| /******************************************************************************* |
| * Copyright (c) 2000, 2003 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Common Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/cpl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.swt.dnd; |
| |
| |
| import org.eclipse.swt.*; |
| import org.eclipse.swt.internal.ole.win32.*; |
| import org.eclipse.swt.widgets.*; |
| import org.eclipse.swt.internal.win32.*; |
| |
| /** |
| * |
| * <code>DragSource</code> defines the source object for a drag and drop transfer. |
| * |
| * <p>IMPORTANT: This class is <em>not</em> intended to be subclassed.</p> |
| * |
| * <p>A drag source is the object which originates a drag and drop operation. For the specified widget, |
| * it defines the type of data that is available for dragging and the set of operations that can |
| * be performed on that data. The operations can be any bit-wise combination of DND.MOVE, DND.COPY or |
| * DND.LINK. The type of data that can be transferred is specified by subclasses of Transfer such as |
| * TextTransfer or FileTransfer. The type of data transferred can be a predefined system type or it |
| * can be a type defined by the application. For instructions on how to define your own transfer type, |
| * refer to <code>ByteArrayTransfer</code>.</p> |
| * |
| * <p>You may have several DragSources in an application but you can only have one DragSource |
| * per Control. Data dragged from this DragSource can be dropped on a site within this application |
| * or it can be dropped on another application such as an external Text editor.</p> |
| * |
| * <p>The application supplies the content of the data being transferred by implementing the |
| * <code>DragSourceListener</code> and associating it with the DragSource via DragSource#addDragListener.</p> |
| * |
| * <p>When a successful move operation occurs, the application is required to take the appropriate |
| * action to remove the data from its display and remove any associated operating system resources or |
| * internal references. Typically in a move operation, the drop target makes a copy of the data |
| * and the drag source deletes the original. However, sometimes copying the data can take a long |
| * time (such as copying a large file). Therefore, on some platforms, the drop target may actually |
| * move the data in the operating system rather than make a copy. This is usually only done in |
| * file transfers. In this case, the drag source is informed in the DragEnd event that a |
| * DROP_TARGET_MOVE was performed. It is the responsibility of the drag source at this point to clean |
| * up its displayed information. No action needs to be taken on the operating system resources.</p> |
| * |
| * <p> The following example shows a Label widget that allows text to be dragged from it.</p> |
| * |
| * <code><pre> |
| * // Enable a label as a Drag Source |
| * Label label = new Label(shell, SWT.NONE); |
| * // This example will allow text to be dragged |
| * Transfer[] types = new Transfer[] {TextTransfer.getInstance()}; |
| * // This example will allow the text to be copied or moved to the drop target |
| * int operations = DND.DROP_MOVE | DND.DROP_COPY; |
| * |
| * DragSource source = new DragSource (label, operations); |
| * source.setTransfer(types); |
| * source.addDragListener (new DragSourceListener() { |
| * public void dragStart(DragSourceEvent e) { |
| * // Only start the drag if there is actually text in the |
| * // label - this text will be what is dropped on the target. |
| * if (label.getText().length() == 0) { |
| * event.doit = false; |
| * } |
| * }; |
| * public void dragSetData (DragSourceEvent event) { |
| * // A drop has been performed, so provide the data of the |
| * // requested type. |
| * // (Checking the type of the requested data is only |
