Improve ELK support

src/net/sourceforge/plantuml/elk/CucaDiagramFileMakerElk.java

@@ -59,15 +59,19 @@ import org.eclipse.elk.graph.ElkNode;
 import org.eclipse.elk.graph.util.ElkGraphUtil;
 
 import net.sourceforge.plantuml.FileFormatOption;
+import net.sourceforge.plantuml.FontParam;
 import net.sourceforge.plantuml.ISkinParam;
 import net.sourceforge.plantuml.StringUtils;
 import net.sourceforge.plantuml.UmlDiagram;
 import net.sourceforge.plantuml.api.ImageDataSimple;
 import net.sourceforge.plantuml.core.ImageData;
 import net.sourceforge.plantuml.cucadiagram.CucaDiagram;
+import net.sourceforge.plantuml.cucadiagram.Display;
 import net.sourceforge.plantuml.cucadiagram.ILeaf;
 import net.sourceforge.plantuml.cucadiagram.Link;
 import net.sourceforge.plantuml.graphic.AbstractTextBlock;
+import net.sourceforge.plantuml.graphic.FontConfiguration;
+import net.sourceforge.plantuml.graphic.HorizontalAlignment;
 import net.sourceforge.plantuml.graphic.QuoteUtils;
 import net.sourceforge.plantuml.graphic.StringBounder;
 import net.sourceforge.plantuml.graphic.TextBlock;
@@ -91,6 +95,7 @@ public class CucaDiagramFileMakerElk implements CucaDiagramFileMaker {
 	private final DotStringFactory dotStringFactory;
 
 	private final Map<ILeaf, ElkNode> nodes = new LinkedHashMap<ILeaf, ElkNode>();
+	private final Map<Link, ElkEdge> edges = new LinkedHashMap<Link, ElkEdge>();
 
 	public CucaDiagramFileMakerElk(CucaDiagram diagram, StringBounder stringBounder) {
 		this.diagram = diagram;
@@ -99,6 +104,36 @@ public class CucaDiagramFileMakerElk implements CucaDiagramFileMaker {
 
 	}
 
+	// Unused right now
+	private TextBlock getLabel(Link link) {
+		final double marginLabel = 1; // startUid.equals(endUid) ? 6 : 1;
+		ISkinParam skinParam = diagram.getSkinParam();
+		final FontConfiguration labelFont = new FontConfiguration(skinParam, FontParam.ARROW, null);
+		final TextBlock label = link.getLabel().create(labelFont,
+				skinParam.getDefaultTextAlignment(HorizontalAlignment.CENTER), skinParam);
+		if (TextBlockUtils.isEmpty(label, stringBounder)) {
+			return label;
+		}
+		return TextBlockUtils.withMargin(label, marginLabel, marginLabel);
+	}
+
+	// Unused right now
+	private TextBlock getQualifier(Link link, int n) {
+		final String tmp = n == 1 ? link.getQualifier1() : link.getQualifier2();
+		if (tmp == null) {
+			return null;
+		}
+		final double marginLabel = 1; // startUid.equals(endUid) ? 6 : 1;
+		ISkinParam skinParam = diagram.getSkinParam();
+		final FontConfiguration labelFont = new FontConfiguration(skinParam, FontParam.ARROW, null);
+		final TextBlock label = Display.getWithNewlines(tmp).create(labelFont,
+				skinParam.getDefaultTextAlignment(HorizontalAlignment.CENTER), skinParam);
+		if (TextBlockUtils.isEmpty(label, stringBounder)) {
+			return label;
+		}
+		return TextBlockUtils.withMargin(label, marginLabel, marginLabel);
+	}
+
 	// The Drawing class does the real drawing
 	class Drawing extends AbstractTextBlock implements TextBlockBackcolored {
 
@@ -125,6 +160,17 @@ public class CucaDiagramFileMakerElk implements CucaDiagramFileMaker {
 				image.drawU(ug.apply(new UTranslate(corner)));
 			}
 
