implement shape rotation partially

src/main/java/com/github/creme332/controller/canvas/CanvasController.java

@@ -34,6 +34,7 @@
 import com.github.creme332.controller.canvas.drawing.DrawIrregularPolygon;
 import com.github.creme332.controller.canvas.drawing.DrawLine;
 import com.github.creme332.controller.canvas.drawing.DrawRegularPolygon;
+import com.github.creme332.controller.canvas.transform.Rotator;
 import com.github.creme332.controller.canvas.transform.Translator;
 import com.github.creme332.model.AppState;
 import com.github.creme332.model.CanvasModel;
@@ -77,6 +78,7 @@ public CanvasController(AppState app, Canvas canvas) {
 
         // initialize other canvas sub-controllers
         new Translator(app, canvas);
+        new Rotator(app, canvas);
 
         // when canvas is resized, update dimensions and reset zoom
         canvas.addComponentListener(new ComponentAdapter() {

src/main/java/com/github/creme332/controller/canvas/transform/Rotator.java

@@ -0,0 +1,38 @@
+package com.github.creme332.controller.canvas.transform;
+
+import java.awt.geom.Point2D;
+
+import com.github.creme332.model.AppState;
+import com.github.creme332.model.Mode;
+import com.github.creme332.model.ShapeWrapper;
+import com.github.creme332.view.Canvas;
+
+public class Rotator extends AbstractTransformer {
+
+    public Rotator(AppState app, Canvas canvas) {
+        super(app, canvas);
+    }
+
+    @Override
+    public void handleShapeSelection(int shapeIndex) {
+        // get copy of selected shape
+        ShapeWrapper selectedWrapperCopy = canvasModel.getShapeManager().getShapes().get(shapeIndex);
+
+        // TODO: Get rotation details
+
+        // perform rotation
+        selectedWrapperCopy.rotate(30, new Point2D.Double(0, 0));
+
+        // replace old shape with new one
+        canvasModel.getShapeManager().editShape(shapeIndex, selectedWrapperCopy);
+
+        // repaint canvas
+        canvas.repaint();
+    }
+
+    @Override
+    public boolean shouldDraw() {
+        return getCanvasMode() == Mode.ROTATE_ABOUT_POINT;
+    }
+
+}

src/main/java/com/github/creme332/model/ShapeWrapper.java

@@ -130,6 +130,47 @@ public void translate(final Point2D translationVector) {
         }
     }
 
+    /**
+     * Rotates shape and plotted points clockwise about a specified point.
+     * 
+     * @param radAngle the angle of rotation in radians
+     * @param pivot    the x-y coordinates of the rotation point
+     */
+    public void rotate(double radAngle, Point2D pivot) {
+        AffineTransform transform = new AffineTransform();
+
+        // Step 1: Translate the shape to the origin (negative of the rotation point)
+        transform.translate(pivot.getX(), pivot.getY());
+
+        // Step 2: Rotate the shape
+        transform.rotate(radAngle);
+
+        // Step 3: Translate the shape back to its original position
+        transform.translate(-pivot.getX(), -pivot.getY());
+
+        final Shape oldShape = shape;
+        Shape transformedShape;
+
+        if (oldShape instanceof Polygon) {
+            // if selected shape is of type polygon, ensure that the transformed shape is of
+            // type Polygon as well
+            transformedShape = PolygonCalculator.transformPolygon((Polygon) oldShape,
+                    transform);
+        } else {
+            transformedShape = transform.createTransformedShape(oldShape);
+        }
+
+        // replace old shape with transformed shape
+        setShape(transformedShape);
+
+        // rotate plotted points
+        for (int i = 0; i < plottedPoints.size(); i++) {
+            Point2D oldPoint = plottedPoints.get(i);
+            Point2D rotatedPoint = PolygonCalculator.rotatePointAboutPivot(oldPoint, pivot, radAngle);
+            plottedPoints.set(i, rotatedPoint);
+        }
+    }
+
     public Shape getShape() {
         return shape;
     }