Merge PR #713: Scrollpane rounded border

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

@@ -28,7 +28,6 @@ import javax.swing.JComboBox;
 import javax.swing.JComponent;
 import javax.swing.JScrollPane;
 import javax.swing.JSpinner;
-import javax.swing.JViewport;
 import javax.swing.UIManager;
 import javax.swing.plaf.basic.BasicBorders;
 import com.formdev.flatlaf.FlatClientProperties;
@@ -195,8 +194,7 @@ public class FlatBorder
 	protected boolean isEnabled( Component c ) {
 		if( c instanceof JScrollPane ) {
 			// check whether view component is disabled
-			JViewport viewport = ((JScrollPane)c).getViewport();
-			Component view = (viewport != null) ? viewport.getView() : null;
+			Component view = FlatScrollPaneUI.getView( (JScrollPane) c );
 			if( view != null && !isEnabled( view ) )
 				return false;
 		}

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

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2023 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.ui;
+
+import java.awt.Component;
+import java.awt.Insets;
+import javax.swing.JList;
+import javax.swing.JScrollPane;
+import javax.swing.JTable;
+import javax.swing.JTree;
+import javax.swing.UIManager;
+import javax.swing.text.JTextComponent;
+import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
+import com.formdev.flatlaf.util.UIScale;
+
+/**
+ * Border for {@link javax.swing.JScrollPane}.
+ *
+ * @uiDefault ScrollPane.arc				int
+ * @uiDefault ScrollPane.List.arc			int
+ * @uiDefault ScrollPane.Table.arc			int
+ * @uiDefault ScrollPane.TextComponent.arc	int
+ * @uiDefault ScrollPane.Tree.arc			int
+
+ * @author Karl Tauber
+ * @since 3.3
+ */
+public class FlatScrollPaneBorder
+	extends FlatBorder
+{
+	@Styleable protected int arc = UIManager.getInt( "ScrollPane.arc" );
+
+	private boolean isArcStyled;
+	private final int listArc = FlatUIUtils.getUIInt( "ScrollPane.List.arc", -1 );
+	private final int tableArc = FlatUIUtils.getUIInt( "ScrollPane.Table.arc", -1 );
+	private final int textComponentArc = FlatUIUtils.getUIInt( "ScrollPane.TextComponent.arc", -1 );
+	private final int treeArc = FlatUIUtils.getUIInt( "ScrollPane.Tree.arc", -1 );
+
+	@Override
+	public Object applyStyleProperty( String key, Object value ) {
+		Object oldValue = super.applyStyleProperty( key, value );
+
+		if( "arc".equals( key ) )
+			isArcStyled = true;
+
+		return oldValue;
+	}
+
+	@Override
+	public Insets getBorderInsets( Component c, Insets insets ) {
+		insets = super.getBorderInsets( c, insets );
+
+		// if view is rounded, increase left and right insets to avoid that the viewport
+		// is painted over the rounded border on the corners
+		int padding = getLeftRightPadding( c );
+		if( padding > 0 ) {
+			insets.left += padding;
+			insets.right += padding;
+		}
+
+		return insets;
+	}
+
+	@Override
+	protected int getArc( Component c ) {
+		if( isCellEditor( c ) )
+			return 0;
+
+		if( isArcStyled )
+			return arc;
+
+		if( c instanceof JScrollPane ) {
+			Component view = FlatScrollPaneUI.getView( (JScrollPane) c );
+			if( listArc >= 0 && view instanceof JList )
+				return listArc;
+			if( tableArc >= 0 && view instanceof JTable )
+				return tableArc;
+			if( textComponentArc >= 0&& view instanceof JTextComponent )
+				return textComponentArc;
+			if( treeArc >= 0 && view instanceof JTree )
+				return treeArc;
+		}
+
+		return arc;
+	}
+
+	/**
+	 * Returns the scaled left/right padding used when arc is larger than zero.
+	 * <p>
+	 * This is the distance from the inside of the left border to the left side of the view component.
+	 * On the right side, this is the distance between the right side of the view component and
+	 * the vertical scrollbar. Or the inside of the right border if the scrollbar is hidden.
+	 */
+	public int getLeftRightPadding( Component c ) {
+		// Subtract lineWidth from radius because radius is given for the outside
+		// of the painted line, but insets from super already include lineWidth.
+		// Reduce padding by 10% to make padding slightly smaller because it is not recognizable
+		// when the view is minimally painted over the beginning of the border curve.
+		int arc = getArc( c );
+		return (arc > 0)
+			? Math.max( Math.round( UIScale.scale( ((arc / 2f) - getLineWidth( c )) * 0.9f ) ), 0 )
+			: 0;
+	}
+}

