Made svg icon load the svg model load lazily.

MAde ThemedIcon patch colors lazily.
Added TristateCheckBox.
Fixed NPE during titlePane uninstall process.
Added missing properties for striped table/tree.

src/main/java/com/weis/darklaf/DarkLaf.java

@@ -3,7 +3,6 @@ package com.weis.darklaf;
 import com.weis.darklaf.platform.windows.JNIDecorations;
 import com.weis.darklaf.theme.Theme;
 import com.weis.darklaf.ui.menu.DarkPopupMenuUI;
-import com.weis.darklaf.util.LafUtil;
 import com.weis.darklaf.util.SystemInfo;
 import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
@@ -203,8 +202,6 @@ public class DarkLaf extends BasicLookAndFeel {
 
         StyleSheet styleSheet = currentTheme.loadStyleSheet();
         new HTMLEditorKit().setStyleSheet(styleSheet);
-
-        LafUtil.patchIcons(defaults);
         setDecorationsEnabled(currentTheme.useCustomDecorations());
     }
 

src/main/java/com/weis/darklaf/components/tristate/TristateButtonModel.java

@@ -0,0 +1,78 @@
+package com.weis.darklaf.components.tristate;
+
+import javax.swing.*;
+import java.awt.event.ItemEvent;
+
+public class TristateButtonModel extends JToggleButton.ToggleButtonModel {
+    private TristateState state = TristateState.DESELECTED;
+
+    public TristateButtonModel(final TristateState state) {
+        setState(state);
+    }
+
+    public TristateButtonModel() {
+        this(TristateState.DESELECTED);
+    }
+
+    public void setIndeterminate() {
+        setState(TristateState.INDETERMINATE);
+    }
+
+    public boolean isIndeterminate() {
+        return state == TristateState.INDETERMINATE;
+    }
+
+    // Overrides of superclass methods
+    public void setEnabled(final boolean enabled) {
+        super.setEnabled(enabled);
+        // Restore state display
+        displayState();
+    }
+
+    public void setSelected(final boolean selected) {
+        setState(selected ? TristateState.SELECTED : TristateState.DESELECTED);
+    }
+
+    @Override
+    public boolean isSelected() {
+        return state == TristateState.SELECTED;
+    }
+
+    // Empty overrides of superclass methods
+    public void setArmed(final boolean b) {
+    }
+
+    public void setPressed(final boolean b) {
+    }
+
+    protected void iterateState() {
+        setState(state.next());
+    }
+
+    public void setState(final TristateState state) {
+        //Set internal state
+        this.state = state;
+        displayState();
+        if (state == TristateState.INDETERMINATE && isEnabled()) {
+            // force the events to fire
+
+            // Send ChangeEvent
+            fireStateChanged();
+
+            // Send ItemEvent
+            int indeterminate = 3;
+            //noinspection MagicConstant
+            fireItemStateChanged(new ItemEvent(this, ItemEvent.ITEM_STATE_CHANGED, this, indeterminate));
+        }
+    }
+
+    protected void displayState() {
+        super.setSelected(state != TristateState.DESELECTED);
+        super.setArmed(state == TristateState.INDETERMINATE);
+        super.setPressed(state == TristateState.INDETERMINATE);
+    }
+
+    public TristateState getState() {
+        return state;
+    }
+}

