Merge PR #936: CheckBox: support styling indeterminate state of tri-state check boxes

CHANGELOG.md

@@ -5,6 +5,9 @@ FlatLaf Change Log
 
 #### New features and improvements
 
+- CheckBox: Support styling indeterminate state of
+  [tri-state check boxes](https://www.javadoc.io/doc/com.formdev/flatlaf-extras/latest/com/formdev/flatlaf/extras/components/FlatTriStateCheckBox.html).
+  (issue #919)
 - Tree: Support for alternate row highlighting. (PR #903)
 - Tree: Support wide cell renderer. (issue #922)
 - Extras: `FlatSVGIcon` color filters now can access painting component to

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatCheckBoxIcon.java

@@ -17,6 +17,7 @@
 package com.formdev.flatlaf.icons;
 
 import static com.formdev.flatlaf.FlatClientProperties.*;
+import static com.formdev.flatlaf.ui.FlatUIUtils.stateColor;
 import java.awt.BasicStroke;
 import java.awt.Color;
 import java.awt.Component;
@@ -48,6 +49,8 @@ import com.formdev.flatlaf.ui.FlatUIUtils;
  * @uiDefault CheckBox.icon.borderWidth					int or float	optional; defaults to Component.borderWidth
  * @uiDefault CheckBox.icon.selectedBorderWidth			int or float	optional; defaults to CheckBox.icon.borderWidth
  * @uiDefault CheckBox.icon.disabledSelectedBorderWidth	int or float	optional; defaults to CheckBox.icon.selectedBorderWidth
+ * @uiDefault CheckBox.icon.indeterminateBorderWidth			int or float	optional; defaults to CheckBox.icon.selectedBorderWidth
+ * @uiDefault CheckBox.icon.disabledIndeterminateBorderWidth	int or float	optional; defaults to CheckBox.icon.disabledSelectedBorderWidth
  * @uiDefault CheckBox.arc								int
  *
  * @uiDefault CheckBox.icon.focusColor					Color	optional; defaults to Component.focusColor
@@ -56,30 +59,45 @@ import com.formdev.flatlaf.ui.FlatUIUtils;
  * @uiDefault CheckBox.icon.selectedBorderColor			Color
  * @uiDefault CheckBox.icon.selectedBackground			Color
  * @uiDefault CheckBox.icon.checkmarkColor				Color
+ * @uiDefault CheckBox.icon.indeterminateBorderColor	Color	optional; defaults to CheckBox.icon.selectedBorderColor
+ * @uiDefault CheckBox.icon.indeterminateBackground		Color	optional; defaults to CheckBox.icon.selectedBackground
+ * @uiDefault CheckBox.icon.indeterminateCheckmarkColor	Color	optional; defaults to CheckBox.icon.checkmarkColor
  *
  * @uiDefault CheckBox.icon.disabledBorderColor					Color
  * @uiDefault CheckBox.icon.disabledBackground					Color
- * @uiDefault CheckBox.icon.disabledSelectedBorderColor	Color	optional; CheckBox.icon.disabledBorderColor is used if not specified
+ * @uiDefault CheckBox.icon.disabledSelectedBorderColor			Color	optional; defaults to CheckBox.icon.disabledBorderColor
- * @uiDefault CheckBox.icon.disabledSelectedBackground	Color	optional; CheckBox.icon.disabledBackground is used if not specified
+ * @uiDefault CheckBox.icon.disabledSelectedBackground			Color	optional; defaults to CheckBox.icon.disabledBackground
  * @uiDefault CheckBox.icon.disabledCheckmarkColor				Color
+ * @uiDefault CheckBox.icon.disabledIndeterminateBorderColor	Color	optional; defaults to CheckBox.icon.disabledSelectedBorderColor
+ * @uiDefault CheckBox.icon.disabledIndeterminateBackground		Color	optional; defaults to CheckBox.icon.disabledSelectedBackground
+ * @uiDefault CheckBox.icon.disabledIndeterminateCheckmarkColor	Color	optional; defaults to CheckBox.icon.disabledCheckmarkColor
  *
  * @uiDefault CheckBox.icon.focusedBorderColor					Color	optional
  * @uiDefault CheckBox.icon.focusedBackground					Color	optional
- * @uiDefault CheckBox.icon.focusedSelectedBorderColor	Color	optional; CheckBox.icon.focusedBorderColor is used if not specified
+ * @uiDefault CheckBox.icon.focusedSelectedBorderColor			Color	optional; defaults to CheckBox.icon.focusedBorderColor
- * @uiDefault CheckBox.icon.focusedSelectedBackground	Color	optional; CheckBox.icon.focusedBackground is used if not specified
+ * @uiDefault CheckBox.icon.focusedSelectedBackground			Color	optional; defaults to CheckBox.icon.focusedBackground