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

@@ -17,9 +17,12 @@
 package com.formdev.flatlaf.ui;
 
 import java.awt.Component;
+import java.awt.Container;
 import java.awt.Graphics;
+import java.awt.Graphics2D;
 import java.awt.Insets;
 import java.awt.KeyboardFocusManager;
+import java.awt.LayoutManager;
 import java.awt.Rectangle;
 import java.awt.event.ContainerEvent;
 import java.awt.event.ContainerListener;
@@ -41,16 +44,19 @@ import javax.swing.JTree;
 import javax.swing.JViewport;
 import javax.swing.LookAndFeel;
 import javax.swing.ScrollPaneConstants;
+import javax.swing.ScrollPaneLayout;
 import javax.swing.Scrollable;
 import javax.swing.SwingConstants;
 import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
+import javax.swing.border.Border;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicScrollPaneUI;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
 import com.formdev.flatlaf.util.LoggingFacade;
+import com.formdev.flatlaf.util.UIScale;
 
 /**
  * Provides the Flat LaF UI delegate for {@link javax.swing.JScrollPane}.
@@ -97,7 +103,13 @@ public class FlatScrollPaneUI
 		super.installUI( c );
 
 		int focusWidth = UIManager.getInt( "Component.focusWidth" );
-		LookAndFeel.installProperty( c, "opaque", focusWidth == 0 );
+		int arc = UIManager.getInt( "ScrollPane.arc" );
+		LookAndFeel.installProperty( c, "opaque", focusWidth == 0 && arc == 0 );
+
+		// install layout manager
+		LayoutManager layout = c.getLayout();
+		if( layout != null && layout.getClass() == ScrollPaneLayout.UIResource.class )
+			c.setLayout( createScrollPaneLayout() );
 
 		installStyle();
 
@@ -108,6 +120,10 @@ public class FlatScrollPaneUI
 	public void uninstallUI( JComponent c ) {
 		MigLayoutVisualPadding.uninstall( scrollpane );
 
+		// uninstall layout manager
+		if( c.getLayout() instanceof FlatScrollPaneLayout )
+			c.setLayout( new ScrollPaneLayout.UIResource() );
+
 		super.uninstallUI( c );
 
 		oldStyleValues = null;
@@ -130,6 +146,13 @@ public class FlatScrollPaneUI
 		handler = null;
 	}
 
+	/**
+	 * @since 3.3
+	 */
+	protected FlatScrollPaneLayout createScrollPaneLayout() {
+		return new FlatScrollPaneLayout();
+	}
+
 	@Override
 	protected MouseWheelListener createMouseWheelListener() {
 		MouseWheelListener superListener = super.createMouseWheelListener();
@@ -290,8 +313,7 @@ public class FlatScrollPaneUI
 					Object corner = e.getNewValue();
 					if( corner instanceof JButton &&
 						((JButton)corner).getBorder() instanceof FlatButtonBorder &&
-						scrollpane.getViewport() != null &&
-						scrollpane.getViewport().getView() instanceof JTable )
+						getView( scrollpane ) instanceof JTable )
 					{
 						((JButton)corner).setBorder( BorderFactory.createEmptyBorder() );
 						((JButton)corner).setFocusable( false );
@@ -308,6 +330,18 @@ public class FlatScrollPaneUI
 					scrollpane.revalidate();
 					scrollpane.repaint();
 					break;
+
+				case "border":
+					Object newBorder = e.getNewValue();
+					if( newBorder != null && newBorder == UIManager.getBorder( "Table.scrollPaneBorder" ) ) {
+						// JTable.configureEnclosingScrollPaneUI() replaces the scrollpane border
+						// with another one --> re-apply style on new border
+						borderShared = null;
+						installStyle();
+						scrollpane.revalidate();
+						scrollpane.repaint();
+					}
+					break;
 			}
 		};
 	}
@@ -334,9 +368,10 @@ public class FlatScrollPaneUI
 
