| /******************************************************************************* |
| * Copyright (c) 2007, 2012 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.swt.dnd; |
| |
| import org.eclipse.swt.*; |
| import org.eclipse.swt.graphics.*; |
| import org.eclipse.swt.internal.*; |
| import org.eclipse.swt.internal.DPIUtil.*; |
| import org.eclipse.swt.internal.win32.*; |
| import org.eclipse.swt.widgets.*; |
| |
| /** |
| * This class provides default implementations to display a source image |
| * when a drag is initiated from a <code>Tree</code>. |
| * |
| * <p>Classes that wish to provide their own source image for a <code>Tree</code> can |
| * extend <code>TreeDragSourceEffect</code> class and override the <code>TreeDragSourceEffect.dragStart</code> |
| * method and set the field <code>DragSourceEvent.image</code> with their own image.</p> |
| * |
| * Subclasses that override any methods of this class must call the corresponding |
| * <code>super</code> method to get the default drag under effect implementation. |
| * |
| * @see DragSourceEffect |
| * @see DragSourceEvent |
| * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a> |
| * |
| * @since 3.3 |
| */ |
| public class TreeDragSourceEffect extends DragSourceEffect { |
| Image dragSourceImage = null; |
| |
| /** |
| * Creates a new <code>TreeDragSourceEffect</code> to handle drag effect |
| * from the specified <code>Tree</code>. |
| * |
| * @param tree the <code>Tree</code> that the user clicks on to initiate the drag |
| */ |
| public TreeDragSourceEffect(Tree tree) { |
| super(tree); |
| } |
| |
| /** |
| * This implementation of <code>dragFinished</code> disposes the image |
| * that was created in <code>TreeDragSourceEffect.dragStart</code>. |
| * |
| * Subclasses that override this method should call <code>super.dragFinished(event)</code> |
| * to dispose the image in the default implementation. |
| * |
| * @param event the information associated with the drag finished event |
| */ |
| @Override |
| public void dragFinished(DragSourceEvent event) { |
| if (dragSourceImage != null) dragSourceImage.dispose(); |
| dragSourceImage = null; |
| } |
| |
| /** |
| * This implementation of <code>dragStart</code> will create a default |
| * image that will be used during the drag. The image should be disposed |
| * when the drag is completed in the <code>TreeDragSourceEffect.dragFinished</code> |
| * method. |
| * |
| * Subclasses that override this method should call <code>super.dragStart(event)</code> |
| * to use the image from the default implementation. |
| * |
| * @param event the information associated with the drag start event |
| */ |
| @Override |
| public void dragStart(DragSourceEvent event) { |
| event.image = getDragSourceImage(event); |
| } |
| |
| Image getDragSourceImage(DragSourceEvent event) { |
| if (dragSourceImage != null) dragSourceImage.dispose(); |
| dragSourceImage = null; |
| SHDRAGIMAGE shdi = new SHDRAGIMAGE(); |
| int DI_GETDRAGIMAGE = OS.RegisterWindowMessage (new TCHAR (0, "ShellGetDragImage", true)); //$NON-NLS-1$ |
| if (OS.SendMessage (control.handle, DI_GETDRAGIMAGE, 0, shdi) != 0) { |
| if ((control.getStyle() & SWT.MIRRORED) != 0) { |
| event.offsetX = shdi.sizeDragImage.cx - shdi.ptOffset.x; |
| } else { |
| event.offsetX = shdi.ptOffset.x; |
| } |
| event.offsetY = shdi.ptOffset.y; |
| long hImage = shdi.hbmpDragImage; |
| if (hImage != 0) { |
| BITMAP bm = new BITMAP (); |
| OS.GetObject (hImage, BITMAP.sizeof, bm); |
| int srcWidth = bm.bmWidth; |
| int srcHeight = bm.bmHeight; |
| |
| /* Create resources */ |
| long hdc = OS.GetDC (0); |
| long srcHdc = OS.CreateCompatibleDC (hdc); |
| long oldSrcBitmap = OS.SelectObject (srcHdc, hImage); |
| long memHdc = OS.CreateCompatibleDC (hdc); |
| BITMAPINFOHEADER bmiHeader = new BITMAPINFOHEADER (); |
| bmiHeader.biSize = BITMAPINFOHEADER.sizeof; |
| bmiHeader.biWidth = srcWidth; |
| bmiHeader.biHeight = -srcHeight; |
| bmiHeader.biPlanes = 1; |
| bmiHeader.biBitCount = 32; |
| bmiHeader.biCompression = OS.BI_RGB; |
| byte [] bmi = new byte[BITMAPINFOHEADER.sizeof]; |
| OS.MoveMemory (bmi, bmiHeader, BITMAPINFOHEADER.sizeof); |
| long [] pBits = new long [1]; |
| long memDib = OS.CreateDIBSection (0, bmi, OS.DIB_RGB_COLORS, pBits, 0, 0); |
| if (memDib == 0) SWT.error (SWT.ERROR_NO_HANDLES); |
| long oldMemBitmap = OS.SelectObject (memHdc, memDib); |
| |
| BITMAP dibBM = new BITMAP (); |
| OS.GetObject (memDib, BITMAP.sizeof, dibBM); |
| int sizeInBytes = dibBM.bmWidthBytes * dibBM.bmHeight; |
| |
| /* Get the foreground pixels */ |
| OS.BitBlt (memHdc, 0, 0, srcWidth, srcHeight, srcHdc, 0, 0, OS.SRCCOPY); |
| byte[] srcData = new byte [sizeInBytes]; |
| OS.MoveMemory (srcData, dibBM.bmBits, sizeInBytes); |
| |
| PaletteData palette = new PaletteData(0xFF00, 0xFF0000, 0xFF000000); |
| ImageData data = new ImageData(srcWidth, srcHeight, bm.bmBitsPixel, palette, bm.bmWidthBytes, srcData); |
| if (shdi.crColorKey == -1) { |
| byte[] alphaData = new byte[srcWidth * srcHeight]; |
| int spinc = dibBM.bmWidthBytes - srcWidth * 4; |
| int ap = 0, sp = 3; |
| for (int y = 0; y < srcHeight; ++y) { |
| for (int x = 0; x < srcWidth; ++x) { |
| alphaData [ap++] = srcData [sp]; |
| sp += 4; |
| } |
| sp += spinc; |
| } |
| data.alphaData = alphaData; |
| } else { |
| data.transparentPixel = shdi.crColorKey << 8; |
| } |
| Display display = control.getDisplay (); |
| dragSourceImage = new Image (display, new AutoScaleImageDataProvider(display, data, DPIUtil.getDeviceZoom())); |
| OS.SelectObject (memHdc, oldMemBitmap); |
| OS.DeleteDC (memHdc); |
| OS.DeleteObject (memDib); |
| OS.SelectObject (srcHdc, oldSrcBitmap); |
| OS.DeleteDC (srcHdc); |
| OS.ReleaseDC (0, hdc); |
| OS.DeleteObject (hImage); |
| return dragSourceImage; |
| } |
| } |
| return null; |
| } |
| } |