SplitPane:

- removed `SplitPaneDivider.showHover` (hover is now enabled if hover color is specified)
- added `SplitPaneDivider.pressedColor` (for pressed/dragging in continuous layout)
- fixed painting of dragging divider in non-continuous layout (was 1px too small; added grip)
- updated styling unit tests

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

@@ -16,12 +16,13 @@
 
 package com.formdev.flatlaf.ui;
 
+import java.awt.Canvas;
 import java.awt.Color;
+import java.awt.Component;
 import java.awt.Container;
 import java.awt.Cursor;
 import java.awt.Graphics;
 import java.awt.Insets;
-import java.awt.Dimension;
 import java.awt.event.MouseEvent;
 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
@@ -53,8 +54,6 @@ import com.formdev.flatlaf.util.UIScale;
  * @uiDefault SplitPane.border							Border
  * @uiDefault SplitPaneDivider.border					Border
  * @uiDefault SplitPaneDivider.draggingColor			Color	only used if continuousLayout is false
- * @uiDefault SplitPaneDivider.showHover				boolean	optional; default is false
- * @uiDefault SplitPaneDivider.hoverColor				Color	the divider color on mouse hover if SplitPaneDivider.showHover is enabled
  *
  * <!-- BasicSplitPaneDivider -->
  *
@@ -70,6 +69,8 @@ import com.formdev.flatlaf.util.UIScale;
  * <!-- FlatSplitPaneUI -->
  *
  * @uiDefault Component.arrowType						String	chevron (default) or triangle
+ * @uiDefault SplitPaneDivider.hoverColor				Color	optional
+ * @uiDefault SplitPaneDivider.pressedColor				Color	optional
  * @uiDefault SplitPaneDivider.oneTouchArrowColor		Color
  * @uiDefault SplitPaneDivider.oneTouchHoverArrowColor	Color
  * @uiDefault SplitPaneDivider.oneTouchPressedArrowColor Color
@@ -86,13 +87,12 @@ public class FlatSplitPaneUI
 	implements StyleableUI
 {
 	@Styleable protected String arrowType;
+	/** @since 3.3 */ @Styleable protected Color draggingColor;
 	@Styleable protected Color oneTouchArrowColor;
 	@Styleable protected Color oneTouchHoverArrowColor;
 	@Styleable protected Color oneTouchPressedArrowColor;
 
 	private Map<String, Object> oldStyleValues;
-	
-	private boolean dragging;
 
 	public static ComponentUI createUI( JComponent c ) {
 		return new FlatSplitPaneUI();
@@ -109,6 +109,8 @@ public class FlatSplitPaneUI
 	protected void installDefaults() {
 		arrowType = UIManager.getString( "Component.arrowType" );
 
+		draggingColor = UIManager.getColor( "SplitPaneDivider.draggingColor" );
+
 		// get one-touch colors before invoking super.installDefaults() because they are
 		// used in there on LaF switching
 		oneTouchArrowColor = UIManager.getColor( "SplitPaneDivider.oneTouchArrowColor" );
@@ -122,6 +124,8 @@ public class FlatSplitPaneUI
 	protected void uninstallDefaults() {
 		super.uninstallDefaults();
 
