TabbedPane: support equal and compact tab width modes

CHANGELOG.md

@@ -21,9 +21,13 @@ FlatLaf Change Log
 - TabbedPane: Support closable tabs. (PR #193; issues #31 and #40)
 - TabbedPane: Support minimum or maximum tab widths. (set client property
   `JTabbedPane.minimumTabWidth` or `JTabbedPane.maximumTabWidth` to an integer)
+  (PR #199)
 - TabbedPane: Support alignment of tab area. (set client property
   `JTabbedPane.tabAreaAlignment` to `"leading"`, `"trailing"`, `"center"` or
-  `"fill"`)
+  `"fill"`) (PR #199)
+- TabbedPane: Support equal and compact tab width modes. (set client property
+  `JTabbedPane.tabWidthMode` to `"preferred"`, `"equal"` or `"compact"`) (PR
+  #199)
 - Support painting separator line between window title and content (use UI value
   `TitlePane.borderColor`). (issue #184)
 - Extras: `FlatSVGIcon` now allows specifying icon width and height in

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

@@ -410,6 +410,38 @@ public interface FlatClientProperties
 	 */
 	String TABBED_PANE_TAB_AREA_ALIGN_FILL = "fill";
 
+	/**
+	 * Specifies how the tabs should be sized.
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}<br>
+	 * <strong>Value type</strong> {@link java.lang.String}
+	 * <strong>Allowed Values</strong> {@link #TABBED_PANE_TAB_WIDTH_MODE_PREFERRED} (default),
+	 * {@link #TABBED_PANE_TAB_WIDTH_MODE_EQUAL} or {@link #TABBED_PANE_TAB_WIDTH_MODE_COMPACT}
+	 */
+	String TABBED_PANE_TAB_WIDTH_MODE = "JTabbedPane.tabWidthMode";
+
+	/**
+	 * Tab width is adjusted to tab icon and title.
+	 *
+	 * @see #TABBED_PANE_TAB_WIDTH_MODE
+	 */
+	String TABBED_PANE_TAB_WIDTH_MODE_PREFERRED = "preferred";
+
+	/**
+	 * All tabs in a tabbed pane has same width.
+	 *
+	 * @see #TABBED_PANE_TAB_WIDTH_MODE
+	 */
+	String TABBED_PANE_TAB_WIDTH_MODE_EQUAL = "equal";
+
+	/**
+	 * Unselected tabs are smaller because they show only the tab icon, but no tab title.
+	 * Selected tabs show both.
+	 *
+	 * @see #TABBED_PANE_TAB_WIDTH_MODE
+	 */
+	String TABBED_PANE_TAB_WIDTH_MODE_COMPACT = "compact";
+
 	/**
 	 * Specifies a component that will be placed at the leading edge of the tabs area.
 	 * <p>

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

@@ -128,6 +128,7 @@ import com.formdev.flatlaf.util.UIScale;
  * @uiDefault TabbedPane.hasFullBorder					boolean
  * @uiDefault TabbedPane.hiddenTabsNavigation			String	moreTabsButton (default) or arrowButtons
  * @uiDefault TabbedPane.tabAreaAlignment				String	leading (default), center, trailing or fill
+ * @uiDefault TabbedPane.tabWidthMode					String	preferred (default), equal or compact
  * @uiDefault ScrollPane.smoothScrolling				boolean
  * @uiDefault TabbedPane.closeIcon						Icon
  *
@@ -148,6 +149,10 @@ public class FlatTabbedPaneUI
 	protected static final int ALIGN_CENTER = 2;
 	protected static final int ALIGN_FILL = 3;
 
+	protected static final int WIDTH_MODE_PREFERRED = 0;
+	protected static final int WIDTH_MODE_EQUAL = 1;
+	protected static final int WIDTH_MODE_COMPACT = 2;
+
 	private static Set<KeyStroke> focusForwardTraversalKeys;
 	private static Set<KeyStroke> focusBackwardTraversalKeys;
 