| * // necessary if the drag source supports more than |
| * // one data type but is shown here as an example). |
| * if (TextTransfer.getInstance().isSupportedType(event.dataType)){ |
| * event.data = label.getText(); |
| * } |
| * } |
| * public void dragFinished(DragSourceEvent event) { |
| * // A Move operation has been performed so remove the data |
| * // from the source |
| * if (event.detail == DND.DROP_MOVE) |
| * label.setText(""); |
| * } |
| * }); |
| * </pre></code> |
| * |
| * |
| * <dl> |
| * <dt><b>Styles</b></dt> <dd>DND.DROP_NONE, DND.DROP_COPY, DND.DROP_MOVE, DND.DROP_LINK</dd> |
| * <dt><b>Events</b></dt> <dd>DND.DragStart, DND.DragSetData, DND.DragEnd</dd> |
| * </dl> |
| */ |
| public class DragSource extends Widget { |
| |
| // ole interfaces |
| private COMObject iDropSource; |
| private COMObject iDataObject; |
| private int refCount; |
| |
| // info for registering as a drag source |
| private Control control; |
| private Transfer[] transferAgents = new Transfer[0]; |
| |
| private Listener controlListener; |
| |
| private int dataEffect; |
| |
| private static final String DRAGSOURCEID = "DragSource"; //$NON-NLS-1$ |
| /** |
| * Creates a new <code>DragSource</code> to handle dragging from the specified <code>Control</code>. |
| * Creating an instance of a DragSource may cause system resources to be allocated depending on the platform. |
| * It is therefore mandatory that the DragSource instance be disposed when no longer required. |
| * |
| * @param control the <code>Control</code> that the user clicks on to initiate the drag |
| * @param style the bitwise OR'ing of allowed operations; this may be a combination of any of |
| * DND.DROP_NONE, DND.DROP_COPY, DND.DROP_MOVE, DND.DROP_LINK |
| * |
| * @exception SWTException <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> |
| * @exception SWTError <ul> |
| * <li>ERROR_CANNOT_INIT_DRAG - unable to initiate drag source</li> |
| * </ul> |
| * |
| * @see DragSource#dispose |
| * @see DragSource#checkSubclass |
| * @see DND#DROP_NONE |
| * @see DND#DROP_COPY |
| * @see DND#DROP_MOVE |
| * @see DND#DROP_LINK |
| */ |
| public DragSource(Control control, int style) { |
| |
| super (control, checkStyle (style)); |
| this.control = control; |
| if (control.getData(DRAGSOURCEID) != null) |
| DND.error(DND.ERROR_CANNOT_INIT_DRAG); |
| control.setData(DRAGSOURCEID, this); |
| createCOMInterfaces(); |
| this.AddRef(); |
| |
| controlListener = new Listener () { |
| public void handleEvent (Event event) { |
| if (event.type == SWT.Dispose){ |
| DragSource.this.dispose(); |
| } |
| if (event.type == SWT.DragDetect) { |
| DragSource.this.drag(); |
| } |
| } |
| }; |
| control.addListener (SWT.Dispose, controlListener); |
| control.addListener (SWT.DragDetect, controlListener); |
| |
| this.addListener(SWT.Dispose, new Listener() { |
| public void handleEvent(Event e) { |
| onDispose(); |
| } |
| }); |
| } |
| |
| /** |
| * Adds the listener to the collection of listeners who will |
| * be notified when a drag and drop operation is in progress, by sending |
| * it one of the messages defined in the <code>DragSourceListener</code> |
| * interface. |
| * |
| * <p><ul> |
| * <li><code>dragStart</code> is called when the user has begun the actions required to drag the widget. |
| * This event gives the application the chance to decide if a drag should be started. |
| * <li><code>dragSetData</code> is called when the data is required from the drag source. |
| * <li><code>dragFinished</code> is called when the drop has successfully completed (mouse up |
| * over a valid target) or has been terminated (such as hitting the ESC key). Perform cleanup |
| * such as removing data from the source side on a successful move operation. |
| * </ul></p> |
| * |
| * @param listener the listener which should be notified |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> |
| * </ul> |
