/*******************************************************************************
* Copyright (c) 2000, 2011 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.widgets.Display;
import org.eclipse.swt.internal.Converter;
import org.eclipse.swt.internal.motif.OS;
import org.eclipse.swt.internal.motif.XTextProperty;
/**
* 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 {
static TextTransfer _instance = new TextTransfer();
static final String COMPOUND_TEXT = "COMPOUND_TEXT"; //$NON-NLS-1$
static final String STRING = "STRING"; //$NON-NLS-1$
static final int COMPOUND_TEXT_ID = registerType(COMPOUND_TEXT);
static final int STRING_ID = registerType(STRING);
TextTransfer() {/*empty*/}
/**
* 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) {
transferData.result = 0;
if (!checkText(object) || !isSupportedType(transferData)) {
DND.error(DND.ERROR_INVALID_DATA);
}
String string = (String)object;
byte[] buffer = Converter.wcsToMbcs (null, string, true);
if (transferData.type == COMPOUND_TEXT_ID) {
Display display = Display.getCurrent();
if (display == null) return;
int xDisplay = display.xDisplay;
int pBuffer = OS.XtMalloc(buffer.length);
if (pBuffer == 0) return;
try {
OS.memmove(pBuffer, buffer, buffer.length);
int list = OS.XtMalloc(4);
if (list == 0) return;
OS.memmove(list, new int[] {pBuffer}, 4);
XTextProperty text_prop_return = new XTextProperty();
int result = OS.XmbTextListToTextProperty (xDisplay, list, 1, OS.XCompoundTextStyle, text_prop_return);
OS.XtFree(list);
if (result != 0)return;
transferData.format = text_prop_return.format;
transferData.length = text_prop_return.nitems;
transferData.pValue = text_prop_return.value;
transferData.type = text_prop_return.encoding;
transferData.result = 1;
} finally {
OS.XtFree(pBuffer);
}
}
if (transferData.type == STRING_ID) {
int pValue = OS.XtMalloc(buffer.length);
if (pValue == 0) return;
OS.memmove(pValue, buffer, buffer.length);
transferData.type = STRING_ID;
transferData.format = 8;
transferData.length = buffer.length - 1;
transferData.pValue = pValue;
transferData.result = 1;
}
}
/**
* 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.pValue == 0) return null;
byte[] buffer = null;
if (transferData.type == COMPOUND_TEXT_ID) {
Display display = Display.getCurrent();
if (display == null) return null;
int xDisplay = display.xDisplay;
XTextProperty text_prop = new XTextProperty();
text_prop.encoding = transferData.type;
text_prop.format = transferData.format;
text_prop.nitems = transferData.length;
text_prop.value = transferData.pValue;
int[] list_return = new int[1];
int[] count_return = new int[1];
int result = OS.XmbTextPropertyToTextList (xDisplay, text_prop, list_return, count_return);
if (result != 0 || list_return[0] == 0) return null;
//Note: only handling the first string in list
int[] ptr = new int[1];
OS.memmove(ptr, list_return[0], 4);
int length = OS.strlen(ptr[0]);
buffer = new byte[length];
OS.memmove(buffer, ptr[0], length);
OS.XFreeStringList(list_return[0]);
}
if (transferData.type == STRING_ID) {
int size = transferData.format * transferData.length / 8;
if (size == 0) return null;
buffer = new byte[size];
OS.memmove(buffer, transferData.pValue, size);
}
if (buffer == null) return null;
// convert byte array to a string
char [] unicode = Converter.mbcsToWcs (null, buffer);
String string = new String (unicode);
int end = string.indexOf('\0');
return (end == -1) ? string : string.substring(0, end);
}
protected int[] getTypeIds() {
return new int[] {COMPOUND_TEXT_ID, STRING_ID};
}
protected String[] getTypeNames() {
return new String[] {COMPOUND_TEXT, STRING};
}
boolean checkText(Object object) {
return (object != null && object instanceof String && ((String)object).length() > 0);
}
protected boolean validate(Object object) {
return checkText(object);
}
}