/*******************************************************************************
* Copyright (c) 2000, 2012 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.ole.win32.*;
import org.eclipse.swt.internal.win32.*;
/**
* The class <code>TextTransfer</code> provides a platform specific mechanism
* for converting plain text represented as a java <code>String</code>
* to a platform specific representation of the data and vice versa.
*
* <p>An example of a java <code>String</code> containing plain text is shown
* below:</p>
*
* <code><pre>
* String textData = "Hello World";
* </code></pre>
*
* <p>Note the <code>TextTransfer</code> 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.
* </p>
*
* @see Transfer
*/
public class TextTransfer extends ByteArrayTransfer {
private static TextTransfer _instance = new TextTransfer();
private static final String CF_UNICODETEXT = "CF_UNICODETEXT"; //$NON-NLS-1$
private static final String CF_TEXT = "CF_TEXT"; //$NON-NLS-1$
private static final int CF_UNICODETEXTID = COM.CF_UNICODETEXT;
private static final int CF_TEXTID = COM.CF_TEXT;
private 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 <code>javaToNative</code> converts plain text
* represented by a java <code>String</code> to a platform specific representation.
*
* @param object a java <code>String</code> containing text
* @param transferData an empty <code>TransferData</code> object that will
* be filled in on return with the platform specific format of the data
*
* @see Transfer#nativeToJava
*/
public void javaToNative (Object object, TransferData transferData){
if (!checkText(object) || !isSupportedType(transferData)) {
DND.error(DND.ERROR_INVALID_DATA);
}
transferData.result = COM.E_FAIL;
String string = (String)object;
switch (transferData.type) {
case COM.CF_UNICODETEXT: {
int charCount = string.length ();
char[] chars = new char[charCount+1];
string.getChars (0, charCount, chars, 0);
int byteCount = chars.length * 2;
long /*int*/ newPtr = OS.GlobalAlloc(COM.GMEM_FIXED | COM.GMEM_ZEROINIT, byteCount);
OS.MoveMemory(newPtr, chars, byteCount);
transferData.stgmedium = new STGMEDIUM();
transferData.stgmedium.tymed = COM.TYMED_HGLOBAL;
transferData.stgmedium.unionField = newPtr;
transferData.stgmedium.pUnkForRelease = 0;
transferData.result = COM.S_OK;
break;
}
case COM.CF_TEXT: {
int count = string.length();
char[] chars = new char[count + 1];
string.getChars(0, count, chars, 0);
int codePage = OS.GetACP();
int cchMultiByte = OS.WideCharToMultiByte(codePage, 0, chars, -1, null, 0, null, null);
if (cchMultiByte == 0) {
transferData.stgmedium = new STGMEDIUM();
transferData.result = COM.DV_E_STGMEDIUM;
return;
}
long /*int*/ lpMultiByteStr = OS.GlobalAlloc(COM.GMEM_FIXED | COM.GMEM_ZEROINIT, cchMultiByte);
OS.WideCharToMultiByte(codePage, 0, chars, -1, lpMultiByteStr, cchMultiByte, null, null);
transferData.stgmedium = new STGMEDIUM();
transferData.stgmedium.tymed = COM.TYMED_HGLOBAL;
transferData.stgmedium.unionField = lpMultiByteStr;
transferData.stgmedium.pUnkForRelease = 0;
transferData.result = COM.S_OK;
break;
}
}
return;
}
/**
* This implementation of <code>nativeToJava</code> converts a platform specific
* representation of plain text to a java <code>String</code>.
*
* @param transferData the platform specific representation of the data to be converted
* @return a java <code>String</code> containing text if the conversion was successful; otherwise null
*
* @see Transfer#javaToNative
*/
public Object nativeToJava(TransferData transferData){
if (!isSupportedType(transferData) || transferData.pIDataObject == 0) return null;
IDataObject data = new IDataObject(transferData.pIDataObject);
data.AddRef();
FORMATETC formatetc = transferData.formatetc;
STGMEDIUM stgmedium = new STGMEDIUM();
stgmedium.tymed = COM.TYMED_HGLOBAL;
transferData.result = getData(data, formatetc, stgmedium);
data.Release();
if (transferData.result != COM.S_OK) return null;
long /*int*/ hMem = stgmedium.unionField;
try {
switch (transferData.type) {
case CF_UNICODETEXTID: {
/* Ensure byteCount is a multiple of 2 bytes */
int size = OS.GlobalSize(hMem) / 2 * 2;
if (size == 0) return null;
char[] chars = new char[size/2];
long /*int*/ ptr = OS.GlobalLock(hMem);
if (ptr == 0) return null;
try {
OS.MoveMemory(chars, ptr, size);
int length = chars.length;
for (int i=0; i<chars.length; i++) {
if (chars [i] == '\0') {
length = i;
break;
}
}
return new String (chars, 0, length);
} finally {
OS.GlobalUnlock(hMem);
}
}
case CF_TEXTID: {
long /*int*/ lpMultiByteStr = OS.GlobalLock(hMem);
if (lpMultiByteStr == 0) return null;
try {
int codePage = OS.GetACP();
int cchWideChar = OS.MultiByteToWideChar (codePage, OS.MB_PRECOMPOSED, lpMultiByteStr, -1, null, 0);
if (cchWideChar == 0) return null;
char[] lpWideCharStr = new char [cchWideChar - 1];
OS.MultiByteToWideChar (codePage, OS.MB_PRECOMPOSED, lpMultiByteStr, -1, lpWideCharStr, lpWideCharStr.length);
return new String(lpWideCharStr);
} finally {
OS.GlobalUnlock(hMem);
}
}
}
} finally {
OS.GlobalFree(hMem);
}
return null;
}
protected int[] getTypeIds(){
return new int[] {CF_UNICODETEXTID, CF_TEXTID};
}
protected String[] getTypeNames(){
return new String[] {CF_UNICODETEXT, CF_TEXT};
}
boolean checkText(Object object) {
return (object != null && object instanceof String && ((String)object).length() > 0);
}
protected boolean validate(Object object) {
return checkText(object);
}
}