+			// Draw all edges
+			for (Entry<Link, ElkEdge> ent : edges.entrySet()) {
+				final Link link = ent.getKey();
+				if (link.isInvis()) {
+					continue;
+				}
+				final ElkEdge edge = ent.getValue();
+				new ElkPath(link, edge, diagram, getLabel(link), getQualifier(link, 1), getQualifier(link, 2))
+						.drawU(ug);
+			}
+
 		}
 
 		public Dimension2D calculateDimension(StringBounder stringBounder) {
@@ -146,7 +192,9 @@ public class CucaDiagramFileMakerElk implements CucaDiagramFileMaker {
 
 		try {
 			final ElkNode root = ElkGraphUtil.createGraph();
-			final ElkPadding labelPadding = new ElkPadding(2.0);
+
+			// This padding setting have no impact ?
+			final ElkPadding labelPadding = new ElkPadding(100.0);
 
 			// Convert all "leaf" to ELK node
 			for (ILeaf leaf : diagram.getLeafsvalues()) {
@@ -162,7 +210,11 @@ public class CucaDiagramFileMakerElk implements CucaDiagramFileMaker {
 				// There is no real "label" here
 				// We just would like to force node dimension
 				final ElkLabel label = ElkGraphUtil.createLabel(node);
-				label.setDimensions(dimension.getWidth(), dimension.getHeight());
+				label.setText("X");
+
+				// I don't know why we have to do this hack, but somebody has to fix it
+				final double VERY_STRANGE_OFFSET = 10;
+				label.setDimensions(dimension.getWidth() - VERY_STRANGE_OFFSET, dimension.getHeight());
 
 				// No idea of what we are doing here :-)
 				label.setProperty(CoreOptions.NODE_LABELS_PLACEMENT, EnumSet.of(NodeLabelPlacement.INSIDE,
@@ -175,22 +227,31 @@ public class CucaDiagramFileMakerElk implements CucaDiagramFileMaker {
 				nodes.put(leaf, node);
 			}
 
+			// https://www.eclipse.org/forums/index.php/t/1095737/
+
 			for (final Link link : diagram.getLinks()) {
 				final ElkEdge edge = ElkGraphUtil.createEdge(root);
-				System.err.println("edge=" + edge);
 				edge.getSources().add(nodes.get(link.getEntity1()));
 				edge.getTargets().add(nodes.get(link.getEntity2()));
+				edges.put(link, edge);
 			}
 
 			final RecursiveGraphLayoutEngine engine = new RecursiveGraphLayoutEngine();
 			engine.layout(root, new NullElkProgressMonitor());
 
 			// Debug
-			for (final ElkNode node : nodes.values()) {
+//			for (final ElkNode node : nodes.values()) {
-				final String name = node.getLabels().get(0).getText();
+//				final String name = node.getLabels().get(0).getText();
-				System.out.println("node " + name + " : " + node.getX() + ", " + node.getY() + " (" + node.getWidth()
+//				System.out.println("node " + name + " : " + node.getX() + ", " + node.getY() + " (" + node.getWidth()
-						+ ", " + node.getHeight() + ")");
+//						+ ", " + node.getHeight() + ")");
-			}
+//			}
+//			for (final ElkEdge edge : edges.values()) {
+//				final EList<ElkEdgeSection> sections = edge.getSections();
+//				System.out.println("edge=" + edge.getSections());
+//				System.out.println("edge=" + edge.getProperty(LayeredOptions.JUNCTION_POINTS));
+//				for (ElkEdgeSection s : sections)
+//					System.out.println(s.getBendPoints());
+//			}
 
 			final MinMax minMax = TextBlockUtils.getMinMax(new Drawing(null), stringBounder, false);
 

