TabbedPane: support separators between tabs (TabbedPane.showTabSeparators)

CHANGELOG.md

@@ -9,7 +9,9 @@ FlatLaf Change Log
   - changed style to rounded rectangle
   - fixed painting issues on low values
 - ProgressBar: Support configure of arc with `ProgressBar.arc`.
-- TabbedPane: Support background color for selected tabs.
+- TabbedPane: Support background color for selected tabs
+  (`TabbedPane.selectedBackground`) and separators between tabs
+  (`TabbedPane.showTabSeparators`).
 - CheckBox: changed `CheckBox.arc` from radius to diameter to be consistent with
   `Button.arc` and `Component.arc`
 - Button: Enabled `Button.defaultButtonFollowsFocus` on Windows, which allows

flatlaf-core/src/main/java/com/formdev/flatlaf/FlatClientProperties.java

@@ -64,6 +64,14 @@ public interface FlatClientProperties
 	 */
 	String SCROLL_BAR_SHOW_BUTTONS = "JScrollBar.showButtons";
 
+	/**
+	 * Specifies whether separators are shown between tabs.
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}<br>
+	 * <strong>Value type</strong> {@link java.lang.Boolean}
+	 */
+	String TABBED_PANE_SHOW_TAB_SEPARATORS = "JTabbedPane.showTabSeparators";
+
 	/**
 	 * Specifies whether a full border is painted around a tabbed pane.
 	 * <p>
@@ -78,4 +86,13 @@ public interface FlatClientProperties
 	static boolean clientPropertyEquals( JComponent c, String key, Object value ) {
 		return Objects.equals( c.getClientProperty( key ), value );
 	}
+
+	/**
+	 * Checks whether a client property of a component is a boolean and returns its value.
+	 * If the client property is not set, or not a boolean, defaultValue is returned.
+	 */
+	static boolean clientPropertyBoolean( JComponent c, String key, boolean defaultValue ) {
+		Object value = c.getClientProperty( key );
+		return (value instanceof Boolean) ? (boolean) value : defaultValue;
+	}
 }

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

@@ -41,6 +41,7 @@ import javax.swing.plaf.UIResource;
 import javax.swing.plaf.basic.BasicTabbedPaneUI;
 import javax.swing.text.View;
 import com.formdev.flatlaf.FlatLaf;
+import com.formdev.flatlaf.util.UIScale;
 
 /**
  * Provides the Flat LaF UI delegate for {@link javax.swing.JTabbedPane}.
@@ -59,6 +60,7 @@ import com.formdev.flatlaf.FlatLaf;
  * @uiDefault TabbedPane.disabledUnderlineColor			Color
  * @uiDefault TabbedPane.hoverColor						Color
  * @uiDefault TabbedPane.focusColor						Color
+ * @uiDefault TabbedPane.tabSeparatorColor				Color	optional; defaults to TabbedPane.contentAreaColor
  * @uiDefault TabbedPane.contentAreaColor				Color
  * @uiDefault TabbedPane.textIconGap					int
  * @uiDefault TabbedPane.tabInsets						Insets
@@ -66,6 +68,7 @@ import com.formdev.flatlaf.FlatLaf;
  * @uiDefault TabbedPane.tabHeight						int
  * @uiDefault TabbedPane.tabSelectionHeight				int
  * @uiDefault TabbedPane.contentSeparatorHeight			int
+ * @uiDefault TabbedPane.showTabSeparators				boolean
  * @uiDefault TabbedPane.hasFullBorder					boolean
  *
  * @author Karl Tauber
@@ -80,11 +83,13 @@ public class FlatTabbedPaneUI
 	protected Color disabledUnderlineColor;
 	protected Color hoverColor;
 	protected Color focusColor;
+	protected Color tabSeparatorColor;
 	protected Color contentAreaColor;
 
 	protected int tabHeight;
 	protected int tabSelectionHeight;
 	protected int contentSeparatorHeight;
+	protected boolean showTabSeparators;
 	protected boolean hasFullBorder;
 	protected boolean tabsOverlapBorder;
 
