Mercurial > projects > dwt-mac
view dwt/custom/StyledTextDropTargetEffect.d @ 143:c41e13089a3c
Fixes #21
author | Jacob Carlborg <doob@me.com> |
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date | Fri, 05 Jun 2009 01:25:10 +0200 |
parents | 6337764516f1 |
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/******************************************************************************* * Copyright (c) 2000, 2008 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.custom.StyledTextDropTargetEffect; import dwt.DWT; import dwt.dnd.DND; import dwt.dnd.DropTargetAdapter; import dwt.dnd.DropTargetEffect; import dwt.dnd.DropTargetEvent; import dwt.graphics.FontMetrics; import dwt.graphics.GC; import dwt.graphics.Point; import dwt.graphics.Rectangle; import dwt.widgets.Event; import dwt.widgets.Listener; import dwt.custom.StyledText; import dwt.custom.StyledTextContent; static import tango.core.Exception; import dwt.dwthelper.utils; /** * This adapter class provides a default drag under effect (eg. select and scroll) * when a drag occurs over a <code>StyledText</code>. * * <p>Classes that wish to provide their own drag under effect for a <code>StyledText</code> * can extend this class, override the <code>StyledTextDropTargetEffect.dragOver</code> * method and override any other applicable methods in <code>StyledTextDropTargetEffect</code> to * display their own drag under effect.</p> * * Subclasses that override any methods of this class should call the corresponding * <code>super</code> method to get the default drag under effect implementation. * * <p>The feedback value is either one of the FEEDBACK constants defined in * class <code>DND</code> which is applicable to instances of this class, * or it 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> effect constants. * </p> * <p> * <dl> * <dt><b>Feedback:</b></dt> * <dd>FEEDBACK_SELECT, FEEDBACK_SCROLL</dd> * </dl> * </p> * * @see DropTargetAdapter * @see DropTargetEvent * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a> * * @since 3.3 */ public class StyledTextDropTargetEffect : DropTargetEffect { static final int CARET_WIDTH = 2; static final int SCROLL_HYSTERESIS = 100; // milli seconds static final int SCROLL_TOLERANCE = 20; // pixels int currentOffset = -1; long scrollBeginTime; int scrollX = -1, scrollY = -1; Listener paintListener; /** * Creates a new <code>StyledTextDropTargetEffect</code> to handle the drag under effect on the specified * <code>StyledText</code>. * * @param styledText the <code>StyledText</code> over which the user positions the cursor to drop the data */ public this(StyledText styledText) { super(styledText); paintListener = new class() Listener { public void handleEvent (Event event) { if (currentOffset !is -1) { StyledText text = cast(StyledText) getControl(); Point position = text.getLocationAtOffset(currentOffset); int height = text.getLineHeight(currentOffset); event.gc.setBackground(event.display.getSystemColor (DWT.COLOR_BLACK)); event.gc.fillRectangle(position.x, position.y, CARET_WIDTH, height); } } }; } /** * This implementation of <code>dragEnter</code> provides a default drag under effect * for the feedback specified in <code>event.feedback</code>. * * For additional information see <code>DropTargetAdapter.dragEnter</code>. * * Subclasses that override this method should call <code>super.dragEnter(event)</code> * to get the default drag under effect implementation. * * @param event the information associated with the drag start event * * @see DropTargetAdapter * @see DropTargetEvent */ public override void dragEnter(DropTargetEvent event) { currentOffset = -1; scrollBeginTime = 0; scrollX = -1; scrollY = -1; getControl().removeListener(DWT.Paint, paintListener); getControl().addListener (DWT.Paint, paintListener); } /** * This implementation of <code>dragLeave</code> provides a default drag under effect * for the feedback specified in <code>event.feedback</code>. * * For additional information see <code>DropTargetAdapter.dragLeave</code>. * * Subclasses