TabbedPane:

- made tabs separator color lighter in dark themes so that it is easier to recognize the tabbed pane
- added top and bottom tab insets to avoid that large tab icons are painted over active tab underline

CHANGELOG.md

@@ -1,6 +1,16 @@
 FlatLaf Change Log
 ==================
 
+## Unreleased
+
+#### New features and improvements
+
+- TabbedPane: Made tabs separator color lighter in dark themes so that it is
+  easier to recognize the tabbed pane.
+- TabbedPane: Added top and bottom tab insets to avoid that large tab icons are
+  painted over active tab underline.
+
+
 ## 0.42
 
 #### New features and improvements

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

@@ -257,7 +257,7 @@ TabbedPane.underlineColor=#4A88C7
 TabbedPane.disabledUnderlineColor=#7a7a7a
 TabbedPane.hoverColor=#2e3133
 TabbedPane.focusColor=#3d4b5c
-TabbedPane.contentAreaColor=#323232
+TabbedPane.contentAreaColor=#646464
 
 
 #---- Table ----

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

@@ -539,7 +539,7 @@ TabbedPane.tabHeight=32
 TabbedPane.tabSelectionHeight=3
 TabbedPane.contentSeparatorHeight=1
 TabbedPane.hasFullBorder=false
-TabbedPane.tabInsets=0,12,0,12
+TabbedPane.tabInsets=4,12,4,12
 TabbedPane.tabAreaInsets=0,0,0,0
 TabbedPane.selectedTabPadInsets=0,0,0,0
 TabbedPane.tabRunOverlay=0

flatlaf-testing/dumps/uidefaults/FlatDarkLaf_1.8.0_202.txt

@@ -445,7 +445,7 @@ JideTabbedPane.foreground      #bbbbbb    javax.swing.plaf.ColorUIResource [UI]
 JideTabbedPane.shadow          #3c3f41    javax.swing.plaf.ColorUIResource [UI]
 JideTabbedPane.tabAreaBackground #3c3f41    javax.swing.plaf.ColorUIResource [UI]
 JideTabbedPane.tabAreaInsets   0,0,0,0    javax.swing.plaf.InsetsUIResource [UI]
-JideTabbedPane.tabInsets       0,12,0,12    javax.swing.plaf.InsetsUIResource [UI]
+JideTabbedPane.tabInsets       4,12,4,12    javax.swing.plaf.InsetsUIResource [UI]
 JideTabbedPane.tabRunOverlay   0
 JideTabbedPaneUI               com.formdev.flatlaf.jideoss.ui.FlatJideTabbedPaneUI
 
@@ -905,7 +905,7 @@ SplitPaneUI                    com.formdev.flatlaf.ui.FlatSplitPaneUI
 #---- TabbedPane ----
 
 TabbedPane.background          #3c3f41    javax.swing.plaf.ColorUIResource [UI]
-TabbedPane.contentAreaColor    #323232    javax.swing.plaf.ColorUIResource [UI]
+TabbedPane.contentAreaColor    #646464    javax.swing.plaf.ColorUIResource [UI]
 TabbedPane.contentOpaque       true
 TabbedPane.contentSeparatorHeight 1
 TabbedPane.darkShadow          #7e7e7e    javax.swing.plaf.ColorUIResource [UI]
@@ -926,7 +926,7 @@ TabbedPane.selectionFollowsFocus true
 TabbedPane.shadow              #3c3f41    javax.swing.plaf.ColorUIResource [UI]
 TabbedPane.tabAreaInsets       0,0,0,0    javax.swing.plaf.InsetsUIResource [UI]
 TabbedPane.tabHeight           32
-TabbedPane.tabInsets           0,12,0,12    javax.swing.plaf.InsetsUIResource [UI]
+TabbedPane.tabInsets           4,12,4,12    javax.swing.plaf.InsetsUIResource [UI]
 TabbedPane.tabRunOverlay       0
 TabbedPane.tabSelectionHeight  3
 TabbedPane.tabsOpaque          true