src/main/java/com/weis/darklaf/components/tristate/TristateCheckBox.java

@@ -0,0 +1,100 @@
+package com.weis.darklaf.components.tristate;
+
+import com.weis.darklaf.DarkLaf;
+import org.jetbrains.annotations.Contract;
+import org.jetbrains.annotations.NotNull;
+
+import javax.swing.*;
+import javax.swing.event.ChangeListener;
+import javax.swing.plaf.ActionMapUIResource;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.InputEvent;
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
+
+public class TristateCheckBox extends JCheckBox {
+    private final ChangeListener enableListener = e -> TristateCheckBox.this.setFocusable(getModel().isEnabled());
+
+    public TristateCheckBox(final String text) {
+        this(text, null, TristateState.DESELECTED);
+    }
+
+    @NotNull
+    @Contract(pure = true)
+    public String getUIClassID() {
+        if (UIManager.getLookAndFeel() instanceof DarkLaf) {
+            return "TristateCheckBoxUI";
+        } else {
+            return super.getUIClassID();
+        }
+    }
+
+    public TristateCheckBox(final String text, final Icon icon, final TristateState initial) {
+        super(text, icon);
+        setModel(new TristateButtonModel(initial));
+        // override action behaviour
+        super.addMouseListener(new MouseAdapter() {
+            public void mousePressed(final MouseEvent e) {
+                System.out.println(getState());
+                TristateCheckBox.this.iterateState();
+            }
+        });
+        ActionMap actions = new ActionMapUIResource();
+        actions.put("pressed", new AbstractAction() {
+            public void actionPerformed(final ActionEvent e) {
+                TristateCheckBox.this.iterateState();
+            }
+        });
+        actions.put("released", null);
+        SwingUtilities.replaceUIActionMap(this, actions);
+    }
+
+    public void setIndeterminate() {
+        getTristateModel().setIndeterminate();
+    }
+
+    public void setState(final TristateState state) {
+        getTristateModel().setState(state);
+    }
+
+    public boolean isIndeterminate() {
+        return getTristateModel().isIndeterminate();
+    }
+
+    public TristateState getState() {
+        return getTristateModel().getState();
+    }
+
+    @Override
+    public void setModel(final ButtonModel newModel) {
+        super.setModel(newModel);
+
+        if (model instanceof TristateButtonModel) {
+            model.addChangeListener(enableListener);
+        }
+    }
+
+    private void iterateState() {
+        if (!getModel().isEnabled()) return;
+
+        grabFocus();
+        getTristateModel().iterateState();
+        repaint();
+
+        int modifiers = 0;
+        AWTEvent currentEvent = EventQueue.getCurrentEvent();
+        if (currentEvent instanceof InputEvent) {
+            modifiers = ((InputEvent) currentEvent).getModifiersEx();
+        } else if (currentEvent instanceof ActionEvent) {
+            modifiers = ((ActionEvent) currentEvent).getModifiers();
+        }
+        fireActionPerformed(new ActionEvent(this,
+                                            ActionEvent.ACTION_PERFORMED, getText(),
+                                            System.currentTimeMillis(), modifiers));
+    }
+
+    public TristateButtonModel getTristateModel() {
+        return (TristateButtonModel) super.getModel();
+    }
+}

src/main/java/com/weis/darklaf/components/tristate/TristateState.java

@@ -0,0 +1,21 @@
+package com.weis.darklaf.components.tristate;
+
+public enum TristateState {
+    SELECTED {
+        public TristateState next() {
+            return INDETERMINATE;
+        }
+    },
+    INDETERMINATE {
+        public TristateState next() {
+            return DESELECTED;
+        }
+    },
+    DESELECTED {
+        public TristateState next() {
+            return SELECTED;
+        }
+    };
+
+    public abstract TristateState next();
+}

src/main/java/com/weis/darklaf/icons/DarkSVGIcon.java

@@ -9,6 +9,7 @@ import java.awt.*;
 import java.awt.geom.AffineTransform;
 import java.io.Serializable;
 import java.net.URI;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * Icon from SVG image.
@@ -20,6 +21,8 @@ public class DarkSVGIcon implements Icon, Serializable {
 
     private final Dimension size;
     private final SVGIcon icon;
+    private final URI uri;
+    private final AtomicBoolean loaded;
 
     /**
      * Method to fetch the SVG icon from a url.
@@ -29,18 +32,20 @@ public class DarkSVGIcon implements Icon, Serializable {
      * @param displayHeight display height of icon.
      */
     public DarkSVGIcon(@NotNull final URI uri, final int displayWidth, final int displayHeight) {
+        this.uri = uri;
         size = new Dimension(displayWidth, displayHeight);
-
         icon = new SVGIcon();
-        icon.setSvgURI(uri);
         icon.setScaleToFit(true);
         icon.setAntiAlias(true);
+        loaded = new AtomicBoolean(false);
     }
 
     @Contract(pure = true)
     private DarkSVGIcon(final int width, final int height, @NotNull final DarkSVGIcon icon) {
         this.size = new Dimension(width, height);
         this.icon = icon.icon;
+        this.uri = icon.uri;
+        this.loaded = icon.loaded;
     }
 
     public DarkSVGIcon derive(final int width, final int height) {
@@ -49,9 +54,17 @@ public class DarkSVGIcon implements Icon, Serializable {
 