@@ -103,11 +108,13 @@ public class FlatTabbedPaneUI
 		disabledUnderlineColor = UIManager.getColor( "TabbedPane.disabledUnderlineColor" );
 		hoverColor = UIManager.getColor( "TabbedPane.hoverColor" );
 		focusColor = UIManager.getColor( "TabbedPane.focusColor" );
+		tabSeparatorColor = UIManager.getColor( "TabbedPane.tabSeparatorColor" );
 		contentAreaColor = UIManager.getColor( "TabbedPane.contentAreaColor" );
 
 		tabHeight = UIManager.getInt( "TabbedPane.tabHeight" );
 		tabSelectionHeight = UIManager.getInt( "TabbedPane.tabSelectionHeight" );
 		contentSeparatorHeight = UIManager.getInt( "TabbedPane.contentSeparatorHeight" );
+		showTabSeparators = UIManager.getBoolean( "TabbedPane.showTabSeparators" );
 		hasFullBorder = UIManager.getBoolean( "TabbedPane.hasFullBorder" );
 		tabsOverlapBorder = UIManager.getBoolean( "TabbedPane.tabsOverlapBorder" );
 
@@ -133,6 +140,7 @@ public class FlatTabbedPaneUI
 		disabledUnderlineColor = null;
 		hoverColor = null;
 		focusColor = null;
+		tabSeparatorColor = null;
 		contentAreaColor = null;
 
 		MigLayoutVisualPadding.uninstall( tabPane );
@@ -145,9 +153,12 @@ public class FlatTabbedPaneUI
 			public void propertyChange( PropertyChangeEvent e ) {
 				super.propertyChange( e );
 
-				if( TABBED_PANE_HAS_FULL_BORDER.equals( e.getPropertyName() ) ) {
+				switch( e.getPropertyName() ) {
-					tabPane.revalidate();
+					case TABBED_PANE_SHOW_TAB_SEPARATORS:
-					tabPane.repaint();
+					case TABBED_PANE_HAS_FULL_BORDER:
+						tabPane.revalidate();
+						tabPane.repaint();
+						break;
 				}
 			}
 		};
@@ -201,7 +212,7 @@ public class FlatTabbedPaneUI
 	 */
 	@Override
 	protected Insets getContentBorderInsets( int tabPlacement ) {
-		boolean hasFullBorder = this.hasFullBorder || clientPropertyEquals( tabPane, TABBED_PANE_HAS_FULL_BORDER, true );
+		boolean hasFullBorder = clientPropertyBoolean( tabPane, TABBED_PANE_HAS_FULL_BORDER, this.hasFullBorder );
 		int sh = scale( contentSeparatorHeight );
 		Insets insets = hasFullBorder ? new Insets( sh, sh, sh, sh ) : new Insets( sh, 0, 0, 0 );
 
@@ -276,6 +287,26 @@ public class FlatTabbedPaneUI
 	protected void paintTabBorder( Graphics g, int tabPlacement, int tabIndex,
 		int x, int y, int w, int h, boolean isSelected )
 	{
+		// paint tab separators
+		if( clientPropertyBoolean( tabPane, TABBED_PANE_SHOW_TAB_SEPARATORS, showTabSeparators ) &&
+			!isLastInRun( tabIndex ) )
+		{
+			float sepWidth = UIScale.scale( 1f );
+			float offset = UIScale.scale( 5f );
+
+			g.setColor( (tabSeparatorColor != null) ? tabSeparatorColor : contentAreaColor );
+			if( tabPlacement == LEFT || tabPlacement == RIGHT ) {
+				// paint tab separator at bottom side
+				((Graphics2D)g).fill( new Rectangle2D.Float( x + offset, y + h - sepWidth, w - (offset * 2), sepWidth ) );
+			} else if( tabPane.getComponentOrientation().isLeftToRight() ) {
+				// paint tab separator at right side
+				((Graphics2D)g).fill( new Rectangle2D.Float( x + w - sepWidth, y + offset, sepWidth, h - (offset * 2) ) );
+			} else {
+				// paint tab separator at left side
+				((Graphics2D)g).fill( new Rectangle2D.Float( x, y + offset, sepWidth, h - (offset * 2) ) );
+			}
+		}
+
 		if( isSelected )
 			paintTabSelection( g, tabPlacement, x, y, w, h );
 	}
@@ -385,7 +416,7 @@ public class FlatTabbedPaneUI
 		}
 
