/*******************************************************************************
* Copyright (c) 2000, 2003 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Common Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/cpl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.swt.dnd;
/**
* Transfer
provides a mechanism for converting between a java
* representation of data and a platform specific representation of data and
* vice versa. It is used in data transfer operations such as drag and drop and
* clipboard copy/paste.
*
*
You should only need to become familiar with this class if you are * implementing a Transfer subclass and you are unable to subclass the * ByteArrayTransfer class.
* * @see ByteArrayTransfer */ public abstract class Transfer { /** * Returns a list of the platform specific data types that can be converted using * this transfer agent. * *Only the data type fields of the TransferData
objects are filled
* in.
TransferData
data type can be converted
* using this transfer agent.
*
* @param transferData a platform specific description of a data type; only the data
* type fields of the TransferData
object need to be filled in
*
* @return true if the transferData data type can be converted using this transfer
* agent
*/
abstract public boolean isSupportedType(TransferData transferData);
/**
* Returns the platform specfic names of the data types that can be converted
* using this transfer agent.
*
* @return the platform specfic names of the data types that can be converted
* using this transfer agent.
*/
abstract protected String[] getTypeNames();
/**
* Returns the platform specfic ids of the data types that can be converted using
* this transfer agent.
*
* @return the platform specfic ids of the data types that can be converted using
* this transfer agent
*/
abstract protected int[] getTypeIds();
/**
* Converts a java representation of data to a platform specific representation of
* the data.
*
* On a successful conversion, the transferData.result field will be set as follows: *
If this transfer agent is unable to perform the conversion, the transferData.result * field will be set to a failure value as follows: *
Transfer
subclass.
*
* @param transferData an empty TransferData object; this object will be
* filled in on return with the platform specific representation of the data
*/
abstract protected void javaToNative (Object object, TransferData transferData);
/**
* Converts a platform specific representation of data to a java representation.
*
* @param transferData the platform specific representation of the data to be
* converted
*
* @return a java representation of the converted data if the conversion was
* successful; otherwise null. The type of Object that is returned is dependant
* on the Transfer
subclass
*/
abstract protected Object nativeToJava(TransferData transferData);
/**
* Registers a name for a data type and returns the associated unique identifier.
*
* You may register the same type more than once, the same unique identifier * will be returned if the type has been previously registered.
* *Note: On windows, do not call this method with pre-defined * Clipboard Format types such as CF_TEXT or CF_BITMAP because the * pre-defined identifier will not be returned
* * @param formatName the name of a data type * * @return the unique identifier associated with this data type */ public static int registerType(String formatName){ return 0; } }