Adds Dragging and Dropping Steps in the Pipeline

core/src/main/java/edu/wpi/grip/core/Pipeline.java

@@ -232,14 +232,13 @@ public void onSourceRemoved(SourceRemovedEvent event) {
     }
 
     /**
-     * Adds the step between two other steps.
-     * @param stepToAdd The step to add to the pipeline
-     * @param lower     The step to be added above
-     * @param higher    The step to be added below
+     * Finds the index between the two steps
+     * @param lower The lower step
+     * @param higher The higher step
+     * @return The index that is in between the two of these steps
      */
-    public void addStepBetween(Step stepToAdd, @Nullable Step lower, @Nullable Step higher) {
-        checkNotNull(stepToAdd, "The step to add cannot be null");
-        int index = readStepsSafely(steps -> {
+    private int indexBetween(@Nullable Step lower, @Nullable Step higher) {
+        return readStepsSafely(steps -> {
             // If not in the list these can return -1
             int lowerIndex = steps.indexOf(lower);
             int upperIndex = steps.indexOf(higher);
@@ -259,9 +258,33 @@ public void addStepBetween(Step stepToAdd, @Nullable Step lower, @Nullable Step
                 return steps.size();
             }
         });
+    }
+
+    /**
+     * Adds the step between two other steps.
+     * @param stepToAdd The step to add to the pipeline
+     * @param lower     The step to be added above
+     * @param higher    The step to be added below
+     */
+    public void addStepBetween(Step stepToAdd, @Nullable Step lower, @Nullable Step higher) {
+        checkNotNull(stepToAdd, "The step to add cannot be null");
+        final int index = indexBetween(lower, higher);
         addStep(index, stepToAdd);
     }
 
+    /**
+     *
+     * @param toMove The step to move
+     * @param lower The lower step
+     * @param higher The upper step
+     */
+    public void moveStepBetween(Step toMove, @Nullable Step lower, @Nullable Step higher) {
+        checkNotNull(toMove, "The step to move cannot be null");
+        final int index = indexBetween(lower, higher);
+        final int currentIndex = readStepsSafely(steps -> steps.indexOf(toMove));
+        moveStep(toMove, index > currentIndex ? index - (currentIndex + 1 ) : index - currentIndex);
+    }
+
     public void addStep(int index, Step step) {
         checkNotNull(step, "The step can not be null");
         checkArgument(!step.removed(), "The step must not have been disabled already");

core/src/test/java/edu/wpi/grip/core/PipelineTest.java

@@ -335,4 +335,34 @@ public void testAddBetweenStepsOutOfOrder() {
 
         pipeline.addStepBetween(stepToAdd, upperStep, lowerStep);
     }
+
+    @Test
+    public void testMoveStepToLeft() {
+        final Step
+                stepToMove = new MockStep(),
+                lowerStep = new MockStep(),
+                upperStep = new MockStep();
+        pipeline.addStep(lowerStep);
+        pipeline.addStep(upperStep);
+        pipeline.addStep(stepToMove);
+        pipeline.moveStepBetween(stepToMove, lowerStep, upperStep);
+
+        assertEquals("The step should have been moved within the pipeline",
+                Arrays.asList(lowerStep, stepToMove, upperStep), pipeline.getSteps());
+    }
+
+    @Test
+    public void testMoveStepToRight() {
+        final Step
+                stepToMove = new MockStep(),
+                lowerStep = new MockStep(),
+                upperStep = new MockStep();
+        pipeline.addStep(stepToMove);
+        pipeline.addStep(lowerStep);
+        pipeline.addStep(upperStep);
+        pipeline.moveStepBetween(stepToMove, lowerStep, upperStep);
+
+        assertEquals("The step should have been moved within the pipeline",
+                Arrays.asList(lowerStep, stepToMove, upperStep), pipeline.getSteps());
+    }
 }

ui/src/main/java/edu/wpi/grip/ui/OperationController.java

@@ -13,13 +13,8 @@
 import javafx.scene.control.Tooltip;
 import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
-import javafx.scene.input.DataFormat;
-import javafx.scene.input.Dragboard;
-import javafx.scene.input.TransferMode;
 import javafx.scene.layout.GridPane;
 
-import java.util.Collections;
-
 /**
  * A JavaFX control that renders information about an {@link Operation}.  This is used in the palette view to present
  * the user with information on the various operations to choose from.
@@ -76,19 +71,15 @@ public void initialize() {
 
 
         root.setOnDragDetected(mouseEvent -> {
-            // Create a snapshot to use as the cursor
-            final ImageView preview = new ImageView(root.snapshot(null, null));
-
-            final Dragboard db = root.startDragAndDrop(TransferMode.ANY);
-            db.setContent(Collections.singletonMap(DataFormat.PLAIN_TEXT, operation.getName()));
-            db.setDragView(preview.getImage());
-            // Begin the dragging
-            root.startFullDrag();
             // Tell the drag service that this is the operation that will be received
-            operationDragService.beginDrag(operation);
+            operationDragService.beginDrag(operation, root, operation.getName());
 
             mouseEvent.consume();
         });
+
+        root.setOnDragDone(mouseEvent -> {
+            operationDragService.completeDrag();
+        });
     }
 
