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Table of Contents
Plugin development
This exercise aims at developing a basic plugin that enables editing of a new type of graph model in Workcraft. Follow the step-by-step instructions to proceed from the initial setup of the project all the way to the implementation of the model components. If you want to skip some of the steps, then just download the complete plugin source code: exercise01plugin.zip ( B)
Project setup
To begin, create a new project directory called _Exercise01Plugin
. Note that the directories starting with an underscore are automatically ignored both by Git and the distribution builder script, therefore this is a good way to add experimental plugins that should not become part of the main Workcraft build.
Next either create or download and add the following build.gradle
file below into the project directory to specify the project dependency on the Workcraft framework. For the purpose of our exercise, we will make our Exercise01Plugin
only depend on the WorkcraftCore
plugin:
- build.gradle
dependencies { compile project(':WorkcraftCore') }
Now let us call the package for our Exercise01 plugin: org.workcraft.plugins.basic
. This follows Workcraft's standard of any new plugin to be packaged as org.workcraft.plugins.NewPluginName
and is typically where all the plugin classes will live. For this step, we create the directory src/org/workcraft/plugins/basic
under _Exercise01Plugin
.
To complete the set up, go to the top directory of Workcraft and follow either step depending on your development IDE:
For IntelliJ IDEA
- Run the
$./gradlew idea
command to generate the IntelliJ IDEA project with the newly created plugin. - Open the
workcraft.ipr
file in IDEA to load the project.
For Eclipse
- Run the
$./gradlew eclipse
command to generate the Eclipse project with the newly created plugin. - Once opening Eclipse, ensure that you have selected
workcraft
as the current Workspace directory and imported the project as necessary. For further information on this, see the Eclipse Integration page.
If everything has went smoothly, you are now set to go.
Module class
As a first step to creating any new Workcraft plugin, a module class needs to be created. This class is essentially the plugin's top-most class, which implements the Module
interface that allows Workcraft to detect the plugin as a new (available) model type. For this exercise, we simply just create the BasicModule
class as follows:
- BasicModule.java
package org.workcraft.plugins.basic; import org.workcraft.Framework; import org.workcraft.Module; import org.workcraft.PluginManager; public class BasicModule implements Module { @Override public String getDescription() { return "Basic Module"; } @Override public void init() { final Framework framework = Framework.getInstance(); final PluginManager pm = framework.getPluginManager(); pm.registerModelDescriptor(BasicDescriptor.class); } }
One may notice that inside the BasicModule
class, the PluginManager
registers a new class called BasicDescriptor
. The purpose of this class is to define the name of the model and how its mathematical and visual representations are given, by making it implement the ModelDescriptor
class.
In the case of the BasicDescriptor
class, we simply set the display name as Basic Model and make it create a new Basic
class that will represent its mathematical representation (which will later be discussed in the Mathematical layer classes section) like below:
- BasicDescriptor.java
package org.workcraft.plugins.basic; import org.workcraft.dom.ModelDescriptor; import org.workcraft.dom.VisualModelDescriptor; import org.workcraft.dom.math.MathModel; public class BasicDescriptor implements ModelDescriptor { @Override public String getDisplayName() { return "Basic Model"; } @Override public MathModel createMathModel() { return new Basic(); } @Override public VisualModelDescriptor getVisualModelDescriptor() { return new VisualBasicDescriptor(); } }
However, unlike how the BasicDescriptor
handles the mathematical representation directly, it directly calls the VisualBasicDescriptor
class instead to handle its visual representation. Hence, it essentially specifies the visual layer that is associated with the model.
The class does this by implementing the VisualModelDescriptor
interface, which has a method that takes in the mathematical model as an argument and uses its data to create a visual model of it. In our case, the class checks if the provided math model is a Basic
model and produces either a new VisualBasic
model (if successful) or an exception (if unsuccessful):
- VisualBasicDescriptor.java
package org.workcraft.plugins.basic; import org.workcraft.dom.VisualModelDescriptor; import org.workcraft.dom.math.MathModel; import org.workcraft.dom.visual.VisualModel; public class VisualBasicDescriptor implements VisualModelDescriptor { @Override public VisualModel create(MathModel mathModel) { if (mathModel instanceof Basic) { return new VisualBasic((Basic) mathModel); } throw new RuntimeException("Unsupported math model type"); } }
As a result, we have registered the Basic
and VisualBasic
classes as the implementations of the mathematical and visual layers of our basic model respectively.
