4 files changed, 185 insertions, 6 deletions
diff --git a/src/jcgp/gui/handlers/InputHandlers.java b/src/jcgp/gui/handlers/InputHandlers.java
index 1d18ef5..cc677eb 100644
--- a/src/jcgp/gui/handlers/InputHandlers.java
+++ b/src/jcgp/gui/handlers/InputHandlers.java
@@ -17,6 +17,11 @@ import jcgp.gui.population.GUIInput;
  *
  */
 public final class InputHandlers {
+	
+	/**
+	 * Private constructor to prevent instantiation.
+	 */
+	private InputHandlers() {}
 
 	/**
 	 * Inputs don't do much; set state to hover when mouse enters.
diff --git a/src/jcgp/gui/handlers/NodeHandlers.java b/src/jcgp/gui/handlers/NodeHandlers.java
index 10a334a..b413a62 100644
--- a/src/jcgp/gui/handlers/NodeHandlers.java
+++ b/src/jcgp/gui/handlers/NodeHandlers.java
@@ -1,9 +1,15 @@
 package jcgp.gui.handlers;
 
 import javafx.event.EventHandler;
+import javafx.scene.input.MouseDragEvent;
 import javafx.scene.input.MouseEvent;
+import javafx.scene.shape.Circle;
+import javafx.scene.shape.Line;
 import jcgp.backend.population.Gene;
 import jcgp.gui.GUI;
+import jcgp.gui.constants.Position;
+import jcgp.gui.population.ChromosomePane;
+import jcgp.gui.population.GUIConnection;
 import jcgp.gui.population.GUIGene;
 import jcgp.gui.population.GUIGene.GUIGeneState;
 import jcgp.gui.population.GUINode;
@@ -22,6 +28,11 @@ import jcgp.gui.population.GUINode;
 public final class NodeHandlers {
 
 	/**
+	 * Private constructor to prevent instantiation.
+	 */
+	private NodeHandlers() {}
+
+	/**
 	 * Set the node to {@code GUIGeneState.HOVER} state, and set its immediate connections to {@code GUIGeneState.EXTENDED_HOVER}.
 	 */
 	private static EventHandler<MouseEvent> mouseEnteredHandler = new EventHandler<MouseEvent>() {
@@ -29,7 +40,7 @@ public final class NodeHandlers {
 		public void handle(MouseEvent event) {
 			// acquire the source, we can safely cast it to GUINode
 			GUINode source = (GUINode) event.getSource();
-			
+
 			source.setState(GUIGeneState.HOVER);
 			for (int i = 0; i < GUI.resources.arity(); i++) {
 				((GUIGene) ((Gene) source.getNode().getConnection(i)).getGUIObject()).setState(GUIGeneState.EXTENDED_HOVER);
@@ -46,13 +57,89 @@ public final class NodeHandlers {
 			// acquire the source, we can safely cast it to GUINode
 			GUINode source = (GUINode) event.getSource();
 
-			source.setState(GUIGeneState.NEUTRAL);
-			for (int i = 0; i < GUI.resources.arity(); i++) {
-				((GUIGene) ((Gene) source.getNode().getConnection(i)).getGUIObject()).setState(GUIGeneState.NEUTRAL);
+			if (Target.getSourceMutable() != source) {
+				source.setState(GUIGeneState.NEUTRAL);
+				for (int i = 0; i < GUI.resources.arity(); i++) {
+					((GUIGene) ((Gene) source.getNode().getConnection(i)).getGUIObject()).setState(GUIGeneState.NEUTRAL);
+				}
+			}
+		}
+	};
+
+	private static EventHandler<MouseEvent> socketDragDetected = new EventHandler<MouseEvent>() {
+		@Override
+		public void handle(MouseEvent event) {
+			// it's safe to assume that the source is the socket
+			((GUINode) ((Circle) event.getSource()).getParent()).startFullDrag();
+		}
+	};
+
+	private static EventHandler<MouseEvent> socketMousePressedHandler = new EventHandler<MouseEvent>() {
+		@Override
+		public void handle(MouseEvent event) {
+			// it's safe to assume that the source is the socket
+			Target.start((Circle) event.getSource());
+		}
+	};
+
+	private static EventHandler<MouseEvent> socketMouseDraggedHandler = new EventHandler<MouseEvent>() {
+		@Override
+		public void handle(MouseEvent event) {
+			// this can only happen after a press, so we know Target is up-to-date
+			if (!Target.isProspecting()) {
+				GUINode node = (GUINode) Target.getSourceMutable();
+				Line line = Target.getConnectionLine();
+				line.setEndX(event.getX() + node.getLayoutX());
+				line.setEndY(event.getY() + node.getLayoutY());
+			}
+
+		}
+	};
+
+	private static EventHandler<MouseEvent> socketMouseReleasedHandler = new EventHandler<MouseEvent>() {
+		@Override
+		public void handle(MouseEvent event) {
+
+			GUINode node = (GUINode) ((Circle) event.getSource()).getParent();
+			int connectionId = Integer.valueOf(((Circle) event.getSource()).getId());
+
+			Position.connect(node.getLines()[connectionId], (GUIGene) ((Gene) node.getNode().getConnection(connectionId)).getGUIObject());
+		}
+	};
+
+	private static EventHandler<MouseDragEvent> dragEnteredHandler = new EventHandler<MouseDragEvent>() {
+		@Override
+		public void handle(MouseDragEvent event) {
+			// acquire the source, we can safely cast it to GUINode
+			GUINode source = (GUINode) event.getSource();
+			if (Target.getCurrentConnection() == source) {
+				source.setState(GUIGeneState.NEUTRAL_TARGET);
+				// we are now prospecting
+				Target.setProspecting(true);
+				Position.connect(Target.getConnectionLine(), source);
+			} else if (ChromosomePane.isAllowed(Target.getSourceMutable(), (GUIConnection) source)) {
+				source.setState(GUIGeneState.GOOD_TARGET);
+				// we are now prospecting
+				Target.setProspecting(true);
+				Position.connect(Target.getConnectionLine(), source);
+			} else {
+				source.setState(GUIGeneState.BAD_TARGET);
 			}
 		}
 	};
 
