Introduce utility method to rescale an icon.

property-loader/src/main/java/com/github/weisj/darklaf/icons/IconLoader.java

@@ -383,6 +383,20 @@ public final class IconLoader {
         return IconUtil.createFrameIcon(icon, window);
     }
 
+    /**
+     * Create an derived version of the icon with the given width and height. This method will return
+     * the best possible result if the given icon implements {@link DerivableIcon} or
+     * {@link ImageSource}.
+     *
+     * @param icon the icon to drive.
+     * @param w the new width.
+     * @param h the new height.
+     * @return the derived icon.
+     */
+    public static Icon createDerivedIcon(final Icon icon, final int w, final int h) {
+        return IconUtil.createDerivedIcon(icon, w, h);
+    }
+
     protected URL getResource(final String name) {
         if (parentClass != null) {
             return parentClass.getResource(name);

property-loader/src/main/java/com/github/weisj/darklaf/icons/IconUtil.java

@@ -102,4 +102,16 @@ public class IconUtil {
             return image;
         }
     }
+
+    public static Icon createDerivedIcon(final Icon icon, final int w, final int h) {
+        int iconWidth = icon.getIconWidth();
+        int iconHeight = icon.getIconHeight();
+        if (iconHeight == h && iconWidth == w) return icon;
+        if (icon instanceof DerivableIcon<?>) {
+            return ((DerivableIcon<?>) icon).derive(w, h);
+        } else {
+            return new DerivableImageIcon(
+                    IconUtil.createScaledImage(icon, iconWidth / (double) w, iconHeight / (double) h));
+        }
+    }
 }