TabbedPane: support left, right, top and bottom tab icon placement

CHANGELOG.md

@@ -28,6 +28,10 @@ FlatLaf Change Log
 - TabbedPane: Support equal and compact tab width modes. (set client property
   `JTabbedPane.tabWidthMode` to `"preferred"`, `"equal"` or `"compact"`) (PR
   #199)
+- TabbedPane: Support left, right, top and bottom tab icon placement. (set
+  client property `JTabbedPane.tabIconPlacement` to `SwingConstants.LEADING`,
+  `SwingConstants.TRAILING`, `SwingConstants.TOP` or `SwingConstants.BOTTOM`)
+  (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

@@ -19,6 +19,7 @@ package com.formdev.flatlaf;
 import java.awt.Color;
 import java.util.Objects;
 import javax.swing.JComponent;
+import javax.swing.SwingConstants;
 
 /**
  * @author Karl Tauber
@@ -101,7 +102,7 @@ public interface FlatClientProperties
 	/**
 	 * Specifies whether the button preferred size will be made square (quadratically).
 	 * <p>
-	 * <strong>Components</strong> {@link javax.swing.JButton} and {@link javax.swing.JToggleButton}
+	 * <strong>Components</strong> {@link javax.swing.JButton} and {@link javax.swing.JToggleButton}<br>
 	 * <strong>Value type</strong> {@link java.lang.Boolean}
 	 */
 	String SQUARE_SIZE = "JButton.squareSize";
@@ -113,7 +114,7 @@ public interface FlatClientProperties
 	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JButton}, {@link javax.swing.JToggleButton},
 	 * {@link javax.swing.JComboBox}, {@link javax.swing.JSpinner} and {@link javax.swing.text.JTextComponent}<br>
-	 * <strong>Value type</strong> {@link java.lang.Integer}<br>
+	 * <strong>Value type</strong> {@link java.lang.Integer}
 	 */
 	String MINIMUM_WIDTH = "JComponent.minimumWidth";
 
@@ -121,7 +122,7 @@ public interface FlatClientProperties
 	 * Specifies minimum height of a component.
 	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JButton} and {@link javax.swing.JToggleButton}<br>
-	 * <strong>Value type</strong> {@link java.lang.Integer}<br>
+	 * <strong>Value type</strong> {@link java.lang.Integer}
 	 */
 	String MINIMUM_HEIGHT = "JComponent.minimumHeight";
 
