ProgressBar: support square painting and larger height even if no string is painted

CHANGELOG.md

@@ -23,6 +23,9 @@ FlatLaf Change Log
   and "Flat Darcula" themes.
 - TabbedPane: Support per component tab height (set client property
   `JTabbedPane.tabHeight` to an integer).
+- ProgressBar: Support square painting (set client property
+  `JProgressBar.square` to `true`) and larger height even if no string is
+  painted (set client property `JProgressBar.largeHeight` to `true`).
 
 
 ## 0.24

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

@@ -93,6 +93,22 @@ public interface FlatClientProperties
 	 */
 	String MINIMUM_HEIGHT = "JComponent.minimumHeight";
 
+	/**
+	 * Specifies whether the progress bar has always the larger height even if no string is painted.
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JProgressBar}<br>
+	 * <strong>Value type</strong> {@link java.lang.Boolean}
+	 */
+	String PROGRESS_BAR_LARGE_HEIGHT = "JProgressBar.largeHeight";
+
+	/**
+	 * Specifies whether the progress bar is paint with square edges.
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JProgressBar}<br>
+	 * <strong>Value type</strong> {@link java.lang.Boolean}
+	 */
+	String PROGRESS_BAR_SQUARE = "JProgressBar.square";
+
 	/**
 	 * Specifies whether the decrease/increase arrow buttons of a scrollbar are shown.
 	 * <p>

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

@@ -16,6 +16,7 @@
 
 package com.formdev.flatlaf.ui;
 
+import static com.formdev.flatlaf.FlatClientProperties.*;
 import java.awt.Dimension;
 import java.awt.FontMetrics;
 import java.awt.Graphics;
@@ -23,6 +24,7 @@ import java.awt.Graphics2D;
 import java.awt.Insets;
 import java.awt.geom.Area;
 import java.awt.geom.RoundRectangle2D;
+import java.beans.PropertyChangeListener;
 import javax.swing.JComponent;
 import javax.swing.JProgressBar;
 import javax.swing.LookAndFeel;
@@ -60,6 +62,8 @@ public class FlatProgressBarUI
 	protected Dimension horizontalSize;
 	protected Dimension verticalSize;
 
+	private PropertyChangeListener propertyChangeListener;
+
 	public static ComponentUI createUI( JComponent c ) {
 		return new FlatProgressBarUI();
 	}
@@ -75,11 +79,35 @@ public class FlatProgressBarUI
 		verticalSize = UIManager.getDimension( "ProgressBar.verticalSize" );
 	}
 
+	@Override
+	protected void installListeners() {
+		super.installListeners();
+
+		propertyChangeListener = e -> {
+			switch( e.getPropertyName() ) {
+				case PROGRESS_BAR_LARGE_HEIGHT:
+				case PROGRESS_BAR_SQUARE:
+					progressBar.revalidate();
+					progressBar.repaint();
+					break;
+			}
+		};
+		progressBar.addPropertyChangeListener( propertyChangeListener );
+	}
+
+	@Override
+	protected void uninstallListeners() {
+		super.uninstallListeners();
+
+		progressBar.removePropertyChangeListener( propertyChangeListener );
+		propertyChangeListener = null;
+	}
+
 	@Override
 	public Dimension getPreferredSize( JComponent c ) {
 		Dimension size = super.getPreferredSize( c );
 
-		if( progressBar.isStringPainted() ) {
+		if( progressBar.isStringPainted() || clientPropertyBoolean( c, PROGRESS_BAR_LARGE_HEIGHT, false ) ) {
 			// recalculate progress height/width to make it smaller
 			Insets insets = progressBar.getInsets();
 			FontMetrics fm = progressBar.getFontMetrics( progressBar.getFont() );
@@ -122,7 +150,9 @@ public class FlatProgressBarUI
 			return;
 
 		boolean horizontal = (progressBar.getOrientation() == JProgressBar.HORIZONTAL);
-		int arc = Math.min( UIScale.scale( this.arc ), horizontal ? height : width );
+		int arc = clientPropertyBoolean( c, PROGRESS_BAR_SQUARE, false )
+			? 0
+			: Math.min( UIScale.scale( this.arc ), horizontal ? height : width );
 
 		FlatUIUtils.setRenderingHints( (Graphics2D) g );