Summary

Add explicit constructors to API classes of javax.swing.plaf.synth that have default constructors

Problem

Default constructors are not recommended for classes that are parts of a formal API.

Solution

Add explicit public no-arg constructors for public classes and protected no-arg constructor for public abstract classes.

Specification

--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalBorders.java 2020-08-15 17:34:22.792149000 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalBorders.java 2020-08-15 17:34:21.332125900 +0530
@@ -58,10 +58,20 @@
         new StringUIClientPropertyKey("NoButtonRollover");

     /**
+     * Constructs a {@code MetalBorders}.
+     */
+    public MetalBorders() {}
+
+    /**
      * The class represents the 3D border.
      */
     @SuppressWarnings("serial") // Superclass is not serializable across versions
     public static class Flush3DBorder extends AbstractBorder implements UIResource{
+        /**
+         * Constructs a {@code Flush3DBorder}.
+         */
+        public Flush3DBorder() {}
+
         public void paintBorder(Component c, Graphics g, int x, int y,
                           int w, int h) {
             if (c.isEnabled()) {
@@ -88,6 +98,11 @@
          */
         protected static Insets borderInsets = new Insets( 3, 3, 3, 3 );

+        /**
+         * Constructs a {@code ButtonBorder}.
+         */
+        public ButtonBorder() {}
+
         public void paintBorder(Component c, Graphics g, int x, int y, int w, int h) {
             if (!(c instanceof AbstractButton)) {
                 return;
@@ -205,6 +220,11 @@
     public static class InternalFrameBorder extends AbstractBorder implements UIResource {
         private static final int corner = 14;

+        /**
+         * Constructs a {@code InternalFrameBorder}.
+         */
+        public InternalFrameBorder() {}
+
         public void paintBorder(Component c, Graphics g, int x, int y,
                           int w, int h) {

@@ -464,6 +484,11 @@
     public static class PaletteBorder extends AbstractBorder implements UIResource {
         int titleHeight = 0;

+        /**
+         * Constructs a {@code PaletteBorder}.
+         */
+        public PaletteBorder() {}
+
         public void paintBorder( Component c, Graphics g, int x, int y, int w, int h ) {

             g.translate(x,y);
@@ -490,6 +515,11 @@
     public static class OptionDialogBorder extends AbstractBorder implements UIResource {
         int titleHeight = 0;

+        /**
+         * Constructs a {@code OptionDialogBorder}.
+         */
+        public OptionDialogBorder() {}
+
         public void paintBorder( Component c, Graphics g, int x, int y, int w, int h ) {

             g.translate(x,y);
@@ -559,6 +589,11 @@
          */
         protected static Insets borderInsets = new Insets( 1, 0, 1, 0 );

+        /**
+         * Constructs a {@code MenuBarBorder}.
+         */
+        public MenuBarBorder() {}
+
         public void paintBorder( Component c, Graphics g, int x, int y, int w, int h ) {
             g.translate(x, y);

@@ -600,6 +635,11 @@
          */
         protected static Insets borderInsets = new Insets( 2, 2, 2, 2 );

+        /**
+         * Constructs a {@code MenuItemBorder}.
+         */
+        public MenuItemBorder() {}
+
         public void paintBorder( Component c, Graphics g, int x, int y, int w, int h ) {
             if (!(c instanceof JMenuItem)) {
                 return;
@@ -655,6 +695,11 @@
          */
         protected static Insets borderInsets = new Insets( 3, 1, 2, 1 );

+        /**
+         * Constructs a {@code PopupMenuBorder}.
+         */
+        public PopupMenuBorder() {}
+
         public void paintBorder( Component c, Graphics g, int x, int y, int w, int h ) {
             g.translate( x, y );

@@ -682,6 +727,11 @@
     @SuppressWarnings("serial") // Superclass is not serializable across versions
     public static class RolloverButtonBorder extends ButtonBorder {

+        /**
+         * Constructs a {@code RolloverButtonBorder}.
+         */
+        public RolloverButtonBorder() {}
+
         public void paintBorder( Component c, Graphics g, int x, int y, int w, int h ) {
             AbstractButton b = (AbstractButton) c;
             ButtonModel model = b.getModel();
@@ -744,6 +794,11 @@
                                       MetalLookAndFeel.getControlDarkShadow(),
                                      UIManager.getColor("ToolBar.background"));