     @FXML

ui/src/main/java/edu/wpi/grip/ui/dragging/DragService.java

@@ -4,7 +4,13 @@
 import javafx.beans.property.ObjectProperty;
 import javafx.beans.property.ReadOnlyObjectProperty;
 import javafx.beans.property.SimpleObjectProperty;
+import javafx.scene.Node;
+import javafx.scene.image.ImageView;
+import javafx.scene.input.DataFormat;
+import javafx.scene.input.Dragboard;
+import javafx.scene.input.TransferMode;
 
+import java.util.Collections;
 import java.util.Optional;
 
 /**
@@ -39,11 +45,22 @@ public Optional<T> getValue() {
     }
 
     /**
-     * Begins the drag action
+     * Begins the drag action.
+     * Creates the dragboard on the root node and adds a
+     * snapshot of the root node as the view.
      *
      * @param value The value to be transferred during the drag.
+     * @param root  The root node to drag
+     * @param name  The name to set as the content of the dragboard
      */
-    public void beginDrag(T value) {
+    public void beginDrag(T value, Node root, String name) {
+        // Create a snapshot to use as the cursor
+        final ImageView preview = new ImageView(root.snapshot(null, null));
+
+        final Dragboard db = root.startDragAndDrop(TransferMode.ANY);
+        db.setContent(Collections.singletonMap(DataFormat.PLAIN_TEXT, name));
+        db.setDragView(preview.getImage());
+
         this.dragProperty.set(value);
     }
 

ui/src/main/java/edu/wpi/grip/ui/dragging/StepDragService.java

@@ -0,0 +1,15 @@
+package edu.wpi.grip.ui.dragging;
+
+import com.google.inject.Singleton;
+import edu.wpi.grip.core.Step;
+
+/**
+ * Service for dragging and dropping a step
+ */
+@Singleton
+public class StepDragService extends DragService<Step> {
+
+    public StepDragService() {
+        super("step");
+    }
+}

ui/src/main/java/edu/wpi/grip/ui/pipeline/PipelineController.java

@@ -13,6 +13,7 @@
 import edu.wpi.grip.core.sockets.OutputSocket;
 import edu.wpi.grip.ui.annotations.ParametrizedController;
 import edu.wpi.grip.ui.dragging.OperationDragService;
+import edu.wpi.grip.ui.dragging.StepDragService;
 import edu.wpi.grip.ui.pipeline.input.InputSocketController;
 import edu.wpi.grip.ui.pipeline.source.SourceController;
 import edu.wpi.grip.ui.pipeline.source.SourceControllerFactory;
@@ -31,6 +32,7 @@
 import javafx.scene.layout.Pane;
 import javafx.scene.layout.VBox;
 
+import javax.annotation.Nullable;
 import javax.inject.Inject;
 import java.util.Collection;
 import java.util.Map;
@@ -70,6 +72,8 @@ public final class PipelineController {
     private AddSourceView addSourceView;
     @Inject
     private OperationDragService operationDragService;
+    @Inject
+    private StepDragService stepDragService;
 
     private ControllerMap<StepController, Node> stepsMapManager;
     private ControllerMap<SourceController, Node> sourceMapManager;
@@ -98,55 +102,90 @@ public void initialize() throws Exception {
                 dragEvent.acceptTransferModes(TransferMode.ANY);
             });
 
+            stepDragService.getValue().ifPresent(step -> {
+                dragEvent.acceptTransferModes(TransferMode.ANY);
+            });
+
         });
 