+		draggingColor = null;
+
 		oneTouchArrowColor = null;
 		oneTouchHoverArrowColor = null;
 		oneTouchPressedArrowColor = null;
@@ -187,27 +191,40 @@ public class FlatSplitPaneUI
 		}
 		return FlatStylingSupport.getAnnotatedStyleableValue( this, key );
 	}
-	
-	/*
-	 * @see javax.swing.plaf.basic.BasicSplitPaneUI#startDragging()
-	 */
+
 	@Override
-	protected void startDragging() {
-		super.startDragging();
-		
-		// update dragging status
-		dragging = true;
+	protected Component createDefaultNonContinuousLayoutDivider() {
+		// only used for non-continuous layout if left or right component is heavy weight
+		return new Canvas() {
+			@Override
+			public void paint( Graphics g ) {
+				if( !isContinuousLayout() && getLastDragLocation() != -1 )
+					paintDragDivider( g, 0 );
+			}
+		};
 	}
-	
-	/*
-	 * @see javax.swing.plaf.basic.BasicSplitPaneUI#finishDraggingTo(int)
-	 */
+
 	@Override
-	protected void finishDraggingTo( int location ) {
-		super.finishDraggingTo( location );
-		
-		// update dragging status
-		dragging = false;
+	public void finishedPaintingChildren( JSplitPane sp, Graphics g ) {
+		if( sp == splitPane && getLastDragLocation() != -1 && !isContinuousLayout() && !draggingHW )
+			paintDragDivider( g, getLastDragLocation() );
+	}
+
+	private void paintDragDivider( Graphics g, int dividerLocation ) {
+		// divider bounds
+		boolean horizontal = (getOrientation() == JSplitPane.HORIZONTAL_SPLIT);
+		int x = horizontal ? dividerLocation : 0;
+		int y = !horizontal ? dividerLocation : 0;
+		int width = horizontal ? dividerSize : splitPane.getWidth();
+		int height = !horizontal ? dividerSize : splitPane.getHeight();
+
+		// paint background
+		g.setColor( FlatUIUtils.deriveColor( draggingColor, splitPane.getBackground() ) );
+		g.fillRect( x, y, width, height );
+
+		// paint divider style (e.g. grip)
+		if( divider instanceof FlatSplitPaneDivider )
+			((FlatSplitPaneDivider)divider).paintStyle( g, x, y, width, height );
 	}
 
 	//---- class FlatSplitPaneDivider -----------------------------------------
@@ -215,9 +232,9 @@ public class FlatSplitPaneUI
 	protected class FlatSplitPaneDivider
 		extends BasicSplitPaneDivider
 	{
-		@Styleable protected Color hoverColor = UIManager.getColor("SplitPaneDivider.hoverColor");
-		@Styleable protected boolean showHover = UIManager.getBoolean("SplitPaneDivider.showHover");
 		@Styleable protected String style = UIManager.getString( "SplitPaneDivider.style" );
+		/** @since 3.3 */ @Styleable protected Color hoverColor = UIManager.getColor( "SplitPaneDivider.hoverColor" );
+		/** @since 3.3 */ @Styleable protected Color pressedColor = UIManager.getColor( "SplitPaneDivider.pressedColor" );
 		@Styleable protected Color gripColor = UIManager.getColor( "SplitPaneDivider.gripColor" );
 		@Styleable protected int gripDotCount = FlatUIUtils.getUIInt( "SplitPaneDivider.gripDotCount", 3 );
 		@Styleable protected int gripDotSize = FlatUIUtils.getUIInt( "SplitPaneDivider.gripDotSize", 3 );
@@ -280,44 +297,34 @@ public class FlatSplitPaneUI
 
 		@Override
 		public void paint( Graphics g ) {
-
-			if( showHover && isMouseOver() && !dragging ) {
-				g.setColor( hoverColor );		
-				
-				// respect basic ui paint code
-				Dimension size = splitPane.getSize();
-	            if( orientation == JSplitPane.HORIZONTAL_SPLIT ) {
-	                g.fillRect( 0, 0, dividerSize - 1,
-	                           size.height - 1 );
-	            } else {
-	                g.fillRect( 0, 0, size.width - 1,
-	                           dividerSize - 1 );
-	            }
+			// paint hover or pressed background
+			Color hoverOrPressedColor = (isContinuousLayout() && dragger != null)
+				? pressedColor
+				: (isMouseOver() && dragger == null
+					? hoverColor
+					: null);
+			if( hoverOrPressedColor != null ) {
+				g.setColor( FlatUIUtils.deriveColor( hoverOrPressedColor, splitPane.getBackground() ) );
+				g.fillRect( 0, 0, getWidth(), getHeight() );
 			}
 
 			super.paint( g );
-			
+
+			paintStyle( g, 0, 0, getWidth(), getHeight() );
+		}
+
+		/** @since 3.3 */
+		protected void paintStyle( Graphics g, int x, int y, int width, int height ) {
 			if( "plain".equals( style ) )
 				return;
 