+        /**
+         * Constructs a {@code ToolBarBorder}.
+         */
+        public ToolBarBorder() {}
+
         public void paintBorder( Component c, Graphics g, int x, int y, int w, int h )
         {
             if (!(c instanceof JToolBar)) {
@@ -876,6 +931,11 @@
     @SuppressWarnings("serial") // Superclass is not serializable across versions
     public static class TextFieldBorder extends Flush3DBorder {

+        /**
+         * Constructs a {@code TextFieldBorder}.
+         */
+        public TextFieldBorder() {}
+
         public void paintBorder(Component c, Graphics g, int x, int y,
                                 int w, int h) {

@@ -903,6 +963,11 @@
      */
     @SuppressWarnings("serial") // Superclass is not serializable across versions
     public static class ScrollPaneBorder extends AbstractBorder implements UIResource {
+        /**
+         * Constructs a {@code ScrollPaneBorder}.
+         */
+        public ScrollPaneBorder() {}
+
         public void paintBorder(Component c, Graphics g, int x, int y,
                           int w, int h) {

@@ -966,6 +1031,11 @@
      */
     @SuppressWarnings("serial") // Superclass is not serializable across versions
     public static class ToggleButtonBorder extends ButtonBorder {
+        /**
+         * Constructs a {@code ToggleButtonBorder}.
+         */
+        public ToggleButtonBorder() {}
+
         public void paintBorder(Component c, Graphics g, int x, int y, int w, int h) {
             AbstractButton button = (AbstractButton)c;
             ButtonModel model = button.getModel();
@@ -1001,6 +1071,11 @@
     public static class TableHeaderBorder extends javax.swing.border.AbstractBorder {

         /**
+         * Constructs a {@code TableHeaderBorder}.
+         */
+        public TableHeaderBorder() {}
+
+        /**
          * The border insets.
          */
         protected Insets editorBorderInsets = new Insets( 2, 2, 2, 0 );
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalButtonUI.java    2020-08-15 17:34:32.903658200 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalButtonUI.java    2020-08-15 17:34:31.441369800 +0530
@@ -77,6 +77,11 @@
     // ********************************

     /**
+     * Constructs a {@code MetalButtonUI}.
+     */
+    public MetalButtonUI() {}
+
+    /**
      * Returns an instance of {@code MetalButtonUI}.
      *
      * @param c a component
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalCheckBoxIcon.java    2020-08-15 17:34:41.649434200 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalCheckBoxIcon.java    2020-08-15 17:34:40.163066600 +0530
@@ -50,6 +50,11 @@
 public class MetalCheckBoxIcon implements Icon, UIResource, Serializable {

     /**
+     * Constructs a {@code MetalCheckBoxIcon}.
+     */
+    public MetalCheckBoxIcon() {}
+
+    /**
      * Returns the size of the control.
      *
      * @return the size of the control
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalCheckBoxUI.java  2020-08-15 17:34:50.449596600 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalCheckBoxUI.java  2020-08-15 17:34:48.972379200 +0530
@@ -69,6 +69,11 @@
     // ********************************

     /**
+     * Constructs a {@code MetalCheckBoxUI}.
+     */
+    public MetalCheckBoxUI() {}
+
+    /**
      * Returns an instance of {@code MetalCheckBoxUI}.
      *
      * @param b a component
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalComboBoxEditor.java  2020-08-15 17:34:59.301984100 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalComboBoxEditor.java  2020-08-15 17:34:57.837906900 +0530
@@ -140,5 +140,9 @@
     @SuppressWarnings("serial") // Same-version serialization only
     public static class UIResource extends MetalComboBoxEditor
     implements javax.swing.plaf.UIResource {
+        /**
+         * Constructs a {@code UIResource}.
+         */
+        public UIResource() {}
     }
 }
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalComboBoxIcon.java    2020-08-15 17:35:08.256668100 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalComboBoxIcon.java    2020-08-15 17:35:06.744908600 +0530
@@ -44,6 +44,11 @@
 public class MetalComboBoxIcon implements Icon, Serializable {

