/*******************************************************************************
 * Copyright (c) 2000, 2007 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.*;
import dwt.widgets.*;
import dwt.internal.cocoa.OS;

/**
 * The <code>Clipboard</code> provides a mechanism for transferring data from one
 * application to another or within an application.
 * 
 * <p>IMPORTANT: This class is <em>not</em> intended to be subclassed.</p>
 */
public class Clipboard {

    Display display;
    int scrap = 0;

/**
 * Constructs a new instance of this class.  Creating an instance of a Clipboard
 * may cause system resources to be allocated depending on the platform.  It is therefore
 * mandatory that the Clipboard instance be disposed when no longer required.
 *
 * @param display the display on which to allocate the clipboard
 *
 * @exception DWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
 * </ul>
 *
 * @see Clipboard#dispose
 * @see Clipboard#checkSubclass
 */
public Clipboard(Display display) { 
    checkSubclass ();
    if (display is null) {
        display = Display.getCurrent();
        if (display is null) {
            display = Display.getDefault();
        }
    }
    if (display.getThread() !is Thread.currentThread()) {
        DND.error(DWT.ERROR_THREAD_INVALID_ACCESS);
    }
    this.display = display;
}

/**
 * Checks that this class can be subclassed.
 * <p>
 * The DWT class library is intended to be subclassed 
 * only at specific, controlled points. This method enforces this
 * rule unless it is overridden.
 * </p><p>
 * <em>IMPORTANT:</em> By providing an implementation of this
 * method that allows a subclass of a class which does not 
 * normally allow subclassing to be created, the implementer
 * agrees to be fully responsible for the fact that any such
 * subclass will likely fail between DWT releases and will be
 * strongly platform specific. No support is provided for
 * user-written classes which are implemented in this fashion.
 * </p><p>
 * The ability to subclass outside of the allowed DWT classes
 * is intended purely to enable those not on the DWT development
 * team to implement patches in order to get around specific
 * limitations in advance of when those limitations can be
 * addressed by the team. Subclassing should not be attempted
 * without an intimate and detailed understanding of the hierarchy.
 * </p>
 *
 * @exception DWTException <ul>
 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
 * </ul>
 */
protected void checkSubclass () {
    String name = getClass().getName ();
    String validName = Clipboard.class.getName();
    if (!validName.opEquals(name)) {
        DND.error (DWT.ERROR_INVALID_SUBCLASS);
    }
}
/**
 * Throws an <code>DWTException</code> if the receiver can not
 * be accessed by the caller. This may include both checks on
 * the state of the receiver and more generally on the entire
 * execution context. This method <em>should</em> be called by
 * widget implementors to enforce the standard DWT invariants.
 * <p>
 * Currently, it is an error to invoke any method (other than
 * <code>isDisposed()</code>) on a widget that has had its 
 * <code>dispose()</code> method called. It is also an error
 * to call widget methods from any thread that is different
 * from the thread that created the widget.
 * </p><p>
 * In future releases of DWT, there may be more or fewer error
 * checks and exceptions may be thrown for different reasons.
 * </p>
 *
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
protected void checkWidget () {
    Display display = this.display;
    if (display is null) DND.error (DWT.ERROR_WIDGET_DISPOSED);
    if (display.getThread() !is Thread.currentThread ()) DND.error (DWT.ERROR_THREAD_INVALID_ACCESS);
    if (display.isDisposed()) DND.error(DWT.ERROR_WIDGET_DISPOSED);
}

/**
 * If this clipboard is currently the owner of the data on the system clipboard,
 * clear the contents.  If this clipboard is not the owner, then nothing is done.
 * Note that there are clipboard assistant applications that take ownership of 
 * data or make copies of data when it is placed on the clipboard.  In these 
 * cases, it may not be possible to clear the clipboard.
 * 
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.1
 */
public void clearContents() {
    clearContents(DND.CLIPBOARD);
}