| * @exception SWTException <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 DragSourceListener |
| * @see #removeDragListener |
| * @see DragSourceEvent |
| */ |
| public void addDragListener(DragSourceListener listener) { |
| if (listener == null) DND.error (SWT.ERROR_NULL_ARGUMENT); |
| DNDListener typedListener = new DNDListener (listener); |
| addListener (DND.DragStart, typedListener); |
| addListener (DND.DragEnd, typedListener); |
| addListener (DND.DragSetData, typedListener); |
| |
| } |
| private int AddRef() { |
| refCount++; |
| return refCount; |
| } |
| static int checkStyle (int style) { |
| if (style == SWT.NONE) return DND.DROP_MOVE; |
| return style; |
| } |
| private void createCOMInterfaces() { |
| // register each of the interfaces that this object implements |
| iDropSource = new COMObject(new int[]{2, 0, 0, 2, 1}){ |
| public int method0(int[] args) {return QueryInterface(args[0], args[1]);} |
| public int method1(int[] args) {return AddRef();} |
| public int method2(int[] args) {return Release();} |
| public int method3(int[] args) {return QueryContinueDrag(args[0], args[1]);} |
| public int method4(int[] args) {return GiveFeedback(args[0]);} |
| }; |
| |
| iDataObject = new COMObject(new int[]{2, 0, 0, 2, 2, 1, 2, 3, 2, 4, 1, 1}){ |
| public int method0(int[] args) {return QueryInterface(args[0], args[1]);} |
| public int method1(int[] args) {return AddRef();} |
| public int method2(int[] args) {return Release();} |
| public int method3(int[] args) {return GetData(args[0], args[1]);} |
| // method4 GetDataHere - not implemented |
| public int method5(int[] args) {return QueryGetData(args[0]);} |
| // method6 GetCanonicalFormatEtc - not implemented |
| public int method7(int[] args) {return SetData(args[0], args[1], args[2]);} |
| public int method8(int[] args) {return EnumFormatEtc(args[0], args[1]);} |
| // method9 DAdvise - not implemented |
| // method10 DUnadvise - not implemented |
| // method11 EnumDAdvise - not implemented |
| }; |
| } |
| private void onDispose () { |
| this.Release(); |
| |
| if (control != null && controlListener != null){ |
| control.removeListener(SWT.Dispose, controlListener); |
| control.removeListener(SWT.DragDetect, controlListener); |
| } |
| controlListener = null; |
| control.setData(DRAGSOURCEID, null); |
| control = null; |
| |
| transferAgents = null; |
| } |
| private int opToOs(int operation) { |
| int osOperation = 0; |
| if ((operation & DND.DROP_COPY) != 0){ |
| osOperation |= COM.DROPEFFECT_COPY; |
| } |
| if ((operation & DND.DROP_LINK) != 0) { |
| osOperation |= COM.DROPEFFECT_LINK; |
| } |
| if ((operation & DND.DROP_MOVE) != 0) { |
| osOperation |= COM.DROPEFFECT_MOVE; |
| } |
| return osOperation; |
| } |
| 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; |
| |
| } |
| private void disposeCOMInterfaces() { |
| if (iDropSource != null) |
| iDropSource.dispose(); |
| iDropSource = null; |
| |
| if (iDataObject != null) |
| iDataObject.dispose(); |
| iDataObject = null; |
| } |
| private void drag() { |
| if (transferAgents == null || getStyle() == 0) return; |
| |
| DNDEvent event = new DNDEvent(); |
| event.widget = this; |
| event.time = OS.GetMessageTime(); |
| event.doit = true; |
| |
| try { |
| notifyListeners(DND.DragStart,event); |
| } catch (Throwable e) { |
| return; |
| } |
| |
| if (!event.doit) return; |
| |
| dataEffect = DND.DROP_NONE; //dataEffect will be updated in SetData callback |
| int[] pdwEffect = new int[1]; |
| int operations = opToOs(getStyle()); |
| int result = COM.DoDragDrop(iDataObject.getAddress(), iDropSource.getAddress(), operations, pdwEffect); |
| int operation = osToOp(pdwEffect[0]); |
| event = new DNDEvent(); |
| event.widget = this; |
| event.time = OS.GetMessageTime(); |
| if (dataEffect == DND.DROP_MOVE && (operation == DND.DROP_NONE || operation == DND.DROP_COPY)) { |