- * @uiDefault CheckBox.icon.focusedCheckmarkColor		Color	optional; CheckBox.icon.checkmarkColor is used if not specified
+ * @uiDefault CheckBox.icon.focusedCheckmarkColor				Color	optional; defaults to CheckBox.icon.checkmarkColor
+ * @uiDefault CheckBox.icon.focusedIndeterminateBorderColor		Color	optional; defaults to CheckBox.icon.focusedSelectedBorderColor
+ * @uiDefault CheckBox.icon.focusedIndeterminateBackground		Color	optional; defaults to CheckBox.icon.focusedSelectedBackground
+ * @uiDefault CheckBox.icon.focusedIndeterminateCheckmarkColor	Color	optional; defaults to CheckBox.icon.focusedCheckmarkColor
  *
  * @uiDefault CheckBox.icon.hoverBorderColor					Color	optional
  * @uiDefault CheckBox.icon.hoverBackground						Color	optional
- * @uiDefault CheckBox.icon.hoverSelectedBorderColor	Color	optional; CheckBox.icon.hoverBorderColor is used if not specified
+ * @uiDefault CheckBox.icon.hoverSelectedBorderColor			Color	optional; defaults to CheckBox.icon.hoverBorderColor
- * @uiDefault CheckBox.icon.hoverSelectedBackground		Color	optional; CheckBox.icon.hoverBackground is used if not specified
+ * @uiDefault CheckBox.icon.hoverSelectedBackground				Color	optional; defaults to CheckBox.icon.hoverBackground
- * @uiDefault CheckBox.icon.hoverCheckmarkColor			Color	optional; CheckBox.icon.checkmarkColor is used if not specified
+ * @uiDefault CheckBox.icon.hoverCheckmarkColor					Color	optional; defaults to CheckBox.icon.checkmarkColor
+ * @uiDefault CheckBox.icon.hoverIndeterminateBorderColor		Color	optional; defaults to CheckBox.icon.hoverSelectedBorderColor
+ * @uiDefault CheckBox.icon.hoverIndeterminateBackground		Color	optional; defaults to CheckBox.icon.hoverSelectedBackground
+ * @uiDefault CheckBox.icon.hoverIndeterminateCheckmarkColor	Color	optional; defaults to CheckBox.icon.hoverCheckmarkColor
  *
  * @uiDefault CheckBox.icon.pressedBorderColor					Color	optional
  * @uiDefault CheckBox.icon.pressedBackground					Color	optional
- * @uiDefault CheckBox.icon.pressedSelectedBorderColor	Color	optional; CheckBox.icon.pressedBorderColor is used if not specified
+ * @uiDefault CheckBox.icon.pressedSelectedBorderColor			Color	optional; defaults to CheckBox.icon.pressedBorderColor
- * @uiDefault CheckBox.icon.pressedSelectedBackground	Color	optional; CheckBox.icon.pressedBackground is used if not specified
+ * @uiDefault CheckBox.icon.pressedSelectedBackground			Color	optional; defaults to CheckBox.icon.pressedBackground
- * @uiDefault CheckBox.icon.pressedCheckmarkColor		Color	optional; CheckBox.icon.checkmarkColor is used if not specified
+ * @uiDefault CheckBox.icon.pressedCheckmarkColor				Color	optional; defaults to CheckBox.icon.checkmarkColor
+ * @uiDefault CheckBox.icon.pressedIndeterminateBorderColor		Color	optional; defaults to CheckBox.icon.pressedSelectedBorderColor
+ * @uiDefault CheckBox.icon.pressedIndeterminateBackground		Color	optional; defaults to CheckBox.icon.pressedSelectedBackground
+ * @uiDefault CheckBox.icon.pressedIndeterminateCheckmarkColor	Color	optional; defaults to CheckBox.icon.pressedCheckmarkColor
  *
  * @author Karl Tauber
  */
@@ -92,6 +110,8 @@ public class FlatCheckBoxIcon
 	/** @since 2 */ @Styleable protected float borderWidth = getUIFloat( "CheckBox.icon.borderWidth", FlatUIUtils.getUIFloat( "Component.borderWidth", 1 ), style );
 	/** @since 2 */ @Styleable protected float selectedBorderWidth = getUIFloat( "CheckBox.icon.selectedBorderWidth", Float.MIN_VALUE, style );
 	/** @since 2 */ @Styleable protected float disabledSelectedBorderWidth = getUIFloat( "CheckBox.icon.disabledSelectedBorderWidth", Float.MIN_VALUE, style );
+	/** @since 3.6 */ @Styleable protected float indeterminateBorderWidth = getUIFloat( "CheckBox.icon.indeterminateBorderWidth", Float.MIN_VALUE, style );
+	/** @since 3.6 */ @Styleable protected float disabledIndeterminateBorderWidth = getUIFloat( "CheckBox.icon.disabledIndeterminateBorderWidth", Float.MIN_VALUE, style );
 	@Styleable protected int arc = FlatUIUtils.getUIInt( "CheckBox.arc", 2 );
 