     /**
+     * Constructs a {@code MetalComboBoxIcon}.
+     */
+    public MetalComboBoxIcon() {}
+
+    /**
      * Paints the horizontal bars for the
      */
     public void paintIcon(Component c, Graphics g, int x, int y){
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalComboBoxUI.java  2020-08-15 17:35:17.228508700 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalComboBoxUI.java  2020-08-15 17:35:15.631214600 +0530
@@ -55,6 +55,11 @@
 public class MetalComboBoxUI extends BasicComboBoxUI {

     /**
+     * Constructs a {@code MetalComboBoxUI}.
+     */
+    public MetalComboBoxUI() {}
+
+    /**
      * Constructs an instance of {@code MetalComboBoxUI}.
      *
      * @param c a component
@@ -210,6 +215,11 @@
      * Instantiate it only within subclasses of {@code MetalComboBoxUI}.
      */
     public class MetalPropertyChangeListener extends BasicComboBoxUI.PropertyChangeHandler {
+        /**
+         * Constructs a {@code MetalPropertyChangeListener}.
+         */
+        public MetalPropertyChangeListener() {}
+
         public void propertyChange(PropertyChangeEvent e) {
             super.propertyChange( e );
             String propertyName = e.getPropertyName();
@@ -255,6 +265,11 @@
      * Instantiate it only within subclasses of {@code MetalComboBoxUI}.
      */
     public class MetalComboBoxLayoutManager extends BasicComboBoxUI.ComboBoxLayoutManager {
+        /**
+         * Constructs a {@code MetalComboBoxLayoutManager}.
+         */
+        public MetalComboBoxLayoutManager() {}
+
         public void layoutContainer( Container parent ) {
             layoutComboBox( parent, this );
         }
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalFileChooserUI.java   2020-08-15 17:35:26.006977000 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalFileChooserUI.java   2020-08-15 17:35:24.499208100 +0530
@@ -1129,6 +1129,11 @@
      */
     @SuppressWarnings("serial") // Superclass is not serializable across versions
     public class FilterComboBoxRenderer extends DefaultListCellRenderer {
+        /**
+         * Constructs a {@code FilterComboBoxRenderer}.
+         */
+        public FilterComboBoxRenderer() {}
+
         public Component getListCellRendererComponent(JList<?> list,
             Object value, int index, boolean isSelected,
             boolean cellHasFocus) {
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalIconFactory.java 2020-08-15 17:35:35.668564800 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalIconFactory.java 2020-08-15 17:35:34.150609100 +0530
@@ -102,6 +102,11 @@
      */
     public static final boolean LIGHT = true;

+    /**
+     * Constructs a {@code MetalIconFactory}.
+     */
+    public MetalIconFactory() {}
+
     // Accessor functions for Icons. Does the caching work.
     /**
      * Returns the instance of {@code FileChooserDetailViewIcon}.
@@ -645,6 +650,11 @@
     public static class PaletteCloseIcon implements Icon, UIResource, Serializable{
         int iconSize = 7;

+        /**
+         * Constructs a {@code PaletteCloseIcon}.
+         */
+        public PaletteCloseIcon() {}
+
         public void paintIcon(Component c, Graphics g, int x, int y) {
             JButton parentButton = (JButton)c;
             ButtonModel buttonModel = parentButton.getModel();
@@ -1648,6 +1658,11 @@

         ImageCacher imageCacher;

+        /**
+         * Constructs a {@code FolderIcon16}.
+         */
+        public FolderIcon16() {}
+
         public void paintIcon(Component c, Graphics g, int x, int y) {
             GraphicsConfiguration gc = c.getGraphicsConfiguration();
             if (imageCacher == null) {
@@ -1739,6 +1754,11 @@
      */
     @SuppressWarnings("serial") // Same-version serialization only
     public static class TreeFolderIcon extends FolderIcon16 {
+        /**
+         * Constructs a {@code TreeFolderIcon}.
+         */
+        public TreeFolderIcon() {}
+
         public int getShift() { return -1; }
         public int getAdditionalHeight() { return 2; }
     }
@@ -1762,6 +1782,11 @@