 			Object[] oldRenderingHints = FlatUIUtils.setRenderingHints( g );
 
 			g.setColor( gripColor );
-			paintGrip( g, 0, 0, getWidth(), getHeight() );
+			paintGrip( g, x, y, width, height );
 
 			FlatUIUtils.resetRenderingHints( g, oldRenderingHints );
 		}
-		
-		/*
-		 * @see javax.swing.plaf.basic.BasicSplitPaneDivider#setMouseOver(boolean)
-		 */
-		@Override
-		protected void setMouseOver( boolean mouseOver ) {
-			super.setMouseOver( mouseOver );
-			
-			if( showHover )
-				repaint();
-		}
 
 		protected void paintGrip( Graphics g, int x, int y, int width, int height ) {
 			FlatUIUtils.paintGrip( g, x, y, width, height,
@@ -341,6 +348,29 @@ public class FlatSplitPaneUI
 				: location == (splitPane.getWidth() - getWidth() - insets.right);
 		}
 
+		@Override
+		protected void setMouseOver( boolean mouseOver ) {
+			super.setMouseOver( mouseOver );
+			repaintIfNecessary();
+		}
+
+		@Override
+		protected void prepareForDragging() {
+			super.prepareForDragging();
+			repaintIfNecessary();
+		}
+
+		@Override
+		protected void finishDraggingTo( int location ) {
+			super.finishDraggingTo( location );
+			repaintIfNecessary();
+		}
+
+		private void repaintIfNecessary() {
+			if( hoverColor != null || pressedColor != null )
+				repaint();
+		}
+
 		//---- class FlatOneTouchButton ---------------------------------------
 
 		protected class FlatOneTouchButton

flatlaf-core/src/main/resources/com/formdev/flatlaf/FlatDarkLaf.properties

@@ -303,8 +303,6 @@ Slider.disabledThumbColor = $Slider.disabledTrackColor
 #---- SplitPane ----
 
 SplitPaneDivider.draggingColor = $Component.borderColor
-SplitPaneDivider.showHover = false
-SplitPaneDivider.hoverColor = darken($Component.borderColor,5%,derived)
 
 
 #---- TabbedPane ----

flatlaf-core/src/main/resources/com/formdev/flatlaf/FlatLightLaf.properties

@@ -309,8 +309,6 @@ Slider.disabledThumbColor = $Slider.disabledTrackColor
 #---- SplitPane ----
 
 SplitPaneDivider.draggingColor = $Component.borderColor
-SplitPaneDivider.showHover = false
-SplitPaneDivider.hoverColor = darken($Component.borderColor,5%,derived)
 
 
 #---- TabbedPane ----

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

@@ -689,12 +689,13 @@ public class TestFlatStyleableInfo
 
 		Map<String, Class<?>> expected = expectedMap(
 			"arrowType", String.class,
+			"draggingColor", Color.class,
+			"hoverColor", Color.class,
+			"pressedColor", Color.class,
 			"oneTouchArrowColor", Color.class,
 			"oneTouchHoverArrowColor", Color.class,
 			"oneTouchPressedArrowColor", Color.class,
-			
-			"hoverColor", Color.class,
-			"showHover", boolean.class,
+
 			"style", String.class,
 			"gripColor", Color.class,
 			"gripDotCount", int.class,

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

@@ -699,6 +699,9 @@ public class TestFlatStyleableValue
 		FlatSplitPaneUI ui = (FlatSplitPaneUI) c.getUI();
 
 		testString( c, ui, "arrowType", "chevron" );
+		testColor( c, ui, "draggingColor", 0x123456 );
+		testColor( c, ui, "hoverColor", 0x123456 );
+		testColor( c, ui, "pressedColor", 0x123456 );
 		testColor( c, ui, "oneTouchArrowColor", 0x123456 );
 		testColor( c, ui, "oneTouchHoverArrowColor", 0x123456 );
 		testColor( c, ui, "oneTouchPressedArrowColor", 0x123456 );

