ArrowRenderer.java

/*
Copyright 2008-2011 Gephi
Authors : Yudi Xue <yudi.xue@usask.ca>, Mathieu Bastian
Website : http://www.gephi.org

This file is part of Gephi.

DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

Copyright 2011 Gephi Consortium. All rights reserved.

The contents of this file are subject to the terms of either the GNU
General Public License Version 3 only ("GPL") or the Common
Development and Distribution License("CDDL") (collectively, the
"License"). You may not use this file except in compliance with the
License. You can obtain a copy of the License at
http://gephi.org/about/legal/license-notice/
or /cddl-1.0.txt and /gpl-3.0.txt. See the License for the
specific language governing permissions and limitations under the
License.  When distributing the software, include this License Header
Notice in each file and include the License files at
/cddl-1.0.txt and /gpl-3.0.txt. If applicable, add the following below the
License Header, with the fields enclosed by brackets [] replaced by
your own identifying information:
"Portions Copyrighted [year] [name of copyright owner]"

If you wish your version of this file to be governed by only the CDDL
or only the GPL Version 3, indicate your decision by adding
"[Contributor] elects to include this software in this distribution
under the [CDDL or GPL Version 3] license." If you do not indicate a
single choice of license, a recipient has the option to distribute
your version of this file under either the CDDL, the GPL Version 3 or
to extend the choice of license to its licensees as provided above.
However, if you add GPL Version 3 code and therefore, elected the GPL
Version 3 license, then the option applies only if the new code is
made subject to such option by the copyright holder.

Contributor(s):

Portions Copyrighted 2011 Gephi Consortium.
 */
package org.gephi.preview.plugin.renderers;

import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfGState;
import java.awt.Color;
import java.util.Locale;
import org.gephi.graph.api.Edge;
import org.gephi.preview.api.Item;
import org.gephi.preview.api.PreviewModel;
import org.gephi.preview.api.PreviewProperties;
import org.gephi.preview.api.PreviewProperty;
import org.gephi.preview.api.ProcessingTarget;
import org.gephi.preview.api.RenderTarget;
import org.gephi.preview.api.SVGTarget;
import org.gephi.preview.api.PDFTarget;
import org.gephi.preview.plugin.items.EdgeItem;
import org.gephi.preview.plugin.items.NodeItem;
import org.gephi.preview.spi.Renderer;
import org.gephi.preview.types.EdgeColor;
import org.openide.util.NbBundle;
import org.openide.util.lookup.ServiceProvider;
import org.w3c.dom.Element;
import processing.core.PGraphics;
import processing.core.PVector;

/**
 *
 * @author Yudi Xue, Mathieu Bastian
 */
@ServiceProvider(service = Renderer.class, position = 200)
public class ArrowRenderer implements Renderer {

    //Const
    protected final float BASE_RATIO = 0.5f;
    //Default values
    protected float defaultArrowSize = 3f;

    public void preProcess(PreviewModel previewModel) {
    }

    public void render(Item item, RenderTarget target, PreviewProperties properties) {
        float size = properties.getFloatValue(PreviewProperty.ARROW_SIZE);
        if (size > 0) {
            //Get nodes
            Item sourceItem = item.getData(EdgeRenderer.SOURCE);
            Item targetItem = item.getData(EdgeRenderer.TARGET);

            //Weight and color
            Float weight = item.getData(EdgeItem.WEIGHT);
            EdgeColor edgeColor = (EdgeColor) properties.getValue(PreviewProperty.EDGE_COLOR);
            Color color = edgeColor.getColor((Color) item.getData(EdgeItem.COLOR),
                    (Color) sourceItem.getData(NodeItem.COLOR),
                    (Color) targetItem.getData(NodeItem.COLOR));
            int alpha = (int) ((properties.getFloatValue(PreviewProperty.EDGE_OPACITY) / 100f) * 255f);
            color = new Color(color.getRed(), color.getGreen(), color.getBlue(), alpha);

            //Size and radius
            float radius = properties.getFloatValue(PreviewProperty.EDGE_RADIUS);

            size *= weight;
            radius = -(radius + (Float) targetItem.getData(NodeItem.SIZE) / 2f + Math.max(0, properties.getFloatValue(PreviewProperty.NODE_BORDER_WIDTH)));

            //Avoid arrow from passing the node's center:
            if (radius > 0) {
                radius = 0;
            }

