Add utility method to find all descendant components of a particular …

…type. This is useful for custom serach fialogs, e.g. FindInFilesDialog, in applications

RSTAUI/build.gradle

@@ -11,8 +11,6 @@ archivesBaseName = 'rstaui'
 dependencies {
     api 'com.fifesoft:rsyntaxtextarea:3.3.1'
     api 'com.fifesoft:autocomplete:3.3.1-SNAPSHOT'
-    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.9.1'
-    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.9.1'
 }
 
 ext.isReleaseVersion = !project.version.endsWith('SNAPSHOT')

RSTAUI/src/main/java/org/fife/rsta/ui/DecorativeIconPanel.java

@@ -36,7 +36,7 @@ public class DecorativeIconPanel extends JPanel {
 	 * listening to with other combo boxes or text fields without a
 	 * DecorativeIconPanel.
 	 */
-	private static final int DEFAULT_WIDTH = 8;
+	public static final int DEFAULT_WIDTH = 8;
 
 	private JLabel iconLabel;
 	private boolean showIcon;

RSTAUI/src/main/java/org/fife/rsta/ui/UIUtil.java

@@ -14,9 +14,7 @@
 import java.lang.reflect.Method;
 import java.net.URI;
 import java.net.URISyntaxException;
-import java.util.Locale;
-import java.util.MissingResourceException;
-import java.util.ResourceBundle;
+import java.util.*;
 import javax.swing.BorderFactory;
 import javax.swing.JButton;
 import javax.swing.JComboBox;
@@ -144,6 +142,34 @@ private static SpringLayout.Constraints getConstraintsForCell(
 	}
 
 
+	/**
+	 * Returns all components that are ancestors of {@code comp} that are of the
+	 * specified class (or a subclass of it).
+	 *
+	 * @param comp The parent component.
+	 * @param clazz The class of children to look for.
+	 * @param <T> The type of children to look for.
+	 * @return The matching children. This will be an empty list if none are found.
+	 */
+	@SuppressWarnings("unchecked")
+	public static <T> List<T> getDescendantsOfType(Container comp, Class<T> clazz) {
+		List<T> result = new ArrayList<>();
+		Stack<Component> stack = new Stack<>();
+		stack.add(comp);
+		while (!stack.isEmpty()) {
+			Component current = stack.pop();
+			if (clazz.isAssignableFrom(current.getClass())) {
+				result.add((T)current);
+			}
+			if (current instanceof Container) {
+				Container container = (Container)current;
+				stack.addAll(Arrays.asList(container.getComponents()));
+			}
+		}
+		return result;
+	}
+
+
 	/**
 	 * Returns the singleton <code>java.awt.Desktop</code> instance, or
 	 * <code>null</code> if it is unsupported on this platform (or the JRE
@@ -209,7 +235,7 @@ public static Color getErrorTextForeground() {
 				defaultFG.getBlue()>=160) {
 			return new Color(255, 160, 160);
 		}
-		return Color.red;
+		return Color.RED;
 	}
 
 

RSTAUI/src/test/java/org/fife/rsta/ui/UIUtilTest.java

@@ -0,0 +1,82 @@
+/*
+ * Licensed under a modified BSD license.
+ * See the included license file for details.
+ */
+package org.fife.rsta.ui;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import javax.swing.*;
+import java.util.List;
+
+
+/**
+ * Unit tests for the {@code UIUtil} class.
+ *
+ * @author Robert Futrell
+ * @version 1.0
+ */
+class UIUtilTest {
+
+	@Test
+	void testGetDescendantsOfType_topLevelMatch() {
+		JLabel label = new JLabel();
+		List<JLabel> result = UIUtil.getDescendantsOfType(label, JLabel.class);
+		Assertions.assertEquals(1, result.size());
+		Assertions.assertEquals(label, result.get(0));
+	}
+
+	@Test
+	void testGetDescendantsOfType_nestedMatch() {
+		JPanel panel = new JPanel();
+		JLabel label = new JLabel();
+		panel.add(label);
+		List<JLabel> result = UIUtil.getDescendantsOfType(panel, JLabel.class);
+		Assertions.assertEquals(1, result.size());
+		Assertions.assertEquals(label, result.get(0));
+	}
+
+	@Test
+	void testGetDescendantsOfType_nestedTwoDeepMatch() {
+		JPanel panel = new JPanel();
+		JPanel nestedPanel = new JPanel();
+		panel.add(nestedPanel);
+		JLabel label = new JLabel();
+		nestedPanel.add(label);
+		List<JLabel> result = UIUtil.getDescendantsOfType(panel, JLabel.class);
+		Assertions.assertEquals(1, result.size());
+		Assertions.assertEquals(label, result.get(0));
+	}
+
+	@Test
+	void testGetDescendantsOfType_subclass() {
+		JPanel panel = new JPanel();
+		SubclassedJLabel label = new SubclassedJLabel();
+		panel.add(label);
+		List<JLabel> result = UIUtil.getDescendantsOfType(panel, JLabel.class);
+		Assertions.assertEquals(1, result.size());
+		Assertions.assertEquals(label, result.get(0));
+	}
+
+	@Test
+	void testGetDescendantsOfType_multiple() {
+		JPanel panel = new JPanel();
+		JPanel nestedPanel = new JPanel();
+		panel.add(nestedPanel);
+		JLabel label = new JLabel();
+		nestedPanel.add(label);
+		SubclassedJLabel label2 = new SubclassedJLabel();
+		panel.add(label2);
+		List<JLabel> result = UIUtil.getDescendantsOfType(panel, JLabel.class);
+		Assertions.assertEquals(2, result.size());
+		Assertions.assertEquals(label2, result.get(0));
+		Assertions.assertEquals(label, result.get(1));
+	}
+
+	/**
+	 * A dummy subclass used for unit testing purposes.
+	 */
+	private static class SubclassedJLabel extends JLabel {
+	}
+}

build.gradle

@@ -26,6 +26,10 @@ subprojects {
     apply plugin: 'checkstyle'
     apply plugin: 'com.github.spotbugs'
 
+    test {
+        useJUnitPlatform()
+    }
+
     checkstyle {
         toolVersion = '9.3'
     }
@@ -56,6 +60,11 @@ subprojects {
         }
     }
 
+    dependencies {
+        testImplementation 'org.junit.jupiter:junit-jupiter-api:5.9.1'
+        testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.9.1'
+    }
+
     compileJava {
         sourceCompatibility javaVersion.toString()
         targetCompatibility javaVersion.toString()