Styling: support ScrollBar

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

@@ -39,13 +39,13 @@ public class FlatArrowButton
 {
 	public static final int DEFAULT_ARROW_WIDTH = 8;
 
-	protected final boolean chevron;
+	protected boolean chevron;
-	protected final Color foreground;
+	protected Color foreground;
-	protected final Color disabledForeground;
+	protected Color disabledForeground;
-	protected final Color hoverForeground;
+	protected Color hoverForeground;
-	protected final Color hoverBackground;
+	protected Color hoverBackground;
-	protected final Color pressedForeground;
+	protected Color pressedForeground;
-	protected final Color pressedBackground;
+	protected Color pressedBackground;
 
 	private int arrowWidth = DEFAULT_ARROW_WIDTH;
 	private int xOffset = 0;
@@ -58,14 +58,8 @@ public class FlatArrowButton
 		Color hoverForeground, Color hoverBackground, Color pressedForeground, Color pressedBackground )
 	{
 		super( direction, Color.WHITE, Color.WHITE, Color.WHITE, Color.WHITE );
-
+		update( type, foreground, disabledForeground, hoverForeground, hoverBackground,
-		this.chevron = FlatUIUtils.isChevron( type );
+			pressedForeground, pressedBackground );
-		this.foreground = foreground;
-		this.disabledForeground = disabledForeground;
-		this.hoverForeground = hoverForeground;
-		this.hoverBackground = hoverBackground;
-		this.pressedForeground = pressedForeground;
-		this.pressedBackground = pressedBackground;
 
 		setOpaque( false );
 		setBorder( null );
@@ -101,6 +95,21 @@ public class FlatArrowButton
 		}
 	}
 
+	/**
+	 * @since TODO
+	 */
+	public void update( String type, Color foreground, Color disabledForeground,
+		Color hoverForeground, Color hoverBackground, Color pressedForeground, Color pressedBackground )
+	{
+		this.chevron = FlatUIUtils.isChevron( type );
+		this.foreground = foreground;
+		this.disabledForeground = disabledForeground;
+		this.hoverForeground = hoverForeground;
+		this.hoverBackground = hoverBackground;
+		this.pressedForeground = pressedForeground;
+		this.pressedBackground = pressedBackground;
+	}
+
 	public int getArrowWidth() {
 		return arrowWidth;
 	}

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

@@ -24,6 +24,7 @@ import java.awt.Rectangle;
 import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
 import java.beans.PropertyChangeListener;
+import java.util.Map;
 import java.util.Objects;
 import javax.swing.InputMap;
 import javax.swing.JButton;
@@ -35,6 +36,7 @@ import javax.swing.UIManager;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicScrollBarUI;
 import com.formdev.flatlaf.FlatClientProperties;
+import com.formdev.flatlaf.ui.FlatStyleSupport.Styleable;
 import com.formdev.flatlaf.util.UIScale;
 
 /**
@@ -75,32 +77,44 @@ import com.formdev.flatlaf.util.UIScale;
 public class FlatScrollBarUI
 	extends BasicScrollBarUI
 {
-	protected Insets trackInsets;
+	// overrides BasicScrollBarUI.supportsAbsolutePositioning (which is private)
-	protected Insets thumbInsets;
+	@Styleable protected boolean allowsAbsolutePositioning;
-	protected int trackArc;
-	protected int thumbArc;
-	protected Color hoverTrackColor;
-	protected Color hoverThumbColor;
-	protected boolean hoverThumbWithTrack;
-	protected Color pressedTrackColor;
-	protected Color pressedThumbColor;
-	protected boolean pressedThumbWithTrack;
 
-	protected boolean showButtons;
+	@Styleable protected Insets trackInsets;
-	protected String arrowType;
+	@Styleable protected Insets thumbInsets;
-	protected Color buttonArrowColor;
+	@Styleable protected int trackArc;
-	protected Color buttonDisabledArrowColor;
+	@Styleable protected int thumbArc;
-	protected Color hoverButtonBackground;
+	@Styleable protected Color hoverTrackColor;
-	protected Color pressedButtonBackground;
+	@Styleable protected Color hoverThumbColor;
+	@Styleable protected boolean hoverThumbWithTrack;
+	@Styleable protected Color pressedTrackColor;
+	@Styleable protected Color pressedThumbColor;
+	@Styleable protected boolean pressedThumbWithTrack;
+
+	@Styleable protected boolean showButtons;
+	@Styleable protected String arrowType;
+	@Styleable protected Color buttonArrowColor;
+	@Styleable protected Color buttonDisabledArrowColor;
+	@Styleable protected Color hoverButtonBackground;
+	@Styleable protected Color pressedButtonBackground;
 
 	private MouseAdapter hoverListener;
 	protected boolean hoverTrack;
 	protected boolean hoverThumb;
 
+	private Map<String, Object> oldStyleValues;
+
 	public static ComponentUI createUI( JComponent c ) {
 		return new FlatScrollBarUI();
 	}
 
+	@Override
+	public void installUI( JComponent c ) {
+		super.installUI( c );
+
+		applyStyle( FlatStyleSupport.getStyle( c ) );
+	}
+
 	@Override
 	protected void installListeners() {
 		super.installListeners();
@@ -123,6 +137,8 @@ public class FlatScrollBarUI
 	protected void installDefaults() {
 		super.installDefaults();
 