         stepBox.setOnDragDropped(mouseEvent -> {
             // If this is an operation being dropped
             operationDragService.getValue().ifPresent(operation -> {
-                // Then we need to figure out where to put it in the pipeline
-                // First create a map of every node in the steps list to its x position
-                final Map<Double, Node> positionMapping = stepsMapManager
-                        .entrySet()
-                        .stream()
-                        .collect(
-                                Collectors
-                                        .toMap(e -> calculateMiddleXPosOfNodeInParent(e.getValue()),
-                                                Map.Entry::getValue));
-
-                // A tree map is an easy way to sort the values
-                final NavigableMap<Double, Node> sortedPositionMapping
-                        = new TreeMap<>(positionMapping);
-
-                // Now we find the sockets that are to the immediate left and
-                // immediate right of the drop point
-
-                // These can be null
-                final Map.Entry<Double, Node>
-                        lowerEntry = sortedPositionMapping.floorEntry(mouseEvent.getX()),
-                        higherEntry = sortedPositionMapping.ceilingEntry(mouseEvent.getX());
-                // These can be null
-                final StepController
-                        lowerStepController =
-                        lowerEntry == null ?
-                                null : stepsMapManager.getWithNode(lowerEntry.getValue());
-                final StepController
-                        higherStepController =
-                        higherEntry == null ?
-                                null : stepsMapManager.getWithNode(higherEntry.getValue());
-                final Step
-                        lowerStep = lowerStepController == null ? null : lowerStepController.getStep(),
-                        higherStep = higherStepController == null ? null : higherStepController.getStep();
-
-
                 operationDragService.completeDrag();
+                final StepPair pair = lowerAndHigherStep(mouseEvent.getX());
                 // Add the new step to the pipeline between these two steps
-                pipeline.addStepBetween(stepFactory.create(operation), lowerStep, higherStep);
+                pipeline.addStepBetween(stepFactory.create(operation), pair.lower, pair.higher);
+            });
+
+            // If this is a step being dropped
+            stepDragService.getValue().ifPresent(step -> {
+                stepDragService.completeDrag();
+                final StepPair pair = lowerAndHigherStep(mouseEvent.getX());
+                // Move the new step to the pipeline between these two steps
+                pipeline.moveStepBetween(step, pair.lower, pair.higher);
             });
         });
 
         addSourcePane.getChildren().add(addSourceView);
     }
 
+    /**
+     * Simple class for returning two steps
+     */
+    private static final class StepPair {
+        final Step lower;
+        final Step higher;
+
+        StepPair(@Nullable Step lower, @Nullable Step higher) {
+            this.lower = lower;
+            this.higher = higher;
+        }
+    }
+
+    /**
+     * Determines the steps (via the {@link StepController} that are above and below the given
+     * {@code x} value in the list of steps.
+     *
+     * @param x The x value to find what steps this is between
+     * @return The pair of steps that are above and below this x position.
+     */
+    private StepPair lowerAndHigherStep(double x) {
+        // Then we need to figure out where to put it in the pipeline
+        // First create a map of every node in the steps list to its x position
+        final Map<Double, Node> positionMapping = stepsMapManager
+                .entrySet()
+                .stream()
+                .collect(
+                        Collectors
+                                .toMap(e -> calculateMiddleXPosOfNodeInParent(e.getValue()),
+                                        Map.Entry::getValue));
+
+        // A tree map is an easy way to sort the values
+        final NavigableMap<Double, Node> sortedPositionMapping
+                = new TreeMap<>(positionMapping);
+
+        // Now we find the sockets that are to the immediate left and
+        // immediate right of the drop point
+
+        // These can be null
+        final Map.Entry<Double, Node>
+                lowerEntry = sortedPositionMapping.floorEntry(x),
+                higherEntry = sortedPositionMapping.ceilingEntry(x);
+        // These can be null
+        final StepController
+                lowerStepController =
+                lowerEntry == null ?
+                        null : stepsMapManager.getWithNode(lowerEntry.getValue());
+        final StepController
+                higherStepController =
+                higherEntry == null ?
+                        null : stepsMapManager.getWithNode(higherEntry.getValue());
+        return new StepPair(
+                lowerStepController == null ? null : lowerStepController.getStep(),
+                higherStepController == null ? null : higherStepController.getStep()
+        );
+    }
+
     private double calculateMiddleXPosOfNodeInParent(Node node) {
         return node.getLayoutX() + (node.getBoundsInParent().getWidth() / 2.);
     }

ui/src/main/java/edu/wpi/grip/ui/pipeline/SocketHandleView.java

@@ -19,11 +19,8 @@
 import javafx.css.PseudoClass;
 import javafx.scene.control.Button;
 import javafx.scene.control.Tooltip;
-import javafx.scene.input.DataFormat;
-import javafx.scene.input.Dragboard;
 import javafx.scene.input.TransferMode;
 
-import java.util.Collections;
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -95,12 +92,9 @@ public interface Factory {
         // When the user starts dragging a socket handle, starting forming a connection.  This involves keeping a
         // reference to the SocketView that the drag started at.
         this.setOnDragDetected(mouseEvent -> {
-            Dragboard db = this.startDragAndDrop(TransferMode.ANY);
-            db.setContent(Collections.singletonMap(DataFormat.PLAIN_TEXT, "socket"));
-            mouseEvent.consume();
-
             this.connectingProperty.set(true);
-            socketDragService.beginDrag(this.socket);
+            socketDragService.beginDrag(this.socket, this, "socket");
+            mouseEvent.consume();
         });
 
         // Remove the "connecting" property (which changes the appearance of the handle) when the user moves the cursor