 	// enabled
@@ -100,6 +120,9 @@ public class FlatCheckBoxIcon
 	@Styleable protected Color selectedBorderColor = getUIColor( "CheckBox.icon.selectedBorderColor", style );
 	@Styleable protected Color selectedBackground = getUIColor( "CheckBox.icon.selectedBackground", style );
 	@Styleable protected Color checkmarkColor = getUIColor( "CheckBox.icon.checkmarkColor", style );
+	/** @since 3.6 */ @Styleable protected Color indeterminateBorderColor = getUIColor( "CheckBox.icon.indeterminateBorderColor", style );
+	/** @since 3.6 */ @Styleable protected Color indeterminateBackground = getUIColor( "CheckBox.icon.indeterminateBackground", style );
+	/** @since 3.6 */ @Styleable protected Color indeterminateCheckmarkColor = getUIColor( "CheckBox.icon.indeterminateCheckmarkColor", style );
 
 	// disabled
 	@Styleable protected Color disabledBorderColor = getUIColor( "CheckBox.icon.disabledBorderColor", style );
@@ -107,6 +130,9 @@ public class FlatCheckBoxIcon
 	/** @since 2 */ @Styleable protected Color disabledSelectedBorderColor = getUIColor( "CheckBox.icon.disabledSelectedBorderColor", style );
 	/** @since 2 */ @Styleable protected Color disabledSelectedBackground = getUIColor( "CheckBox.icon.disabledSelectedBackground", style );
 	@Styleable protected Color disabledCheckmarkColor = getUIColor( "CheckBox.icon.disabledCheckmarkColor", style );
+	/** @since 3.6 */ @Styleable protected Color disabledIndeterminateBorderColor = getUIColor( "CheckBox.icon.disabledIndeterminateBorderColor", style );
+	/** @since 3.6 */ @Styleable protected Color disabledIndeterminateBackground = getUIColor( "CheckBox.icon.disabledIndeterminateBackground", style );
+	/** @since 3.6 */ @Styleable protected Color disabledIndeterminateCheckmarkColor = getUIColor( "CheckBox.icon.disabledIndeterminateCheckmarkColor", style );
 
 	// focused
 	@Styleable protected Color focusedBorderColor = getUIColor( "CheckBox.icon.focusedBorderColor", style );
@@ -114,6 +140,9 @@ public class FlatCheckBoxIcon
 	/** @since 2 */ @Styleable protected Color focusedSelectedBorderColor = getUIColor( "CheckBox.icon.focusedSelectedBorderColor", style );
 	/** @since 2 */ @Styleable protected Color focusedSelectedBackground = getUIColor( "CheckBox.icon.focusedSelectedBackground", style );
 	/** @since 2 */ @Styleable protected Color focusedCheckmarkColor = getUIColor( "CheckBox.icon.focusedCheckmarkColor", style );
+	/** @since 3.6 */ @Styleable protected Color focusedIndeterminateBorderColor = getUIColor( "CheckBox.icon.focusedIndeterminateBorderColor", style );
+	/** @since 3.6 */ @Styleable protected Color focusedIndeterminateBackground = getUIColor( "CheckBox.icon.focusedIndeterminateBackground", style );
+	/** @since 3.6 */ @Styleable protected Color focusedIndeterminateCheckmarkColor = getUIColor( "CheckBox.icon.focusedIndeterminateCheckmarkColor", style );
 
 	// hover
 	@Styleable protected Color hoverBorderColor = getUIColor( "CheckBox.icon.hoverBorderColor", style );
@@ -121,6 +150,9 @@ public class FlatCheckBoxIcon
 	/** @since 2 */ @Styleable protected Color hoverSelectedBorderColor = getUIColor( "CheckBox.icon.hoverSelectedBorderColor", style );
 	/** @since 2 */ @Styleable protected Color hoverSelectedBackground = getUIColor( "CheckBox.icon.hoverSelectedBackground", style );
 	/** @since 2 */ @Styleable protected Color hoverCheckmarkColor = getUIColor( "CheckBox.icon.hoverCheckmarkColor", style );
+	/** @since 3.6 */ @Styleable protected Color hoverIndeterminateBorderColor = getUIColor( "CheckBox.icon.hoverIndeterminateBorderColor", style );
+	/** @since 3.6 */ @Styleable protected Color hoverIndeterminateBackground = getUIColor( "CheckBox.icon.hoverIndeterminateBackground", style );
+	/** @since 3.6 */ @Styleable protected Color hoverIndeterminateCheckmarkColor = getUIColor( "CheckBox.icon.hoverIndeterminateCheckmarkColor", style );
 
 	// pressed
 	/** @since 2 */ @Styleable protected Color pressedBorderColor = getUIColor( "CheckBox.icon.pressedBorderColor", style );
@@ -128,6 +160,9 @@ public class FlatCheckBoxIcon
 	/** @since 2 */ @Styleable protected Color pressedSelectedBorderColor = getUIColor( "CheckBox.icon.pressedSelectedBorderColor", style );
 	/** @since 2 */ @Styleable protected Color pressedSelectedBackground = getUIColor( "CheckBox.icon.pressedSelectedBackground", style );
 	/** @since 2 */ @Styleable protected Color pressedCheckmarkColor = getUIColor( "CheckBox.icon.pressedCheckmarkColor", style );
+	/** @since 3.6 */ @Styleable protected Color pressedIndeterminateBorderColor = getUIColor( "CheckBox.icon.pressedIndeterminateBorderColor", style );
+	/** @since 3.6 */ @Styleable protected Color pressedIndeterminateBackground = getUIColor( "CheckBox.icon.pressedIndeterminateBackground", style );
+	/** @since 3.6 */ @Styleable protected Color pressedIndeterminateCheckmarkColor = getUIColor( "CheckBox.icon.pressedIndeterminateCheckmarkColor", style );
 
 	protected String getPropertyPrefix() {
 		return "CheckBox.";
@@ -182,11 +217,17 @@ public class FlatCheckBoxIcon
 		boolean indeterminate = isIndeterminate( c );
 		boolean selected = indeterminate || isSelected( c );
 		boolean isFocused = FlatUIUtils.isPermanentFocusOwner( c );
-		float bw = selected
+		float bw = Float.MIN_VALUE;
-			? (disabledSelectedBorderWidth != Float.MIN_VALUE && !c.isEnabled()
+		if( !c.isEnabled() ) {
-				? disabledSelectedBorderWidth
+			bw = (indeterminate && disabledIndeterminateBorderWidth != Float.MIN_VALUE)
-				: (selectedBorderWidth != Float.MIN_VALUE ? selectedBorderWidth : borderWidth))
+				? disabledIndeterminateBorderWidth
-			: borderWidth;
+				: (selected ? disabledSelectedBorderWidth : selectedBorderWidth);
+		}
+		if( bw == Float.MIN_VALUE ) {
+			bw = (indeterminate && indeterminateBorderWidth != Float.MIN_VALUE)
+				? indeterminateBorderWidth
+				: ((selected && selectedBorderWidth != Float.MIN_VALUE) ? selectedBorderWidth : borderWidth);
+		}
 