         ImageCacher imageCacher;

+        /**
+         * Constructs a {@code FileIcon16}.
+         */
+        public FileIcon16() {}
+
         public void paintIcon(Component c, Graphics g, int x, int y) {
             GraphicsConfiguration gc = c.getGraphicsConfiguration();
             if (imageCacher == null) {
@@ -1839,6 +1864,10 @@
      * The class represents a tree leaf icon.
      */
     public static class TreeLeafIcon extends FileIcon16 {
+        /**
+         * Constructs a {@code TreeLeafIcon}.
+         */
+        public TreeLeafIcon() {}
         public int getShift() { return 2; }
         public int getAdditionalHeight() { return 4; }
     }
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalLabelUI.java 2020-08-15 17:35:44.843324300 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalLabelUI.java 2020-08-15 17:35:43.292334200 +0530
@@ -57,6 +57,11 @@
     private static final Object METAL_LABEL_UI_KEY = new Object();

     /**
+     * Constructs a {@code MetalLabelUI}.
+     */
+    public MetalLabelUI() {}
+
+    /**
      * Returns an instance of {@code MetalLabelUI}.
      *
      * @param c a component
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalLookAndFeel.java 2020-08-15 17:35:53.820359300 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalLookAndFeel.java 2020-08-15 17:35:52.323129800 +0530
@@ -108,6 +108,10 @@
      */
     private static boolean useSystemFonts;

+    /**
+     * Constructs a {@code MetalLookAndFeel}.
+     */
+    public MetalLookAndFeel() {}

     /**
      * Returns true if running on Windows.
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalMenuBarUI.java   2020-08-15 17:36:03.317352900 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalMenuBarUI.java   2020-08-15 17:36:01.826517200 +0530
@@ -40,6 +40,11 @@
  */
 public class MetalMenuBarUI extends BasicMenuBarUI  {
     /**
+     * Constructs a {@code MetalMenuBarUI}.
+     */
+    public MetalMenuBarUI() {}
+
+    /**
      * Creates the <code>ComponentUI</code> implementation for the passed
      * in component.
      *
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalPopupMenuSeparatorUI.java    2020-08-15 17:36:12.470442100 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalPopupMenuSeparatorUI.java    2020-08-15 17:36:10.821631500 +0530
@@ -44,6 +44,11 @@
 public class MetalPopupMenuSeparatorUI extends MetalSeparatorUI
 {
     /**
+     * Constructs a {@code MetalPopupMenuSeparatorUI}.
+     */
+    public MetalPopupMenuSeparatorUI() {}
+
+    /**
      * Constructs a new {@code MetalPopupMenuSeparatorUI} instance.
      *
      * @param c a component
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalProgressBarUI.java   2020-08-15 17:36:21.333259100 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalProgressBarUI.java   2020-08-15 17:36:19.843836700 +0530
@@ -51,6 +51,11 @@
     private Rectangle box;

     /**
+     * Constructs a {@code MetalProgressBarUI}.
+     */
+    public MetalProgressBarUI() {}
+
+    /**
      * Constructs an instance of {@code MetalProgressBarUI}.
      *
      * @param c a component
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalRadioButtonUI.java   2020-08-15 17:36:30.364800400 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalRadioButtonUI.java   2020-08-15 17:36:28.781338700 +0530
@@ -80,6 +80,11 @@
     // ********************************

     /**
+     * Constructs a {@code MetalRadioButtonUI}.
+     */
+    public MetalRadioButtonUI() {}
+
+    /**
      * Returns an instance of {@code MetalRadioButtonUI}.
      *
      * @param c a component
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalRootPaneUI.java  2020-08-15 17:36:40.315827200 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalRootPaneUI.java  2020-08-15 17:36:38.171396100 +0530
@@ -124,6 +124,11 @@
             Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR);