 		// compute insets for separator or full border
-		boolean hasFullBorder = this.hasFullBorder || clientPropertyEquals( tabPane, TABBED_PANE_HAS_FULL_BORDER, true );
+		boolean hasFullBorder = clientPropertyBoolean( tabPane, TABBED_PANE_HAS_FULL_BORDER, this.hasFullBorder );
 		int sh = scale( contentSeparatorHeight * 100 ); // multiply by 100 because rotateInsets() does not use floats
 		Insets ci = new Insets( 0, 0, 0, 0 );
 		rotateInsets( hasFullBorder ? new Insets( sh, sh, sh, sh ) : new Insets( sh, 0, 0, 0 ), ci, tabPlacement );
@@ -420,6 +451,11 @@ public class FlatTabbedPaneUI
 	{
 	}
 
+	private boolean isLastInRun( int tabIndex ) {
+		int run = getRunForTab( tabPane.getTabCount(), tabIndex );
+		return lastTabInRun( tabPane.getTabCount(), run ) == tabIndex;
+	}
+
 	private boolean isScrollTabLayout() {
 		return tabPane.getTabLayoutPolicy() == JTabbedPane.SCROLL_TAB_LAYOUT;
 	}

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/TabsPanel.java

@@ -5,6 +5,7 @@
 package com.formdev.flatlaf.demo;
 
 import static com.formdev.flatlaf.FlatClientProperties.TABBED_PANE_HAS_FULL_BORDER;
+import static com.formdev.flatlaf.FlatClientProperties.TABBED_PANE_SHOW_TAB_SEPARATORS;
 import java.awt.*;
 import javax.swing.*;
 import javax.swing.border.*;
@@ -29,6 +30,14 @@ class TabsPanel
 		tabbedPane4.setTabLayoutPolicy( tabLayoutPolicy );
 	}
 
+	private void showTabSeparatorsChanged() {
+		Boolean showTabSeparators = showTabSeparatorsCheckBox.isSelected() ? true : null;
+		tabbedPane1.putClientProperty( TABBED_PANE_SHOW_TAB_SEPARATORS, showTabSeparators );
+		tabbedPane2.putClientProperty( TABBED_PANE_SHOW_TAB_SEPARATORS, showTabSeparators );
+		tabbedPane3.putClientProperty( TABBED_PANE_SHOW_TAB_SEPARATORS, showTabSeparators );
+		tabbedPane4.putClientProperty( TABBED_PANE_SHOW_TAB_SEPARATORS, showTabSeparators );
+	}
+
 	private void hasFullBorderChanged() {
 		Boolean hasFullBorder = hasFullBorderCheckBox.isSelected() ? true : null;
 		tabbedPane1.putClientProperty( TABBED_PANE_HAS_FULL_BORDER, hasFullBorder );
@@ -96,6 +105,7 @@ class TabsPanel
 		JPanel panel14 = new JPanel();
 		moreTabsCheckBox = new JCheckBox();
 		tabScrollCheckBox = new JCheckBox();
+		showTabSeparatorsCheckBox = new JCheckBox();
 		hasFullBorderCheckBox = new JCheckBox();
 		CellConstraints cc = new CellConstraints();
 