@@ -174,6 +179,7 @@ public class FlatTabbedPaneUI
 
 	private String hiddenTabsNavigationStr;
 	private String tabAreaAlignmentStr;
+	private String tabWidthModeStr;
 	protected Icon closeIcon;
 
 	protected String moreTabsButtonToolTipText;
@@ -241,6 +247,7 @@ public class FlatTabbedPaneUI
 		tabsOpaque = UIManager.getBoolean( "TabbedPane.tabsOpaque" );
 		hiddenTabsNavigationStr = UIManager.getString( "TabbedPane.hiddenTabsNavigation" );
 		tabAreaAlignmentStr = UIManager.getString( "TabbedPane.tabAreaAlignment" );
+		tabWidthModeStr = UIManager.getString( "TabbedPane.tabWidthMode" );
 		closeIcon = UIManager.getIcon( "TabbedPane.closeIcon" );
 
 		Locale l = tabPane.getLocale();
@@ -529,12 +536,35 @@ public class FlatTabbedPaneUI
 			tabPane.repaint( r );
 	}
 
+	private boolean inCalculateEqual;
+
 	@Override
 	protected int calculateTabWidth( int tabPlacement, int tabIndex, FontMetrics metrics ) {
+		int tabWidthMode = getTabWidthMode();
+		if( tabWidthMode == WIDTH_MODE_EQUAL && isHorizontalTabPlacement() && !inCalculateEqual ) {
+			inCalculateEqual = true;
+			try {
+				return calculateMaxTabWidth( tabPlacement );
+			} finally {
+				inCalculateEqual = false;
+			}
+		}
+
 		// update textIconGap before used in super class
 		textIconGap = scale( textIconGapUnscaled );
 
-		int tabWidth = super.calculateTabWidth( tabPlacement, tabIndex, metrics ) - 3 /* was added by superclass */;
+		int tabWidth;
+		Icon icon;
+		if( tabWidthMode == WIDTH_MODE_COMPACT &&
+			tabIndex != tabPane.getSelectedIndex() &&
+			isHorizontalTabPlacement() &&
+			tabPane.getTabComponentAt( tabIndex ) == null &&
+			(icon = getIconForTab( tabIndex )) != null )
+		{
+			Insets tabInsets = getTabInsets( tabPlacement, tabIndex );
+			tabWidth = icon.getIconWidth() + tabInsets.left + tabInsets.right;
+		} else
+			tabWidth = super.calculateTabWidth( tabPlacement, tabIndex, metrics ) - 3 /* was added by superclass */;
 
 		// make tab wider if closable
 		if( isTabClosable( tabIndex ) )
@@ -663,14 +693,26 @@ public class FlatTabbedPaneUI
 		int tabIndex, Rectangle iconRect, Rectangle textRect )
 	{
 		Rectangle tabRect = rects[tabIndex];
+		int x = tabRect.x;
+		int y = tabRect.y;
+		int w = tabRect.width;
+		int h = tabRect.height;
 		boolean isSelected = (tabIndex == tabPane.getSelectedIndex());
 
 		// paint background
 		if( tabsOpaque || tabPane.isOpaque() )
-			paintTabBackground( g, tabPlacement, tabIndex, tabRect.x, tabRect.y, tabRect.width, tabRect.height, isSelected );
+			paintTabBackground( g, tabPlacement, tabIndex, x, y, w, h, isSelected );
 
 		// paint border
-		paintTabBorder( g, tabPlacement, tabIndex, tabRect.x, tabRect.y, tabRect.width, tabRect.height, isSelected );
+		paintTabBorder( g, tabPlacement, tabIndex, x, y, w, h, isSelected );
+
+		// paint tab close button
+		if( isTabClosable( tabIndex ) )
+			paintTabCloseButton( g, tabIndex, x, y, w, h );
+
+		// paint selection indicator
+		if( isSelected )
+			paintTabSelection( g, tabPlacement, x, y, w, h );
 
 		if( tabPane.getTabComponentAt( tabIndex ) != null )
 			return;
@@ -680,9 +722,12 @@ public class FlatTabbedPaneUI
 		Icon icon = getIconForTab( tabIndex );
 		Font font = tabPane.getFont();
 		FontMetrics metrics = tabPane.getFontMetrics( font );
+		boolean isCompact = (icon != null && !isSelected && getTabWidthMode() == WIDTH_MODE_COMPACT && isHorizontalTabPlacement());
+		if( isCompact )
+			title = null;
 		String clippedTitle = layoutAndClipLabel( tabPlacement, metrics, tabIndex, title, icon, tabRect, iconRect, textRect, isSelected );
 