 		// paint focused border
 		if( isFocused && focusWidth > 0 && FlatButtonUI.isFocusPainted( c ) ) {
@@ -195,15 +236,15 @@ public class FlatCheckBoxIcon
 		}
 
 		// paint border
-		g.setColor( getBorderColor( c, selected ) );
+		g.setColor( getBorderColor( c, selected, indeterminate ) );
 		paintBorder( c, g, bw );
 
 		// paint background
-		Color bg = FlatUIUtils.deriveColor( getBackground( c, selected ),
+		Color baseBg = stateColor( indeterminate, indeterminateBackground, selected, selectedBackground, background );
-			selected ? selectedBackground : background );
+		Color bg = FlatUIUtils.deriveColor( getBackground( c, selected, indeterminate ), baseBg );
 		if( bg.getAlpha() < 255 ) {
 			// fill background with default color before filling with non-opaque background
-			g.setColor( selected ? selectedBackground : background );
+			g.setColor( baseBg );
 			paintBackground( c, g, bw );
 		}
 		g.setColor( bg );
@@ -211,7 +252,7 @@ public class FlatCheckBoxIcon
 
 		// paint checkmark
 		if( selected ) {
-			g.setColor( getCheckmarkColor( c ) );
+			g.setColor( getCheckmarkColor( c, indeterminate ) );
 			if( indeterminate )
 				paintIndeterminate( c, g );
 			else
@@ -272,30 +313,33 @@ public class FlatCheckBoxIcon
 		return focusColor;
 	}
 
-	protected Color getBorderColor( Component c, boolean selected ) {
+	/** @since 3.6 */
+	protected Color getBorderColor( Component c, boolean selected, boolean indeterminate ) {
 		return FlatButtonUI.buttonStateColor( c,
-			selected ? selectedBorderColor : borderColor,
+			stateColor( indeterminate, indeterminateBorderColor,         selected, selectedBorderColor,         borderColor ),
-			(selected && disabledSelectedBorderColor != null) ? disabledSelectedBorderColor : disabledBorderColor,
+			stateColor( indeterminate, disabledIndeterminateBorderColor, selected, disabledSelectedBorderColor, disabledBorderColor ),
-			(selected && focusedSelectedBorderColor != null) ? focusedSelectedBorderColor : focusedBorderColor,
+			stateColor( indeterminate, focusedIndeterminateBorderColor,  selected, focusedSelectedBorderColor,  focusedBorderColor ),
-			(selected && hoverSelectedBorderColor != null) ? hoverSelectedBorderColor : hoverBorderColor,
+			stateColor( indeterminate, hoverIndeterminateBorderColor,    selected, hoverSelectedBorderColor,    hoverBorderColor ),
-			(selected && pressedSelectedBorderColor != null) ? pressedSelectedBorderColor : pressedBorderColor );
+			stateColor( indeterminate, pressedIndeterminateBorderColor,  selected, pressedSelectedBorderColor,  pressedBorderColor ) );
 	}
 
-	protected Color getBackground( Component c, boolean selected ) {
+	/** @since 3.6 */
+	protected Color getBackground( Component c, boolean selected, boolean indeterminate ) {
 		return FlatButtonUI.buttonStateColor( c,
-			selected ? selectedBackground : background,
+			stateColor( indeterminate, indeterminateBackground,          selected, selectedBackground,          background ),
-			(selected && disabledSelectedBackground != null) ? disabledSelectedBackground : disabledBackground,
+			stateColor( indeterminate, disabledIndeterminateBackground,  selected, disabledSelectedBackground,  disabledBackground ),
-			(selected && focusedSelectedBackground != null) ? focusedSelectedBackground : focusedBackground,
+			stateColor( indeterminate, focusedIndeterminateBackground,   selected, focusedSelectedBackground,   focusedBackground ),
-			(selected && hoverSelectedBackground != null) ? hoverSelectedBackground : hoverBackground,
+			stateColor( indeterminate, hoverIndeterminateBackground,     selected, hoverSelectedBackground,     hoverBackground ),
-			(selected && pressedSelectedBackground != null) ? pressedSelectedBackground : pressedBackground );
+			stateColor( indeterminate, pressedIndeterminateBackground,   selected, pressedSelectedBackground,   pressedBackground ) );
 	}
 
-	protected Color getCheckmarkColor( Component c ) {
+	/** @since 3.6 */
+	protected Color getCheckmarkColor( Component c, boolean indeterminate ) {
 		return FlatButtonUI.buttonStateColor( c,
-			checkmarkColor,
+			stateColor( indeterminate, indeterminateCheckmarkColor, checkmarkColor ),
-			disabledCheckmarkColor,
+			stateColor( indeterminate, disabledIndeterminateCheckmarkColor, disabledCheckmarkColor ),
-			focusedCheckmarkColor,
+			stateColor( indeterminate, focusedIndeterminateCheckmarkColor, focusedCheckmarkColor ),
-			hoverCheckmarkColor,
+			stateColor( indeterminate, hoverIndeterminateCheckmarkColor, hoverCheckmarkColor ),
-			pressedCheckmarkColor );
+			stateColor( indeterminate, pressedIndeterminateCheckmarkColor, pressedCheckmarkColor ) );
 	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatUIUtils.java