 	/** @since 2 */
 	protected Object applyStyleProperty( String key, Object value ) {
-		if( key.equals( "focusWidth" ) ) {
+		if( key.equals( "focusWidth" ) || key.equals( "arc" ) ) {
 			int focusWidth = (value instanceof Integer) ? (int) value : UIManager.getInt( "Component.focusWidth" );
-			LookAndFeel.installProperty( scrollpane, "opaque", focusWidth == 0 );
+			int arc = (value instanceof Integer) ? (int) value : UIManager.getInt( "ScrollPane.arc" );
+			LookAndFeel.installProperty( scrollpane, "opaque", focusWidth == 0 && arc == 0 );
 		}
 
 		if( borderShared == null )
@@ -402,13 +437,46 @@ public class FlatScrollPaneUI
 				c.getHeight() - insets.top - insets.bottom );
 		}
 
+		// if view is rounded, paint rounded background with view background color
+		// to ensure that free areas at left and right have same color as view
+		Component view;
+		float arc = getBorderArc( scrollpane );
+		if( arc > 0 && (view = getView( scrollpane )) != null ) {
+			float focusWidth = FlatUIUtils.getBorderFocusWidth( c );
+
+			g.setColor( view.getBackground() );
+
+			Object[] oldRenderingHints = FlatUIUtils.setRenderingHints( g );
+			FlatUIUtils.paintComponentBackground( (Graphics2D) g, 0, 0, c.getWidth(), c.getHeight(), focusWidth, arc );
+			FlatUIUtils.resetRenderingHints( g, oldRenderingHints );
+		}
+
 		paint( g, c );
 	}
 
+	@Override
+	public void paint( Graphics g, JComponent c ) {
+		Border viewportBorder = scrollpane.getViewportBorder();
+		if( viewportBorder != null ) {
+			Rectangle r = scrollpane.getViewportBorderBounds();
+			int padding = getBorderLeftRightPadding( scrollpane );
+			JScrollBar vsb = scrollpane.getVerticalScrollBar();
+			if( padding > 0 &&
+				vsb != null && vsb.isVisible() &&
+				scrollpane.getLayout() instanceof FlatScrollPaneLayout &&
+				((FlatScrollPaneLayout)scrollpane.getLayout()).canIncreaseViewportWidth( scrollpane ) )
+			{
+				boolean ltr = scrollpane.getComponentOrientation().isLeftToRight();
+				int extraWidth = Math.min( padding, vsb.getWidth() );
+				viewportBorder.paintBorder( scrollpane, g, r.x - (ltr ? 0 : extraWidth), r.y, r.width + extraWidth, r.height );
+			} else
+				viewportBorder.paintBorder( scrollpane, g, r.x, r.y, r.width, r.height );
+		}
+	}
+
 	/** @since 1.3 */
 	public static boolean isPermanentFocusOwner( JScrollPane scrollPane ) {
-		JViewport viewport = scrollPane.getViewport();
-		Component view = (viewport != null) ? viewport.getView() : null;
+		Component view = getView( scrollPane );
 		if( view == null )
 			return false;
 
@@ -428,6 +496,25 @@ public class FlatScrollPaneUI
 		return false;
 	}
 
+	static Component getView( JScrollPane scrollPane ) {
+		JViewport viewport = scrollPane.getViewport();
+		return (viewport != null) ? viewport.getView() : null;
+	}
+
+	private static float getBorderArc( JScrollPane scrollPane ) {
+		Border border = scrollPane.getBorder();
+		return (border instanceof FlatScrollPaneBorder)
+			? UIScale.scale( (float) ((FlatScrollPaneBorder)border).getArc( scrollPane ) )
+			: 0;
+	}
+
+	private static int getBorderLeftRightPadding( JScrollPane scrollPane ) {
+		Border border = scrollPane.getBorder();
+		return (border instanceof FlatScrollPaneBorder)
+			? ((FlatScrollPaneBorder)border).getLeftRightPadding( scrollPane )
+			: 0;
+	}
+
 	//---- class Handler ------------------------------------------------------
 