     /**
+     * Constructs a {@code MetalRootPaneUI}.
+     */
+    public MetalRootPaneUI() {}
+
+    /**
      * Creates a UI for a <code>JRootPane</code>.
      *
      * @param c the JRootPane the RootPaneUI will be created for
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalScrollBarUI.java 2020-08-15 17:36:51.566166700 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalScrollBarUI.java 2020-08-15 17:36:49.587804300 +0530
@@ -90,6 +90,11 @@
     protected boolean isFreeStanding = true;

     /**
+     * Constructs a {@code MetalScrollBarUI}.
+     */
+    public MetalScrollBarUI() {}
+
+    /**
      * Constructs a new {@code MetalScrollBarUI} instance.
      *
      * @param c a component
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalScrollPaneUI.java    2020-08-15 17:37:02.857591900 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalScrollPaneUI.java    2020-08-15 17:37:00.938565100 +0530
@@ -57,6 +57,11 @@
     private PropertyChangeListener scrollBarSwapListener;

     /**
+     * Constructs a {@code MetalScrollPaneUI}.
+     */
+    public MetalScrollPaneUI() {}
+
+    /**
      * Constructs a new {@code MetalScrollPaneUI}.
      *
      * @param x a component
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalSeparatorUI.java 2020-08-15 17:37:11.931248000 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalSeparatorUI.java 2020-08-15 17:37:10.429122700 +0530
@@ -54,6 +54,11 @@
 public class MetalSeparatorUI extends BasicSeparatorUI
 {
     /**
+     * Constructs a {@code MetalSeparatorUI}.
+     */
+    public MetalSeparatorUI() {}
+
+    /**
      * Constructs a new {@code MetalSeparatorUI} instance.
      *
      * @param c a component
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalSplitPaneUI.java 2020-08-15 17:37:20.964121400 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalSplitPaneUI.java 2020-08-15 17:37:19.450296900 +0530
@@ -46,7 +46,10 @@
 @SuppressWarnings("serial") // Same-version serialization only
 public class MetalSplitPaneUI extends BasicSplitPaneUI
 {
-
+    /**
+     * Constructs a {@code MetalSplitPaneUI}.
+     */
+    public MetalSplitPaneUI() {}

     /**
      * Creates a new {@code MetalSplitPaneUI} instance
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalTabbedPaneUI.java    2020-08-15 17:37:30.298155100 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalTabbedPaneUI.java    2020-08-15 17:37:28.710332400 +0530
@@ -81,6 +81,11 @@
     private Color oceanSelectedBorderColor;

     /**
+     * Constructs a {@code MetalTabbedPaneUI}.
+     */
+    public MetalTabbedPaneUI() {}
+
+    /**
      * Constructs {@code MetalTabbedPaneUI}.
      *
      * @param x a component
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalTextFieldUI.java 2020-08-15 17:37:39.414843100 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalTextFieldUI.java 2020-08-15 17:37:37.691645200 +0530
@@ -51,6 +51,11 @@
 public class MetalTextFieldUI extends BasicTextFieldUI {

     /**
+     * Constructs a {@code MetalTextFieldUI}.
+     */
+    public MetalTextFieldUI() {}
+
+    /**
      * Constructs {@code MetalTextFieldUI}.
      *
      * @param c a component
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalTheme.java   2020-08-15 17:37:48.341319500 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalTheme.java   2020-08-15 17:37:46.819658900 +0530
@@ -77,6 +77,11 @@
     private static ColorUIResource black = new ColorUIResource( 0, 0, 0 );

     /**
+     * Constructor for subclasses to call.
+     */
+    protected MetalTheme() {}
+
+    /**
      * Returns the name of this theme.
      *
      * @return the name of this theme
--- old/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalToggleButtonUI.java  2020-08-15 17:37:58.119098300 +0530
+++ new/src/java.desktop/share/classes/javax/swing/plaf/metal/MetalToggleButtonUI.java  2020-08-15 17:37:56.191270800 +0530
@@ -82,6 +82,11 @@
     // ********************************

     /**
+     * Constructs a {@code MetalToggleButtonUI}.
+     */
+    public MetalToggleButtonUI() {}
+
+    /**
      * Constructs the {@code MetalToogleButtonUI}.
      *
      * @param b a component