@@ -285,6 +295,7 @@ class TabsPanel
 					// columns
 					"[]" +
 					"[]" +
+					"[]" +
 					"[]",
 					// rows
 					"[center]"));
@@ -301,11 +312,16 @@ class TabsPanel
 				tabScrollCheckBox.addActionListener(e -> tabScrollChanged());
 				panel14.add(tabScrollCheckBox, "cell 1 0,alignx left,growx 0");
 
+				//---- showTabSeparatorsCheckBox ----
+				showTabSeparatorsCheckBox.setText("JTabbedPane.showTabSeparators");
+				showTabSeparatorsCheckBox.addActionListener(e -> showTabSeparatorsChanged());
+				panel14.add(showTabSeparatorsCheckBox, "cell 2 0");
+
 				//---- hasFullBorderCheckBox ----
 				hasFullBorderCheckBox.setText("JTabbedPane.hasFullBorder");
 				hasFullBorderCheckBox.setMnemonic('F');
 				hasFullBorderCheckBox.addActionListener(e -> hasFullBorderChanged());
-				panel14.add(hasFullBorderCheckBox, "cell 2 0,alignx left,growx 0");
+				panel14.add(hasFullBorderCheckBox, "cell 3 0,alignx left,growx 0");
 			}
 			panel9.add(panel14, cc.xywh(1, 11, 3, 1));
 		}
@@ -320,6 +336,7 @@ class TabsPanel
 	private JTabbedPane tabbedPane4;
 	private JCheckBox moreTabsCheckBox;
 	private JCheckBox tabScrollCheckBox;
+	private JCheckBox showTabSeparatorsCheckBox;
 	private JCheckBox hasFullBorderCheckBox;
 	// JFormDesigner - End of variables declaration  //GEN-END:variables
 }

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/TabsPanel.jfd

@@ -199,7 +199,7 @@ new FormModel {
 				} )
 				add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 					"$layoutConstraints": "insets 0,hidemode 3"
-					"$columnConstraints": "[][][]"
+					"$columnConstraints": "[][][][]"
 					"$rowConstraints": "[center]"
 				} ) {
 					name: "panel14"
@@ -225,6 +225,16 @@ new FormModel {
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 						"value": "cell 1 0,alignx left,growx 0"
 					} )
+					add( new FormComponent( "javax.swing.JCheckBox" ) {
+						name: "showTabSeparatorsCheckBox"
+						"text": "JTabbedPane.showTabSeparators"
+						auxiliary() {
+							"JavaCodeGenerator.variableLocal": false
+						}
+						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "showTabSeparatorsChanged", false ) )
+					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+						"value": "cell 2 0"
+					} )
 					add( new FormComponent( "javax.swing.JCheckBox" ) {
 						name: "hasFullBorderCheckBox"
 						"text": "JTabbedPane.hasFullBorder"
@@ -234,7 +244,7 @@ new FormModel {
 						}
 						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "hasFullBorderChanged", false ) )
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-						"value": "cell 2 0,alignx left,growx 0"
+						"value": "cell 3 0,alignx left,growx 0"
 					} )
 				}, new FormLayoutConstraints( class com.jgoodies.forms.layout.CellConstraints ) {
 					"gridY": 11
@@ -245,7 +255,7 @@ new FormModel {
 			} )
 		}, new FormLayoutConstraints( null ) {
 			"location": new java.awt.Point( 0, 0 )
-			"size": new java.awt.Dimension( 500, 515 )
+			"size": new java.awt.Dimension( 610, 515 )
 		} )
 	}
 }

flatlaf-jide-oss/src/main/java/com/formdev/flatlaf/jideoss/ui/FlatJideTabbedPaneUI.java

