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/*******************************************************************************
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* Copyright (c) 2000, 2010 IBM Corporation and others.
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* All rights reserved. This program and the accompanying materials
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* are made available under the terms of the Eclipse Public License v1.0
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* which accompanies this distribution, and is available at
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* http://www.eclipse.org/legal/epl-v10.html
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*
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* Contributors:
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* IBM Corporation - initial API and implementation
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*******************************************************************************/
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package org.eclipse.draw2d;
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import org.eclipse.draw2d.geometry.Point;
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/**
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* A ConnectionLocator that is used to place figures at the midpoint between two
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* points on a {@link org.eclipse.draw2d.Connection}.
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*/
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public class MidpointLocator extends ConnectionLocator {
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private int index;
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/**
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* Constructs a MidpointLocator with associated Connection <i>c</i> and
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* index <i>i</i>. The points at index i and i+1 on the connection are used
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* to calculate the midpoint of the line segment.
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*
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* @param c
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* the connection associated with the locator
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* @param i
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* the point from where the connection's midpoint will be
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* calculated.
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* @since 2.0
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*/
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public MidpointLocator(Connection c, int i) {
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super(c);
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index = i;
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}
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/**
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* Returns this MidpointLocator's index. This integer represents the
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* position of the start point in this MidpointLocator's associated
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* {@link Connection} from where midpoint calculation will be made.
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*
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* @return the locator's index
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* @since 2.0
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*/
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protected int getIndex() {
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return index;
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}
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/**
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* Returns the point of reference associated with this locator. This point
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* will be midway between points at 'index' and 'index' + 1.
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*
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* @return the reference point
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* @since 2.0
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*/
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protected Point getReferencePoint() {
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Connection conn = getConnection();
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Point p = Point.SINGLETON;
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Point p1 = conn.getPoints().getPoint(getIndex());
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Point p2 = conn.getPoints().getPoint(getIndex() + 1);
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conn.translateToAbsolute(p1);
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conn.translateToAbsolute(p2);
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p.x = (p2.x - p1.x) / 2 + p1.x;
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p.y = (p2.y - p1.y) / 2 + p1.y;
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return p;
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}
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}
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