-		// special title clipping for scroll layout where title off last visible tab on right side may be truncated
+		// special title clipping for scroll layout where title of last visible tab on right side may be truncated
 		if( tabViewport != null && (tabPlacement == TOP || tabPlacement == BOTTOM) ) {
 			Rectangle viewRect = tabViewport.getViewRect();
 			viewRect.width -= 4; // subtract width of cropped edge
@@ -694,7 +739,8 @@ public class FlatTabbedPaneUI
 		}
 
 		// paint title and icon
-		paintText( g, tabPlacement, font, metrics, tabIndex, clippedTitle, textRect, isSelected );
+		if( !isCompact )
+			paintText( g, tabPlacement, font, metrics, tabIndex, clippedTitle, textRect, isSelected );
 		paintIcon( g, tabPlacement, tabIndex, icon, iconRect, isSelected );
 	}
 
@@ -747,17 +793,10 @@ public class FlatTabbedPaneUI
 	protected void paintTabBorder( Graphics g, int tabPlacement, int tabIndex,
 		int x, int y, int w, int h, boolean isSelected )
 	{
-		// paint tab close button
-		if( isTabClosable( tabIndex ) )
-			paintTabCloseButton( g, tabIndex, x, y, w, h );
-
 		// paint tab separators
 		if( clientPropertyBoolean( tabPane, TABBED_PANE_SHOW_TAB_SEPARATORS, showTabSeparators ) &&
 			!isLastInRun( tabIndex ) )
 		  paintTabSeparator( g, tabPlacement, x, y, w, h );
-
-		if( isSelected )
-			paintTabSelection( g, tabPlacement, x, y, w, h );
 	}
 
 	protected void paintTabCloseButton( Graphics g, int tabIndex, int x, int y, int w, int h ) {
@@ -1104,6 +1143,13 @@ public class FlatTabbedPaneUI
 		return parseTabAreaAlignment( str );
 	}
 
+	protected int getTabWidthMode() {
+		String str = (String) tabPane.getClientProperty( TABBED_PANE_TAB_WIDTH_MODE );
+		if( str == null )
+			str = tabWidthModeStr;
+		return parseTabWidthMode( str );
+	}
+
 	protected static int parseHiddenTabsNavigation( String str ) {
 		if( str == null )
 			return MORE_TABS_BUTTON;
@@ -1128,6 +1174,18 @@ public class FlatTabbedPaneUI
 		}
 	}
 
+	protected static int parseTabWidthMode( String str ) {
+		if( str == null )
+			return WIDTH_MODE_PREFERRED;
+
+		switch( str ) {
+			default:
+			case TABBED_PANE_TAB_WIDTH_MODE_PREFERRED:	return WIDTH_MODE_PREFERRED;
+			case TABBED_PANE_TAB_WIDTH_MODE_EQUAL:		return WIDTH_MODE_EQUAL;
+			case TABBED_PANE_TAB_WIDTH_MODE_COMPACT:	return WIDTH_MODE_COMPACT;
+		}
+	}
+
 	private void runWithOriginalLayoutManager( Runnable runnable ) {
 		LayoutManager layout = tabPane.getLayout();
 		if( layout instanceof FlatTabbedPaneScrollLayout ) {
@@ -1881,6 +1939,7 @@ public class FlatTabbedPaneUI
 				case TABBED_PANE_TAB_INSETS:
 				case TABBED_PANE_HIDDEN_TABS_NAVIGATION:
 				case TABBED_PANE_TAB_AREA_ALIGNMENT:
+				case TABBED_PANE_TAB_WIDTH_MODE:
 				case TABBED_PANE_TAB_CLOSABLE:
 					tabPane.revalidate();
 					tabPane.repaint();