@@ -157,7 +158,7 @@ public interface FlatClientProperties
 	 * Paint the component with round edges.
 	 * <p>
 	 * <strong>Components</strong> {@link javax.swing.JComboBox}, {@link javax.swing.JSpinner},
-	 * {@link javax.swing.JTextField}, {@link javax.swing.JFormattedTextField} and {@link javax.swing.JPasswordField}
+	 * {@link javax.swing.JTextField}, {@link javax.swing.JFormattedTextField} and {@link javax.swing.JPasswordField}<br>
 	 * <strong>Value type</strong> {@link java.lang.Boolean}
 	 */
 	String COMPONENT_ROUND_RECT = "JComponent.roundRect";
@@ -249,7 +250,7 @@ public interface FlatClientProperties
 	/**
 	 * Specifies the minimum width of a tab.
 	 * <p>
-	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}<br>
+	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}
 	 * or tab content components (see {@link javax.swing.JTabbedPane#setComponentAt(int, java.awt.Component)})<br>
 	 * <strong>Value type</strong> {@link java.lang.Integer}
 	 */
@@ -261,7 +262,7 @@ public interface FlatClientProperties
 	 * Applied only if tab does not have a custom tab component
 	 * (see {@link javax.swing.JTabbedPane#setTabComponentAt(int, java.awt.Component)}).
 	 * <p>
-	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}<br>
+	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}
 	 * or tab content components (see {@link javax.swing.JTabbedPane#setComponentAt(int, java.awt.Component)})<br>
 	 * <strong>Value type</strong> {@link java.lang.Integer}
 	 */
@@ -287,7 +288,7 @@ public interface FlatClientProperties
 	/**
 	 * Specifies the insets of the tab area.
 	 * <p>
-	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}
+	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}<br>
 	 * <strong>Value type</strong> {@link java.awt.Insets}
 	 */
 	String TABBED_PANE_TAB_AREA_INSETS = "JTabbedPane.tabAreaInsets";
@@ -359,7 +360,7 @@ public interface FlatClientProperties
 	 * Specifies how to navigate to hidden tabs.
 	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}<br>
-	 * <strong>Value type</strong> {@link java.lang.String}
+	 * <strong>Value type</strong> {@link java.lang.String}<br>
 	 * <strong>Allowed Values</strong> {@link #TABBED_PANE_HIDDEN_TABS_NAVIGATION_MORE_TABS_BUTTON}
 	 * or {@link #TABBED_PANE_HIDDEN_TABS_NAVIGATION_ARROW_BUTTONS}
 	 */
@@ -383,7 +384,7 @@ public interface FlatClientProperties
 	 * Specifies the alignment of the tab area.
 	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}<br>
-	 * <strong>Value type</strong> {@link java.lang.String}
+	 * <strong>Value type</strong> {@link java.lang.String}<br>
 	 * <strong>Allowed Values</strong> {@link #TABBED_PANE_TAB_AREA_ALIGN_LEADING} (default),
 	 * {@link #TABBED_PANE_TAB_AREA_ALIGN_TRAILING}, {@link #TABBED_PANE_TAB_AREA_ALIGN_CENTER}
 	 * or {@link #TABBED_PANE_TAB_AREA_ALIGN_FILL}
@@ -422,7 +423,7 @@ public interface FlatClientProperties
 	 * 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>Value type</strong> {@link java.lang.String}<br>
 	 * <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}
 	 */
@@ -450,6 +451,17 @@ public interface FlatClientProperties
 	 */
 	String TABBED_PANE_TAB_WIDTH_MODE_COMPACT = "compact";
 
+	/**
+	 * Specifies the tab icon placement (relative to tab title).
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}<br>
+	 * <strong>Value type</strong> {@link java.lang.Integer}<br>
+	 * <strong>Allowed Values</strong> {@link SwingConstants#LEADING} (default),
+	 * {@link SwingConstants#TRAILING}, {@link SwingConstants#TOP}
+	 * or {@link SwingConstants#BOTTOM}
+	 */
+	String TABBED_PANE_TAB_ICON_PLACEMENT = "JTabbedPane.tabIconPlacement";
+
 	/**
 	 * 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

@@ -563,8 +563,29 @@ public class FlatTabbedPaneUI
 		{
 			Insets tabInsets = getTabInsets( tabPlacement, tabIndex );
 			tabWidth = icon.getIconWidth() + tabInsets.left + tabInsets.right;
-		} else
+		} else {
-			tabWidth = super.calculateTabWidth( tabPlacement, tabIndex, metrics ) - 3 /* was added by superclass */;
+			int iconPlacement = clientPropertyInt( tabPane, TABBED_PANE_TAB_ICON_PLACEMENT, LEADING );
+			if( (iconPlacement == TOP || iconPlacement == BOTTOM) &&
+				tabPane.getTabComponentAt( tabIndex ) == null &&
+				(icon = getIconForTab( tabIndex )) != null )
+			{
+				// TOP and BOTTOM icon placement
+				tabWidth = icon.getIconWidth();
+
+				View view = getTextViewForTab( tabIndex );
+				if( view != null )
+					tabWidth = Math.max( tabWidth, (int) view.getPreferredSpan( View.X_AXIS ) );
+				else {
+					String title = tabPane.getTitleAt( tabIndex );
+					if( title != null )
+						tabWidth = Math.max( tabWidth, metrics.stringWidth( title ) );
+				}
+
+				Insets tabInsets = getTabInsets( tabPlacement, tabIndex );
+				tabWidth += tabInsets.left + tabInsets.right;
+			} else
+				tabWidth = super.calculateTabWidth( tabPlacement, tabIndex, metrics ) - 3 /* was added by superclass */;
+		}
 
