OptionsLookAndFeel: Support for FlatLaf

This implements support for FlatLaf Look and Feels.
A static method is also included so that Look and Feel can be set at
startup. E.g., for Fjii the following call in the StartupMacros could be
used to set the Look and Feel programmatically at startup:

    eval("js","importClass(Packages.org.scijava.ui.swing.options.OptionsLookAndFeel);OptionsLookAndFeel.setupLookAndFeel('FlatLaf Dark');")

NB: there are currently several hardwired foreground/background colors in several classes (e.g., ConsolePanel) that will interfere with dark themes.

Signed-off-by: Curtis Rueden <ctrueden@wisc.edu>

Author: tferr

pom.xml

@@ -110,6 +110,7 @@
 		<!-- NB: Deploy releases to the SciJava Maven repository. -->
 		<releaseProfiles>sign,deploy-to-scijava</releaseProfiles>
 
+		<flatlaf.version>2.4</flatlaf.version>
 		<jdatepicker.version>1.3.2</jdatepicker.version>
 		<object-inspector.version>0.1</object-inspector.version>
 	</properties>
@@ -157,6 +158,11 @@
 			<groupId>org.jfree</groupId>
 			<artifactId>jfreesvg</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>com.formdev</groupId>
+			<artifactId>flatlaf</artifactId>
+			<version>${flatlaf.version}</version>
+		</dependency>
 		<dependency>
 			<groupId>com.github.sbridges.object-inspector</groupId>
 			<artifactId>object-inspector</artifactId>

src/main/java/org/scijava/ui/swing/options/OptionsLookAndFeel.java

@@ -41,6 +41,11 @@
 import javax.swing.UIManager.LookAndFeelInfo;
 import javax.swing.UnsupportedLookAndFeelException;
 
+import com.formdev.flatlaf.FlatLightLaf;
+import com.formdev.flatlaf.FlatDarkLaf;
+import com.formdev.flatlaf.FlatIntelliJLaf;
+import com.formdev.flatlaf.FlatDarculaLaf;
+
 import org.scijava.display.Display;
 import org.scijava.display.DisplayService;
 import org.scijava.log.LogService;
@@ -131,8 +136,15 @@ public void run() {
 
 	protected void initLookAndFeel() {
 		final String lafClass = UIManager.getLookAndFeel().getClass().getName();
+		LookAndFeelInfo[] lookAndFeels = UIManager.getInstalledLookAndFeels();
+
+		// Make UIManager aware of FlatLaf look and feels, as needed
+		if (!isRegistered(lookAndFeels, FlatLightLaf.NAME)) FlatLightLaf.installLafInfo();
+		if (!isRegistered(lookAndFeels, FlatDarkLaf.NAME)) FlatDarkLaf.installLafInfo();
+		if (!isRegistered(lookAndFeels, FlatDarculaLaf.NAME)) FlatDarculaLaf.installLafInfo();
+		if (!isRegistered(lookAndFeels, FlatIntelliJLaf.NAME)) FlatIntelliJLaf.installLafInfo();
+		lookAndFeels = UIManager.getInstalledLookAndFeels(); // retrieve updated list
 
-		final LookAndFeelInfo[] lookAndFeels = UIManager.getInstalledLookAndFeels();
 		final ArrayList<String> lookAndFeelChoices = new ArrayList<>();
 		for (final LookAndFeelInfo lafInfo : lookAndFeels) {
 			final String lafName = lafInfo.getName();
@@ -149,6 +161,15 @@ protected void initLookAndFeel() {
 
 	// -- Helper methods --
 
+	/** Assesses whether lookAndFeels contains the laf associated with lafName*/
+	private boolean isRegistered(final LookAndFeelInfo[] lookAndFeels, final String lafName) {
+		for (final LookAndFeelInfo lafInfo : lookAndFeels) {
+			if (lafInfo.getName().equals(lafName))
+				return true;
+		}
+		return false;
+	}
+
 	/** Tells all known Swing components to change to the new Look &amp; Feel. */
 	private void refreshSwingComponents() {
 		// TODO: Change this hacky logic to call a clean UIService API
@@ -202,6 +223,41 @@ private DisplayService displayService() {
 		return getContext().service(DisplayService.class);
 	}
 
+	/**
+	 * Sets the application look and feel.
+	 * <p>
+	 * Useful for setting up the look and feel early on in application startup
+	 * routine (e.g., through a macro or script)
+	 * </p>
+	 * 
+	 * @param lookAndFeel the look and feel. Supported values include "FlatLaf
+	 *                    Light", "FlatLaf Dark", "FlatLaf Darcula", "FlatLaf
+	 *                    IntelliJ", and JVM defaults
+	 *                    ("javax.swing.plaf.metal.MetalLookAndFeel", etc.)
+	 */
+	public static void setupLookAndFeel(final String lookAndFeel) {
+		switch (lookAndFeel) {
+		case FlatLightLaf.NAME:
+			FlatLightLaf.setup();
+			return;
+		case FlatDarkLaf.NAME:
+			FlatDarkLaf.setup();
+			return;
+		case FlatDarculaLaf.NAME:
+			FlatDarculaLaf.setup();
+			return;
+		case FlatIntelliJLaf.NAME:
+			FlatIntelliJLaf.setup();
+			return;
+		default:
+			try {
+				UIManager.setLookAndFeel(lookAndFeel);
+			} catch (final Exception ex) {
+				ex.printStackTrace();
+			}
+		}
+	}
+
 	// -- Deprecated methods --
 
 	@Deprecated