PIPELineWithTextEdgePainter.java

/*
 * PIPELineWithTextEdgePainter.java
 */

package pipe.gui.reachability;

import net.sourceforge.jpowergraph.SubGraphHighlighter;
import net.sourceforge.jpowergraph.painters.edge.LineEdgePainter;
import net.sourceforge.jpowergraph.pane.JGraphPane;
import net.sourceforge.jpowergraph.swtswinginteraction.JPowerGraphGraphics;
import net.sourceforge.jpowergraph.swtswinginteraction.color.JPowerGraphColor;
import net.sourceforge.jpowergraph.swtswinginteraction.geometry.JPowerGraphPoint;

import java.awt.geom.Point2D;


//REMARK: this class extends a jpowergraph's class which is LGPL

/**
 * This class defines the edge painter for edges with text used in the reachability graph
 */
public class PIPELineWithTextEdgePainter<T extends DirectedTextEdge> extends LineEdgePainter<T> {


    /**
     * Constructor
     * @param dragging dragging
     * @param normal normal
     * @param isDashedLine true if dashed
     */
    public PIPELineWithTextEdgePainter(JPowerGraphColor dragging, JPowerGraphColor normal, boolean isDashedLine) {
        super(dragging, normal, isDashedLine);
    }


    /**
     * Displays the edge and text on the graph
     * @param graphPane graph pane
     * @param g graphics
     * @param edge edge
     * @param theSubGraphHighlighter highlighter 
     */
    @Override
    public void paintEdge(JGraphPane graphPane, JPowerGraphGraphics g, T edge,
                          SubGraphHighlighter theSubGraphHighlighter) {

        JPowerGraphPoint from = graphPane.getScreenPointForNode(edge.getFrom());
        JPowerGraphPoint to = graphPane.getScreenPointForNode(edge.getTo());
        JPowerGraphColor oldFGColor = g.getForeground();
        JPowerGraphColor oldBGColor = g.getBackground();

        g.setForeground(getEdgeColor(edge, graphPane, false, theSubGraphHighlighter));
        g.setBackground(getEdgeColor(edge, graphPane, false, theSubGraphHighlighter));
        paintArrow(g, from.x, from.y, to.x, to.y, false);
        g.setForeground(oldFGColor);
        g.setBackground(oldBGColor);

        String text = edge.getText();

        Point2D midpoint = new Point2D.Double((from.x + 2 * to.x) / 3, (from.y + 2 * to.y) / 3);

        double slopeTop = from.y - to.y;
        double slopeBottom = from.x - to.x;
        double slope = Double.POSITIVE_INFINITY;
        if (slopeBottom != 0) {
            slope = slopeTop / slopeBottom;
        }

        int stringWidth = g.getStringWidth(text);

        if (slope > 2.0) {
            double xDiff = -(stringWidth + 10);
            double yDiff = -10;
            if (from.y < to.y) {
                yDiff = -5;
            }
            midpoint.setLocation(midpoint.getX() + xDiff, midpoint.getY() + yDiff);
        } else if (slope < -2.0) {
            double xDiff = 10;
            double yDiff = -10;
            if (from.y < to.y) {
                yDiff = -5;
            }
            midpoint.setLocation(midpoint.getX() + xDiff, midpoint.getY() + yDiff);
        } else if (slope > 0.4 || slope < -0.4) {
            double xDiff = 10;
            double yDiff = -10;
            if (from.x > to.x) {
                xDiff = -(stringWidth + 10);
            }
            if (from.y < to.y) {
                yDiff = -5;
            }
            midpoint.setLocation(midpoint.getX() + xDiff, midpoint.getY() + yDiff);
        } else {
            double xDiff = -stringWidth / 2;
            double yDiff = -20;
            midpoint.setLocation(midpoint.getX() + xDiff, midpoint.getY() + yDiff);
        }

        g.setForeground(getEdgeColor(edge, graphPane, false, theSubGraphHighlighter));
        g.drawString(text, (int) midpoint.getX(), (int) midpoint.getY(), 1);
        g.setForeground(oldFGColor);
    }


    /**
     * Paints an arrow in the correct direction
     * @param g graphics
     * @param x1 coordinate
     * @param y1 coordinate
     * @param x2 coordinate
     * @param y2 coordinate
     * @param isDashedLine true if dashed 
     */
    public static void paintArrow(JPowerGraphGraphics g, int x1, int y1, int x2, int y2, boolean isDashedLine) {
        double middleX = (x1 + 2 * x2) / 3;
        double middleY = (y1 + 2 * y2) / 3;

        double slope = Math.atan2(y2 - y1, x2 - x1);

        double pinnacleX = middleX + SQUARE_ROOT_OF_3_OVER_2 * ARROW_BASE_LENGTH * Math.cos(slope);
        double pinnacleY = middleY + SQUARE_ROOT_OF_3_OVER_2 * ARROW_BASE_LENGTH * Math.sin(slope);
        double backwardX = pinnacleX + ARROW_BASE_LENGTH * Math.cos(slope + Math.PI + Math.PI / 6.0);
        double backwardY = pinnacleY + ARROW_BASE_LENGTH * Math.sin(slope + Math.PI + Math.PI / 6.0);
        double forwardX = pinnacleX + ARROW_BASE_LENGTH * Math.cos(slope + Math.PI - Math.PI / 6.0);
        double forwardY = pinnacleY + ARROW_BASE_LENGTH * Math.sin(slope + Math.PI - Math.PI / 6.0);
        double baseX = (forwardX + backwardX) / 2.0;
        double baseY = (forwardY + backwardY) / 2.0;

        g.setLineDashed(isDashedLine);
        g.drawLine(x1, y1, (int) baseX, (int) baseY);
        g.drawLine((int) pinnacleX, (int) pinnacleY, x2, y2);
        g.setLineDashed(false);
        g.fillPolygon(new int[]{(int) backwardX, (int) backwardY, (int) pinnacleX, (int) pinnacleY, (int) forwardX,
                (int) forwardY});
    }

}