@@ -129,6 +129,20 @@ public class FlatUIUtils
 		return insets.top == 0 && insets.left == 0 && insets.bottom == 0 && insets.right == 0;
 	}
 
+	/** @since 3.6 */
+	public static Color stateColor( boolean state, Color stateColor, Color defaultColor ) {
+		return (state && stateColor != null) ? stateColor : defaultColor;
+	}
+
+	/** @since 3.6 */
+	public static Color stateColor( boolean state1, Color state1Color,
+		boolean state2, Color state2Color, Color defaultColor )
+	{
+		return (state1 && state1Color != null)
+			? state1Color
+			: ((state2 && state2Color != null) ? state2Color : defaultColor);
+	}
+
 	public static Color getUIColor( String key, int defaultColorRGB ) {
 		Color color = UIManager.getColor( key );
 		return (color != null) ? color : new Color( defaultColorRGB );

flatlaf-core/src/test/java/com/formdev/flatlaf/ui/TestFlatStyleableInfo.java

@@ -517,6 +517,8 @@ public class TestFlatStyleableInfo
 			"icon.borderWidth", float.class,
 			"icon.selectedBorderWidth", float.class,
 			"icon.disabledSelectedBorderWidth", float.class,
+			"icon.indeterminateBorderWidth", float.class,
+			"icon.disabledIndeterminateBorderWidth", float.class,
 			"icon.arc", int.class,
 
 			// enabled
@@ -525,6 +527,9 @@ public class TestFlatStyleableInfo
 			"icon.selectedBorderColor", Color.class,
 			"icon.selectedBackground", Color.class,
 			"icon.checkmarkColor", Color.class,
+			"icon.indeterminateBorderColor", Color.class,
+			"icon.indeterminateBackground", Color.class,
+			"icon.indeterminateCheckmarkColor", Color.class,
 
 			// disabled
 			"icon.disabledBorderColor", Color.class,
@@ -532,6 +537,9 @@ public class TestFlatStyleableInfo
 			"icon.disabledSelectedBorderColor", Color.class,
 			"icon.disabledSelectedBackground", Color.class,
 			"icon.disabledCheckmarkColor", Color.class,
+			"icon.disabledIndeterminateBorderColor", Color.class,
+			"icon.disabledIndeterminateBackground", Color.class,
+			"icon.disabledIndeterminateCheckmarkColor", Color.class,
 
 			// focused
 			"icon.focusedBorderColor", Color.class,
@@ -539,6 +547,9 @@ public class TestFlatStyleableInfo
 			"icon.focusedSelectedBorderColor", Color.class,
 			"icon.focusedSelectedBackground", Color.class,
 			"icon.focusedCheckmarkColor", Color.class,
+			"icon.focusedIndeterminateBorderColor", Color.class,
+			"icon.focusedIndeterminateBackground", Color.class,
+			"icon.focusedIndeterminateCheckmarkColor", Color.class,
 
 			// hover
 			"icon.hoverBorderColor", Color.class,
@@ -546,13 +557,19 @@ public class TestFlatStyleableInfo
 			"icon.hoverSelectedBorderColor", Color.class,
 			"icon.hoverSelectedBackground", Color.class,
 			"icon.hoverCheckmarkColor", Color.class,
+			"icon.hoverIndeterminateBorderColor", Color.class,
+			"icon.hoverIndeterminateBackground", Color.class,
+			"icon.hoverIndeterminateCheckmarkColor", Color.class,
 
 			// pressed
 			"icon.pressedBorderColor", Color.class,
 			"icon.pressedBackground", Color.class,
 			"icon.pressedSelectedBorderColor", Color.class,
 			"icon.pressedSelectedBackground", Color.class,
-			"icon.pressedCheckmarkColor", Color.class
+			"icon.pressedCheckmarkColor", Color.class,
+			"icon.pressedIndeterminateBorderColor", Color.class,
+			"icon.pressedIndeterminateBackground", Color.class,
+			"icon.pressedIndeterminateCheckmarkColor", Color.class
 		);
 	}
 
@@ -1146,6 +1163,8 @@ public class TestFlatStyleableInfo
 			"borderWidth", float.class,
 			"selectedBorderWidth", float.class,
 			"disabledSelectedBorderWidth", float.class,
+			"indeterminateBorderWidth", float.class,
+			"disabledIndeterminateBorderWidth", float.class,
 			"arc", int.class,
 
 			// enabled
@@ -1154,6 +1173,9 @@ public class TestFlatStyleableInfo
 			"selectedBorderColor", Color.class,
 			"selectedBackground", Color.class,
 			"checkmarkColor", Color.class,
+			"indeterminateBorderColor", Color.class,
+			"indeterminateBackground", Color.class,
+			"indeterminateCheckmarkColor", Color.class,
 
 			// disabled
 			"disabledBorderColor", Color.class,
@@ -1161,6 +1183,9 @@ public class TestFlatStyleableInfo
 			"disabledSelectedBorderColor", Color.class,
 			"disabledSelectedBackground", Color.class,
 			"disabledCheckmarkColor", Color.class,
+			"disabledIndeterminateBorderColor", Color.class,
+			"disabledIndeterminateBackground", Color.class,
+			"disabledIndeterminateCheckmarkColor", Color.class,
 
 			// focused
 			"focusedBorderColor", Color.class,
@@ -1168,6 +1193,9 @@ public class TestFlatStyleableInfo
 			"focusedSelectedBorderColor", Color.class,
 			"focusedSelectedBackground", Color.class,
 			"focusedCheckmarkColor", Color.class,
+			"focusedIndeterminateBorderColor", Color.class,
+			"focusedIndeterminateBackground", Color.class,
+			"focusedIndeterminateCheckmarkColor", Color.class,
 