/**
 * If this clipboard is currently the owner of the data on the specified 
 * clipboard, clear the contents.  If this clipboard is not the owner, then 
 * nothing is done.
 * 
 * <p>Note that there are clipboard assistant applications that take ownership
 * of data or make copies of data when it is placed on the clipboard.  In these 
 * cases, it may not be possible to clear the clipboard.</p>
 * 
 * <p>The clipboards value is either one of the clipboard constants defined in
 * class <code>DND</code>, or must be built by <em>bitwise OR</em>'ing together 
 * (that is, using the <code>int</code> "|" operator) two or more
 * of those <code>DND</code> clipboard constants.</p>
 * 
 * @param clipboards to be cleared
 * 
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @see DND#CLIPBOARD
 * @see DND#SELECTION_CLIPBOARD
 * 
 * @since 3.1
 */
public void clearContents(int clipboards) {
    checkWidget();
    if ((clipboards & DND.CLIPBOARD) is 0 || scrap is 0) return;
    int oldScrap = scrap;
    scrap = 0;
    int[] currentScrap = new int[1];
    if (OS.GetCurrentScrap(currentScrap) !is OS.noErr) return;
    if (currentScrap[0] is oldScrap) {
        OS.ClearCurrentScrap();
    }
}

/**
 * Disposes of the operating system resources associated with the clipboard. 
 * The data will still be available on the system clipboard after the dispose 
 * method is called.  
 * 
 * <p>NOTE: On some platforms the data will not be available once the application
 * has exited or the display has been disposed.</p>
 * 
 * @exception DWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
 * </ul>
 */
public void dispose () {
    if (isDisposed()) return;
    if (display.getThread() !is Thread.currentThread()) DND.error(DWT.ERROR_THREAD_INVALID_ACCESS);
    display = null;
}

/**
 * Retrieve the data of the specified type currently available on the system 
 * clipboard.  Refer to the specific subclass of <code>Transfer</code> to 
 * determine the type of object returned.
 * 
 * <p>The following snippet shows text and RTF text being retrieved from the 
 * clipboard:</p>
 * 
 *    <code><pre>
 *    Clipboard clipboard = new Clipboard(display);
 *    TextTransfer textTransfer = TextTransfer.getInstance();
 *    String textData = (String)clipboard.getContents(textTransfer);
 *    if (textData !is null) System.out.println("Text is "+textData);
 *    RTFTransfer rtfTransfer = RTFTransfer.getInstance();
 *    String rtfData = (String)clipboard.getContents(rtfTransfer);
 *    if (rtfData !is null) System.out.println("RTF Text is "+rtfData);
 *    clipboard.dispose();
 *    </code></pre>
 * 
 * @param transfer the transfer agent for the type of data being requested
 * @return the data obtained from the clipboard or null if no data of this type is available
 * 
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if transfer is null</li>
 * </ul>
 * 
 * @see Transfer
 */
public Object getContents(Transfer transfer) {
    return getContents(transfer, DND.CLIPBOARD);
}