that override this method should call <code>super.dragLeave(event)</code> * to get the default drag under effect implementation. * * @param event the information associated with the drag leave event * * @see DropTargetAdapter * @see DropTargetEvent */ public override void dragLeave(DropTargetEvent event) { StyledText text = cast(StyledText) getControl(); if (currentOffset !is -1) { refreshCaret(text, currentOffset, -1); } text.removeListener(DWT.Paint, paintListener); scrollBeginTime = 0; scrollX = -1; scrollY = -1; } /** * This implementation of <code>dragOver</code> provides a default drag under effect * for the feedback specified in <code>event.feedback</code>. * * For additional information see <code>DropTargetAdapter.dragOver</code>. * * Subclasses that override this method should call <code>super.dragOver(event)</code> * to get the default drag under effect implementation. * * @param event the information associated with the drag over event * * @see DropTargetAdapter * @see DropTargetEvent * @see DND#FEEDBACK_SELECT * @see DND#FEEDBACK_SCROLL */ public override void dragOver(DropTargetEvent event) { int effect = event.feedback; StyledText text = cast(StyledText) getControl(); Point pt = text.getDisplay().map(null, text, event.x, event.y); if ((effect & DND.FEEDBACK_SCROLL) is 0) { scrollBeginTime = 0; scrollX = scrollY = -1; } else { if (text.getCharCount() is 0) { scrollBeginTime = 0; scrollX = scrollY = -1; } else { if (scrollX !is -1 && scrollY !is -1 && scrollBeginTime !is 0 && (pt.x >= scrollX && pt.x <= (scrollX + SCROLL_TOLERANCE) || pt.y >= scrollY && pt.y <= (scrollY + SCROLL_TOLERANCE))) { if (System.currentTimeMillis() >= scrollBeginTime) { Rectangle area = text.getClientArea(); GC gc = new GC(text); FontMetrics fm = gc.getFontMetrics(); gc.dispose(); int charWidth = fm.getAverageCharWidth(); int scrollAmount = 10*charWidth; if (pt.x < area.x + 3*charWidth) { int leftPixel = text.getHorizontalPixel(); text.setHorizontalPixel(leftPixel - scrollAmount); } if (pt.x > area.width - 3*charWidth) { int leftPixel = text.getHorizontalPixel(); text.setHorizontalPixel(leftPixel + scrollAmount); } int lineHeight = text.getLineHeight(); if (pt.y < area.y + lineHeight) { int topPixel = text.getTopPixel(); text.setTopPixel(topPixel - lineHeight); } if (pt.y > area.height - lineHeight) { int topPixel = text.getTopPixel(); text.setTopPixel(topPixel + lineHeight); } scrollBeginTime = 0; scrollX = scrollY = -1; } } else { scrollBeginTime = System.currentTimeMillis() + SCROLL_HYSTERESIS; scrollX = pt.x; scrollY = pt.y; } } } if ((effect & DND.FEEDBACK_SELECT) !is 0) { int[] trailing = new int [1]; int newOffset = text.getOffsetAtPoint(pt.x, pt.y, trailing, false); newOffset += trailing [0]; if (newOffset !is currentOffset) { refreshCaret(text, currentOffset, newOffset); currentOffset = newOffset; } } } void refreshCaret(StyledText text, int oldOffset, int newOffset) { if (oldOffset !is newOffset) { if (oldOffset !is -1) { Point oldPos = text.getLocationAtOffset(oldOffset); int oldHeight = text.getLineHeight(oldOffset); text.redraw (oldPos.x, oldPos.y, CARET_WIDTH, oldHeight, false); } if (newOffset !is -1) { Point newPos = text.getLocationAtOffset(newOffset); int newHeight = text.getLineHeight(newOffset); text.redraw (newPos.x, newPos.y, CARET_WIDTH, newHeight, false); } } } /** * This implementation of <code>dropAccept</code> provides a default drag under effect * for the feedback specified in <code>event.feedback</code>. * * For additional information see <code>DropTargetAdapter.dropAccept</code>. * * Subclasses that override this method should call <code>super.dropAccept(event)</code> * to get the default drag under effect implementation. * * @param event the information associated with the drop accept event * * @see DropTargetAdapter * @see DropTargetEvent */ public override void dropAccept(DropTargetEvent event) { if (currentOffset !is -1) { StyledText text = cast(StyledText) getControl(); text.setSelection(currentOffset); currentOffset = -1; } } }