Spinner: fixed NullPointerException in case that arrow buttons were removed to create button-less spinner (issue #181)

CHANGELOG.md

@@ -22,6 +22,8 @@ FlatLaf Change Log
 - FileChooser: Fixed localizing special Windows folders (e.g. "Documents") and
   enabled hiding known file extensions (if enabled in Windows Explorer). (issue
   #178)
+- Spinner: Fixed `NullPointerException` in case that arrow buttons were removed
+  to create button-less spinner. (issue #181)
 
 
 ## 0.42

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

@@ -268,31 +268,34 @@ public class FlatSpinnerUI
 
 		int width = c.getWidth();
 		int height = c.getHeight();
-		Component nextButton = getHandler().nextButton;
-		int arrowX = nextButton.getX();
-		int arrowWidth = nextButton.getWidth();
-		boolean paintButton = !"none".equals( buttonStyle );
 		boolean enabled = spinner.isEnabled();
-		boolean isLeftToRight = spinner.getComponentOrientation().isLeftToRight();
 
 		// paint background
 		g2.setColor( getBackground( enabled ) );
 		FlatUIUtils.paintComponentBackground( g2, 0, 0, width, height, focusWidth, arc );
 
-		// paint arrow buttons background
+		// paint button background and separator
-		if( paintButton && enabled ) {
+		boolean paintButton = !"none".equals( buttonStyle );
-			g2.setColor( buttonBackground );
+		Handler handler = getHandler();
-			Shape oldClip = g2.getClip();
+		if( paintButton && (handler.nextButton != null || handler.previousButton != null) ) {
-			if( isLeftToRight )
+			Component button = (handler.nextButton != null) ? handler.nextButton : handler.previousButton;
-				g2.clipRect( arrowX, 0, width - arrowX, height );
+			int arrowX = button.getX();
-			else
+			int arrowWidth = button.getWidth();
-				g2.clipRect( 0, 0, arrowX + arrowWidth, height );
+			boolean isLeftToRight = spinner.getComponentOrientation().isLeftToRight();
-			FlatUIUtils.paintComponentBackground( g2, 0, 0, width, height, focusWidth, arc );
-			g2.setClip( oldClip );
-		}
 
-		// paint vertical line between value and arrow buttons
+			// paint arrow buttons background
-		if( paintButton ) {
+			if( enabled ) {
+				g2.setColor( buttonBackground );
+				Shape oldClip = g2.getClip();
+				if( isLeftToRight )
+					g2.clipRect( arrowX, 0, width - arrowX, height );
+				else
+					g2.clipRect( 0, 0, arrowX + arrowWidth, height );
+				FlatUIUtils.paintComponentBackground( g2, 0, 0, width, height, focusWidth, arc );
+				g2.setClip( oldClip );
+			}
+
+			// paint vertical line between value and arrow buttons
 			g2.setColor( enabled ? borderColor : disabledBorderColor );
 			float lw = scale( 1f );
 			float lx = isLeftToRight ? arrowX : arrowX + arrowWidth - lw;
@@ -359,7 +362,7 @@ public class FlatSpinnerUI
 
 			if( nextButton == null && previousButton == null ) {
 				if( editor != null )
-					editor.setBounds( r );
+					editor.setBounds( FlatUIUtils.subtractInsets( r, padding ) );
 				return;
 			}
 

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

@@ -186,6 +186,8 @@ public class FlatComponentsTest
 		JLabel spinnerLabel = new JLabel();
 		JSpinner spinner1 = new JSpinner();
 		JSpinner spinner2 = new JSpinner();
+		FlatComponentsTest.ButtonlessSpinner buttonlessSpinner1 = new FlatComponentsTest.ButtonlessSpinner();
+		FlatComponentsTest.ButtonlessSpinner buttonlessSpinner2 = new FlatComponentsTest.ButtonlessSpinner();
 		JComboBox<String> comboBox7 = new JComboBox<>();
 		JSpinner spinner3 = new JSpinner();
 		JLabel textFieldLabel = new JLabel();
@@ -678,6 +680,8 @@ public class FlatComponentsTest
 		//---- spinner2 ----
 		spinner2.setEnabled(false);
 		add(spinner2, "cell 2 6,growx");
+		add(buttonlessSpinner1, "cell 3 6,growx");
+		add(buttonlessSpinner2, "cell 4 6,growx");
 
 		//---- comboBox7 ----
 		comboBox7.setEditable(true);
@@ -1427,4 +1431,22 @@ public class FlatComponentsTest
 			setBorder( null );
 		}
 	}
+
+	//---- class ButtonlessSpinner --------------------------------------------
+
+	private static class ButtonlessSpinner
+		extends JSpinner
+	{
+		@Override
+		public void updateUI() {
+			super.updateUI();
+
+			// remove arrow buttons
+			for( Component c : getComponents() ) {
+				String name = c.getName();
+				if( "Spinner.nextButton".equals( name ) || "Spinner.previousButton".equals( name ) )
+					remove( c );
+			}
+		}
+	}
 }

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

@@ -1,4 +1,4 @@
-JFDML JFormDesigner: "7.0.2.0.298" Java: "14" encoding: "UTF-8"
+JFDML JFormDesigner: "7.0.2.0.298" Java: "15" encoding: "UTF-8"
 
 new FormModel {
 	contentType: "form/swing"
@@ -456,6 +456,16 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 2 6,growx"
 			} )
+			add( new FormComponent( "com.formdev.flatlaf.testing.FlatComponentsTest$ButtonlessSpinner" ) {
+				name: "buttonlessSpinner1"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 3 6,growx"
+			} )
+			add( new FormComponent( "com.formdev.flatlaf.testing.FlatComponentsTest$ButtonlessSpinner" ) {
+				name: "buttonlessSpinner2"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 4 6,growx"
+			} )
 			add( new FormComponent( "javax.swing.JComboBox" ) {
 				name: "comboBox7"
 				"editable": true