8250849: Address reliance on default constructors in the javax.swing.plaf APIs

Reviewed-by: prr, serb

src/java.desktop/share/classes/javax/swing/plaf/ButtonUI.java

@@ -36,4 +36,8 @@ import java.awt.Insets;
  * @author Jeff Dinkins
  */
 public abstract class ButtonUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected ButtonUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/ColorChooserUI.java

@@ -37,5 +37,8 @@ import javax.swing.colorchooser.*;
 
 public abstract class ColorChooserUI extends ComponentUI
 {
-
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected ColorChooserUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/ComboBoxUI.java

@@ -35,6 +35,11 @@ import javax.swing.JComboBox;
  */
 public abstract class ComboBoxUI extends ComponentUI {
 
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected ComboBoxUI() {}
+
     /**
      * Set the visibility of the popup
      *

src/java.desktop/share/classes/javax/swing/plaf/DesktopIconUI.java

@@ -32,4 +32,8 @@ package javax.swing.plaf;
  * @author David Kloba
  */
 public abstract class DesktopIconUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected DesktopIconUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/DesktopPaneUI.java

@@ -32,4 +32,8 @@ package javax.swing.plaf;
  * @author David Kloba
  */
 public abstract class DesktopPaneUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected DesktopPaneUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/FileChooserUI.java

@@ -38,6 +38,11 @@ import java.io.File;
 
 public abstract class FileChooserUI extends ComponentUI
 {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected FileChooserUI() {}
+
     /**
      * Returns an accept-all file filter.
      * @param fc the file chooser

src/java.desktop/share/classes/javax/swing/plaf/InternalFrameUI.java

@@ -31,4 +31,8 @@ package javax.swing.plaf;
  * @author David Kloba
  */
 public abstract class InternalFrameUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected InternalFrameUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/LabelUI.java

@@ -31,4 +31,9 @@ package javax.swing.plaf;
  * @author Hans Muller
  */
 public abstract class LabelUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected LabelUI() {}
 }
+

src/java.desktop/share/classes/javax/swing/plaf/LayerUI.java

@@ -65,6 +65,11 @@ public class LayerUI<V extends Component>
     private final PropertyChangeSupport propertyChangeSupport =
             new PropertyChangeSupport(this);
 
+    /**
+     * Constructs a {@code LayerUI}.
+     */
+    public LayerUI() {}
+
     /**
      * Paints the specified component.
      * Subclasses should override this method and use

src/java.desktop/share/classes/javax/swing/plaf/ListUI.java

@@ -38,6 +38,11 @@ import java.awt.Rectangle;
 
 public abstract class ListUI extends ComponentUI
 {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected ListUI() {}
+
     /**
      * Returns the cell index in the specified {@code JList} closest to the
      * given location in the list's coordinate system. To determine if the

src/java.desktop/share/classes/javax/swing/plaf/MenuBarUI.java

@@ -36,4 +36,9 @@ import javax.swing.JMenu;
  * @author David Karlton
  */
 
-public abstract class MenuBarUI extends ComponentUI { }
+public abstract class MenuBarUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected MenuBarUI() {}
+}

src/java.desktop/share/classes/javax/swing/plaf/MenuItemUI.java

@@ -35,4 +35,8 @@ import java.awt.event.*;
  * @author Arnaud Weber
  */
 public abstract class MenuItemUI extends ButtonUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected MenuItemUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/OptionPaneUI.java

@@ -35,6 +35,11 @@ import javax.swing.JOptionPane;
 
 public abstract class OptionPaneUI extends ComponentUI
 {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected OptionPaneUI() {}
+
     /**
      * Requests the component representing the default value to have
      * focus.

src/java.desktop/share/classes/javax/swing/plaf/PanelUI.java

@@ -32,4 +32,8 @@ package javax.swing.plaf;
  * @author Steve Wilson
  */
 public abstract class PanelUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected PanelUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/PopupMenuUI.java