 		// make tab wider if closable
 		if( isTabClosable( tabIndex ) )
@@ -583,8 +604,29 @@ public class FlatTabbedPaneUI
 
 	@Override
 	protected int calculateTabHeight( int tabPlacement, int tabIndex, int fontHeight ) {
-		int tabHeight = scale( clientPropertyInt( tabPane, TABBED_PANE_TAB_HEIGHT, this.tabHeight ) );
+		int tabHeight;
-		return Math.max( tabHeight, super.calculateTabHeight( tabPlacement, tabIndex, fontHeight ) - 2 /* was added by superclass */ );
+
+		Icon icon;
+		int iconPlacement = clientPropertyInt( tabPane, TABBED_PANE_TAB_ICON_PLACEMENT, LEADING );
+		if( (iconPlacement == TOP || iconPlacement == BOTTOM) &&
+			tabPane.getTabComponentAt( tabIndex ) == null &&
+			(icon = getIconForTab( tabIndex )) != null )
+		{
+			// TOP and BOTTOM icon placement
+			tabHeight = icon.getIconHeight();
+
+			View view = getTextViewForTab( tabIndex );
+			if( view != null )
+				tabHeight += (int) view.getPreferredSpan( View.Y_AXIS ) + scale( textIconGapUnscaled );
+			else if( tabPane.getTitleAt( tabIndex ) != null )
+				tabHeight += fontHeight + scale( textIconGapUnscaled );
+
+			Insets tabInsets = getTabInsets( tabPlacement, tabIndex );
+			tabHeight += tabInsets.top + tabInsets.bottom;
+		} else
+			tabHeight = super.calculateTabHeight( tabPlacement, tabIndex, fontHeight ) - 2 /* was added by superclass */;
+
+		return Math.max( tabHeight, scale( clientPropertyInt( tabPane, TABBED_PANE_TAB_HEIGHT, this.tabHeight ) ) );
 	}
 
 	@Override
@@ -988,6 +1030,16 @@ public class FlatTabbedPaneUI
 				tabRect.x += closeIcon.getIconWidth();
 		}
 
+		// icon placement
+		int iconPlacement = clientPropertyInt( tabPane, TABBED_PANE_TAB_ICON_PLACEMENT, LEADING );
+		int verticalTextPosition = CENTER;
+		int horizontalTextPosition = TRAILING;
+		switch( iconPlacement ) {
+			case TRAILING:                                horizontalTextPosition = LEADING; break;
+			case TOP:      verticalTextPosition = BOTTOM; horizontalTextPosition = CENTER; break;
+			case BOTTOM:   verticalTextPosition = TOP;    horizontalTextPosition = CENTER; break;
+		}
+
 		// reset rectangles
 		textRect.setBounds( 0, 0, 0, 0 );
 		iconRect.setBounds( 0, 0, 0, 0 );
@@ -999,8 +1051,7 @@ public class FlatTabbedPaneUI
 
 		// layout label
 		String clippedTitle = SwingUtilities.layoutCompoundLabel( tabPane, metrics, title, icon,
-			SwingUtilities.CENTER, SwingUtilities.CENTER,
+			CENTER, CENTER, verticalTextPosition, horizontalTextPosition,
-			SwingUtilities.CENTER, SwingUtilities.TRAILING,
 			tabRect, iconRect, textRect, scale( textIconGapUnscaled ) );
 