@@ -17,7 +17,7 @@
 package com.formdev.flatlaf.jideoss.ui;
 
 import static com.formdev.flatlaf.FlatClientProperties.TABBED_PANE_HAS_FULL_BORDER;
-import static com.formdev.flatlaf.FlatClientProperties.clientPropertyEquals;
+import static com.formdev.flatlaf.FlatClientProperties.clientPropertyBoolean;
 import static com.formdev.flatlaf.util.UIScale.scale;
 import java.awt.Color;
 import java.awt.Dimension;
@@ -181,7 +181,7 @@ public class FlatJideTabbedPaneUI
 	}
 
 	private Insets getContentBorderInsets0( int tabPlacement ) {
-		boolean hasFullBorder = this.hasFullBorder || clientPropertyEquals( _tabPane, TABBED_PANE_HAS_FULL_BORDER, true );
+		boolean hasFullBorder = clientPropertyBoolean( _tabPane, TABBED_PANE_HAS_FULL_BORDER, this.hasFullBorder );
 		int sh = scale( contentSeparatorHeight );
 		Insets insets = hasFullBorder ? new Insets( sh, sh, sh, sh ) : new Insets( sh, 0, 0, 0 );
 
@@ -339,7 +339,7 @@ public class FlatJideTabbedPaneUI
 		}
 
 		// compute insets for separator or full border
-		boolean hasFullBorder = this.hasFullBorder || clientPropertyEquals( _tabPane, TABBED_PANE_HAS_FULL_BORDER, true );
+		boolean hasFullBorder = clientPropertyBoolean( _tabPane, TABBED_PANE_HAS_FULL_BORDER, this.hasFullBorder );
 		int sh = scale( contentSeparatorHeight * 100 ); // multiply by 100 because rotateInsets() does not use floats
 		Insets ci = new Insets( 0, 0, 0, 0 );
 		rotateInsets( hasFullBorder ? new Insets( sh, sh, sh, sh ) : new Insets( sh, 0, 0, 0 ), ci, tabPlacement );

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

@@ -5,6 +5,7 @@
 package com.formdev.flatlaf.testing;
 
 import static com.formdev.flatlaf.FlatClientProperties.TABBED_PANE_HAS_FULL_BORDER;
+import static com.formdev.flatlaf.FlatClientProperties.TABBED_PANE_SHOW_TAB_SEPARATORS;
 import java.awt.*;
 import javax.swing.*;
 import javax.swing.border.*;
@@ -36,6 +37,14 @@ public class FlatContainerTest
 		tabbedPane4.setTabLayoutPolicy( tabLayoutPolicy );
 	}
 
+	private void showTabSeparatorsChanged() {
+		Boolean showTabSeparators = showTabSeparatorsCheckBox.isSelected() ? true : null;
+		tabbedPane1.putClientProperty( TABBED_PANE_SHOW_TAB_SEPARATORS, showTabSeparators );
+		tabbedPane2.putClientProperty( TABBED_PANE_SHOW_TAB_SEPARATORS, showTabSeparators );
+		tabbedPane3.putClientProperty( TABBED_PANE_SHOW_TAB_SEPARATORS, showTabSeparators );
+		tabbedPane4.putClientProperty( TABBED_PANE_SHOW_TAB_SEPARATORS, showTabSeparators );
+	}
+
 	private void hasFullBorderChanged() {
 		Boolean hasFullBorder = hasFullBorderCheckBox.isSelected() ? true : null;
 		tabbedPane1.putClientProperty( TABBED_PANE_HAS_FULL_BORDER, hasFullBorder );
@@ -100,6 +109,7 @@ public class FlatContainerTest
 		JPanel panel14 = new JPanel();
 		moreTabsCheckBox = new JCheckBox();
 		tabScrollCheckBox = new JCheckBox();
+		showTabSeparatorsCheckBox = new JCheckBox();
 		hasFullBorderCheckBox = new JCheckBox();
 		CellConstraints cc = new CellConstraints();
 