     @Override
     public void paintIcon(final Component c, final Graphics g, final int x, final int y) {
+        ensureLoaded();
         paintIcon(c, g, x, y, 0);
     }
 
+    private void ensureLoaded() {
+        if (!loaded.get()) {
+            icon.setSvgURI(uri);
+            loaded.set(true);
+        }
+    }
+
     /**
      * Paint the icon with rotation.
      *
@@ -63,6 +76,7 @@ public class DarkSVGIcon implements Icon, Serializable {
      */
     public void paintIcon(final Component c, @NotNull final Graphics g, final int x, final int y,
                           final double rotation) {
+        ensureLoaded();
         var g2 = (Graphics2D) g.create();
         g2.translate(x, y);
         if (rotation != 0) {
@@ -85,6 +99,7 @@ public class DarkSVGIcon implements Icon, Serializable {
     }
 
     public SVGIcon getSVGIcon() {
+        ensureLoaded();
         return icon;
     }
 }

src/main/java/com/weis/darklaf/icons/IconColorMapper.java

@@ -16,18 +16,17 @@ import java.util.logging.Logger;
 public final class IconColorMapper {
     private static final Logger LOGGER = Logger.getLogger(IconLoader.class.getName());
 
-    public static void patchColors(@NotNull final SVGIcon svgIcon, @NotNull final UIDefaults defaults) {
+    public static void patchColors(@NotNull final SVGIcon svgIcon) {
         var universe = svgIcon.getSvgUniverse();
         SVGDiagram diagram = universe.getDiagram(svgIcon.getSvgURI());
         try {
-            loadColors(diagram, defaults);
+            loadColors(diagram);
         } catch (SVGElementException e) {
             LOGGER.log(Level.SEVERE, "Failed patching colors. " + e.getMessage(), e.getStackTrace());
         }
     }
 
-    private static void loadColors(@NotNull final SVGDiagram diagram,
-                                   @NotNull final UIDefaults defaults) throws SVGElementException {
+    private static void loadColors(@NotNull final SVGDiagram diagram) throws SVGElementException {
         var root = diagram.getRoot();
         var defs = diagram.getElement("colors");
         if (defs == null) return;
@@ -41,7 +40,7 @@ public final class IconColorMapper {
         for (var child : children) {
             if (child instanceof LinearGradient) {
                 var id = ((LinearGradient) child).getId();
-                var c = defaults.getColor(id);
+                var c = UIManager.getColor(id);
                 if (c == null) {
                     c = Color.RED;
                     LOGGER.warning("Could not load color with id'" + id + "'. Using Color.RED instead.");

src/main/java/com/weis/darklaf/icons/IconLoader.java

@@ -19,6 +19,7 @@ public final class IconLoader {
     private final Class<?> parentClass;
     private final Map<IconKey, UIAwareIcon> awareIconMap = new HashMap<>();
     private final Map<IconKey, Icon> iconMap = new HashMap<>();
+
     @Contract(pure = true)
     private IconLoader(final Class<?> parentClass) {
         this.parentClass = parentClass;
@@ -67,6 +68,10 @@ public final class IconLoader {
     }
 
     public Icon getIcon(final String path, final int w, final int h) {
+        return getIcon(path, w, h, false);
+    }
+
+    public Icon getIcon(final String path, final int w, final int h, final boolean themed) {
         IconKey key = new IconKey(path, w, h);
         if (iconMap.containsKey(key)) {
             return iconMap.get(key);
@@ -87,7 +92,7 @@ public final class IconLoader {
             }
             key.w = w; //Restore key.
             if (path.endsWith(".svg")) {
-                Icon icon = loadIcon(path, w, h);
+                Icon icon = loadSVGIcon(path, w, h, themed);
                 iconMap.put(key, icon);
                 return icon;
             } else {
@@ -100,10 +105,14 @@ public final class IconLoader {
 