flatlaf-testing/dumps/uidefaults/FlatLightLaf_1.8.0_202.txt

@@ -450,7 +450,7 @@ JideTabbedPane.foreground      #000000    javax.swing.plaf.ColorUIResource [UI]
 JideTabbedPane.shadow          #f2f2f2    javax.swing.plaf.ColorUIResource [UI]
 JideTabbedPane.tabAreaBackground #f2f2f2    javax.swing.plaf.ColorUIResource [UI]
 JideTabbedPane.tabAreaInsets   0,0,0,0    javax.swing.plaf.InsetsUIResource [UI]
-JideTabbedPane.tabInsets       0,12,0,12    javax.swing.plaf.InsetsUIResource [UI]
+JideTabbedPane.tabInsets       4,12,4,12    javax.swing.plaf.InsetsUIResource [UI]
 JideTabbedPane.tabRunOverlay   0
 JideTabbedPaneUI               com.formdev.flatlaf.jideoss.ui.FlatJideTabbedPaneUI
 
@@ -931,7 +931,7 @@ TabbedPane.selectionFollowsFocus true
 TabbedPane.shadow              #f2f2f2    javax.swing.plaf.ColorUIResource [UI]
 TabbedPane.tabAreaInsets       0,0,0,0    javax.swing.plaf.InsetsUIResource [UI]
 TabbedPane.tabHeight           32
-TabbedPane.tabInsets           0,12,0,12    javax.swing.plaf.InsetsUIResource [UI]
+TabbedPane.tabInsets           4,12,4,12    javax.swing.plaf.InsetsUIResource [UI]
 TabbedPane.tabRunOverlay       0
 TabbedPane.tabSelectionHeight  3
 TabbedPane.tabsOpaque          true

flatlaf-testing/dumps/uidefaults/FlatTestLaf_1.8.0_202.txt

@@ -438,7 +438,7 @@ JideTabbedPane.foreground      #ff0000    javax.swing.plaf.ColorUIResource [UI]
 JideTabbedPane.shadow          #ccffcc    javax.swing.plaf.ColorUIResource [UI]
 JideTabbedPane.tabAreaBackground #ccffcc    javax.swing.plaf.ColorUIResource [UI]
 JideTabbedPane.tabAreaInsets   0,0,0,0    javax.swing.plaf.InsetsUIResource [UI]
-JideTabbedPane.tabInsets       0,12,0,12    javax.swing.plaf.InsetsUIResource [UI]
+JideTabbedPane.tabInsets       4,12,4,12    javax.swing.plaf.InsetsUIResource [UI]
 JideTabbedPane.tabRunOverlay   0
 JideTabbedPaneUI               com.formdev.flatlaf.jideoss.ui.FlatJideTabbedPaneUI
 
@@ -921,7 +921,7 @@ TabbedPane.selectionFollowsFocus true
 TabbedPane.shadow              #ccffcc    javax.swing.plaf.ColorUIResource [UI]
 TabbedPane.tabAreaInsets       0,0,0,0    javax.swing.plaf.InsetsUIResource [UI]
 TabbedPane.tabHeight           32
-TabbedPane.tabInsets           0,12,0,12    javax.swing.plaf.InsetsUIResource [UI]
+TabbedPane.tabInsets           4,12,4,12    javax.swing.plaf.InsetsUIResource [UI]
 TabbedPane.tabRunOverlay       0
 TabbedPane.tabSelectionHeight  3
 TabbedPane.tabSeparatorColor   #0000ff    javax.swing.plaf.ColorUIResource [UI]

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

@@ -131,6 +131,27 @@ public class FlatContainerTest
 		return tab;
 	}
 
+	private void tabIconsChanged() {
+		boolean showTabIcons = tabIconsCheckBox.isSelected();
+
+		setTabIcons( tabbedPane1, showTabIcons );
+		setTabIcons( tabbedPane2, showTabIcons );
+		setTabIcons( tabbedPane3, showTabIcons );
+		setTabIcons( tabbedPane4, showTabIcons );
+
+		tabIconSizeSpinner.setEnabled( showTabIcons );
+	}
+
+	private void setTabIcons( JTabbedPane tabbedPane, boolean showTabIcons ) {
+		Object iconSize = tabIconSizeSpinner.getValue();
+
+		Icon icon = showTabIcons
+			? new ImageIcon( getClass().getResource( "/com/formdev/flatlaf/testing/test" + iconSize + ".png" ) )
+			: null;
+		tabbedPane.setIconAt( 0, icon );
+		tabbedPane.setIconAt( 1, icon );
+	}
+
 	private void initComponents() {
 		// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
 		JPanel panel9 = new JPanel();
@@ -154,6 +175,8 @@ public class FlatContainerTest
 		tabScrollCheckBox = new JCheckBox();
 		showTabSeparatorsCheckBox = new JCheckBox();
 		hasFullBorderCheckBox = new JCheckBox();
+		tabIconsCheckBox = new JCheckBox();
+		tabIconSizeSpinner = new JSpinner();
 		CellConstraints cc = new CellConstraints();
 