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

@@ -870,6 +870,9 @@ public class TestFlatStyling
 		FlatSplitPaneUI ui = (FlatSplitPaneUI) c.getUI();
 
 		ui.applyStyle( "arrowType: chevron" );
+		ui.applyStyle( "draggingColor: #fff" );
+		ui.applyStyle( "hoverColor: #fff" );
+		ui.applyStyle( "pressedColor: #fff" );
 		ui.applyStyle( "oneTouchArrowColor: #fff" );
 		ui.applyStyle( "oneTouchHoverArrowColor: #fff" );
 		ui.applyStyle( "oneTouchPressedArrowColor: #fff" );

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

@@ -175,6 +175,9 @@ Spinner.buttonPressedArrowColor = Spinner.buttonArrowColor
 
 #---- SplitPaneDivider ----
 
+SplitPaneDivider.draggingColor = SplitPane.background
+SplitPaneDivider.hoverColor = SplitPane.background
+SplitPaneDivider.pressedColor = SplitPane.background
 SplitPaneDivider.oneTouchHoverArrowColor = SplitPaneDivider.oneTouchArrowColor
 SplitPaneDivider.oneTouchPressedArrowColor = SplitPaneDivider.oneTouchArrowColor
 

flatlaf-testing/dumps/uidefaults/FlatTestLaf_1.8.0.txt

@@ -1050,9 +1050,11 @@ SplitPaneDivider.gripColor     #afafaf  HSL   0   0  69    javax.swing.plaf.Colo
 SplitPaneDivider.gripDotCount  3
 SplitPaneDivider.gripDotSize   3
 SplitPaneDivider.gripGap       2
+SplitPaneDivider.hoverColor    #008800  HSL 120 100  27    javax.swing.plaf.ColorUIResource [UI]
 SplitPaneDivider.oneTouchArrowColor #00ff00  HSL 120 100  50    javax.swing.plaf.ColorUIResource [UI]
 SplitPaneDivider.oneTouchHoverArrowColor #ff0000  HSL   0 100  50    javax.swing.plaf.ColorUIResource [UI]
 SplitPaneDivider.oneTouchPressedArrowColor #0000ff  HSL 240 100  50    javax.swing.plaf.ColorUIResource [UI]
+SplitPaneDivider.pressedColor  #000088  HSL 240 100  27    javax.swing.plaf.ColorUIResource [UI]
 SplitPaneDivider.style         grip
 
 

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatContainerTest.java

@@ -76,6 +76,13 @@ public class FlatContainerTest
 		tabScrollChanged();
 	}
 
+	private void continuousLayoutChanged() {
+		boolean continuousLayout = continuousLayoutCheckBox.isSelected();
+		splitPane1.setContinuousLayout( continuousLayout );
+		splitPane2.setContinuousLayout( continuousLayout );
+		splitPane3.setContinuousLayout( continuousLayout );
+	}
+
 	private void showOnlyOne() {
 		boolean showOnlyOne = showOnlyOneCheckBox.isSelected();
 
@@ -519,11 +526,12 @@ public class FlatContainerTest
 		// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
 		JPanel panel9 = new JPanel();
 		JLabel splitPaneLabel = new JLabel();
-		JSplitPane splitPane3 = new JSplitPane();
-		JSplitPane splitPane1 = new JSplitPane();
+		continuousLayoutCheckBox = new JCheckBox();
+		splitPane3 = new JSplitPane();
+		splitPane1 = new JSplitPane();
 		FlatContainerTest.Panel1 panel15 = new FlatContainerTest.Panel1();
 		FlatContainerTest.Panel2 panel21 = new FlatContainerTest.Panel2();
-		JSplitPane splitPane2 = new JSplitPane();
+		splitPane2 = new JSplitPane();
 		JPanel panel12 = new JPanel();
 		JLabel label3 = new JLabel();
 		JPanel panel13 = new JPanel();
@@ -601,6 +609,12 @@ public class FlatContainerTest
 			splitPaneLabel.setText("JSplitPane:");
 			panel9.add(splitPaneLabel, cc.xy(1, 1));
 
