8346227: Seal Paint and Material

Reviewed-by: nlisker, angorya, kcr

Author: Michael Strauß

modules/javafx.graphics/src/main/java/com/sun/javafx/tk/Toolkit.java

@@ -594,23 +594,12 @@ private Object getPaint(RadialGradient paint) {
     }
 
     public Object getPaint(Paint paint) {
-        if (paint instanceof Color) {
-            return createColorPaint((Color) paint);
-        }
-
-        if (paint instanceof LinearGradient) {
-            return getPaint((LinearGradient) paint);
-        }
-
-        if (paint instanceof RadialGradient) {
-            return getPaint((RadialGradient) paint);
-        }
-
-        if (paint instanceof ImagePattern) {
-            return createImagePatternPaint((ImagePattern) paint);
-        }
-
-        return null;
+        return switch (paint) {
+            case Color color -> createColorPaint(color);
+            case LinearGradient gradient -> getPaint(gradient);
+            case RadialGradient gradient -> getPaint(gradient);
+            case ImagePattern pattern -> createImagePatternPaint(pattern);
+        };
     }
 
     protected static final double clampStopOffset(double offset) {

modules/javafx.graphics/src/main/java/javafx/scene/paint/ImagePattern.java

@@ -383,7 +383,6 @@ void acc_removeListener(AbstractNotifyListener platformChangeListener) {
     @Override Object acc_getPlatformPaint() {
         if (acc_isMutable() || platformPaint == null) {
             platformPaint = Toolkit.getToolkit().getPaint(this);
-            assert platformPaint != null;
         }
         return platformPaint;
     }

modules/javafx.graphics/src/main/java/javafx/scene/paint/Material.java

@@ -45,7 +45,7 @@
  *
  * @since JavaFX 8.0
  */
-public abstract class Material {
+public abstract sealed class Material permits PhongMaterial {
 
     static {
         // This is used by classes in different packages to get access to

modules/javafx.graphics/src/main/java/javafx/scene/paint/Paint.java

@@ -45,7 +45,8 @@
  *
  * @since JavaFX 2.0
  */
-public abstract class Paint implements Interpolatable<Paint> {
+public abstract sealed class Paint implements Interpolatable<Paint>
+                                   permits Color, LinearGradient, RadialGradient, ImagePattern {
 
     static {
         Toolkit.setPaintAccessor(new Toolkit.PaintAccessor() {

modules/javafx.graphics/src/main/java/javafx/scene/paint/PhongMaterial.java

@@ -431,7 +431,7 @@
  * @see Shape3D
  * @since JavaFX 8.0
  */
-public class PhongMaterial extends Material {
+public non-sealed class PhongMaterial extends Material {
 
     private boolean diffuseColorDirty = true;
     private boolean specularColorDirty = true;