     @NotNull
     @Contract("_, _, _ -> new")
-    public Icon loadIcon(@NotNull final String name, final int w, final int h) {
+    public Icon loadSVGIcon(@NotNull final String name, final int w, final int h, final boolean themed) {
         try {
             LOGGER.info("Loading icon '" + name + "'. Resolving from " + parentClass);
-            return new DarkSVGIcon(Objects.requireNonNull(parentClass.getResource(name).toURI()), w, h);
+            if (themed) {
+                return new ThemedSVGIcon(Objects.requireNonNull(parentClass.getResource(name).toURI()), w, h);
+            } else {
+                return new DarkSVGIcon(Objects.requireNonNull(parentClass.getResource(name).toURI()), w, h);
+            }
         } catch (NullPointerException | URISyntaxException e) {
             LOGGER.log(Level.SEVERE, "Exception while loading '" + name + "'" + ". Resolving from " + parentClass,
                        e.getStackTrace());
@@ -112,8 +121,8 @@ public final class IconLoader {
     }
 
     @NotNull
-    public Icon loadIcon(@NotNull final String name) {
-        return loadIcon(name, 16, 16);
+    public Icon loadSVGIcon(@NotNull final String name, final boolean themed) {
+        return loadSVGIcon(name, 16, 16, themed);
     }
 
     @Nullable

src/main/java/com/weis/darklaf/icons/ThemedSVGIcon.java

@@ -0,0 +1,31 @@
+package com.weis.darklaf.icons;
+
+import com.weis.darklaf.LafManager;
+import com.weis.darklaf.theme.Theme;
+import org.jetbrains.annotations.NotNull;
+
+import java.awt.*;
+import java.net.URI;
+
+public class ThemedSVGIcon extends DarkSVGIcon {
+
+    private Theme currentTheme;
+
+    public ThemedSVGIcon(@NotNull final URI uri, final int displayWidth, final int displayHeight) {
+        super(uri, displayWidth, displayHeight);
+    }
+
+    @Override
+    public void paintIcon(final Component c, final Graphics g, final int x, final int y) {
+        ensureTheme();
+        super.paintIcon(c, g, x, y);
+    }
+
+    private void ensureTheme() {
+        var theme = LafManager.getTheme();
+        if (currentTheme != theme) {
+            IconColorMapper.patchColors(getSVGIcon());
+            currentTheme = theme;
+        }
+    }
+}

src/main/java/com/weis/darklaf/theme/Theme.java

@@ -21,7 +21,7 @@ import java.util.logging.Logger;
 public abstract class Theme {
     private static final Logger LOGGER = Logger.getLogger(Theme.class.getName());
     private static final String[] UI_PROPERTIES = new String[]{
-            "borders", "button", "checkBox", "colorChooser", "comboBox", "fileChooser",
+            "borders", "button", "checkBox", "colorChooser", "comboBox", "fileChooser", "tristate",
             "internalFrame", "label", "list", "menu", "menuBar", "menuItem", "optionPane", "panel", "popupMenu",
             "progressBar", "radioButton", "rootPane", "scrollBar", "scrollPane", "separator", "slider", "spinner",
             "splitPane", "statusBar", "tabbedPane", "table", "text", "toggleButton", "toolBar", "toolTip", "tree",

src/main/java/com/weis/darklaf/ui/rootpane/DarkTitlePane.java

@@ -166,8 +166,10 @@ public class DarkTitlePane extends JComponent {
         windowHandle = 0;
         rootPane.removeContainerListener(rootPaneContainerListener);
         rootPane.getLayeredPane().removeContainerListener(layeredPaneContainerListener);
-        menuBar.setPreferredSize(null);
-        rootPane.setJMenuBar(menuBar);
+        if (menuBar != null) {
+            menuBar.setPreferredSize(null);
+            rootPane.setJMenuBar(menuBar);
+        }
         removeAll();
     }
 

src/main/java/com/weis/darklaf/ui/tree/DarkTreeUI.java

@@ -105,6 +105,7 @@ public class DarkTreeUI extends BasicTreeUI {
 
         myOldRepaintAllRowValue = UIManager.getBoolean("Tree.repaintWholeRow");
         UIManager.put("Tree.repaintWholeRow", true);
+        tree.putClientProperty("JTree.alternateRowColor", UIManager.getBoolean("Tree.alternateRowColor"));
 
         tree.setShowsRootHandles(true);
         tree.addMouseListener(mySelectionListener);