+		allowsAbsolutePositioning = super.getSupportsAbsolutePositioning();
+
 		trackInsets = UIManager.getInsets( "ScrollBar.trackInsets" );
 		thumbInsets = UIManager.getInsets( "ScrollBar.thumbInsets" );
 		trackArc = UIManager.getInt( "ScrollBar.trackArc" );
@@ -177,6 +193,12 @@ public class FlatScrollBarUI
 					scrollbar.repaint();
 					break;
 
+				case FlatClientProperties.COMPONENT_STYLE:
+					applyStyle( e.getNewValue() );
+					scrollbar.revalidate();
+					scrollbar.repaint();
+					break;
+
 				case "componentOrientation":
 					// this is missing in BasicScrollBarUI.Handler.propertyChange()
 					InputMap inputMap = (InputMap) UIManager.get( "ScrollBar.ancestorInputMap" );
@@ -193,6 +215,35 @@ public class FlatScrollBarUI
 		};
 	}
 
+	/**
+	 * @since TODO
+	 */
+	protected void applyStyle( Object style ) {
+		oldStyleValues = FlatStyleSupport.parseAndApply( oldStyleValues, style, this::applyStyleProperty );
+
+		if( incrButton instanceof FlatScrollBarButton )
+			((FlatScrollBarButton)incrButton).update();
+		if( decrButton instanceof FlatScrollBarButton )
+			((FlatScrollBarButton)decrButton).update();
+	}
+
+	/**
+	 * @since TODO
+	 */
+	protected Object applyStyleProperty( String key, Object value ) {
+		Object oldValue;
+		switch( key ) {
+			// BasicScrollBarUI
+			case "track": oldValue = trackColor; trackColor = (Color) value; return oldValue;
+			case "thumb": oldValue = thumbColor; thumbColor = (Color) value; return oldValue;
+			case "width": oldValue = scrollBarWidth; scrollBarWidth = (int) value; return oldValue;
+			case "minimumThumbSize": oldValue = minimumThumbSize; minimumThumbSize = (Dimension) value; return oldValue;
+			case "maximumThumbSize": oldValue = maximumThumbSize; maximumThumbSize = (Dimension) value; return oldValue;
+		}
+
+		return FlatStyleSupport.applyToAnnotatedObject( this, key, value );
+	}
+
 	@Override
 	public Dimension getPreferredSize( JComponent c ) {
 		return UIScale.scale( super.getPreferredSize( c ) );
@@ -295,6 +346,11 @@ public class FlatScrollBarUI
 		return UIScale.scale( FlatUIUtils.addInsets( super.getMaximumThumbSize(), thumbInsets ) );
 	}
 
+	@Override
+	public boolean getSupportsAbsolutePositioning() {
+		return allowsAbsolutePositioning;
+	}
+
 	//---- class ScrollBarHoverListener ---------------------------------------
 
 	// using static field to disabling hover for other scroll bars
@@ -368,6 +424,11 @@ public class FlatScrollBarUI
 			setRequestFocusEnabled( false );
 		}
 
+		protected void update() {
+			update( arrowType, buttonArrowColor, buttonDisabledArrowColor,
+				null, hoverButtonBackground, null, pressedButtonBackground );
+		}
+
 		@Override
 		protected Color deriveBackground( Color background ) {
 			return FlatUIUtils.deriveColor( background, scrollbar.getBackground() );

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

@@ -126,6 +126,36 @@ public class FlatStylingTests
 		ui.applyStyle( "icon.selectedPressedBackground: #fff" );
 	}
 
+	@Test
+	void scrollBar() {
+		FlatScrollBarUI ui = new FlatScrollBarUI();
+
+		ui.applyStyle( "track: #fff" );
+		ui.applyStyle( "thumb: #fff" );
+		ui.applyStyle( "width: 10" );
+		ui.applyStyle( "minimumThumbSize: 1,2" );
+		ui.applyStyle( "maximumThumbSize: 1,2" );
+		ui.applyStyle( "allowsAbsolutePositioning: true" );
+
+		ui.applyStyle( "trackInsets: 1,2,3,4" );
+		ui.applyStyle( "thumbInsets: 1,2,3,4" );
+		ui.applyStyle( "trackArc: 5" );
+		ui.applyStyle( "thumbArc: 10" );
+		ui.applyStyle( "hoverTrackColor: #fff" );
+		ui.applyStyle( "hoverThumbColor: #fff" );
+		ui.applyStyle( "hoverThumbWithTrack: true" );
+		ui.applyStyle( "pressedTrackColor: #fff" );
+		ui.applyStyle( "pressedThumbColor: #fff" );
+		ui.applyStyle( "pressedThumbWithTrack: true" );
+
+		ui.applyStyle( "showButtons: true" );
+		ui.applyStyle( "arrowType: chevron" );
+		ui.applyStyle( "buttonArrowColor: #fff" );
+		ui.applyStyle( "buttonDisabledArrowColor: #fff" );
+		ui.applyStyle( "hoverButtonBackground: #fff" );
+		ui.applyStyle( "pressedButtonBackground: #fff" );
+	}
+
 	@Test
 	void slider() {
 		FlatSliderUI ui = new FlatSliderUI();