src/net/sourceforge/plantuml/elk/ElkPath.java

@@ -0,0 +1,147 @@
+/* ========================================================================
+ * PlantUML : a free UML diagram generator
+ * ========================================================================
+ *
+ * (C) Copyright 2009-2020, Arnaud Roques
+ *
+ * Project Info:  http://plantuml.com
+ * 
+ * If you like this project or if you find it useful, you can support us at:
+ * 
+ * http://plantuml.com/patreon (only 1$ per month!)
+ * http://plantuml.com/paypal
+ * 
+ * This file is part of PlantUML.
+ *
+ * PlantUML is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * PlantUML distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
+ * USA.
+ *
+ *
+ * Original Author:  Arnaud Roques
+ * 
+ *
+ */
+package net.sourceforge.plantuml.elk;
+
+import org.eclipse.elk.graph.ElkBendPoint;
+import org.eclipse.elk.graph.ElkEdge;
+import org.eclipse.elk.graph.ElkEdgeSection;
+import org.eclipse.emf.common.util.EList;
+
+import net.sourceforge.plantuml.ColorParam;
+import net.sourceforge.plantuml.LineParam;
+import net.sourceforge.plantuml.UmlDiagramType;
+import net.sourceforge.plantuml.cucadiagram.CucaDiagram;
+import net.sourceforge.plantuml.cucadiagram.Link;
+import net.sourceforge.plantuml.cucadiagram.LinkType;
+import net.sourceforge.plantuml.graphic.TextBlock;
+import net.sourceforge.plantuml.graphic.UDrawable;
+import net.sourceforge.plantuml.graphic.color.ColorType;
+import net.sourceforge.plantuml.skin.rose.Rose;
+import net.sourceforge.plantuml.ugraphic.UGraphic;
+import net.sourceforge.plantuml.ugraphic.ULine;
+import net.sourceforge.plantuml.ugraphic.UStroke;
+import net.sourceforge.plantuml.ugraphic.UTranslate;
+import net.sourceforge.plantuml.ugraphic.color.HColor;
+
+public class ElkPath implements UDrawable {
+
+	private final Link link;
+	private final ElkEdge edge;
+
+	private final CucaDiagram diagram;
+	private final TextBlock label;
+	private final TextBlock headLabel;
+	private final TextBlock tailLabel;
+	private final Rose rose = new Rose();
+
+	public ElkPath(Link link, ElkEdge edge, CucaDiagram diagram, TextBlock label, TextBlock tailLabel,
+			TextBlock headLabel) {
+		this.link = link;
+		this.edge = edge;
+
+		this.diagram = diagram;
+		this.label = label;
+		this.tailLabel = tailLabel;
+		this.headLabel = headLabel;
+	}
+
+	private ColorParam getArrowColorParam() {
+		if (diagram.getUmlDiagramType() == UmlDiagramType.CLASS) {
+			return ColorParam.arrow;
+		} else if (diagram.getUmlDiagramType() == UmlDiagramType.OBJECT) {
+			return ColorParam.arrow;
+		} else if (diagram.getUmlDiagramType() == UmlDiagramType.DESCRIPTION) {
+			return ColorParam.arrow;
+		} else if (diagram.getUmlDiagramType() == UmlDiagramType.ACTIVITY) {
+			return ColorParam.arrow;
+		} else if (diagram.getUmlDiagramType() == UmlDiagramType.STATE) {
+			return ColorParam.arrow;
+		}
+		throw new IllegalStateException();
+	}
+
+	public void drawU(UGraphic ug) {
+
+		if (link.isHidden()) {
+			return;
+		}
+
+		HColor color = rose.getHtmlColor(diagram.getSkinParam(), null, getArrowColorParam());
+
+		if (this.link.getColors() != null) {
+			final HColor newColor = this.link.getColors().getColor(ColorType.ARROW, ColorType.LINE);
+			if (newColor != null) {
+				color = newColor;
+			}
+
+		} else if (this.link.getSpecificColor() != null) {
+			color = this.link.getSpecificColor();
+		}
+
+		final LinkType linkType = link.getType();
+		UStroke stroke = linkType.getStroke3(diagram.getSkinParam().getThickness(LineParam.arrow, null));
+		if (link.getColors() != null && link.getColors().getSpecificLineStroke() != null) {
+			stroke = link.getColors().getSpecificLineStroke();
+		}
+		ug = ug.apply(stroke).apply(color);
+
+		final EList<ElkEdgeSection> sections = edge.getSections();
+
+		for (ElkEdgeSection section : sections) {
+
+			final EList<ElkBendPoint> points = section.getBendPoints();
+
+			double x1 = section.getStartX();
+			double y1 = section.getStartY();
+
+			for (ElkBendPoint pt : points) {
+				drawLine(ug, x1, y1, pt.getX(), pt.getY());
+				x1 = pt.getX();
+				y1 = pt.getY();
+			}
+
+			drawLine(ug, x1, y1, section.getEndX(), section.getEndY());
+
+		}
+
+	}
+
+	private void drawLine(UGraphic ug, final double x1, final double y1, final double x2, final double y2) {
+		final ULine line = new ULine(x2 - x1, y2 - y1);
+		ug.apply(new UTranslate(x1, y1)).draw(line);
+	}
+
+}