            //3 points
            Float x1 = sourceItem.getData(NodeItem.X);
            Float x2 = targetItem.getData(NodeItem.X);
            Float y1 = sourceItem.getData(NodeItem.Y);
            Float y2 = targetItem.getData(NodeItem.Y);

            if (properties.getBooleanValue(PreviewProperty.EDGE_CURVED)) {
            } else {
                renderStraight(target, item, x1, y1, x2, y2, radius, size, color);
            }
        }
    }

    public void renderStraight(RenderTarget target, Item item, float x1, float y1, float x2, float y2, float radius, float size, Color color) {
        Edge edge = (Edge) item.getSource();
        PVector direction = new PVector(x2, y2);
        direction.sub(new PVector(x1, y1));
        direction.normalize();

        PVector p1 = new PVector(direction.x, direction.y);
        p1.mult(radius);
        p1.add(new PVector(x2, y2));

        PVector p1r = new PVector(direction.x, direction.y);
        p1r.mult(radius - size);
        p1r.add(new PVector(x2, y2));

        PVector p2 = new PVector(-direction.y, direction.x);
        p2.mult(size * BASE_RATIO);
        p2.add(p1r);

        PVector p3 = new PVector(direction.y, -direction.x);
        p3.mult(size * BASE_RATIO);
        p3.add(p1r);

        if (target instanceof ProcessingTarget) {
            PGraphics graphics = ((ProcessingTarget) target).getGraphics();
            graphics.noStroke();
            graphics.fill(color.getRed(), color.getGreen(), color.getBlue(), color.getAlpha());
            graphics.triangle(p1.x, p1.y, p2.x, p2.y, p3.x, p3.y);
        } else if (target instanceof SVGTarget) {
            SVGTarget svgTarget = (SVGTarget) target;
            Element arrowElem = svgTarget.createElement("polyline");
            arrowElem.setAttribute("points", String.format(Locale.ENGLISH, "%f,%f %f,%f %f,%f",
                    p1.x, p1.y, p2.x, p2.y, p3.x, p3.y));
            arrowElem.setAttribute("class", edge.getSource().getNodeData().getId() + " " + edge.getTarget().getNodeData().getId());
            arrowElem.setAttribute("fill", svgTarget.toHexString(color));
            arrowElem.setAttribute("fill-opacity", (color.getAlpha() / 255f) + "");
            arrowElem.setAttribute("stroke", "none");
            svgTarget.getTopElement(SVGTarget.TOP_ARROWS).appendChild(arrowElem);
        } else if (target instanceof PDFTarget) {
            PDFTarget pdfTarget = (PDFTarget) target;
            PdfContentByte cb = pdfTarget.getContentByte();
            cb.moveTo(p1.x, -p1.y);
            cb.lineTo(p2.x, -p2.y);
            cb.lineTo(p3.x, -p3.y);
            cb.closePath();
            cb.setRGBColorFill(color.getRed(), color.getGreen(), color.getBlue());
            if (color.getAlpha() < 255) {
                cb.saveState();
                float alpha = color.getAlpha() / 255f;
                PdfGState gState = new PdfGState();
                gState.setFillOpacity(alpha);
                cb.setGState(gState);
            }
            cb.fill();
            if (color.getAlpha() < 255) {
                cb.restoreState();
            }
        }
    }

    public PreviewProperty[] getProperties() {
        return new PreviewProperty[]{
                    PreviewProperty.createProperty(this, PreviewProperty.ARROW_SIZE, Float.class,
                    NbBundle.getMessage(EdgeRenderer.class, "ArrowRenderer.property.size.displayName"),
                    NbBundle.getMessage(EdgeRenderer.class, "ArrowRenderer.property.size.description"),
                    PreviewProperty.CATEGORY_EDGE_ARROWS, PreviewProperty.SHOW_EDGES).setValue(defaultArrowSize)};
    }

    public boolean isRendererForitem(Item item, PreviewProperties properties) {
        return item instanceof EdgeItem && properties.getBooleanValue(PreviewProperty.SHOW_EDGES) && properties.getBooleanValue(PreviewProperty.DIRECTED)
                && (Boolean) item.getData(EdgeItem.DIRECTED) && !(Boolean) item.getData(EdgeItem.SELF_LOOP)
                && !properties.getBooleanValue(PreviewProperty.MOVING);
    }
}