From 1f5e08fdc6f7cc853af97f7436af569d64847fa7 Mon Sep 17 00:00:00 2001
From: Karl Tauber <karl@jformdesigner.com>
Date: Thu, 15 Oct 2020 13:16:21 +0200
Subject: [PATCH] TabbedPane: fixed clipping title if "more tabs" button is
 used (issue #40)

---
 .../formdev/flatlaf/ui/FlatTabbedPaneUI.java  | 15 ++++++++
 .../flatlaf/util/JavaCompatibility.java       | 38 ++++++++++++++++++-
 2 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTabbedPaneUI.java b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTabbedPaneUI.java
index f8df3d51..8b376ce3 100644
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTabbedPaneUI.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTabbedPaneUI.java
@@ -71,6 +71,7 @@ import javax.swing.text.View;
 import com.formdev.flatlaf.FlatLaf;
 import com.formdev.flatlaf.util.Animator;
 import com.formdev.flatlaf.util.CubicBezierEasing;
+import com.formdev.flatlaf.util.JavaCompatibility;
 import com.formdev.flatlaf.util.UIScale;
 
 /**
@@ -497,6 +498,20 @@ public class FlatTabbedPaneUI
 			return;
 		}
 
+		// clip title if "more tabs" button is used
+		// (normally this is done by invoker, but fails in this case)
+		if( hiddenTabsNavigation == MORE_TABS_BUTTON &&
+			tabViewport != null &&
+			(tabPlacement == TOP || tabPlacement == BOTTOM) )
+		{
+			Rectangle viewRect = tabViewport.getViewRect();
+			viewRect.width -= 4; // subtract width of cropped edge
+			if( !viewRect.contains( textRect ) ) {
+				Rectangle r = viewRect.intersection( textRect );
+				title = JavaCompatibility.getClippedString( null, metrics, title, r.width );
+			}
+		}
+
 		// plain text
 		Color color;
 		if( tabPane.isEnabled() && tabPane.isEnabledAt( tabIndex ) ) {
diff --git a/flatlaf-core/src/main/java/com/formdev/flatlaf/util/JavaCompatibility.java b/flatlaf-core/src/main/java/com/formdev/flatlaf/util/JavaCompatibility.java
index dc696af6..f4e740fc 100644
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/util/JavaCompatibility.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/util/JavaCompatibility.java
@@ -16,6 +16,7 @@
 
 package com.formdev.flatlaf.util;
 
+import java.awt.FontMetrics;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.lang.reflect.InvocationTargetException;
@@ -27,7 +28,7 @@ import com.formdev.flatlaf.FlatLaf;
 
 /**
  * Provides Java version compatibility methods.
- *
+ * <p>
  * WARNING: This is private API and may change.
  *
  * @author Karl Tauber
@@ -35,10 +36,12 @@ import com.formdev.flatlaf.FlatLaf;
 public class JavaCompatibility
 {
 	private static Method drawStringUnderlineCharAtMethod;
+	private static Method getClippedStringMethod;
 
 	/**
 	 * Java 8: sun.swing.SwingUtilities2.drawStringUnderlineCharAt( JComponent c,
 	 *				Graphics g, String text, int underlinedIndex, int x, int y )
+	 * <br>
 	 * Java 9: javax.swing.plaf.basic.BasicGraphicsUtils.drawStringUnderlineCharAt( JComponent c,
 	 *				Graphics2D g, String string, int underlinedIndex, float x, float y )
 	 */
@@ -71,4 +74,37 @@ public class JavaCompatibility
 			throw new RuntimeException( ex );
 		}
 	}
+
+	/**
+	 * Java 8: sun.swing.SwingUtilities2.clipStringIfNecessary( JComponent c,
+	 *				FontMetrics fm, String string, int availTextWidth )
+	 * <br>
+	 * Java 9: javax.swing.plaf.basic.BasicGraphicsUtils.getClippedString( JComponent c,
+	 *				FontMetrics fm, String string, int availTextWidth )
+	 */
+	public static String getClippedString( JComponent c, FontMetrics fm, String string, int availTextWidth ) {
+		synchronized( JavaCompatibility.class ) {
+			if( getClippedStringMethod == null ) {
+				try {
+					Class<?> cls = Class.forName( SystemInfo.isJava_9_orLater
+						? "javax.swing.plaf.basic.BasicGraphicsUtils"
+						: "sun.swing.SwingUtilities2" );
+					getClippedStringMethod = cls.getMethod( SystemInfo.isJava_9_orLater
+							? "getClippedString"
+							: "clipStringIfNecessary",
+						new Class[] { JComponent.class, FontMetrics.class, String.class, int.class } );
+				} catch( Exception ex ) {
+					Logger.getLogger( FlatLaf.class.getName() ).log( Level.SEVERE, null, ex );
+					throw new RuntimeException( ex );
+				}
+			}
+		}
+
+		try {
+			return (String) getClippedStringMethod.invoke( null, c, fm, string, availTextWidth );
+		} catch( IllegalAccessException | IllegalArgumentException | InvocationTargetException ex ) {
+			Logger.getLogger( FlatLaf.class.getName() ).log( Level.SEVERE, null, ex );
+			throw new RuntimeException( ex );
+		}
+	}
 }