/**
 * Retrieve the data of the specified type currently available on the specified 
 * clipboard.  Refer to the specific subclass of <code>Transfer</code> to 
 * determine the type of object returned.
 * 
 * <p>The following snippet shows text and RTF text being retrieved from the 
 * clipboard:</p>
 * 
 *    <code><pre>
 *    Clipboard clipboard = new Clipboard(display);
 *    TextTransfer textTransfer = TextTransfer.getInstance();
 *    String textData = (String)clipboard.getContents(textTransfer);
 *    if (textData !is null) System.out.println("Text is "+textData);
 *    RTFTransfer rtfTransfer = RTFTransfer.getInstance();
 *    String rtfData = (String)clipboard.getContents(rtfTransfer, DND.CLIPBOARD);
 *    if (rtfData !is null) System.out.println("RTF Text is "+rtfData);
 *    clipboard.dispose();
 *    </code></pre>
 * 
 * <p>The clipboards value is either one of the clipboard constants defined in
 * class <code>DND</code>, or must be built by <em>bitwise OR</em>'ing together 
 * (that is, using the <code>int</code> "|" operator) two or more
 * of those <code>DND</code> clipboard constants.</p>
 * 
 * @param transfer the transfer agent for the type of data being requested
 * @param clipboards on which to look for data
 *  
 * @return the data obtained from the clipboard or null if no data of this type is available
 * 
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if transfer is null</li>
 * </ul>
 * 
 * @see Transfer
 * @see DND#CLIPBOARD
 * @see DND#SELECTION_CLIPBOARD
 * 
 * @since 3.1
 */
public Object getContents(Transfer transfer, int clipboards) {
    checkWidget();
    if (transfer is null) DND.error(DWT.ERROR_NULL_ARGUMENT);
    if ((clipboards & DND.CLIPBOARD) is 0) return null;
    int[] scrap = new int[1];
    if (OS.GetCurrentScrap(scrap) !is OS.noErr) return null;
    int[] typeIds = transfer.getTypeIds();
    int[] size = new int[1];    
    // get data from system clipboard
    for (int i=0; i<typeIds.length; i++) {
        int type = typeIds[i];
        size[0] = 0;
        if (OS.GetScrapFlavorSize(scrap[0], type, size) is OS.noErr && size[0] > 0) {
            byte[] buffer = new byte[size[0]];
            if (OS.GetScrapFlavorData(scrap[0], type, size, buffer) is OS.noErr) {
                TransferData tdata = new TransferData();
                tdata.type = type;      
                tdata.data = new byte[1][];
                tdata.data[0] = buffer;
                return transfer.nativeToJava(tdata);
            }
        }
    }
    return null;    // No data available for this transfer
}

/**
 * Returns <code>true</code> if the clipboard has been disposed,
 * and <code>false</code> otherwise.
 * <p>
 * This method gets the dispose state for the clipboard.
 * When a clipboard has been disposed, it is an error to
 * invoke any other method using the clipboard.
 * </p>
 *
 * @return <code>true</code> when the widget is disposed and <code>false</code> otherwise
 * 
 * @since 3.0
 */
public bool isDisposed () {
    return (display is null);
}

/**
 * Place data of the specified type on the system clipboard.  More than one type
 * of data can be placed on the system clipboard at the same time.  Setting the
 * data clears any previous data from the system clipboard, regardless of type.
 * 
 * <p>NOTE: On some platforms, the data is immediately copied to the system
 * clipboard but on other platforms it is provided upon request.  As a result,
 * if the application modifies the data object it has set on the clipboard, that 
 * modification may or may not be available when the data is subsequently 
 * requested.</p>
 *
 * <p>The following snippet shows text and RTF text being set on the copy/paste
 * clipboard:
 * </p>
 * 
 * <code><pre>
 *  Clipboard clipboard = new Clipboard(display);
 *  String textData = "Hello World";
 *  String rtfData = "{\\rtf1\\b\\i Hello World}";
 *  TextTransfer textTransfer = TextTransfer.getInstance();
 *  RTFTransfer rtfTransfer = RTFTransfer.getInstance();
 *  Transfer[] transfers = new Transfer[]{textTransfer, rtfTransfer};
 *  Object[] data = new Object[]{textData, rtfData};
 *  clipboard.setContents(data, transfers);
 *  clipboard.dispose();
 * </code></pre>
 *
 * @param data the data to be set in the clipboard
 * @param dataTypes the transfer agents that will convert the data to its 
 * platform specific format; each entry in the data array must have a 
 * corresponding dataType
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if data is null or datatypes is null 
 *          or the length of data is not the same as the length of dataTypes</li>
 * </ul>
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *  @exception DWTError <ul>
 *    <li>ERROR_CANNOT_SET_CLIPBOARD - if the clipboard is locked or otherwise unavailable</li>
 * </ul>
 * 
 * <p>NOTE: ERROR_CANNOT_SET_CLIPBOARD should be an DWTException, since it is a
 * recoverable error, but can not be changed due to backward compatibility.</p>
 */
public void setContents(Object[] data, Transfer[] dataTypes) {
    setContents(data, dataTypes, DND.CLIPBOARD);
}

