org.eclipse.swt.dnd.TextTransfer Maven / Gradle / Ivy

/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.dnd;

import org.eclipse.swt.internal.cocoa.*;

/**
 * The class TextTransfer provides a platform specific mechanism
 * for converting plain text represented as a java String
 * to a platform specific representation of the data and vice versa.
 *
 * An example of a java String containing plain text is shown
 * below:
 *
 *  *     String textData = "Hello World";
 * 
*
* Note the TextTransfer does not change the content of the text
* data. For a better integration with the platform, the application should convert
* the line delimiters used in the text data to the standard line delimiter used by the
* platform.
* 
*
* @see Transfer
*/
public class TextTransfer extends ByteArrayTransfer {
static TextTransfer _instance = new TextTransfer();
static final String ID_NAME = OS.NSPasteboardTypeString.getString();
static final int ID = registerType(ID_NAME);
TextTransfer() {}
/**
* Returns the singleton instance of the TextTransfer class.
*
* @return the singleton instance of the TextTransfer class
*/
public static TextTransfer getInstance () {
return _instance;
}
/**
* This implementation of javaToNative converts plain text
* represented by a java String to a platform specific representation.
*
* @param object a java String containing text
* @param transferData an empty TransferData object that will
* be filled in on return with the platform specific format of the data
*
* @see Transfer#nativeToJava
*/
@Override
public void javaToNative (Object object, TransferData transferData) {
if (!checkText(object) || !isSupportedType(transferData)) {
DND.error(DND.ERROR_INVALID_DATA);
}
transferData.data = NSString.stringWith((String) object);
}
/**
* This implementation of nativeToJava converts a platform specific
* representation of plain text to a java String.
*
* @param transferData the platform specific representation of the data to be converted
* @return a java String containing text if the conversion was successful; otherwise null
*
* @see Transfer#javaToNative
*/
@Override
public Object nativeToJava(TransferData transferData){
if (!isSupportedType(transferData) || transferData.data == null) return null;
NSString string = (NSString) transferData.data;
return string.getString();
}
@Override
protected int[] getTypeIds() {
return new int[] {ID};
}
@Override
protected String[] getTypeNames() {
return new String[] {ID_NAME};
}
boolean checkText(Object object) {
return (object != null && object instanceof String && ((String)object).length() > 0);
}
@Override
protected boolean validate(Object object) {
return checkText(object);
}
}