 			// hover
 			"hoverBorderColor", Color.class,
@@ -1175,13 +1203,19 @@ public class TestFlatStyleableInfo
 			"hoverSelectedBorderColor", Color.class,
 			"hoverSelectedBackground", Color.class,
 			"hoverCheckmarkColor", Color.class,
+			"hoverIndeterminateBorderColor", Color.class,
+			"hoverIndeterminateBackground", Color.class,
+			"hoverIndeterminateCheckmarkColor", Color.class,
 
 			// pressed
 			"pressedBorderColor", Color.class,
 			"pressedBackground", Color.class,
 			"pressedSelectedBorderColor", Color.class,
 			"pressedSelectedBackground", Color.class,
-			"pressedCheckmarkColor", Color.class
+			"pressedCheckmarkColor", Color.class,
+			"pressedIndeterminateBorderColor", Color.class,
+			"pressedIndeterminateBackground", Color.class,
+			"pressedIndeterminateCheckmarkColor", Color.class
 		);
 	}
 

flatlaf-core/src/test/java/com/formdev/flatlaf/ui/TestFlatStyleableValue.java

@@ -1148,6 +1148,8 @@ public class TestFlatStyleableValue
 		testValue( icon, "borderWidth", 1.5f );
 		testValue( icon, "selectedBorderWidth", 1.5f );
 		testValue( icon, "disabledSelectedBorderWidth", 1.5f );
+		testValue( icon, "indeterminateBorderWidth", 1.5f );
+		testValue( icon, "disabledIndeterminateBorderWidth", 1.5f );
 		testValue( icon, "arc", 5 );
 
 		// enabled
@@ -1156,6 +1158,9 @@ public class TestFlatStyleableValue
 		testValue( icon, "selectedBorderColor", Color.WHITE );
 		testValue( icon, "selectedBackground", Color.WHITE );
 		testValue( icon, "checkmarkColor", Color.WHITE );
+		testValue( icon, "indeterminateBorderColor", Color.WHITE );
+		testValue( icon, "indeterminateBackground", Color.WHITE );
+		testValue( icon, "indeterminateCheckmarkColor", Color.WHITE );
 
 		// disabled
 		testValue( icon, "disabledBorderColor", Color.WHITE );
@@ -1163,6 +1168,9 @@ public class TestFlatStyleableValue
 		testValue( icon, "disabledSelectedBorderColor", Color.WHITE );
 		testValue( icon, "disabledSelectedBackground", Color.WHITE );
 		testValue( icon, "disabledCheckmarkColor", Color.WHITE );
+		testValue( icon, "disabledIndeterminateBorderColor", Color.WHITE );
+		testValue( icon, "disabledIndeterminateBackground", Color.WHITE );
+		testValue( icon, "disabledIndeterminateCheckmarkColor", Color.WHITE );
 
 		// focused
 		testValue( icon, "focusedBorderColor", Color.WHITE );
@@ -1170,6 +1178,9 @@ public class TestFlatStyleableValue
 		testValue( icon, "focusedSelectedBorderColor", Color.WHITE );
 		testValue( icon, "focusedSelectedBackground", Color.WHITE );
 		testValue( icon, "focusedCheckmarkColor", Color.WHITE );
+		testValue( icon, "focusedIndeterminateBorderColor", Color.WHITE );
+		testValue( icon, "focusedIndeterminateBackground", Color.WHITE );
+		testValue( icon, "focusedIndeterminateCheckmarkColor", Color.WHITE );
 
 		// hover
 		testValue( icon, "hoverBorderColor", Color.WHITE );
@@ -1177,6 +1188,9 @@ public class TestFlatStyleableValue
 		testValue( icon, "hoverSelectedBorderColor", Color.WHITE );
 		testValue( icon, "hoverSelectedBackground", Color.WHITE );
 		testValue( icon, "hoverCheckmarkColor", Color.WHITE );
+		testValue( icon, "hoverIndeterminateBorderColor", Color.WHITE );
+		testValue( icon, "hoverIndeterminateBackground", Color.WHITE );
+		testValue( icon, "hoverIndeterminateCheckmarkColor", Color.WHITE );
 
 		// pressed
 		testValue( icon, "pressedBorderColor", Color.WHITE );
@@ -1184,6 +1198,9 @@ public class TestFlatStyleableValue
 		testValue( icon, "pressedSelectedBorderColor", Color.WHITE );
 		testValue( icon, "pressedSelectedBackground", Color.WHITE );
 		testValue( icon, "pressedCheckmarkColor", Color.WHITE );
+		testValue( icon, "pressedIndeterminateBorderColor", Color.WHITE );
+		testValue( icon, "pressedIndeterminateBackground", Color.WHITE );
+		testValue( icon, "pressedIndeterminateCheckmarkColor", Color.WHITE );
 	}
 
 	@Test

flatlaf-core/src/test/java/com/formdev/flatlaf/ui/TestFlatStyling.java

@@ -1390,6 +1390,8 @@ public class TestFlatStyling
 		icon.applyStyleProperty( "borderWidth", 1.5f );
 		icon.applyStyleProperty( "selectedBorderWidth", 1.5f );
 		icon.applyStyleProperty( "disabledSelectedBorderWidth", 1.5f );
+		icon.applyStyleProperty( "indeterminateBorderWidth", 1.5f );
+		icon.applyStyleProperty( "disabledIndeterminateBorderWidth", 1.5f );
 		icon.applyStyleProperty( "arc", 5 );
 
