/******************************************************************************* * 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.graphics.*;import org.eclipse.swt.widgets.*;import org.eclipse.swt.internal.win32.LVITEM;import org.eclipse.swt.internal.win32.OS;class TableDragUnderEffect extends DragUnderEffect {	private Table table;	private int currentEffect = DND.FEEDBACK_NONE;	private int[] selection = new int[0];	private TableItem scrollItem;	private long scrollBeginTime;	private static final int SCROLL_HYSTERESIS = 600; // milli seconds	TableDragUnderEffect(Table table) {	this.table = table;}void show(int effect, int x, int y) {	TableItem item = findItem(x, y);	if (item == null) effect = DND.FEEDBACK_NONE;	if (currentEffect == DND.FEEDBACK_NONE && effect != DND.FEEDBACK_NONE) {		selection = table.getSelectionIndices();		table.deselectAll();	}	scrollHover(effect, item, x, y);	setDragUnderEffect(effect, item);	if (currentEffect != DND.FEEDBACK_NONE && effect == DND.FEEDBACK_NONE) {		table.select(selection);		selection = new int[0];	}	currentEffect = effect;}private TableItem findItem(int x, int y){	Point coordinates = new Point(x, y);	coordinates = table.toControl(coordinates);	Rectangle area = table.getClientArea();	if (!area.contains(coordinates)) return null;	TableItem item = table.getItem(coordinates);	if (item != null) return item;	// Scan across the width of the table	for (int x1 = area.x; x1 < area.x + area.width; x1++) {		Point pt = new Point(x1, coordinates.y);		item = table.getItem(pt);		if (item != null) return item;	}	return null;}private void setDragUnderEffect(int effect, TableItem item) {		if ((effect & DND.FEEDBACK_SELECT) != 0) {		setDropSelection(item);		return;	}	if ((currentEffect & DND.FEEDBACK_SELECT) != 0) {		setDropSelection(null);	}}private void setDropSelection (TableItem item) {	LVITEM lvItem = new LVITEM ();	lvItem.stateMask = OS.LVIS_DROPHILITED;	// remove all drop highlighting	OS.SendMessage (table.handle, OS.LVM_SETITEMSTATE, -1, lvItem);	if (item != null) {		int index = table.indexOf(item);		lvItem.state = OS.LVIS_DROPHILITED;		OS.SendMessage (table.handle, OS.LVM_SETITEMSTATE, index, lvItem);	}}private void scrollHover (int effect, TableItem item, int x, int y) {	if ((effect & DND.FEEDBACK_SCROLL) == 0) {		scrollBeginTime = 0;		scrollItem = null;		return;	}	if (scrollItem == item && scrollBeginTime != 0) {		if (System.currentTimeMillis() >= scrollBeginTime) {			scroll(item, x, y);			scrollBeginTime = 0;			scrollItem = null;		}		return;	}	scrollBeginTime = System.currentTimeMillis() + SCROLL_HYSTERESIS;	scrollItem = item;}private void scroll(TableItem item, int x, int y) {	if (item == null) return;	Point coordinates = new Point(x, y);	coordinates = table.toControl(coordinates);	Rectangle area = table.getClientArea();	int top = table.getTopIndex();	int newTop = -1;	// scroll if two lines from top or bottom	int scroll_width = 2*table.getItemHeight();	if (coordinates.y < area.y + scroll_width) {		newTop = Math.max(0, top - 1);	} else if (coordinates.y > area.y + area.height - scroll_width) {		newTop = Math.min(table.getItemCount() - 1, top + 1);	}	if (newTop != -1 && newTop != top) {		table.setTopIndex(newTop);	}}}