+	private static EventHandler<MouseDragEvent> dragExitedHandler = new EventHandler<MouseDragEvent>() {
+		@Override
+		public void handle(MouseDragEvent event) {
+			// acquire the source, we can safely cast it to GUINode
+			GUINode source = (GUINode) event.getSource();
+			source.setState(GUIGeneState.NEUTRAL);
+			
+			// no longer prospecting
+			Target.setProspecting(false);
+		}
+	};
+
 	/**
 	 * Adds all handlers to the specified node.
 	 * 
@@ -61,5 +148,17 @@ public final class NodeHandlers {
 	public static void addHandlers(GUINode node) {
 		node.addEventHandler(MouseEvent.MOUSE_ENTERED, mouseEnteredHandler);
 		node.addEventHandler(MouseEvent.MOUSE_EXITED, mouseExitedHandler);
+
+		node.addEventHandler(MouseDragEvent.MOUSE_DRAG_ENTERED, dragEnteredHandler);
+		node.addEventHandler(MouseDragEvent.MOUSE_DRAG_EXITED, dragExitedHandler);
+
+		Circle[] sockets = node.getSockets();
+		for (int s = 0; s < sockets.length; s++) {
+
+			sockets[s].addEventFilter(MouseEvent.DRAG_DETECTED, socketDragDetected);
+			sockets[s].addEventHandler(MouseEvent.MOUSE_PRESSED, socketMousePressedHandler);
+			sockets[s].addEventHandler(MouseEvent.MOUSE_DRAGGED, socketMouseDraggedHandler);
+			sockets[s].addEventHandler(MouseEvent.MOUSE_RELEASED, socketMouseReleasedHandler);
+		}
 	}
 }
diff --git a/src/jcgp/gui/handlers/OutputHandlers.java b/src/jcgp/gui/handlers/OutputHandlers.java
index f72e430..b89d746 100644
--- a/src/jcgp/gui/handlers/OutputHandlers.java
+++ b/src/jcgp/gui/handlers/OutputHandlers.java
@@ -19,6 +19,11 @@ import jcgp.gui.population.GUIOutput;
  *
  */
 public final class OutputHandlers {
+	
+	/**
+	 * Private constructor to prevent instantiation.
+	 */
+	private OutputHandlers() {}
 
 	/**
 	 * Set the output to {@code GUIGeneState.HOVER} state, and recursively set its active genes
@@ -50,8 +55,8 @@ public final class OutputHandlers {
 	};
 
 	/**
-	 * If the output is locked, unlock it and all of its associated genes recursively. If it is unlocked, 
-	 * lock it and its active genes.
+	 * If the output is locked, unlock it and all of its associated genes recursively.
+	 * If it is unlocked, lock it and its active genes.
 	 */
 	private static EventHandler<MouseEvent> mouseClickHandler = new EventHandler<MouseEvent>() {
 		@Override
diff --git a/src/jcgp/gui/handlers/Target.java b/src/jcgp/gui/handlers/Target.java
new file mode 100644
index 0000000..b050663
--- /dev/null
+++ b/src/jcgp/gui/handlers/Target.java
@@ -0,0 +1,70 @@
+package jcgp.gui.handlers;
+
+import javafx.scene.shape.Circle;
+import javafx.scene.shape.Line;
+import jcgp.gui.population.GUIConnection;
+import jcgp.gui.population.GUIMutable;
+
+/**
+ * @author Eduardo Pedroni
+ *
+ */
+public final class Target {
+
+	/**
+	 * Private constructor to prevent instantiation.
+	 */
+	private Target() {}
+	
+	private static GUIConnection targetConnection;
+	private static GUIMutable sourceMutable;
+	private static int connectionIndex;
+	private static Line connectionLine;
+	private static Circle sourceSocket;
+	private static boolean prospecting = false;
+	
+	public static void start(Circle newSocket) {
+		// store new socket
+		sourceSocket = newSocket;
+		// derive the rest of the information from it
+		connectionIndex = Integer.valueOf(newSocket.getId());
+		sourceMutable = (GUIMutable) newSocket.getParent();
+		connectionLine = sourceMutable.getLines()[connectionIndex];
+	}
+	
+	public static GUIMutable getSourceMutable() {
+		return sourceMutable;
+	}
+	
+	public static int getConnectionIndex() {
+		return connectionIndex;
+	}
+	
+	public static Line getConnectionLine() {
+		return connectionLine;
+	}
+	
+	public static Circle getSourceSocket() {
+		return sourceSocket;
+	}
+	
+	public static GUIConnection getTarget() {
+		return targetConnection;
+	}
+	
+	public static GUIConnection getCurrentConnection() {
+		return sourceMutable.getConnections()[connectionIndex];
+	}
+	
+	public static void setProspecting(boolean value) {
+		prospecting = value;
+	}
+	
+	public static boolean isProspecting() {
+		return prospecting;
+	}
+	
+	public static void setTarget(GUIConnection newTarget) {
+		targetConnection = newTarget;
+	}
+}