/*******************************************************************************
 * Copyright (c) 20007 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
 *******************************************************************************/
module dwt.dnd;

import dwt.internal.cocoa.NSString;
import dwt.internal.cocoa.NSURL;
import dwt.internal.cocoa.OS.URLTransfer;

/**

import dwt.dwthelper.utils;
 * The class <code>URLTransfer</code> provides a platform specific mechanism 
 * for converting text in URL format represented as a java <code>String</code> 
 * to a platform specific representation of the data and vice versa. The string
 * must contain a fully specified url.
 * 
 * <p>An example of a java <code>String</code> containing a URL is shown below:</p>
 * 
 * <code><pre>
 *     String url = "http://www.eclipse.org";
 * </code></pre>
 *
 * @see Transfer
 */
public class URLTransfer extends ByteArrayTransfer {

 static URLTransfer _instance = new URLTransfer();
   static final String URL = OS.NSURLPboardType.getString();
   static final int URL_ID = registerType(URL);

private URLTransfer() {}

/**
 * Returns the singleton instance of the URLTransfer class.
 *
 * @return the singleton instance of the URLTransfer class
 */
public static URLTransfer getInstance () {
   return _instance;
}

/**
 * This implementation of <code>javaToNative</code> converts a URL
 * represented by a java <code>String</code> to a platform specific representation.
 * 
 * @param object a java <code>String</code> containing a URL
 * @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 (!checkURL(object) || !isSupportedType(transferData)) {
      DND.error(DND.ERROR_INVALID_DATA);
  }
   String url = (String)object;
    NSString nsString = NSString.stringWith(url);
   NSString escapedString = nsString.stringByAddingPercentEscapesUsingEncoding(OS.NSUTF8StringEncoding);
   transferData.data = NSURL.URLWithString(escapedString);
}

/**
 * This implementation of <code>nativeToJava</code> converts a platform 
 * specific representation of a URL 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 a URL if the conversion was successful;
 *      otherwise null
 * 
 * @see Transfer#javaToNative
 */
public Object nativeToJava(TransferData transferData){
   if (!isSupportedType(transferData) || transferData.data is null) return null;
   NSURL nsUrl = (NSURL) transferData.data;
    NSString nsString = nsUrl.absoluteString();
 return nsString.getString();
}

protected int[] getTypeIds(){
  return new int[] {URL_ID};
}

protected String[] getTypeNames(){
   return new String[] {URL}; 
}

bool checkURL(Object object) {
  return object !is null && (object instanceof String) && ((String)object).length() > 0;
}

protected bool validate(Object object) {
 return checkURL(object);
}
}