/**
 * Place data of the specified type on the specified clipboard.  More than one 
 * type of data can be placed on the specified clipboard at the same time.
 * Setting the data clears any previous data from the specified
 * clipboard, regardless of type.
 * 
 * <p>NOTE: On some platforms, the data is immediately copied to the specified
 * clipboard but on other platforms it is provided upon request.  As a result, 
 * if the application modifies the data object it has set on the clipboard, that 
 * modification may or may not be available when the data is subsequently 
 * requested.</p>
 *
 * <p>The clipboards value is either one of the clipboard constants defined in
 * class <code>DND</code>, or must be built by <em>bitwise OR</em>'ing together 
 * (that is, using the <code>int</code> "|" operator) two or more
 * of those <code>DND</code> clipboard constants.</p>
 * 
 * <p>The following snippet shows text and RTF text being set on the copy/paste
 * clipboard:
 * </p>
 * 
 * <code><pre>
 *  Clipboard clipboard = new Clipboard(display);
 *  String textData = "Hello World";
 *  String rtfData = "{\\rtf1\\b\\i Hello World}";
 *  TextTransfer textTransfer = TextTransfer.getInstance();
 *  RTFTransfer rtfTransfer = RTFTransfer.getInstance();
 *  Transfer[] transfers = new Transfer[]{textTransfer, rtfTransfer};
 *  Object[] data = new Object[]{textData, rtfData};
 *  clipboard.setContents(data, transfers, DND.CLIPBOARD);
 *  clipboard.dispose();
 * </code></pre>
 *
 * @param data the data to be set in the clipboard
 * @param dataTypes the transfer agents that will convert the data to its 
 * platform specific format; each entry in the data array must have a 
 * corresponding dataType
 * @param clipboards on which to set the data
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if data is null or datatypes is null 
 *          or the length of data is not the same as the length of dataTypes</li>
 * </ul>
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *  @exception DWTError <ul>
 *    <li>ERROR_CANNOT_SET_CLIPBOARD - if the clipboard is locked or otherwise unavailable</li>
 * </ul>
 * 
 * <p>NOTE: ERROR_CANNOT_SET_CLIPBOARD should be an DWTException, since it is a
 * recoverable error, but can not be changed due to backward compatibility.</p>
 * 
 * @see DND#CLIPBOARD
 * @see DND#SELECTION_CLIPBOARD
 * 
 * @since 3.1
 */
public void setContents(Object[] data, Transfer[] dataTypes, int clipboards) {
    checkWidget();
    if (data is null || dataTypes is null || data.length !is dataTypes.length || data.length is 0) {
        DND.error(DWT.ERROR_INVALID_ARGUMENT);
    }
    for (int i = 0; i < data.length; i++) {
        if (data[i] is null || dataTypes[i] is null || !dataTypes[i].validate(data[i])) {
            DND.error(DWT.ERROR_INVALID_ARGUMENT);
        }
    }
    if ((clipboards & DND.CLIPBOARD) is 0) return;
    if (OS.ClearCurrentScrap() !is OS.noErr) {
        DND.error(DND.ERROR_CANNOT_SET_CLIPBOARD);
    }
    scrap = 0;
    int[] currentScrap = new int[1];
    if (OS.GetCurrentScrap(currentScrap) !is OS.noErr) {
        DND.error(DND.ERROR_CANNOT_SET_CLIPBOARD);
    }
    scrap = currentScrap[0];
    // copy data directly over to System clipboard (not deferred)
    for (int i=0; i<dataTypes.length; i++) {
        int[] typeIds = dataTypes[i].getTypeIds();
        for (int j=0; j<typeIds.length; j++) {
            TransferData transferData = new TransferData();
            transferData.type = typeIds[j];
            dataTypes[i].javaToNative(data[i], transferData); 
            if (transferData.result !is OS.noErr) {
                DND.error(DND.ERROR_CANNOT_SET_CLIPBOARD);
            }
            //Drag and Drop can handle multiple items in one transfer but the
            //Clipboard can not.
            byte[] datum = transferData.data[0];
            if (OS.PutScrapFlavor(scrap, transferData.type, 0, datum.length, datum) !is OS.noErr){
                DND.error(DND.ERROR_CANNOT_SET_CLIPBOARD);
            }
        }
    }
}

