Attachment 39258 Details for Bug 31841 – An implementation for the Preferred Drop Effect

An implementation for the Preferred Drop Effect

PreferredDropEffectTransfer.java (text/plain), 3.81 KB, created by Thomas Braun

on 2006-04-23 11:32:57 EDT

(hide)

Description:

Filename:

MIME Type:

Creator: Thomas Braun

Created: 2006-04-23 11:32:57 EDT

Size: 3.81 KB

patch

obsolete

>package org.eclipse.swt.dnd;
>
>
>import org.eclipse.swt.internal.ole.win32.COM;
>import org.eclipse.swt.internal.ole.win32.FORMATETC;
>import org.eclipse.swt.internal.ole.win32.IDataObject;
>import org.eclipse.swt.internal.ole.win32.STGMEDIUM;
>import org.eclipse.swt.internal.win32.OS;
>
>
>/**
> * The class provides a platform specific mechanism for reading and writing
> * the preffered drop effect (copy or paste) from and to the clipboard.<br>
> * This class is intended to be used in addition to {@link FileTransfer}.
> * See {@link Transfer} for additional information.
> * <p>
> * An example is shown below:
> * </p>
> * <code><pre>
> * PreferredDropEffectTransfer pdet = PreferredDropEffectTransfer.getInstance();
> * FileTransfer ft = FileTransfer.getInstance();
> * String[] files = (String[]) clipboard.getContents(ft);
> * int effect = ((Integer) clipboard.getContents(pdet)).intValue();
> * // copy files
> * if ((effect & DND.DROP_MOVE) != 0)
> *     for (int i = 0; i < files.length; i++)
> *         new File(files[i]).delete();
> * </code></pre>
> * 
> * @author Thomas Braun
> */
>public class PreferredDropEffectTransfer extends ByteArrayTransfer
>{
>	private static PreferredDropEffectTransfer _instance = 
>		new PreferredDropEffectTransfer();
>	private static final String CFSTR_PREFERREDDROPEFFECT = 
>		"Preferred DropEffect"; //$NON-NLS-1$
>	private static final int CF_ID = 
>		registerType(CFSTR_PREFERREDDROPEFFECT);
>
>	private PreferredDropEffectTransfer()
>	{}
>
>	/**
>	 * Returns the singleton instance of the class.
>	 * 
>	 * @return the singleton instance of the class
>	 */
>	public static PreferredDropEffectTransfer getInstance()
>	{
>		return _instance;
>	}
>
>	/**
>	 * Not emplemented because the transfer type "Preferred DropEffect"
>	 * generated by windows seems not compatible to the one of SWT.
>	 */
>	@Override
>	public void javaToNative(Object object, TransferData transferData)
>	{
>		if (!validate(object) || !isSupportedType(transferData)) {
>			DND.error(DND.ERROR_INVALID_DATA);
>		}
>		
>		// ...
>	}
>
>	/**
>	 * The method returns the preferred drop operation as integer object.
>	 * The default result is DND.DROP_COPY.
>	 * 
>	 * @see DND#DROP_COPY
>	 * @see DND#DROP_LINK
>	 * @see DND#DROP_MOVE
>	 * @return an <code>Integer</code> containing the preferred drop operation
>	 */
>	@Override
>	public Object nativeToJava(TransferData transferData)
>	{
>		if (!isSupportedType(transferData) || transferData.pIDataObject == 0)
>			return DND.DROP_COPY;
>
>		IDataObject dataObject = new IDataObject(transferData.pIDataObject);
>		dataObject.AddRef();
>		FORMATETC formatetc = new FORMATETC();
>		formatetc.cfFormat = CF_ID;
>		formatetc.ptd = 0;
>		formatetc.dwAspect = COM.DVASPECT_CONTENT;
>		formatetc.lindex = -1;
>		formatetc.tymed = COM.TYMED_HGLOBAL;
>		STGMEDIUM stgmedium = new STGMEDIUM();
>		stgmedium.tymed = COM.TYMED_HGLOBAL;
>		transferData.result = dataObject.GetData(formatetc, stgmedium);
>		int[] i1 = new int[1];
>		OS.MoveMemory(i1, stgmedium.unionField, 4);
>		int[] i2 = new int[1];
>		OS.MoveMemory(i2, i1[0], 4);
>		dataObject.Release();
>		
>		if (transferData.result != COM.S_OK)
>			return DND.DROP_COPY;
>		else
>			return osToOp(i2[0]);
>	}
>
>	@Override
>	protected int[] getTypeIds()
>	{
>		return new int[]{
>			CF_ID
>		};
>	}
>
>	private int osToOp(int osOperation)
>	{
>		int operation = 0;
>		if ((osOperation & COM.DROPEFFECT_COPY) != 0) {
>			operation |= DND.DROP_COPY;
>		}
>		if ((osOperation & COM.DROPEFFECT_LINK) != 0) {
>			operation |= DND.DROP_LINK;
>		}
>		if ((osOperation & COM.DROPEFFECT_MOVE) != 0) {
>			operation |= DND.DROP_MOVE;
>		}
>		return operation;
>	}
>
>	@Override
>	protected String[] getTypeNames()
>	{
>		return new String[]{
>			CFSTR_PREFERREDDROPEFFECT
>		};
>	}
>
>	@Override
>	protected boolean validate(Object object)
>	{
>		return object instanceof Integer;
>	}
>}

Actions: View

Attachments on bug 31841: 39258 | 39900