gecko-dev/grendel/storage/mdb/nsIMdbCell.java

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4.6 KiB
Java

/* -*- Mode: java; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is the Grendel mail/news client.
*
* The Initial Developer of the Original Code is Netscape Communications
* Corporation. Portions created by Netscape are
* Copyright (C) 1997 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*
* Created: Mauro Botelho <mabotelh@email.com>, 20 Mar 1999.
*/
package grendel.storage.mdb;
/*| nsIMdbCell: the text in a single column of a row. The base nsIMdbBlob
**| class provides all the interface related to accessing cell text.
**|
**|| column: each cell in a row appears in a specific column, where this
**| column is identified by the an integer mdb_scope value (generated by
**| the StringToScopeToken() method in the containing nsIMdbPort instance).
**| Because a row cannot have more than one cell with the same column,
**| something must give if one calls SetColumn() with an existing column
**| in the same row. When this happens, the other cell is replaced with
**| this cell (and the old cell is closed if it has outstanding refs).
**|
**|| row: every cell instance is a part of some row, and every cell knows
**| which row is the parent row. (Note this should be represented by a
**| weak backpointer, so that outstanding cell references cannot keep a
**| row open that should be closed. Otherwise we'd have ref graph cycles.)
**|
**|| text: a cell can either be text, or it can have a child row or table,
**| but not both at once. If text is read from a cell with a child, the text
**| content should be empty (for AliasYarn()) or a description of the type
**| of child (perhaps "mdb:cell:child:row" or "mdb:cell:child:table").
**|
**|| child: a cell might reference another row or a table, rather than text.
**| The interface for putting and getting children rows and tables was first
**| defined in the nsIMdbTable interface, but then this was moved to this cell
**| interface as more natural.
|*/
interface nsIMdbCell extends nsIMdbBlob { // text attribute in row with column scope
// { ===== begin nsIMdbCell methods =====
// { ----- begin attribute methods -----
public void SetColumn(nsIMdbEnv ev, int inColumn);
public int GetColumn(nsIMdbEnv ev);
public int GetBlobFill(nsIMdbEnv ev);
public mdbOid GetChildOid(nsIMdbEnv ev);
public boolean IsRowChild(nsIMdbEnv ev);
/*
public mdb_err GetCellInfo( // all cell metainfo except actual content
nsIMdbEnv* ev,
mdb_column* outColumn, // the column in the containing row
mdb_fill* outBlobFill, // the size of text content in bytes
mdbOid* outChildOid, // oid of possible row or table child
mdb_bool* outIsRowChild) = 0; // nonzero if child, and a row child
*/
// Checking all cell metainfo is a good way to avoid forcing a large cell
// in to memory when you don't actually want to use the content.
public nsIMdbRow GetRow(nsIMdbEnv ev); // parent row for this cell
public nsIMdbPort GetPort(nsIMdbEnv ev); // port containing cell
// } ----- end attribute methods -----
// { ----- begin children methods -----
public mdbOid HasAnyChild( // does cell have a child instead of text?
nsIMdbEnv ev);
// out id of row or table (or unbound if no child)
// nonzero if child is a row (rather than a table)
public boolean IsChildRow(nsIMdbEnv ev);
public nsIMdbRow GetChildRow( // access table of specific attribute
nsIMdbEnv ev); // context
public nsIMdbTable GetChildTable( // access table of specific attribute
nsIMdbEnv ev); // context
public void SetChildRow( // access table of specific attribute
nsIMdbEnv ev, // context
nsIMdbRow ioRow); // inRow must be bound inside this same db port
public void SetChildTable( // access table of specific attribute
nsIMdbEnv ev, // context
nsIMdbTable inTable); // table must be bound inside this same db port
// acquire child table (or nil if no child)
// } ----- end children methods -----
// } ===== end nsIMdbCell methods =====
};