 		// enabled
@@ -1398,6 +1400,9 @@ public class TestFlatStyling
 		icon.applyStyleProperty( "selectedBorderColor", Color.WHITE );
 		icon.applyStyleProperty( "selectedBackground", Color.WHITE );
 		icon.applyStyleProperty( "checkmarkColor", Color.WHITE );
+		icon.applyStyleProperty( "indeterminateBorderColor", Color.WHITE );
+		icon.applyStyleProperty( "indeterminateBackground", Color.WHITE );
+		icon.applyStyleProperty( "indeterminateCheckmarkColor", Color.WHITE );
 
 		// disabled
 		icon.applyStyleProperty( "disabledBorderColor", Color.WHITE );
@@ -1405,6 +1410,9 @@ public class TestFlatStyling
 		icon.applyStyleProperty( "disabledSelectedBorderColor", Color.WHITE );
 		icon.applyStyleProperty( "disabledSelectedBackground", Color.WHITE );
 		icon.applyStyleProperty( "disabledCheckmarkColor", Color.WHITE );
+		icon.applyStyleProperty( "disabledIndeterminateBorderColor", Color.WHITE );
+		icon.applyStyleProperty( "disabledIndeterminateBackground", Color.WHITE );
+		icon.applyStyleProperty( "disabledIndeterminateCheckmarkColor", Color.WHITE );
 
 		// focused
 		icon.applyStyleProperty( "focusedBorderColor", Color.WHITE );
@@ -1412,6 +1420,9 @@ public class TestFlatStyling
 		icon.applyStyleProperty( "focusedSelectedBorderColor", Color.WHITE );
 		icon.applyStyleProperty( "focusedSelectedBackground", Color.WHITE );
 		icon.applyStyleProperty( "focusedCheckmarkColor", Color.WHITE );
+		icon.applyStyleProperty( "focusedIndeterminateBorderColor", Color.WHITE );
+		icon.applyStyleProperty( "focusedIndeterminateBackground", Color.WHITE );
+		icon.applyStyleProperty( "focusedIndeterminateCheckmarkColor", Color.WHITE );
 
 		// hover
 		icon.applyStyleProperty( "hoverBorderColor", Color.WHITE );
@@ -1419,6 +1430,9 @@ public class TestFlatStyling
 		icon.applyStyleProperty( "hoverSelectedBorderColor", Color.WHITE );
 		icon.applyStyleProperty( "hoverSelectedBackground", Color.WHITE );
 		icon.applyStyleProperty( "hoverCheckmarkColor", Color.WHITE );
+		icon.applyStyleProperty( "hoverIndeterminateBorderColor", Color.WHITE );
+		icon.applyStyleProperty( "hoverIndeterminateBackground", Color.WHITE );
+		icon.applyStyleProperty( "hoverIndeterminateCheckmarkColor", Color.WHITE );
 
 		// pressed
 		icon.applyStyleProperty( "pressedBorderColor", Color.WHITE );
@@ -1426,6 +1440,9 @@ public class TestFlatStyling
 		icon.applyStyleProperty( "pressedSelectedBorderColor", Color.WHITE );
 		icon.applyStyleProperty( "pressedSelectedBackground", Color.WHITE );
 		icon.applyStyleProperty( "pressedCheckmarkColor", Color.WHITE );
+		icon.applyStyleProperty( "pressedIndeterminateBorderColor", Color.WHITE );
+		icon.applyStyleProperty( "pressedIndeterminateBackground", Color.WHITE );
+		icon.applyStyleProperty( "pressedIndeterminateCheckmarkColor", Color.WHITE );
 	}
 
 	@Test

flatlaf-extras/src/main/resources/com/formdev/flatlaf/extras/resources/DerivedColorKeys.properties

@@ -62,6 +62,9 @@ CheckBox.icon.pressedBackground = CheckBox.icon.background
 CheckBox.icon.focusedSelectedBackground = CheckBox.icon.selectedBackground
 CheckBox.icon.hoverSelectedBackground = CheckBox.icon.selectedBackground
 CheckBox.icon.pressedSelectedBackground = CheckBox.icon.selectedBackground
+CheckBox.icon.focusedIndeterminateBackground = CheckBox.icon.indeterminateBackground
+CheckBox.icon.hoverIndeterminateBackground = CheckBox.icon.indeterminateBackground
+CheckBox.icon.pressedIndeterminateBackground = CheckBox.icon.indeterminateBackground
 
 CheckBox.icon[filled].disabledBackground = CheckBox.icon[filled].background
 CheckBox.icon[filled].focusedBackground = CheckBox.icon[filled].background
@@ -70,7 +73,9 @@ CheckBox.icon[filled].pressedBackground = CheckBox.icon[filled].background
 CheckBox.icon[filled].focusedSelectedBackground = CheckBox.icon[filled].selectedBackground
 CheckBox.icon[filled].hoverSelectedBackground = CheckBox.icon[filled].selectedBackground
 CheckBox.icon[filled].pressedSelectedBackground = CheckBox.icon[filled].selectedBackground
-
+CheckBox.icon[filled].focusedIndeterminateBackground = CheckBox.icon[filled].indeterminateBackground
+CheckBox.icon[filled].hoverIndeterminateBackground = CheckBox.icon[filled].indeterminateBackground
+CheckBox.icon[filled].pressedIndeterminateBackground = CheckBox.icon[filled].indeterminateBackground
 
