Fine Tuned Drop Shadow

 - Made Drop Shadow a bit Softer
 - RectangleDropShadow correctly considers the corner radius for the
   start of the shadow

Added example app showing the shadows.

Author: azoitl

org.eclipse.draw2d.examples/src/org/eclipse/draw2d/examples/shadows/ShadowsExample.java

@@ -0,0 +1,114 @@
+/*******************************************************************************
+ * Copyright (c) 2026 Johannes Kepler University Linz
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Alois Zoitl - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.draw2d.examples.shadows;
+
+import org.eclipse.swt.graphics.Color;
+import org.eclipse.swt.widgets.Shell;
+
+import org.eclipse.draw2d.ColorConstants;
+import org.eclipse.draw2d.Figure;
+import org.eclipse.draw2d.IFigure;
+import org.eclipse.draw2d.examples.AbstractExample;
+import org.eclipse.draw2d.geometry.Rectangle;
+import org.eclipse.draw2d.shadows.EllipseDropShadowBorder;
+import org.eclipse.draw2d.shadows.RectangleDropShadowBorder;
+
+public class ShadowsExample extends AbstractExample {
+
+	public static void main(String[] args) {
+		new ShadowsExample().run();
+	}
+
+	@Override
+	protected IFigure createContents() {
+		IFigure panel = new Figure();
+
+		panel.add(createPage());
+		panel.add(createRectangleFigure(480, 40, 50, 30, ColorConstants.green));
+		panel.add(createRectangleFigure(480, 230, 50, 30, ColorConstants.black));
+
+		return panel;
+	}
+
+	@Override
+	protected void hookShell(Shell shell) {
+		getFigureCanvas().setSize(600, 500);
+	}
+
+	private static IFigure createCircleFigure(int x, int y, int r, Color color) {
+		IFigure circle = new Figure() {
+			@Override
+			protected void paintFigure(org.eclipse.draw2d.Graphics graphics) {
+				// super paint figure first to draw the border
+				super.paintFigure(graphics);
+				graphics.fillOval(getBounds());
+			}
+		};
+
+		circle.setBounds(new Rectangle(x - r, y - r, 2 * r, 2 * r));
+		circle.setBackgroundColor(color);
+		circle.setBorder(new EllipseDropShadowBorder());
+		return circle;
+	}
+
+	private static IFigure createPage() {
+		IFigure page = createRectangleFigure(10, 10, 350, 420, ColorConstants.white);
+		// give page a larger softer schadow
+		RectangleDropShadowBorder pageBorder = new RectangleDropShadowBorder();
+		pageBorder.setDropShadowSize(12);
+		pageBorder.setHaloSize(6);
+		pageBorder.setSoftness(4.5);
+		page.setBorder(pageBorder);
+
+		page.add(createCircleFigure(40, 40, 20, ColorConstants.darkBlue));
+		page.add(createRoundedRectangleFigure(150, 45, 120, 100, 10, ColorConstants.button));
+		page.add(createRectangleFigure(200, 200, 120, 75, ColorConstants.cyan));
+		page.add(createRectangleFigure(75, 300, 200, 100, ColorConstants.lightGreen));
+
+		return page;
+	}
+
+	private static IFigure createRectangleFigure(int x, int y, int w, int h, Color color) {
+		IFigure circle = new Figure() {
+			@Override
+			protected void paintFigure(org.eclipse.draw2d.Graphics graphics) {
+				// super paint figure first to draw the border
+				super.paintFigure(graphics);
+				graphics.fillRectangle(getBounds());
+			}
+		};
+
+		circle.setBounds(new Rectangle(x, y, w, h));
+		circle.setBackgroundColor(color);
+		circle.setBorder(new RectangleDropShadowBorder());
+		return circle;
+	}
+
+	private static IFigure createRoundedRectangleFigure(int x, int y, int w, int h, int cornerRadius, Color color) {
+		IFigure circle = new Figure() {
+			@Override
+			protected void paintFigure(org.eclipse.draw2d.Graphics graphics) {
+				// super paint figure first to draw the border
+				super.paintFigure(graphics);
+				graphics.fillRoundRectangle(getBounds(), cornerRadius, cornerRadius);
+			}
+		};
+
+		circle.setBounds(new Rectangle(x, y, w, h));
+		circle.setBackgroundColor(color);
+		circle.setBorder(new RectangleDropShadowBorder(cornerRadius));
+		return circle;
+	}
+
+}

org.eclipse.draw2d/src/org/eclipse/draw2d/shadows/EllipseDropShadowBorder.java

@@ -44,9 +44,9 @@ protected void paintDropShadow(Graphics graphics, Rectangle shadowRect, int size
 		for (int i = 0; i < size; i++) {
 			final double progress = (double) i / size;
 			graphics.setAlpha(calcAlphaValue(progress));
-			graphics.drawArc(r, 270, 90);
 			r.x++;
 			r.y++;
+			graphics.drawArc(r, 270, 90);
 		}
 	}
 

org.eclipse.draw2d/src/org/eclipse/draw2d/shadows/RectangleDropShadowBorder.java

@@ -64,13 +64,13 @@ public RectangleDropShadowBorder(int cornerRadius) {
 
 	@Override
 	protected void paintDropShadow(final Graphics graphics, final Rectangle shadowRect, final int size) {
-		int bottomXStart = shadowRect.x + 1;
-		int bottomY = shadowRect.y + 1 + shadowRect.height;
-		final int bottomXEnd = shadowRect.x + shadowRect.width + 1 - cornerStartRadius;
+		int bottomXStart = shadowRect.x + cornerStartRadius;
+		int bottomY = shadowRect.y + 2 + shadowRect.height;
+		final int bottomXEnd = shadowRect.x + shadowRect.width + 2 - cornerStartRadius;
 
-		int rightX = shadowRect.x + shadowRect.width + 1;
-		int rightYStart = shadowRect.y + 1;
-		final int rightYEnd = shadowRect.y + shadowRect.height + 1 - cornerStartRadius;
+		int rightX = shadowRect.x + shadowRect.width + 2;
+		int rightYStart = shadowRect.y + cornerStartRadius;
+		final int rightYEnd = shadowRect.y + shadowRect.height + 2 - cornerStartRadius;
 		int cornerDiameter = 2 * cornerStartRadius;
 
 		for (int i = 0; i <= size; i++) {