8318577: Windows Look-and-Feel JProgressBarUI does not render correctly on 2x UI scale

Reviewed-by: tr

Author: prsadhuk

src/java.desktop/windows/classes/com/sun/java/swing/plaf/windows/WindowsProgressBarUI.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -33,6 +33,7 @@
 import java.awt.Graphics2D;
 import java.awt.Insets;
 import java.awt.Rectangle;
+import java.awt.geom.AffineTransform;
 
 import javax.swing.JComponent;
 import javax.swing.JProgressBar;
@@ -128,38 +129,43 @@ protected void paintDeterminate(Graphics g, JComponent c) {
         if (xp != null) {
             boolean vertical = (progressBar.getOrientation() == JProgressBar.VERTICAL);
             boolean isLeftToRight = WindowsGraphicsUtils.isLeftToRight(c);
-            int barRectWidth = progressBar.getWidth();
-            int barRectHeight = progressBar.getHeight()-1;
+            Graphics2D g2 = (Graphics2D) g;
+            AffineTransform at = g2.getTransform();
+            double scaleX = at.getScaleX();
+            double scaleY = at.getScaleY();
+
+            int barRectWidth = (int)Math.ceil(progressBar.getWidth() * scaleX);
+            int barRectHeight = (int)Math.ceil(progressBar.getHeight() * scaleY);
+
             // amount of progress to draw
-            int amountFull = getAmountFull(null, barRectWidth, barRectHeight);
+            int amountFull = (int)(getAmountFull(null, barRectWidth, barRectHeight) / scaleX);
 
             paintXPBackground(g, vertical, barRectWidth, barRectHeight);
+
             // Paint progress
             if (progressBar.isStringPainted()) {
                 // Do not paint the standard stripes from the skin, because they obscure
                 // the text
                 g.setColor(progressBar.getForeground());
-                barRectHeight -= 2;
-                barRectWidth -= 2;
 
                 if (barRectWidth <= 0 || barRectHeight <= 0) {
                     return;
                 }
 
-                Graphics2D g2 = (Graphics2D)g;
                 g2.setStroke(new BasicStroke((float)(vertical ? barRectWidth : barRectHeight),
                                              BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL));
                 if (!vertical) {
                     if (isLeftToRight) {
-                        g2.drawLine(2,              barRectHeight / 2 + 1,
-                                    amountFull - 2, barRectHeight / 2 + 1);
+                        g2.drawLine(0,          barRectHeight / 2,
+                                    amountFull, barRectHeight / 2);
                     } else {
                         g2.drawLine(2 + barRectWidth,
                                     barRectHeight / 2 + 1,
                                     2 + barRectWidth - (amountFull - 2),
                                     barRectHeight / 2 + 1);
                     }
-                    paintString(g, 0, 0, barRectWidth, barRectHeight, amountFull, null);
+                    paintString(g, 0, 0, (int)(barRectWidth / scaleX),
+                                (int)(barRectHeight / scaleY), amountFull, null);
                 } else {
                     g2.drawLine(barRectWidth/2 + 1, barRectHeight + 1,
                                 barRectWidth/2 + 1, barRectHeight + 1 - amountFull + 2);

test/jdk/javax/swing/JProgressBar/TestProgressBarUI.java

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8318577
+ * @summary Tests JProgressBarUI renders correctly in Windows L&F
+ * @requires (os.family == "windows")
+ * @library /java/awt/regtesthelpers
+ * @build PassFailJFrame
+ * @run main/manual TestProgressBarUI
+ */
+
+import java.awt.BorderLayout;
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.FlowLayout;
+
+import javax.swing.JComponent;
+import javax.swing.JFrame;
+import javax.swing.JPanel;
+import javax.swing.JProgressBar;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+
+public class TestProgressBarUI {
+
+    private static final String instructionsText = """
+            Two progressbar "Good" and "Bad"
+            will be shown with different preferred size,
+            If the "Bad" progressbar is rendered at the same
+            height as "Good" progressbar,
+            without any difference in padding internally
+            the test passes, otherwise fails. """;
+
+    public static void main(String[] args) throws Exception {
+        System.setProperty("sun.java2d.uiScale", "2.0");
+        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
+        PassFailJFrame.builder()
+                .title("ProgressBar Instructions")
+                .instructions(instructionsText)
+                .rows(9)
+                .columns(36)
+                .testUI(TestProgressBarUI::doTest)
+                .build()
+                .awaitAndCheck();
+    }
+
+    public static JFrame doTest() {
+        JFrame frame = new JFrame("JProgressBar");
+
+        JPanel panel = new JPanel(new FlowLayout(20, 20, FlowLayout.LEADING));
+        panel.setBackground(Color.white);
+
+        JProgressBar p1 = new JProgressBar(0, 100);
+        p1.setValue(50);
+        p1.setStringPainted(true);
+        p1.setString("GOOD");
+        p1.setPreferredSize(new Dimension(100, 21));
+        panel.add(p1);
+
+        JProgressBar p2 = new JProgressBar(0, 100);
+        p2.setValue(50);
+        p2.setStringPainted(true);
+        p2.setString("BAD");
+
+        p2.setPreferredSize(new Dimension(100, 22));
+        panel.add(p2);
+
+        JComponent c = (JComponent) frame.getContentPane();
+        c.add(panel, BorderLayout.CENTER);
+
+        frame.pack();
+        frame.setLocationByPlatform(true);
+        return frame;
+    }
+}