Mathematical layer classes
The mathematical model extends the AbstractMathModel
class as follows:
- Basic.java
package org.workcraft.plugins.basic; import org.workcraft.dom.Container; import org.workcraft.dom.Node; import org.workcraft.dom.math.AbstractMathModel; import org.workcraft.dom.math.MathConnection; import org.workcraft.dom.math.MathNode; import org.workcraft.dom.references.HierarchicalUniqueNameReferenceManager; import org.workcraft.dom.references.ReferenceManager; import org.workcraft.serialisation.References; import org.workcraft.util.Hierarchy; public class Basic extends AbstractMathModel { public Basic() { this(null); } public Basic(Container root) { super(root); } public MathConnection connect(Node first, Node second) { MathConnection con = new MathConnection((MathNode) first, (MathNode) second); Hierarchy.getNearestContainer(first, second).add(con); return con; } }
This model has one type of node that is implemented by a trivial Vertex
class:
- Vertex.java
package org.workcraft.plugins.basic; import org.workcraft.annotations.VisualClass; import org.workcraft.dom.math.MathNode; @VisualClass(VisualVertex.class) public class Vertex extends MathNode { }
Note that Vertex
is tagged by VisualClass
annotation to specify how it should be visualised.
Visual layer classes
The visual model extends the AbstractVisualModel
and also specifies the tools available for editing the model:
- VisualBasic.java
package org.workcraft.plugins.basic; import org.workcraft.annotations.DisplayName; import org.workcraft.annotations.ShortName; import org.workcraft.dom.Container; import org.workcraft.dom.Node; import org.workcraft.dom.math.MathConnection; import org.workcraft.dom.visual.AbstractVisualModel; import org.workcraft.dom.visual.VisualComponent; import org.workcraft.dom.visual.VisualGroup; import org.workcraft.dom.visual.connections.VisualConnection; import org.workcraft.exceptions.InvalidConnectionException; import org.workcraft.exceptions.NodeCreationException; import org.workcraft.gui.graph.generators.DefaultNodeGenerator; import org.workcraft.gui.graph.tools.*; import org.workcraft.util.Hierarchy; import java.util.ArrayList; import java.util.List; @DisplayName("Basic") @ShortName("basic") public class VisualBasic extends AbstractVisualModel { public VisualBasic(Basic model) { this(model, null); } public VisualBasic(Basic model, VisualGroup root) { super(model, root); setGraphEditorTools(); if (root == null) { try { createDefaultFlatStructure(); } catch (NodeCreationException e) { throw new RuntimeException(e); } } } private void setGraphEditorTools() { List<GraphEditorTool> tools = new ArrayList<>(); tools.add(new SelectionTool()); tools.add(new CommentGeneratorTool()); tools.add(new ConnectionTool()); tools.add(new NodeGeneratorTool(new DefaultNodeGenerator(Vertex.class))); setGraphEditorTools(tools); } @Override public void validateConnection(Node first, Node second) throws InvalidConnectionException { if ((first instanceof VisualVertex) && (second instanceof VisualVertex)) return; throw new InvalidConnectionException("Invalid connection."); } @Override public VisualConnection connect(Node first, Node second, MathConnection mConnection) throws InvalidConnectionException { validateConnection(first, second); VisualComponent v1 = (VisualComponent) first; VisualComponent v2 = (VisualComponent) second; Node m1 = v1.getReferencedComponent(); Node m2 = v2.getReferencedComponent(); if (mConnection == null) { mConnection = ((Basic) getMathModel()).connect(m1, m2); } VisualConnection vConnection = new VisualConnection(mConnection, v1, v2); Container container = Hierarchy.getNearestContainer(v1, v2); container.add(vConnection); return vConnection; } }
Visualisation of vertex node is implemented by VisualVertex
class as follows:
- VisualVertex.java
package org.workcraft.plugins.basic; import org.workcraft.dom.visual.DrawRequest; import org.workcraft.dom.visual.VisualComponent; import org.workcraft.gui.Coloriser; import java.awt.*; import java.awt.geom.Rectangle2D; public class VisualVertex extends VisualComponent { public VisualVertex(Vertex vertex) { super(vertex); } @Override public void draw(DrawRequest r) { Graphics2D g = r.getGraphics(); double xy = -size / 2 + strokeWidth / 2; double wh = size - strokeWidth; Shape shape = new Rectangle2D.Double(xy, xy, wh, wh); Color background = r.getDecoration().getBackground(); g.setColor(Coloriser.colorise(getFillColor(), background)); g.fill(shape); Color colorisation = r.getDecoration().getColorisation(); g.setColor(Coloriser.colorise(getForegroundColor(), colorisation)); g.setStroke(new BasicStroke((float) strokeWidth)); g.draw(shape); drawLabelInLocalSpace(r); drawNameInLocalSpace(r); } }