 		//======== this ========
@@ -262,7 +285,9 @@ public class FlatContainerTest
 					"[]" +
 					"[]" +
 					"[]" +
-					"[]",
+					"[]" +
+					"[fill]" +
+					"[fill]",
 					// rows
 					"[center]"));
 
@@ -287,6 +312,17 @@ public class FlatContainerTest
 				hasFullBorderCheckBox.setText("Show content border");
 				hasFullBorderCheckBox.addActionListener(e -> hasFullBorderChanged());
 				panel14.add(hasFullBorderCheckBox, "cell 3 0,alignx left,growx 0");
+
+				//---- tabIconsCheckBox ----
+				tabIconsCheckBox.setText("Tab icons");
+				tabIconsCheckBox.addActionListener(e -> tabIconsChanged());
+				panel14.add(tabIconsCheckBox, "cell 4 0");
+
+				//---- tabIconSizeSpinner ----
+				tabIconSizeSpinner.setModel(new SpinnerListModel(new String[] {"16", "24", "32", "48", "64"}));
+				tabIconSizeSpinner.setEnabled(false);
+				tabIconSizeSpinner.addChangeListener(e -> tabIconsChanged());
+				panel14.add(tabIconSizeSpinner, "cell 5 0");
 			}
 			panel9.add(panel14, cc.xywh(1, 11, 3, 1));
 		}
@@ -303,6 +339,8 @@ public class FlatContainerTest
 	private JCheckBox tabScrollCheckBox;
 	private JCheckBox showTabSeparatorsCheckBox;
 	private JCheckBox hasFullBorderCheckBox;
+	private JCheckBox tabIconsCheckBox;
+	private JSpinner tabIconSizeSpinner;
 	// JFormDesigner - End of variables declaration  //GEN-END:variables
 
 	//---- class Tab1Panel ----------------------------------------------------

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

@@ -1,4 +1,4 @@
-JFDML JFormDesigner: "7.0.2.0.298" Java: "14" encoding: "UTF-8"
+JFDML JFormDesigner: "7.0.2.0.298" Java: "15" encoding: "UTF-8"
 
 new FormModel {
 	contentType: "form/swing"
@@ -131,7 +131,7 @@ new FormModel {
 				} )
 				add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 					"$layoutConstraints": "insets 0,hidemode 3"
-					"$columnConstraints": "[][][][]"
+					"$columnConstraints": "[][][][][fill][fill]"
 					"$rowConstraints": "[center]"
 				} ) {
 					name: "panel14"
@@ -178,6 +178,35 @@ new FormModel {
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 						"value": "cell 3 0,alignx left,growx 0"
 					} )
+					add( new FormComponent( "javax.swing.JCheckBox" ) {
+						name: "tabIconsCheckBox"
+						"text": "Tab icons"
+						auxiliary() {
+							"JavaCodeGenerator.variableLocal": false
+						}
+						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "tabIconsChanged", false ) )
+					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+						"value": "cell 4 0"
+					} )
+					add( new FormComponent( "javax.swing.JSpinner" ) {
+						name: "tabIconSizeSpinner"
+						"model": new javax.swing.SpinnerListModel {
+							list: new java.util.ArrayList {
+								add( "16" )
+								add( "24" )
+								add( "32" )
+								add( "48" )
+								add( "64" )
+							}
+						}
+						"enabled": false
+						auxiliary() {
+							"JavaCodeGenerator.variableLocal": false
+						}
+						addEvent( new FormEvent( "javax.swing.event.ChangeListener", "stateChanged", "tabIconsChanged", false ) )
+					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+						"value": "cell 5 0"
+					} )
 				}, new FormLayoutConstraints( class com.jgoodies.forms.layout.CellConstraints ) {
 					"gridY": 11
 					"gridWidth": 3