src/main/java/com/weis/darklaf/ui/tristate/DarkTristateCheckBoxUI.java

@@ -0,0 +1,46 @@
+package com.weis.darklaf.ui.tristate;
+
+import com.weis.darklaf.components.tristate.TristateCheckBox;
+import com.weis.darklaf.components.tristate.TristateState;
+import com.weis.darklaf.ui.checkbox.DarkCheckBoxUI;
+import org.jetbrains.annotations.Contract;
+import org.jetbrains.annotations.NotNull;
+
+import javax.swing.*;
+import javax.swing.plaf.ComponentUI;
+
+public class DarkTristateCheckBoxUI extends DarkCheckBoxUI {
+
+    @NotNull
+    @Contract("_ -> new")
+    public static ComponentUI createUI(final JComponent c) {
+        return new DarkTristateCheckBoxUI();
+    }
+
+    private Icon checkBoxIndeterminateIcon;
+    private Icon checkBoxIndeterminateDisabledIcon;
+    private Icon checkBoxIndeterminateFocusedIcon;
+
+    @Override
+    public void installDefaults(final AbstractButton b) {
+        super.installDefaults(b);
+        checkBoxIndeterminateIcon = UIManager.getIcon("CheckBox.indeterminate.icon");
+        checkBoxIndeterminateDisabledIcon = UIManager.getIcon("CheckBox.indeterminateDisabled.icon");
+        checkBoxIndeterminateFocusedIcon = UIManager.getIcon("CheckBox.indeterminateFocused.icon");
+    }
+
+    @Override
+    protected Icon getCheckIcon(@NotNull final AbstractButton b) {
+        if (b instanceof TristateCheckBox) {
+            var state = ((TristateCheckBox) b).getState();
+            if (state == TristateState.INDETERMINATE) {
+                if (b.isEnabled()) {
+                    return b.hasFocus() ? checkBoxIndeterminateFocusedIcon : checkBoxIndeterminateIcon;
+                } else {
+                    return checkBoxIndeterminateDisabledIcon;
+                }
+            }
+        }
+        return super.getCheckIcon(b);
+    }
+}

src/main/java/com/weis/darklaf/util/LafUtil.java

@@ -1,9 +1,6 @@
 package com.weis.darklaf.util;
 
-import com.kitfox.svg.app.beans.SVGIcon;
-import com.weis.darklaf.icons.DarkSVGIcon;
 import com.weis.darklaf.icons.EmptyIcon;
-import com.weis.darklaf.icons.IconColorMapper;
 import com.weis.darklaf.icons.IconLoader;
 import com.weis.darklaf.icons.UIAwareIcon;
 import org.jetbrains.annotations.Contract;
@@ -18,11 +15,9 @@ import java.awt.*;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Arrays;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
-import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -33,8 +28,6 @@ public final class LafUtil {
     private static final String AWARE_KEY = "[aware]";
     private static final String PATCH_KEY = "[patch]";
 
-    private static final Set<SVGIcon> resolveSet = new HashSet<>();
-
     @NotNull
     public static Properties loadProperties(@NotNull final Class<?> clazz, final String name, final String path) {
         final Properties properties = new Properties();
@@ -46,18 +39,6 @@ public final class LafUtil {
         return properties;
     }
 
-    public static void patchIcons(@NotNull final UIDefaults defaults) {
-        new SwingWorker<>() {
-            @Override
-            protected Object doInBackground() {
-                resolveSet.forEach(icon -> IconColorMapper.patchColors(icon, defaults));
-                resolveSet.clear();
-                return null;
-            }
-        }.doInBackground();
-    }
-
-
     @Nullable
     public static Object parseValue(@NotNull final String key, @NotNull final String value,
                                     final Map<Object, Object> defaults) {
@@ -164,14 +145,7 @@ public final class LafUtil {
             }
             var iconPath = path.substring(0, path.length() - tag.length());
             if (tag.equals(PATCH_KEY)) {
-                Icon icon = ICON_LOADER.getIcon(iconPath, dim.width, dim.height);
-                if (icon instanceof DarkSVGIcon) {
-                    resolveSet.add(((DarkSVGIcon) icon).getSVGIcon());
-                    return icon;
-                } else {
-                    LOGGER.warning("Could not patch colours for icon '" + iconPath + "'. Not a SVG icon.");
-                    return icon;
-                }
+                return ICON_LOADER.getIcon(iconPath, dim.width, dim.height, true);
             } else {
                 UIAwareIcon icon = ICON_LOADER.getUIAwareIcon(iconPath, dim.width, dim.height);
                 if (tag.equals(DUAL_KEY)) {