@@ -38,6 +38,11 @@ import javax.swing.JPopupMenu;
  */
 
 public abstract class PopupMenuUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected PopupMenuUI() {}
+
     /**
      * Returns whether or not the given {@code MouseEvent} is the popup menu
      * trigger event for the platform

src/java.desktop/share/classes/javax/swing/plaf/ProgressBarUI.java

@@ -32,4 +32,8 @@ package javax.swing.plaf;
  * @author Rob Davis
  */
 public abstract class ProgressBarUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected ProgressBarUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/RootPaneUI.java

@@ -32,4 +32,8 @@ package javax.swing.plaf;
  * @since 1.3
  */
 public abstract class RootPaneUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected RootPaneUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/ScrollBarUI.java

@@ -31,4 +31,8 @@ package javax.swing.plaf;
  * @author David Kloba
  */
 public abstract class ScrollBarUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected ScrollBarUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/ScrollPaneUI.java

@@ -33,4 +33,8 @@ package javax.swing.plaf;
  */
 
 public abstract class ScrollPaneUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected ScrollPaneUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/SeparatorUI.java

@@ -33,4 +33,8 @@ package javax.swing.plaf;
  */
 
 public abstract class SeparatorUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected SeparatorUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/SliderUI.java

@@ -31,4 +31,8 @@ package javax.swing.plaf;
  * @author Hans Muller
  */
 public abstract class SliderUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected SliderUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/SpinnerUI.java

@@ -33,4 +33,8 @@ package javax.swing.plaf;
  * @since 1.4
  */
 public abstract class SpinnerUI extends javax.swing.plaf.ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected SpinnerUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/SplitPaneUI.java

@@ -35,6 +35,11 @@ import java.awt.Graphics;
  */
 public abstract class SplitPaneUI extends ComponentUI
 {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected SplitPaneUI() {}
+
     /**
      * Messaged to relayout the JSplitPane based on the preferred size
      * of the children components.

src/java.desktop/share/classes/javax/swing/plaf/TabbedPaneUI.java

@@ -35,6 +35,11 @@ import javax.swing.JTabbedPane;
  * @author Amy Fowler
  */
 public abstract class TabbedPaneUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected TabbedPaneUI() {}
+
     /**
      * Returns the tab for the coordinate.
      * @param pane the pane

src/java.desktop/share/classes/javax/swing/plaf/TableHeaderUI.java

@@ -31,4 +31,8 @@ package javax.swing.plaf;
  * @author Alan Chung
  */
 public abstract class TableHeaderUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected TableHeaderUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/TableUI.java

@@ -31,4 +31,8 @@ package javax.swing.plaf;
  * @author Alan Chung
  */
 public abstract class TableUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected TableUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/TextUI.java

@@ -37,6 +37,11 @@ import javax.swing.text.*;
  */
 public abstract class TextUI extends ComponentUI
 {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected TextUI() {}
+
     /**
      * Converts the given location in the model to a place in
      * the view coordinate system.

src/java.desktop/share/classes/javax/swing/plaf/ToolBarUI.java

@@ -35,4 +35,8 @@ import javax.swing.JToolBar;
  */
 
 public abstract class ToolBarUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected ToolBarUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/ToolTipUI.java

@@ -31,4 +31,8 @@ package javax.swing.plaf;
  * @author Dave Moore
  */
 public abstract class ToolTipUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected ToolTipUI() {}
 }

src/java.desktop/share/classes/javax/swing/plaf/TreeUI.java

@@ -37,6 +37,11 @@ import javax.swing.tree.TreePath;
  */
 public abstract class TreeUI extends ComponentUI
 {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected TreeUI() {}
+
     /**
      * Returns the Rectangle enclosing the label portion that the
      * last item in path will be drawn into.  Will return null if

src/java.desktop/share/classes/javax/swing/plaf/ViewportUI.java

@@ -32,4 +32,8 @@ package javax.swing.plaf;
  * @author Rich Schiavi
  */
 public abstract class ViewportUI extends ComponentUI {
+    /**
+     * Constructor for subclasses to call.
+     */
+    protected ViewportUI() {}
 }