/**
 * Returns an array of the data types currently available on the system 
 * clipboard. Use with Transfer.isSupportedType.
 *
 * @return array of data types currently available on the system clipboard
 * 
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see Transfer#isSupportedType
 * 
 * @since 3.0
 */
public TransferData[] getAvailableTypes() {
    return getAvailableTypes(DND.CLIPBOARD);
}

/**
 * Returns an array of the data types currently available on the specified 
 * clipboard. Use with Transfer.isSupportedType.
 * 
 * <p>The clipboards value is either one of the clipboard constants defined in
 * class <code>DND</code>, or must be built by <em>bitwise OR</em>'ing together 
 * (that is, using the <code>int</code> "|" operator) two or more
 * of those <code>DND</code> clipboard constants.</p>
 * 
 * @param clipboards from which to get the data types
 * @return array of data types currently available on the specified clipboard
 * 
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see Transfer#isSupportedType
 * @see DND#CLIPBOARD
 * @see DND#SELECTION_CLIPBOARD
 * 
 * @since 3.1
 */
public TransferData[] getAvailableTypes(int clipboards) {
    checkWidget();
    if ((clipboards & DND.CLIPBOARD) is 0) return new TransferData[0]; 
    int[] types = _getAvailableTypes();
    TransferData[] result = new TransferData[types.length];
    for (int i = 0; i < types.length; i++) {
        result[i] = new TransferData();
        result[i].type = types[i];
    }
    return result;
}

/**
 * Returns a platform specific list of the data types currently available on the 
 * system clipboard.
 * 
 * <p>Note: <code>getAvailableTypeNames</code> is a utility for writing a Transfer 
 * sub-class.  It should NOT be used within an application because it provides 
 * platform specific information.</p>
 * 
 * @return a platform specific list of the data types currently available on the 
 * system clipboard
 * 
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public String[] getAvailableTypeNames() {
    checkWidget();
    int[] types = _getAvailableTypes();
    String[] names = new String[types.length];
    for (int i = 0; i < types.length; i++) {
        int type = types[i];
        StringBuffer sb = new StringBuffer();
        sb.append((char)((type & 0xff000000) >> 24));
        sb.append((char)((type & 0x00ff0000) >> 16));
        sb.append((char)((type & 0x0000ff00) >> 8));
        sb.append((char)((type & 0x000000ff) >> 0));
        names[i] = sb.toString();
    }
    return names;
}

int[] _getAvailableTypes() {
    int[] types = new int[0];
    int[] scrap = new int[1];
    if (OS.GetCurrentScrap(scrap) !is OS.noErr) return types;
    int[] count = new int[1];
    if (OS.GetScrapFlavorCount(scrap[0], count) !is OS.noErr || count[0] is 0) return types;
    int[] info = new int[count[0] * 2];
    if (OS.GetScrapFlavorInfoList(scrap[0], count, info) !is OS.noErr) return types;
    types = new int[count[0]];
    for (int i= 0; i < count [0]; i++) {
        types[i] = info[i*2];
    }
    return types;
}
}