Arrow.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional information regarding
 * copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License. You may obtain a
 * copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package org.apache.geode.sequence;

import java.awt.*;
import java.awt.geom.GeneralPath;

/**
 * Created by IntelliJ IDEA. User: dsmith Date: Nov 12, 2010 Time: 12:02:20 PM To change this
 * template use File | Settings | File Templates.
 */
public class Arrow {
  private static int ARROW_WIDTH = 10;
  private static int CIRCLE_WIDTH = 6;
  private static int LABEL_OFFSET = 10;

  private final String label;
  private final LifelineState startingState;
  private final LifelineState endingState;

  public Arrow(String label, LifelineState startingState, LifelineState endingState) {
    this.label = label;
    this.startingState = startingState;
    this.endingState = endingState;
  }


  public void paint(Graphics2D g) {
    Rectangle boundary = g.getClipBounds();
    int y = endingState.getStartY();

    // don't paint if we're not in the clip area
    if (y + ARROW_WIDTH < boundary.getMinY() || y - ARROW_WIDTH > boundary.getMaxY()) {
      return;
    }

    // TODO - we need to clip by X coordinate as well.

    boolean isReflexsive = getStartingLine() == getEndingLine();
    if (isReflexsive) {
      paintReflexive(g);
    } else {
      paintNormal(g);
    }
  }

  private Lifeline getStartingLine() {
    return startingState.getLine();
  }

  private Lifeline getEndingLine() {
    return endingState.getLine();
  }

  private void paintReflexive(Graphics2D g) {
    Lifeline startingLine = getStartingLine();
    int x = startingLine.getX();
    int y = endingState.getStartY();

    g.drawArc(x + startingLine.getWidth() - ARROW_WIDTH / 2, y - ARROW_WIDTH, ARROW_WIDTH,
        ARROW_WIDTH, 90, -180);
    g.drawString(label, x + startingLine.getWidth() + LABEL_OFFSET, y);
    // GeneralPath path = new GeneralPath();
    // path.moveTo(x, y - ARROW_WIDTH);
    // path.quadTo(x, y - ARROW_WIDTH);
  }

  private void paintNormal(Graphics2D g) {
    Lifeline startingLine = getStartingLine();
    Lifeline endingLine = getEndingLine();
    int x1 = startingLine.getX();
    int x2 = endingLine.getX();
    int y = endingState.getStartY();

    if (x2 > x1) {
      int startX = x1 + startingLine.getWidth();
      int endX = x2;

      GeneralPath path = new GeneralPath();
      path.moveTo(startX, y);
      path.lineTo(endX, y);
      path.lineTo(endX - ARROW_WIDTH, y - ARROW_WIDTH);
      path.moveTo(endX, y);
      path.lineTo(endX - ARROW_WIDTH, y + ARROW_WIDTH);
      g.draw(path);
      g.fillArc(startX, y - CIRCLE_WIDTH / 2, CIRCLE_WIDTH, CIRCLE_WIDTH, 0, 360);
      g.drawString(label, startX + LABEL_OFFSET, y - LABEL_OFFSET);
    } else {
      int startX = x1;
      int endX = x2 + endingLine.getWidth();

      GeneralPath path = new GeneralPath();
      path.moveTo(startX, y);
      path.lineTo(endX, y);
      path.lineTo(endX + ARROW_WIDTH, y - ARROW_WIDTH);
      path.moveTo(endX, y);
      path.lineTo(endX + ARROW_WIDTH, y + ARROW_WIDTH);
      g.draw(path);
      int labelWidth = g.getFontMetrics().stringWidth(label);
      g.fillArc(startX - CIRCLE_WIDTH / 2, y - CIRCLE_WIDTH / 2, CIRCLE_WIDTH, CIRCLE_WIDTH, 0,
          360);
      g.drawString(label, startX - LABEL_OFFSET - labelWidth, y - LABEL_OFFSET);
    }
  }

  public LifelineState getStartingState() {
    return startingState;
  }
}