 		// remove temporary client property
@@ -1945,6 +1996,7 @@ public class FlatTabbedPaneUI
 				case TABBED_PANE_HIDDEN_TABS_NAVIGATION:
 				case TABBED_PANE_TAB_AREA_ALIGNMENT:
 				case TABBED_PANE_TAB_WIDTH_MODE:
+				case TABBED_PANE_TAB_ICON_PLACEMENT:
 				case TABBED_PANE_TAB_CLOSABLE:
 					tabPane.revalidate();
 					tabPane.repaint();

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

@@ -176,6 +176,17 @@ public class FlatContainerTest
 			tabbedPane.setIconAt( i, icon );
 	}
 
+	private void iconPlacementChanged() {
+		Object iconPlacement = null;
+		switch( (String) iconPlacementField.getSelectedItem() ) {
+			case "leading":		iconPlacement = SwingConstants.LEADING; break;
+			case "trailing":	iconPlacement = SwingConstants.TRAILING; break;
+			case "top":			iconPlacement = SwingConstants.TOP; break;
+			case "bottom":		iconPlacement = SwingConstants.BOTTOM; break;
+		}
+		putTabbedPanesClientProperty( TABBED_PANE_TAB_ICON_PLACEMENT, iconPlacement );
+	}
+
 	private void customBorderChanged() {
 		Border border = customBorderCheckBox.isSelected()
 			? new MatteBorder( 10, 20, 25, 35, Color.green )
@@ -390,6 +401,7 @@ public class FlatContainerTest
 		tabPlacementField = new JComboBox<>();
 		tabIconsCheckBox = new JCheckBox();
 		tabIconSizeSpinner = new JSpinner();
+		iconPlacementField = new JComboBox<>();
 		JLabel tabAreaAlignmentLabel = new JLabel();
 		tabAreaAlignmentField = new JComboBox<>();
 		JLabel tabWidthModeLabel = new JLabel();
@@ -592,6 +604,16 @@ public class FlatContainerTest
 				tabIconSizeSpinner.addChangeListener(e -> tabIconsChanged());
 				tabbedPaneControlPanel.add(tabIconSizeSpinner, "cell 2 2");
 
+				//---- iconPlacementField ----
+				iconPlacementField.setModel(new DefaultComboBoxModel<>(new String[] {
+					"leading",
+					"trailing",
+					"top",
+					"bottom"
+				}));
+				iconPlacementField.addActionListener(e -> iconPlacementChanged());
+				tabbedPaneControlPanel.add(iconPlacementField, "cell 2 2");
+
 				//---- tabAreaAlignmentLabel ----
 				tabAreaAlignmentLabel.setText("Tab area alignment:");
 				tabbedPaneControlPanel.add(tabAreaAlignmentLabel, "cell 0 3");
@@ -710,6 +732,7 @@ public class FlatContainerTest
 	private JComboBox<String> tabPlacementField;
 	private JCheckBox tabIconsCheckBox;
 	private JSpinner tabIconSizeSpinner;
+	private JComboBox<String> iconPlacementField;
 	private JComboBox<String> tabAreaAlignmentField;
 	private JComboBox<String> tabWidthModeField;
 	private JCheckBox tabsClosableCheckBox;

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

@@ -261,6 +261,23 @@ new FormModel {
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 						"value": "cell 2 2"
 					} )
+					add( new FormComponent( "javax.swing.JComboBox" ) {
+						name: "iconPlacementField"
+						"model": new javax.swing.DefaultComboBoxModel {
+							selectedItem: "leading"
+							addElement( "leading" )
+							addElement( "trailing" )
+							addElement( "top" )
+							addElement( "bottom" )
+						}
+						auxiliary() {
+							"JavaCodeGenerator.variableLocal": false
+							"JavaCodeGenerator.typeParameters": "String"
+						}
+						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "iconPlacementChanged", false ) )
+					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+						"value": "cell 2 2"
+					} )
 					add( new FormComponent( "javax.swing.JLabel" ) {
 						name: "tabAreaAlignmentLabel"
 						"text": "Tab area alignment:"