fix: setting minimum > 100 via ScaleFieldEditor's ctor arg is ignored

bundles/org.eclipse.jface/src/org/eclipse/jface/preference/ScaleFieldEditor.java

@@ -317,6 +317,10 @@ private void updateScale() {
 		if (scale != null && !scale.isDisposed()) {
 			scale.setMinimum(getMinimum());
 			scale.setMaximum(getMaximum());
+			// Reapplying the minimum to ensure that the scale's value is correctly
+			// adjusted in scenarios where the new minimum exceeds the previous maximum.
+			scale.setMinimum(getMinimum());
+
 			scale.setIncrement(getIncrement());
 			scale.setPageIncrement(getPageIncrement());
 		}

tests/org.eclipse.jface.tests/src/org/eclipse/jface/tests/preferences/AllPrefsTests.java

@@ -18,7 +18,12 @@
 import org.junit.runners.Suite;
 
 @RunWith(Suite.class)
-@Suite.SuiteClasses({ BooleanFieldEditorTest.class, StringFieldEditorTest.class, IntegerFieldEditorTest.class })
+@Suite.SuiteClasses({ //
+		BooleanFieldEditorTest.class, //
+		StringFieldEditorTest.class, //
+		IntegerFieldEditorTest.class, //
+		ScaleFieldEditorTest.class //
+})
 public class AllPrefsTests {
 
 	public static void main(String[] args) {

tests/org.eclipse.jface.tests/src/org/eclipse/jface/tests/preferences/ScaleFieldEditorTest.java

@@ -0,0 +1,184 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Sebastian Thomschke and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Sebastian Thomschke - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jface.tests.preferences;
+
+import static org.junit.Assert.*;
+
+import org.eclipse.jface.preference.PreferenceStore;
+import org.eclipse.jface.preference.ScaleFieldEditor;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.widgets.Scale;
+import org.eclipse.swt.widgets.Shell;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class ScaleFieldEditorTest {
+
+	private static final String PREFKEY = "scaleValue";
+
+	private Shell shell;
+	private ScaleFieldEditor editor;
+
+	@Before
+	public void setUp() {
+		shell = new Shell(SWT.NONE);
+		editor = new ScaleFieldEditor(PREFKEY, "Test Scale", shell);
+	}
+
+	@After
+	public void tearDown() {
+		if (shell != null && !shell.isDisposed()) {
+			shell.dispose();
+		}
+	}
+
+	@Test
+	public void testConstructorArgs() {
+		// determine default OS-specific max (on Windows = 100)
+		final int defaultMax;
+		{
+			final var scale = new Scale(shell, 0);
+			defaultMax = scale.getMaximum();
+			scale.dispose();
+		}
+
+		// choose a new min that is higher than the default max to test proper bounds
+		// handling when setting min to a value that is larger than the OS default max
+		final var newMin = defaultMax + 1;
+		final var newMax = defaultMax + 100;
+
+		editor.dispose();
+		editor = new ScaleFieldEditor(PREFKEY, "Test Scale", shell, newMin, newMax, 3, 9);
+
+		assertEquals(newMin, editor.getMinimum());
+		assertEquals(newMin, editor.getScaleControl().getMinimum());
+		assertEquals(newMax, editor.getMaximum());
+		assertEquals(newMax, editor.getScaleControl().getMaximum());
+
+		assertEquals(3, editor.getIncrement());
+		assertEquals(3, editor.getScaleControl().getIncrement());
+
+		assertEquals(9, editor.getScaleControl().getPageIncrement());
+		assertEquals(9, editor.getPageIncrement());
+	}
+
+	@Test
+	public void testGetterAndSetter() {
+		final Scale widget = editor.getScaleControl();
+
+		assertNotNull(widget);
+
+		assertEquals(10, editor.getMaximum());
+		assertEquals(10, widget.getMaximum());
+		editor.setMaximum(999);
+		assertEquals(999, editor.getMaximum());
+		assertEquals(999, widget.getMaximum());
+
+		assertEquals(0, editor.getMinimum());
+		assertEquals(0, widget.getMinimum());
+		editor.setMinimum(99);
+		assertEquals(99, editor.getMinimum());
+		assertEquals(99, widget.getMinimum());
+
+		assertEquals(1, editor.getIncrement());
+		assertEquals(1, widget.getIncrement());
+		editor.setIncrement(9);
+		assertEquals(9, editor.getIncrement());
+		assertEquals(9, widget.getIncrement());
+
+		assertEquals(1, editor.getPageIncrement());
+		assertEquals(1, widget.getPageIncrement());
+		editor.setPageIncrement(99);
+		assertEquals(99, editor.getPageIncrement());
+		assertEquals(99, widget.getPageIncrement());
+
+		assertTrue(editor.getLabelControl(shell).isEnabled());
+		assertTrue(widget.isEnabled());
+		editor.setEnabled(false, shell);
+		assertFalse(editor.getLabelControl(shell).isEnabled());
+		assertFalse(widget.isEnabled());
+	}
+
+	@Test
+	public void testLoad() {
+		final Scale widget = editor.getScaleControl();
+		assertEquals(0, widget.getSelection());
+
+		final var prefStoreWithDefault = new PreferenceStore();
+		prefStoreWithDefault.setDefault(PREFKEY, 2);
+
+		editor.setPreferenceStore(prefStoreWithDefault);
+
+		editor.load();
+		assertEquals(2, widget.getSelection());
+
+		final var prefStoreWithDefaultAndValue = new PreferenceStore();
+		prefStoreWithDefaultAndValue.setDefault(PREFKEY, 2);
+		prefStoreWithDefaultAndValue.setValue(PREFKEY, 4);
+
+		editor.setPreferenceStore(prefStoreWithDefaultAndValue);
+
+		editor.load();
+		assertEquals(4, widget.getSelection());
+	}
+
+	@Test
+	public void testLoadDefault() {
+		final Scale widget = editor.getScaleControl();
+		assertEquals(0, widget.getSelection());
+
+		final var prefStoreWithDefaultAndValue = new PreferenceStore();
+		prefStoreWithDefaultAndValue.setDefault(PREFKEY, 2);
+		prefStoreWithDefaultAndValue.setValue(PREFKEY, 4);
+
+		editor.setPreferenceStore(prefStoreWithDefaultAndValue);
+
+		editor.load();
+		assertEquals(4, widget.getSelection());
+
+		editor.loadDefault();
+		assertEquals(2, widget.getSelection());
+	}
+
+	@Test
+	public void testSetValueInWidget() {
+		final Scale widget = editor.getScaleControl();
+		assertEquals(0, widget.getSelection());
+
+		final int min = 100;
+		final int max = 103;
+
+		editor.setMinimum(min);
+		editor.setMaximum(max);
+
+		// by setting the minimum bound the selection changes accordingly
+		assertEquals(min, widget.getSelection());
+
+		widget.setSelection(min - 1); // outside lower bound
+		assertEquals(min, widget.getSelection());
+
+		widget.setSelection(min);
+		assertEquals(min, widget.getSelection());
+
+		widget.setSelection(min + 1);
+		assertEquals(min + 1, widget.getSelection());
+
+		widget.setSelection(max);
+		assertEquals(max, widget.getSelection());
+
+		widget.setSelection(max + 1); // outside upper bound
+		assertEquals(max, widget.getSelection());
+	}
+}