/*******************************************************************************
 * Copyright (c) 2000, 2004 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
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module dwt.dnd.RTFTransfer;

import dwt.internal.ole.win32.COM;
import dwt.internal.win32.OS;

/**
 * The class <code>RTFTransfer</code> provides a platform specific mechanism
 * for converting text in RTF format represented as a java <code>String</code>
 * to a platform specific representation of the data and vice versa.  See
 * <code>Transfer</code> for additional information.
 *
 * <p>An example of a java <code>String</code> containing RTF text is shown
 * below:</p>
 *
 * <code><pre>
 *     String rtfData = "{\\rtf1{\\colortbl;\\red255\\green0\\blue0;}\\uc1\\b\\i Hello World}";
 * </code></pre>
 */
public class RTFTransfer : ByteArrayTransfer {

    private static RTFTransfer _instance = new RTFTransfer();
    private static final String CF_RTF = "Rich Text Format"; //$NON-NLS-1$
    private static final int CF_RTFID = registerType(CF_RTF);

private this() {}

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

/**
 * This implementation of <code>javaToNative</code> converts RTF-formatted text
 * represented by a java <code>String</code> to a platform specific representation.
 * For additional information see <code>Transfer#javaToNative</code>.
 *
 * @param object a java <code>String</code> containing RTF text
 * @param transferData an empty <code>TransferData</code> object; this
 *  object will be filled in on return with the platform specific format of the data
 */
public void javaToNative (Object object, TransferData transferData){
    if (!checkRTF(object) || !isSupportedType(transferData)) {
        DND.error(DND.ERROR_INVALID_DATA);
    }
    // CF_RTF is stored as a null terminated byte array
    String string = (String)object;
    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 is 0) {
        transferData.stgmedium = new STGMEDIUM();
        transferData.result = COM.DV_E_STGMEDIUM;
        return;
    }
    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;
    return;
}

/**
 * This implementation of <code>nativeToJava</code> converts a platform specific
 * representation of RTF text to a java <code>String</code>.
 * For additional information see <code>Transfer#nativeToJava</code>.
 *
 * @param transferData the platform specific representation of the data to be
 * been converted
 * @return a java <code>String</code> containing RTF text if the
 * conversion was successful; otherwise null
 */
public Object nativeToJava(TransferData transferData){
    if (!isSupportedType(transferData) || transferData.pIDataObject is 0) return null;
    IDataObject data = new IDataObject(transferData.pIDataObject);
    data.AddRef();
    STGMEDIUM stgmedium = new STGMEDIUM();
    FORMATETC formatetc = transferData.formatetc;
    stgmedium.tymed = COM.TYMED_HGLOBAL;
    transferData.result = data.GetData(formatetc, stgmedium);
    data.Release();
    if (transferData.result !is COM.S_OK) return null;
    int hMem = stgmedium.unionField;
    try {
        int lpMultiByteStr = OS.GlobalLock(hMem);
        if (lpMultiByteStr is 0) return null;
        try {
            int codePage = OS.GetACP();
            int cchWideChar  = OS.MultiByteToWideChar (codePage, OS.MB_PRECOMPOSED, lpMultiByteStr, -1, null, 0);
            if (cchWideChar is 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);
    }
}

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

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

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

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