 #---- CheckBoxMenuItem ----
 

flatlaf-theme-editor/src/main/java/com/formdev/flatlaf/themeeditor/FlatThemePreviewSwitches.java

@@ -672,7 +672,7 @@ class FlatThemePreviewSwitches
 				}
 				@Override
 				public boolean isSelected() {
-					return isStateSelected();
+					return isStateSelected() || isStateIndeterminate();
 				}
 			} );
 

flatlaf-theme-editor/src/main/resources/com/formdev/flatlaf/themeeditor/FlatLafUIKeys.txt

@@ -98,6 +98,10 @@ CheckBox.icon.checkmarkColor
 CheckBox.icon.disabledBackground
 CheckBox.icon.disabledBorderColor
 CheckBox.icon.disabledCheckmarkColor
+CheckBox.icon.disabledIndeterminateBackground
+CheckBox.icon.disabledIndeterminateBorderColor
+CheckBox.icon.disabledIndeterminateBorderWidth
+CheckBox.icon.disabledIndeterminateCheckmarkColor
 CheckBox.icon.disabledSelectedBackground
 CheckBox.icon.disabledSelectedBorderColor
 CheckBox.icon.disabledSelectedBorderWidth
@@ -106,16 +110,29 @@ CheckBox.icon.focusWidth
 CheckBox.icon.focusedBackground
 CheckBox.icon.focusedBorderColor
 CheckBox.icon.focusedCheckmarkColor
+CheckBox.icon.focusedIndeterminateBackground
+CheckBox.icon.focusedIndeterminateBorderColor
+CheckBox.icon.focusedIndeterminateCheckmarkColor
 CheckBox.icon.focusedSelectedBackground
 CheckBox.icon.focusedSelectedBorderColor
 CheckBox.icon.hoverBackground
 CheckBox.icon.hoverBorderColor
 CheckBox.icon.hoverCheckmarkColor
+CheckBox.icon.hoverIndeterminateBackground
+CheckBox.icon.hoverIndeterminateBorderColor
+CheckBox.icon.hoverIndeterminateCheckmarkColor
 CheckBox.icon.hoverSelectedBackground
 CheckBox.icon.hoverSelectedBorderColor
+CheckBox.icon.indeterminateBackground
+CheckBox.icon.indeterminateBorderColor
+CheckBox.icon.indeterminateBorderWidth
+CheckBox.icon.indeterminateCheckmarkColor
 CheckBox.icon.pressedBackground
 CheckBox.icon.pressedBorderColor
 CheckBox.icon.pressedCheckmarkColor
+CheckBox.icon.pressedIndeterminateBackground
+CheckBox.icon.pressedIndeterminateBorderColor
+CheckBox.icon.pressedIndeterminateCheckmarkColor
 CheckBox.icon.pressedSelectedBackground
 CheckBox.icon.pressedSelectedBorderColor
 CheckBox.icon.selectedBackground
@@ -130,6 +147,10 @@ CheckBox.icon[filled].checkmarkColor
 CheckBox.icon[filled].disabledBackground
 CheckBox.icon[filled].disabledBorderColor
 CheckBox.icon[filled].disabledCheckmarkColor
+CheckBox.icon[filled].disabledIndeterminateBackground
+CheckBox.icon[filled].disabledIndeterminateBorderColor
+CheckBox.icon[filled].disabledIndeterminateBorderWidth
+CheckBox.icon[filled].disabledIndeterminateCheckmarkColor
 CheckBox.icon[filled].disabledSelectedBackground
 CheckBox.icon[filled].disabledSelectedBorderColor
 CheckBox.icon[filled].disabledSelectedBorderWidth
@@ -137,16 +158,29 @@ CheckBox.icon[filled].focusWidth
 CheckBox.icon[filled].focusedBackground
 CheckBox.icon[filled].focusedBorderColor
 CheckBox.icon[filled].focusedCheckmarkColor
+CheckBox.icon[filled].focusedIndeterminateBackground
+CheckBox.icon[filled].focusedIndeterminateBorderColor
+CheckBox.icon[filled].focusedIndeterminateCheckmarkColor
 CheckBox.icon[filled].focusedSelectedBackground
 CheckBox.icon[filled].focusedSelectedBorderColor
 CheckBox.icon[filled].hoverBackground
 CheckBox.icon[filled].hoverBorderColor
 CheckBox.icon[filled].hoverCheckmarkColor
+CheckBox.icon[filled].hoverIndeterminateBackground
+CheckBox.icon[filled].hoverIndeterminateBorderColor
+CheckBox.icon[filled].hoverIndeterminateCheckmarkColor
 CheckBox.icon[filled].hoverSelectedBackground
 CheckBox.icon[filled].hoverSelectedBorderColor
+CheckBox.icon[filled].indeterminateBackground
+CheckBox.icon[filled].indeterminateBorderColor
+CheckBox.icon[filled].indeterminateBorderWidth
+CheckBox.icon[filled].indeterminateCheckmarkColor
 CheckBox.icon[filled].pressedBackground
 CheckBox.icon[filled].pressedBorderColor
 CheckBox.icon[filled].pressedCheckmarkColor
+CheckBox.icon[filled].pressedIndeterminateBackground
+CheckBox.icon[filled].pressedIndeterminateBorderColor
+CheckBox.icon[filled].pressedIndeterminateCheckmarkColor
 CheckBox.icon[filled].pressedSelectedBackground
 CheckBox.icon[filled].pressedSelectedBorderColor
 CheckBox.icon[filled].selectedBackground