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

@@ -172,10 +172,8 @@ public class FlatContainerTest
 			? new ScaledImageIcon( new ImageIcon( getClass().getResource( "/com/formdev/flatlaf/testing/test" + iconSize + ".png" ) ) )
 			: null;
 		int tabCount = tabbedPane.getTabCount();
-		if( tabCount > 0 )
-			tabbedPane.setIconAt( 0, icon );
-		if( tabCount > 1 )
-			tabbedPane.setIconAt( 1, icon );
+		for( int i = 0; i < tabCount; i++ )
+			tabbedPane.setIconAt( i, icon );
 	}
 
 	private void customBorderChanged() {
@@ -252,6 +250,13 @@ public class FlatContainerTest
 		putTabbedPanesClientProperty( TABBED_PANE_TAB_AREA_ALIGNMENT, value );
 	}
 
+	private void tabWidthModeChanged() {
+		String value = (String) tabWidthModeField.getSelectedItem();
+		if( "default".equals( value ) )
+			value = null;
+		putTabbedPanesClientProperty( TABBED_PANE_TAB_WIDTH_MODE, value );
+	}
+
 	private void tabBackForegroundChanged() {
 		tabBackForegroundChanged( tabbedPane1 );
 		tabBackForegroundChanged( tabbedPane2 );
@@ -387,6 +392,8 @@ public class FlatContainerTest
 		tabIconSizeSpinner = new JSpinner();
 		JLabel tabAreaAlignmentLabel = new JLabel();
 		tabAreaAlignmentField = new JComboBox<>();
+		JLabel tabWidthModeLabel = new JLabel();
+		tabWidthModeField = new JComboBox<>();
 		tabsClosableCheckBox = new JCheckBox();
 		customBorderCheckBox = new JCheckBox();
 		tabAreaInsetsCheckBox = new JCheckBox();
@@ -600,6 +607,20 @@ public class FlatContainerTest
 				tabAreaAlignmentField.addActionListener(e -> tabAreaAlignmentChanged());
 				tabbedPaneControlPanel.add(tabAreaAlignmentField, "cell 1 3");
 
+				//---- tabWidthModeLabel ----
+				tabWidthModeLabel.setText("Tab width mode:");
+				tabbedPaneControlPanel.add(tabWidthModeLabel, "cell 2 3");
+
+				//---- tabWidthModeField ----
+				tabWidthModeField.setModel(new DefaultComboBoxModel<>(new String[] {
+					"default",
+					"preferred",
+					"equal",
+					"compact"
+				}));
+				tabWidthModeField.addActionListener(e -> tabWidthModeChanged());
+				tabbedPaneControlPanel.add(tabWidthModeField, "cell 2 3");
+
 				//---- tabsClosableCheckBox ----
 				tabsClosableCheckBox.setText("Tabs closable");
 				tabsClosableCheckBox.addActionListener(e -> tabsClosableChanged());
@@ -690,6 +711,7 @@ public class FlatContainerTest
 	private JCheckBox tabIconsCheckBox;
 	private JSpinner tabIconSizeSpinner;
 	private JComboBox<String> tabAreaAlignmentField;
+	private JComboBox<String> tabWidthModeField;
 	private JCheckBox tabsClosableCheckBox;
 	private JCheckBox customBorderCheckBox;
 	private JCheckBox tabAreaInsetsCheckBox;

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

@@ -285,6 +285,29 @@ new FormModel {
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 						"value": "cell 1 3"
 					} )
+					add( new FormComponent( "javax.swing.JLabel" ) {
+						name: "tabWidthModeLabel"
+						"text": "Tab width mode:"
+					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+						"value": "cell 2 3"
+					} )
+					add( new FormComponent( "javax.swing.JComboBox" ) {
+						name: "tabWidthModeField"
+						"model": new javax.swing.DefaultComboBoxModel {
+							selectedItem: "default"
+							addElement( "default" )
+							addElement( "preferred" )
+							addElement( "equal" )
+							addElement( "compact" )
+						}
+						auxiliary() {
+							"JavaCodeGenerator.variableLocal": false
+							"JavaCodeGenerator.typeParameters": "String"
+						}
+						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "tabWidthModeChanged", false ) )
+					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+						"value": "cell 2 3"
+					} )
 					add( new FormComponent( "javax.swing.JCheckBox" ) {
 						name: "tabsClosableCheckBox"
 						"text": "Tabs closable"