src/main/resources/com/weis/darklaf/properties/platform/mac.properties

@@ -14,9 +14,10 @@
 # limitations under the License.
 #
 # suppress inspection "UnusedProperty" for whole file
-darcula.selectionBackground = 2F65CA
+darcula.selectionBackground  = 2F65CA
 #Menu.arrowIcon=AllIcons.Mac.Tree_white_right_arrow
-MenuBar.border              = com.bulenkov.darcula.ui.DarculaMenuBarBorder
-FileChooserUI               = javax.swing.plaf.metal.MetalFileChooserUI
+MenuBar.border               = com.bulenkov.darcula.ui.DarculaMenuBarBorder
+FileChooserUI                = javax.swing.plaf.metal.MetalFileChooserUI
 
-#Table.alternateRowColor
+Table.alternateRowColor      = true
+Table.alternateRowBackground = %backgroundAlternative

src/main/resources/com/weis/darklaf/properties/ui/table.properties

@@ -22,6 +22,9 @@ Table.focusSelectionBackground         = %highlightFillFocus
 Table.selectionNoFocusBackground       = %highlightFill
 Table.selectionBackground              = %highlightFillFocus
 
+Table.alternateRowColor                = false
+Table.alternateRowBackground           = %backgroundAlternative
+
 Table.renderBooleanAsCheckBox          = true
 Table.booleanRenderType                = checkBox
 

src/main/resources/com/weis/darklaf/properties/ui/tree.properties

@@ -18,6 +18,9 @@ Tree.textBackground                      = %textBackground
 Tree.rowHeight                           = 22
 Tree.dropLineColor                       = %dropForeground
 
+Tree.alternateRowColor                   = false
+Tree.alternateRowBackground              = %backgroundAlternative
+
 Tree.renderBooleanAsCheckBox             = true
 Tree.booleanRenderType                   = checkBox
 

src/main/resources/com/weis/darklaf/properties/ui/tristate.properties

@@ -0,0 +1,2 @@
+# suppress inspection "UnusedProperty" for whole file
+TristateCheckBoxUI = com.weis.darklaf.ui.tristate.DarkTristateCheckBoxUI

src/test/java/ColorChooserDemo.java

@@ -1,5 +1,4 @@
 import com.weis.darklaf.LafManager;
-import com.weis.darklaf.theme.Theme;
 
 import javax.swing.*;
 import java.awt.*;
@@ -11,7 +10,6 @@ public final class ColorChooserDemo {
             LafManager.install();
             JColorChooser.showDialog(null, "Color Chooser with transparency",
                                      Color.RED, true);
-//            JOptionPane.showMessageDialog(null, "This is a test!","THis is a test!", JOptionPane.ERROR_MESSAGE);
         });
     }
 }

src/test/java/UIDemo.java

@@ -1,5 +1,6 @@
 import com.weis.darklaf.LafManager;
 import com.weis.darklaf.components.TextFieldHistory;
+import com.weis.darklaf.components.tristate.TristateCheckBox;
 import com.weis.darklaf.icons.IconLoader;
 import org.jdesktop.swingx.JXStatusBar;
 import org.jdesktop.swingx.JXTaskPane;
@@ -27,7 +28,7 @@ public final class UIDemo {
                     taskpanecontainer.add(taskpane);
 
                     JFrame frame = new JFrame("UIDemo");
-                    Icon folderIcon = IconLoader.get().getUIAwareIcon("control/checkBoxFocused.svg", 19, 19);
+                    Icon folderIcon = IconLoader.get().getUIAwareIcon("files/folder.svg", 19, 19);
 
                     var panel = new JPanel(new GridLayout(2, 5));
                     var content = new JPanel(new BorderLayout());
@@ -58,6 +59,13 @@ public final class UIDemo {
                             }});
                             add(new JRadioButton("enabled"));
                         }});
+                        add(new JPanel(new FlowLayout(FlowLayout.LEFT)) {{
+                            add(new TristateCheckBox("disabled") {{
+                                setIndeterminate();
+                                setEnabled(false);
+                            }});
+                            add(new TristateCheckBox("enabled"));
+                        }});
                         add(new JPanel(new FlowLayout(FlowLayout.LEFT)) {{
                             add(new JButton("IconButton", folderIcon) {{
                                 setRolloverEnabled(true);