| dataEffect = DND.DROP_TARGET_MOVE; |
| } |
| if (dataEffect == DND.DROP_NONE) { |
| dataEffect = operation; |
| } |
| event.detail = dataEffect; |
| event.doit = (result == COM.DRAGDROP_S_DROP); |
| |
| try { |
| notifyListeners(DND.DragEnd,event); |
| } catch (Throwable e) { |
| } |
| } |
| private int EnumFormatEtc(int dwDirection, int ppenumFormatetc) { |
| // only allow getting of data - SetData is not currently supported |
| if (dwDirection == COM.DATADIR_SET) return COM.E_NOTIMPL; |
| |
| // what types have been registered? |
| TransferData[] allowedDataTypes = new TransferData[0]; |
| for (int i = 0; i < transferAgents.length; i++){ |
| TransferData[] formats = transferAgents[i].getSupportedTypes(); |
| TransferData[] newAllowedDataTypes = new TransferData[allowedDataTypes.length + formats.length]; |
| System.arraycopy(allowedDataTypes, 0, newAllowedDataTypes, 0, allowedDataTypes.length); |
| System.arraycopy(formats, 0, newAllowedDataTypes, allowedDataTypes.length, formats.length); |
| allowedDataTypes = newAllowedDataTypes; |
| } |
| |
| OleEnumFORMATETC enumFORMATETC = new OleEnumFORMATETC(); |
| enumFORMATETC.AddRef(); |
| |
| FORMATETC[] formats = new FORMATETC[allowedDataTypes.length]; |
| for (int i = 0; i < formats.length; i++){ |
| formats[i] = allowedDataTypes[i].formatetc; |
| } |
| enumFORMATETC.setFormats(formats); |
| |
| COM.MoveMemory(ppenumFormatetc, new int[] {enumFORMATETC.getAddress()}, 4); |
| return COM.S_OK; |
| } |
| /** |
| * Returns the Control which is registered for this DragSource. This is the control that the |
| * user clicks in to initiate dragging. |
| * |
| * @return the Control which is registered for this DragSource |
| */ |
| public Control getControl () { |
| return control; |
| } |
| private int GetData(int pFormatetc, int pmedium) { |
| /* Called by a data consumer to obtain data from a source data object. |
| The GetData method renders the data described in the specified FORMATETC |
| structure and transfers it through the specified STGMEDIUM structure. |
| The caller then assumes responsibility for releasing the STGMEDIUM structure. |
| */ |
| if (pFormatetc == 0 || pmedium == 0) return COM.E_INVALIDARG; |
| |
| if (QueryGetData(pFormatetc) != COM.S_OK) return COM.DV_E_FORMATETC; |
| |
| TransferData transferData = new TransferData(); |
| transferData.formatetc = new FORMATETC(); |
| COM.MoveMemory(transferData.formatetc, pFormatetc, FORMATETC.sizeof); |
| transferData.type = transferData.formatetc.cfFormat; |
| transferData.stgmedium = new STGMEDIUM(); |
| transferData.result = COM.E_FAIL; |
| |
| DNDEvent event = new DNDEvent(); |
| event.widget = this; |
| event.time = OS.GetMessageTime(); |
| event.dataType = transferData; |
| try { |
| notifyListeners(DND.DragSetData,event); |
| } catch (Throwable e) { |
| return COM.E_FAIL; |
| } |
| |
| if (event.data == null) return COM.DV_E_FORMATETC; |
| |
| // get matching transfer agent to perform conversion |
| Transfer transfer = null; |
| for (int i = 0; i < transferAgents.length; i++){ |
| if (transferAgents[i].isSupportedType(event.dataType )){ |
| transfer = transferAgents[i]; |
| break; |
| } |
| } |
| if (transfer == null) return COM.DV_E_FORMATETC; |
| |
| transfer.javaToNative(event.data, transferData); |
| COM.MoveMemory(pmedium, transferData.stgmedium, STGMEDIUM.sizeof); |
| return transferData.result; |
| } |
| public Display getDisplay () { |
| if (control == null) DND.error(SWT.ERROR_WIDGET_DISPOSED); |
| return control.getDisplay (); |
| } |
| /** |
| * Returns the list of data types that can be transferred by this DragSource. |
| * |
| * @return the list of data types that can be transferred by this DragSource |
| */ |
| public Transfer[] getTransfer(){ |
| return transferAgents; |
| } |
| private int GiveFeedback(int dwEffect) { |
| return COM.DRAGDROP_S_USEDEFAULTCURSORS; |
| } |
