, this includes IStream.Write and IStream.SetSize.
    			-- If a parent storage is opened in direct mode without write
    			-- permission, any attempt to open a child stream within it in direct
    			-- mode with write permission will fail, because it causes an implicit
    			-- commit to be made on the storage. Similarly, trying to create or
    			-- destroy a contained element in this storage object also causes an
    			-- implicit commit, resulting in an error.

    feature -- Comparison

    	frozen deep_equal (some: ANY; other: like arg #1): BOOLEAN
    			-- Are `some' and `other' either both void
    			-- or attached to isomorphic object structures?
    			-- (from ANY)
    		ensure -- from ANY
    			shallow_implies_deep: standard_equal (some, other) implies Result
    			both_or_none_void: (some = Void) implies (Result = (other = Void))
    			same_type: (Result and (some /= Void)) implies some.same_type (other)
    			symmetric: Result implies deep_equal (other, some)

    	frozen equal (some: ANY; other: like arg #1): BOOLEAN
    			-- Are `some' and `other' either both void or attached
    			-- to objects considered equal?
    			-- (from ANY)
    		ensure -- from ANY
    			definition: Result = (some = Void and other = Void) or else ((some /= Void and other /= Void) and then some.is_equal (other))

    	is_equal (other: like Current): BOOLEAN
    			-- Is `other' attached to an object considered
    			-- equal to current object?
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    		ensure -- from ANY
    			symmetric: Result implies other.is_equal (Current)
    			consistent: standard_is_equal (other) implies Result

    	frozen standard_equal (some: ANY; other: like arg #1): BOOLEAN
    			-- Are `some' and `other' either both void or attached to
    			-- field-by-field identical objects of the same type?
    			-- Always uses default object comparison criterion.
    			-- (from ANY)
    		ensure -- from ANY
    			definition: Result = (some = Void and other = Void) or else ((some /= Void and other /= Void) and then some.standard_is_equal (other))

    	frozen standard_is_equal (other: like Current): BOOLEAN
    			-- Is `other' attached to an object of the same type
    			-- as current object, and field-by-field identical to it?
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    		ensure -- from ANY
    			same_type: Result implies same_type (other)
    			symmetric: Result implies other.standard_is_equal (Current)

    feature -- Status report

    	conforms_to (other: ANY): BOOLEAN
    			-- Does type of current object conform to type
    			-- of `other' (as per Eiffel: The Language, chapter 13)?
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void

    	same_type (other: ANY): BOOLEAN
    			-- Is type of current object identical to type of `other'?
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    		ensure -- from ANY
    			definition: Result = (conforms_to (other) and other.conforms_to (Current))

    feature -- Duplication

    	copy (other: like Current)
    			-- Update current object using fields of object attached
    			-- to `other', so as to yield equal objects.
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    			type_identity: same_type (other)
    		ensure -- from ANY
    			is_equal: is_equal (other)

    	frozen deep_copy (other: like Current)
    			-- Effect equivalent to that of:
    			--		copy (`other' . deep_twin)
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    		ensure -- from ANY
    			deep_equal: deep_equal (Current, other)

    	frozen deep_twin: like Current
    			-- New object structure recursively duplicated from Current.
    			-- (from ANY)
    		ensure -- from ANY
    			deep_equal: deep_equal (Current, Result)

    	frozen standard_copy (other: like Current)
    			-- Copy every field of `other' onto corresponding field
    			-- of current object.
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    			type_identity: same_type (other)
    		ensure -- from ANY
    			is_standard_equal: standard_is_equal (other)

    	frozen standard_twin: like Current
    			-- New object field-by-field identical to `other'.
    			-- Always uses default copying semantics.
    			-- (from ANY)
    		ensure -- from ANY
    			standard_twin_not_void: Result /= Void
    			equal: standard_equal (Result, Current)

    	frozen twin: like Current
    			-- New object equal to `Current'
    			-- twin calls copy; to change copying/twining semantics, redefine copy.
    			-- (from ANY)
    		ensure -- from ANY
    			twin_not_void: Result /= Void
    			is_equal: Result.is_equal (Current)

    feature -- Basic operations

    	frozen default: like Current
    			-- Default value of object's type
    			-- (from ANY)

    	frozen default_pointer: POINTER
    			-- Default value of type `POINTER'
    			-- (Avoid the need to write `p'.default for
    			-- some `p' of type `POINTER'.)
    			-- (from ANY)

    	default_rescue
    			-- Process exception for routines with no Rescue clause.
    			-- (Default: do nothing.)
    			-- (from ANY)

    	frozen do_nothing
    			-- Execute a null action.
    			-- (from ANY)

    feature -- Output

    	io: STD_FILES
    			-- Handle to standard file setup
    			-- (from ANY)

    	out: STRING_8
    			-- New string containing terse printable representation
    			-- of current object
    			-- Was declared in ANY as synonym of tagged_out.
    			-- (from ANY)

    	print (some: ANY)
    			-- Write terse external representation of `some'
    			-- on standard output.
    			-- (from ANY)

    	frozen tagged_out: STRING_8
    			-- New string containing terse printable representation
    			-- of current object
    			-- Was declared in ANY as synonym of out.
    			-- (from ANY)

    feature -- Platform

    	operating_environment: OPERATING_ENVIRONMENT
    			-- Objects available from the operating system
    			-- (from ANY)

    invariant
    		-- from ANY
    	reflexive_equality: standard_is_equal (Current)
    	reflexive_conformance: conforms_to (Current)

    indexing
    	copyright: "Copyright (c) 1984-2006, Eiffel Software and others"
    	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
    	source: "[
    		Eiffel Software
    		356 Storke Road, Goleta, CA 93117 USA
    		Telephone 805-685-1006, Fax 805-685-6869
    		Website http://www.eiffel.com
    		Customer support http://support.eiffel.com
    	]"

    end -- class ECOM_STGM