+			//---- continuousLayoutCheckBox ----
+			continuousLayoutCheckBox.setText("Continuous Layout");
+			continuousLayoutCheckBox.setSelected(true);
+			continuousLayoutCheckBox.addActionListener(e -> continuousLayoutChanged());
+			panel9.add(continuousLayoutCheckBox, cc.xy(3, 1, CellConstraints.RIGHT, CellConstraints.DEFAULT));
+
 			//======== splitPane3 ========
 			{
 				splitPane3.setResizeWeight(0.5);
@@ -929,6 +943,10 @@ public class FlatContainerTest
 	}
 
 	// JFormDesigner - Variables declaration - DO NOT MODIFY  //GEN-BEGIN:variables
+	private JCheckBox continuousLayoutCheckBox;
+	private JSplitPane splitPane3;
+	private JSplitPane splitPane1;
+	private JSplitPane splitPane2;
 	private JCheckBox showOnlyOneCheckBox;
 	private FlatTabbedPane tabbedPane1;
 	private FlatTabbedPane tabbedPane3;

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatContainerTest.jfd

@@ -22,13 +22,32 @@ new FormModel {
 					name: "splitPaneLabel"
 					"text": "JSplitPane:"
 				}, new FormLayoutConstraints( class com.jgoodies.forms.layout.CellConstraints ) )
+				add( new FormComponent( "javax.swing.JCheckBox" ) {
+					name: "continuousLayoutCheckBox"
+					"text": "Continuous Layout"
+					"selected": true
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "continuousLayoutChanged", false ) )
+				}, new FormLayoutConstraints( class com.jgoodies.forms.layout.CellConstraints ) {
+					"gridX": 3
+					"gridY": 1
+					"hAlign": sfield com.jgoodies.forms.layout.CellConstraints RIGHT
+				} )
 				add( new FormContainer( "javax.swing.JSplitPane", new FormLayoutManager( class javax.swing.JSplitPane ) ) {
 					name: "splitPane3"
 					"resizeWeight": 0.5
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
 					add( new FormContainer( "javax.swing.JSplitPane", new FormLayoutManager( class javax.swing.JSplitPane ) ) {
 						name: "splitPane1"
 						"resizeWeight": 0.5
 						"oneTouchExpandable": true
+						auxiliary() {
+							"JavaCodeGenerator.variableLocal": false
+						}
 						add( new FormComponent( "com.formdev.flatlaf.testing.FlatContainerTest$Panel1" ) {
 							name: "panel15"
 							"background": new java.awt.Color( 217, 163, 67, 255 )
@@ -49,6 +68,9 @@ new FormModel {
 						"orientation": 0
 						"resizeWeight": 0.5
 						"oneTouchExpandable": true
+						auxiliary() {
+							"JavaCodeGenerator.variableLocal": false
+						}
 						add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.BorderLayout ) ) {
 							name: "panel12"
 							"background": new java.awt.Color( 242, 101, 34, 255 )

flatlaf-testing/src/main/resources/com/formdev/flatlaf/testing/FlatTestLaf.properties

@@ -368,8 +368,8 @@ Spinner.focusedBackground = #ff8
 #---- SplitPane ----
 
 SplitPaneDivider.draggingColor = #800
-SplitPaneDivider.showHover = false
-SplitPaneDivider.hoverColor = #a00
+SplitPaneDivider.hoverColor = #080
+SplitPaneDivider.pressedColor = #008
 SplitPaneDivider.oneTouchArrowColor = #0f0
 SplitPaneDivider.oneTouchHoverArrowColor = #f00
 SplitPaneDivider.oneTouchPressedArrowColor = #00f

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

@@ -827,9 +827,11 @@ SplitPaneDivider.gripColor
 SplitPaneDivider.gripDotCount
 SplitPaneDivider.gripDotSize
 SplitPaneDivider.gripGap
+SplitPaneDivider.hoverColor
 SplitPaneDivider.oneTouchArrowColor
 SplitPaneDivider.oneTouchHoverArrowColor
 SplitPaneDivider.oneTouchPressedArrowColor
+SplitPaneDivider.pressedColor
 SplitPaneDivider.style
 SplitPaneUI
 TabbedPane.ancestorInputMap