 	/**
@@ -450,13 +537,71 @@ public class FlatScrollPaneUI
 		@Override
 		public void focusGained( FocusEvent e ) {
 			// necessary to update focus border
-			scrollpane.repaint();
+			if( scrollpane.getBorder() instanceof FlatBorder )
+				scrollpane.repaint();
 		}
 
 		@Override
 		public void focusLost( FocusEvent e ) {
 			// necessary to update focus border
-			scrollpane.repaint();
+			if( scrollpane.getBorder() instanceof FlatBorder )
+				scrollpane.repaint();
+		}
+	}
+
+	//---- class FlatScrollPaneLayout -----------------------------------------
+
+	/**
+	 * @since 3.3
+	 */
+	protected static class FlatScrollPaneLayout
+		extends ScrollPaneLayout.UIResource
+	{
+		@Override
+		public void layoutContainer( Container parent ) {
+			super.layoutContainer( parent );
+
+			JScrollPane scrollPane = (JScrollPane) parent;
+			int padding = getBorderLeftRightPadding( scrollPane );
+			if( padding > 0 && vsb != null && vsb.isVisible() ) {
+				// move vertical scrollbar to trailing edge
+				Insets insets = scrollPane.getInsets();
+				Rectangle r = vsb.getBounds();
+				int y = Math.max( r.y, insets.top + padding );
+				int y2 = Math.min( r.y + r.height, scrollPane.getHeight() - insets.bottom - padding );
+				boolean ltr = scrollPane.getComponentOrientation().isLeftToRight();
+
+				vsb.setBounds( r.x + (ltr ? padding : -padding), y, r.width, y2 - y );
+
+				// increase width of viewport, column header and horizontal scrollbar
+				if( canIncreaseViewportWidth( scrollPane ) ) {
+					int extraWidth = Math.min( padding, vsb.getWidth() );
+					resizeViewport( viewport, extraWidth, ltr );
+					resizeViewport( colHead, extraWidth, ltr );
+					resizeViewport( hsb, extraWidth, ltr );
+				}
+			}
+		}
+
+		boolean canIncreaseViewportWidth( JScrollPane scrollPane ) {
+			return scrollPane.getComponentOrientation().isLeftToRight()
+				? !isCornerVisible( upperRight ) && !isCornerVisible( lowerRight )
+				: !isCornerVisible( upperLeft ) && !isCornerVisible( lowerLeft );
+		}
+
+		private static boolean isCornerVisible( Component corner ) {
+			return corner != null &&
+				corner.getWidth() > 0 &&
+				corner.getHeight() > 0 &&
+				corner.isVisible();
+		}
+
+		private static void resizeViewport( Component c, int extraWidth, boolean ltr ) {
+			if( c == null )
+				return;
+
+			Rectangle vr = c.getBounds();
+			c.setBounds( vr.x - (ltr ? 0 : extraWidth), vr.y, vr.width + extraWidth, vr.height );
 		}
 	}
 }

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

@@ -600,10 +600,15 @@ ScrollBar.allowsAbsolutePositioning = true
 
 #---- ScrollPane ----
 
-ScrollPane.border = com.formdev.flatlaf.ui.FlatBorder
+ScrollPane.border = com.formdev.flatlaf.ui.FlatScrollPaneBorder
 ScrollPane.background = $ScrollBar.track
 ScrollPane.fillUpperCorner = true
 ScrollPane.smoothScrolling = true
+ScrollPane.arc = 0
+#ScrollPane.List.arc = -1
+#ScrollPane.Table.arc = -1
+#ScrollPane.TextComponent.arc = -1
+#ScrollPane.Tree.arc = -1
 