| private int QueryContinueDrag(int fEscapePressed, int grfKeyState) { |
| if (fEscapePressed != 0) |
| return COM.DRAGDROP_S_CANCEL; |
| if ((grfKeyState & (OS.MK_LBUTTON | OS.MK_MBUTTON | OS.MK_RBUTTON)) == 0) |
| return COM.DRAGDROP_S_DROP; |
| |
| return COM.S_OK; |
| } |
| private int QueryGetData(int pFormatetc) { |
| if (transferAgents == null) return COM.E_FAIL; |
| TransferData transferData = new TransferData(); |
| transferData.formatetc = new FORMATETC(); |
| COM.MoveMemory(transferData.formatetc, pFormatetc, FORMATETC.sizeof); |
| transferData.type = transferData.formatetc.cfFormat; |
| |
| // is this type supported by the transfer agent? |
| for (int i = 0; i < transferAgents.length; i++){ |
| if (transferAgents[i].isSupportedType(transferData)) |
| return COM.S_OK; |
| } |
| |
| return COM.DV_E_FORMATETC; |
| } |
| private int QueryInterface(int riid, int ppvObject) { |
| if (riid == 0 || ppvObject == 0) |
| return COM.E_INVALIDARG; |
| GUID guid = new GUID(); |
| COM.MoveMemory(guid, riid, GUID.sizeof); |
| |
| if (COM.IsEqualGUID(guid, COM.IIDIUnknown) || COM.IsEqualGUID(guid, COM.IIDIDropSource)) { |
| COM.MoveMemory(ppvObject, new int[] {iDropSource.getAddress()}, 4); |
| AddRef(); |
| return COM.S_OK; |
| } |
| |
| if (COM.IsEqualGUID(guid, COM.IIDIDataObject) ) { |
| COM.MoveMemory(ppvObject, new int[] {iDataObject.getAddress()}, 4); |
| AddRef(); |
| return COM.S_OK; |
| } |
| |
| COM.MoveMemory(ppvObject, new int[] {0}, 4); |
| return COM.E_NOINTERFACE; |
| } |
| private int Release() { |
| refCount--; |
| if (refCount == 0) { |
| disposeCOMInterfaces(); |
| COM.CoFreeUnusedLibraries(); |
| } |
| return refCount; |
| } |
| /** |
| * Removes the listener from the collection of listeners who will |
| * be notified when a drag and drop operation is in progress. |
| * |
| * @param listener the listener which should be notified |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> |
| * </ul> |
| * @exception SWTException <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 DragSourceListener |
| * @see #addDragListener |
| */ |
| public void removeDragListener(DragSourceListener listener) { |
| if (listener == null) DND.error (SWT.ERROR_NULL_ARGUMENT); |
| removeListener (DND.DragStart, listener); |
| removeListener (DND.DragEnd, listener); |
| removeListener (DND.DragSetData, listener); |
| } |
| private static int CFSTR_PERFORMEDDROPEFFECT = Transfer.registerType("Performed DropEffect"); //$NON-NLS-1$ |
| private int SetData(int pFormatetc, int pmedium, int fRelease) { |
| if (pFormatetc == 0 || pmedium == 0) return COM.E_INVALIDARG; |
| FORMATETC formatetc = new FORMATETC(); |
| COM.MoveMemory(formatetc, pFormatetc, FORMATETC.sizeof); |
| if (formatetc.cfFormat == CFSTR_PERFORMEDDROPEFFECT && formatetc.tymed == COM.TYMED_HGLOBAL) { |
| STGMEDIUM stgmedium = new STGMEDIUM(); |
| COM.MoveMemory(stgmedium, pmedium,STGMEDIUM.sizeof); |
| int[] ptrEffect = new int[1]; |
| OS.MoveMemory(ptrEffect, stgmedium.unionField,4); |
| int[] effect = new int[1]; |
| OS.MoveMemory(effect, ptrEffect[0],4); |
| dataEffect = osToOp(effect[0]); |
| } |
| if (fRelease == 1) { |
| COM.ReleaseStgMedium(pmedium); |
| } |
| return COM.S_OK; |
| } |
| /** |
| * Specifies the list of data types that can be transferred by this DragSource. |
| * The application must be able to provide data to match each of these types when |
| * a successful drop has occurred. |
| * |
| * @param transferAgents a list of Transfer objects which define the types of data that can be |
| * dragged from this source |
| */ |
| public void setTransfer(Transfer[] transferAgents){ |
| this.transferAgents = transferAgents; |
| } |
| protected void checkSubclass () { |
| String name = getClass().getName (); |
| String validName = DragSource.class.getName(); |
| if (!validName.equals(name)) { |
| DND.error (SWT.ERROR_INVALID_SUBCLASS); |
| } |
| } |
| } |