@@ -291,6 +301,7 @@ public class FlatContainerTest
 					// columns
 					"[]" +
 					"[]" +
+					"[]" +
 					"[]",
 					// rows
 					"[center]"));
@@ -307,11 +318,16 @@ public class FlatContainerTest
 				tabScrollCheckBox.addActionListener(e -> tabScrollChanged());
 				panel14.add(tabScrollCheckBox, "cell 1 0,alignx left,growx 0");
 
+				//---- showTabSeparatorsCheckBox ----
+				showTabSeparatorsCheckBox.setText("JTabbedPane.showTabSeparators");
+				showTabSeparatorsCheckBox.addActionListener(e -> showTabSeparatorsChanged());
+				panel14.add(showTabSeparatorsCheckBox, "cell 2 0");
+
 				//---- hasFullBorderCheckBox ----
 				hasFullBorderCheckBox.setText("JTabbedPane.hasFullBorder");
 				hasFullBorderCheckBox.setMnemonic('F');
 				hasFullBorderCheckBox.addActionListener(e -> hasFullBorderChanged());
-				panel14.add(hasFullBorderCheckBox, "cell 2 0,alignx left,growx 0");
+				panel14.add(hasFullBorderCheckBox, "cell 3 0,alignx left,growx 0");
 			}
 			panel9.add(panel14, cc.xywh(1, 11, 3, 1));
 		}
@@ -326,6 +342,7 @@ public class FlatContainerTest
 	private JTabbedPane tabbedPane4;
 	private JCheckBox moreTabsCheckBox;
 	private JCheckBox tabScrollCheckBox;
+	private JCheckBox showTabSeparatorsCheckBox;
 	private JCheckBox hasFullBorderCheckBox;
 	// JFormDesigner - End of variables declaration  //GEN-END:variables
 }

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

@@ -200,7 +200,7 @@ new FormModel {
 				} )
 				add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 					"$layoutConstraints": "insets 0,hidemode 3"
-					"$columnConstraints": "[][][]"
+					"$columnConstraints": "[][][][]"
 					"$rowConstraints": "[center]"
 				} ) {
 					name: "panel14"
@@ -227,6 +227,16 @@ new FormModel {
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 						"value": "cell 1 0,alignx left,growx 0"
 					} )
+					add( new FormComponent( "javax.swing.JCheckBox" ) {
+						name: "showTabSeparatorsCheckBox"
+						"text": "JTabbedPane.showTabSeparators"
+						auxiliary() {
+							"JavaCodeGenerator.variableLocal": false
+						}
+						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "showTabSeparatorsChanged", false ) )
+					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+						"value": "cell 2 0"
+					} )
 					add( new FormComponent( "javax.swing.JCheckBox" ) {
 						name: "hasFullBorderCheckBox"
 						"text": "JTabbedPane.hasFullBorder"
@@ -236,7 +246,7 @@ new FormModel {
 						}
 						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "hasFullBorderChanged", false ) )
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-						"value": "cell 2 0,alignx left,growx 0"
+						"value": "cell 3 0,alignx left,growx 0"
 					} )
 				}, new FormLayoutConstraints( class com.jgoodies.forms.layout.CellConstraints ) {
 					"gridY": 11
@@ -247,7 +257,7 @@ new FormModel {
 			} )
 		}, new FormLayoutConstraints( null ) {
 			"location": new java.awt.Point( 0, 0 )
-			"size": new java.awt.Dimension( 500, 515 )
+			"size": new java.awt.Dimension( 625, 515 )
 		} )
 	}
 }

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

@@ -235,6 +235,7 @@ TabbedPane.underlineColor=#4A88C7
 TabbedPane.disabledUnderlineColor=#7a7a7a
 TabbedPane.hoverColor=#eeeeee
 TabbedPane.focusColor=#dddddd
+TabbedPane.tabSeparatorColor=#00f
 TabbedPane.contentAreaColor=#bbbbbb