 
 #---- SearchField ----
@@ -734,7 +739,7 @@ Table.showVerticalLines = false
 Table.showTrailingVerticalLine = false
 Table.consistentHomeEndKeyBehavior = true
 Table.intercellSpacing = 0,0
-Table.scrollPaneBorder = com.formdev.flatlaf.ui.FlatBorder
+Table.scrollPaneBorder = com.formdev.flatlaf.ui.FlatScrollPaneBorder
 Table.ascendingSortIcon = com.formdev.flatlaf.icons.FlatAscendingSortIcon
 Table.descendingSortIcon = com.formdev.flatlaf.icons.FlatDescendingSortIcon
 Table.sortIconColor = @icon

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

@@ -601,7 +601,7 @@ public class TestFlatStyleableInfo
 		);
 
 		// border
-		flatBorder( expected );
+		flatScrollPaneBorder( expected );
 
 		assertMapEquals( expected, ui.getStyleableInfos( c ) );
 	}
@@ -1008,17 +1008,23 @@ public class TestFlatStyleableInfo
 
 		expectedMap( expected,
 			"arc", int.class,
-
 			"roundRect", Boolean.class
 		);
 	}
 
+	private void flatScrollPaneBorder( Map<String, Class<?>> expected ) {
+		flatBorder( expected );
+
+		expectedMap( expected,
+			"arc", int.class
+		);
+	}
+
 	private void flatTextBorder( Map<String, Class<?>> expected ) {
 		flatBorder( expected );
 
 		expectedMap( expected,
 			"arc", int.class,
-
 			"roundRect", Boolean.class
 		);
 	}

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

@@ -625,7 +625,7 @@ public class TestFlatStyleableValue
 		FlatScrollPaneUI ui = (FlatScrollPaneUI) c.getUI();
 
 		// border
-		flatBorder( c, ui );
+		flatScrollPaneBorder( c, ui );
 
 		testBoolean( c, ui, "showButtons", true );
 	}
@@ -968,15 +968,19 @@ public class TestFlatStyleableValue
 		flatBorder( c, ui );
 
 		testInteger( c, ui, "arc", 123 );
-
 		testBoolean( c, ui, "roundRect", true );
 	}
 
+	private void flatScrollPaneBorder( JComponent c, StyleableUI ui ) {
+		flatBorder( c, ui );
+
+		testInteger( c, ui, "arc", 123 );
+	}
+
 	private void flatTextBorder( JComponent c, StyleableUI ui ) {
 		flatBorder( c, ui );
 
 		testInteger( c, ui, "arc", 123 );
-
 		testBoolean( c, ui, "roundRect", true );
 	}
 
@@ -1037,6 +1041,17 @@ public class TestFlatStyleableValue
 		// FlatRoundBorder extends FlatBorder
 		flatBorder( border );
 
+		testValue( border, "arc", 6 );
+		testValue( border, "roundRect", true );
+	}
+
+	@Test
+	void flatScrollPaneBorder() {
+		FlatScrollPaneBorder border = new FlatScrollPaneBorder();
+
+		// FlatScrollPaneBorder extends FlatBorder
+		flatBorder( border );
+
 		testValue( border, "arc", 6 );
 	}
 
@@ -1048,6 +1063,7 @@ public class TestFlatStyleableValue
 		flatBorder( border );
 
 		testValue( border, "arc", 6 );
+		testValue( border, "roundRect", true );
 	}
 
 	@Test

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

@@ -760,7 +760,7 @@ public class TestFlatStyling
 		FlatScrollPaneUI ui = (FlatScrollPaneUI) c.getUI();
 
 		// border
-		flatBorder( style -> ui.applyStyle( style ) );
+		flatScrollPaneBorder( style -> ui.applyStyle( style ) );
 
 		ui.applyStyle( "showButtons: true" );
 
@@ -1237,15 +1237,19 @@ public class TestFlatStyling
 		flatBorder( applyStyle );
 
 		applyStyle.accept( "arc: 6" );
-
 		applyStyle.accept( "roundRect: true" );
 	}
 
+	private void flatScrollPaneBorder( Consumer<String> applyStyle ) {
+		flatBorder( applyStyle );
+
+		applyStyle.accept( "arc: 6" );
+	}
+
 	private void flatTextBorder( Consumer<String> applyStyle ) {
 		flatBorder( applyStyle );
 
 		applyStyle.accept( "arc: 6" );
-
 		applyStyle.accept( "roundRect: true" );
 	}