Improve support for Look and Feels

This commit introduces a new SwingLookAndFeelService to encapsulate
Look-and-Feel-related logic, and restore the last used L+F on startup.

Closes #3.

Author: ctrueden

src/main/java/org/scijava/ui/swing/AbstractSwingUI.java

@@ -62,6 +62,7 @@
 import org.scijava.ui.awt.AWTWindowEventDispatcher;
 import org.scijava.ui.console.ConsolePane;
 import org.scijava.ui.swing.console.SwingConsolePane;
+import org.scijava.ui.swing.laf.SwingLookAndFeelService;
 import org.scijava.ui.swing.menu.SwingJMenuBarCreator;
 import org.scijava.ui.swing.menu.SwingJPopupMenuCreator;
 import org.scijava.ui.viewer.DisplayViewer;
@@ -92,6 +93,9 @@ public abstract class AbstractSwingUI extends AbstractUserInterface implements
 	@Parameter
 	private UIService uiService;
 
+	@Parameter(required = false)
+	private SwingLookAndFeelService lafService;
+
 	@Parameter
 	private ThreadService threadService;
 
@@ -242,6 +246,9 @@ public void dispose() {
 
 	@Override
 	protected void createUI() {
+		// Before we create any UI components, initialize the Look and Feel.
+		if (lafService != null) lafService.initLookAndFeel();
+
 		final JMenuBar menuBar = createMenus();
 
 		appFrame = new SwingApplicationFrame(appService.getApp().getTitle());

src/main/java/org/scijava/ui/swing/SwingApplicationFrame.java

@@ -72,15 +72,11 @@ public int getLocationY() {
 
 	@Override
 	public void activate() {
-		EventQueue.invokeLater(new Runnable() {
-
-			@Override
-			public void run() {
-				// NB: You might think calling requestFocus() would work, but no.
-				// The following solution is from: http://bit.ly/zAXzd5
-				toFront();
-				repaint();
-			}
+		EventQueue.invokeLater(() -> {
+			// NB: You might think calling requestFocus() would work, but no.
+			// The following solution is from: http://bit.ly/zAXzd5
+			toFront();
+			repaint();
 		});
 	}
 

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

@@ -29,37 +29,21 @@
 
 package org.scijava.ui.swing.laf;
 
-import java.awt.Component;
-import java.awt.EventQueue;
-import java.awt.Window;
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.Set;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
 
-import javax.swing.SwingUtilities;
+import javax.swing.LookAndFeel;
 import javax.swing.UIManager;
 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.FlatLaf;
-import com.formdev.flatlaf.FlatDarculaLaf;
-
-import org.scijava.display.Display;
-import org.scijava.display.DisplayService;
-import org.scijava.log.LogService;
 import org.scijava.menu.MenuConstants;
 import org.scijava.module.MutableModuleItem;
 import org.scijava.options.OptionsPlugin;
 import org.scijava.plugin.Menu;
 import org.scijava.plugin.Parameter;
 import org.scijava.plugin.Plugin;
-import org.scijava.ui.UIService;
-import org.scijava.ui.UserInterface;
-import org.scijava.ui.viewer.DisplayViewer;
-import org.scijava.widget.UIComponent;
 
 /**
  * Runs the Edit::Options::Look and Feel dialog.
@@ -79,9 +63,10 @@ public class OptionsLookAndFeel extends OptionsPlugin {
 
 	// -- Parameters --
 
-	@Parameter
-	private LogService log;
+	@Parameter(required = false)
+	private SwingLookAndFeelService lafService;
 
+	// NB: This setting is persisted by the SwingLookAndFeelService.
 	@Parameter(label = "Look & Feel", persist = false,
 		initializer = "initLookAndFeel")
 	private String lookAndFeel;
@@ -100,164 +85,28 @@ public void setLookAndFeel(final String lookAndFeel) {
 
 	@Override
 	public void run() {
-		// set look and feel
-		final LookAndFeelInfo[] lookAndFeels = UIManager.getInstalledLookAndFeels();
-		for (final LookAndFeelInfo lookAndFeelInfo : lookAndFeels) {
-			if (lookAndFeelInfo.getName().equals(lookAndFeel)) {
-				try {
-					UIManager.setLookAndFeel(lookAndFeelInfo.getClassName());
-					EventQueue.invokeLater(new Runnable() {
-
-						@Override
-						public void run() {
-							refreshSwingComponents();
-						}
-					});
-				}
-				catch (final ClassNotFoundException e) {
-					log.error(e);
-				}
-				catch (final InstantiationException e) {
-					log.error(e);
-				}
-				catch (final IllegalAccessException e) {
-					log.error(e);
-				}
-				catch (final UnsupportedLookAndFeelException e) {
-					log.error(e);
-				}
-				break;
-			}
-		}
-
+		if (lafService != null) lafService.setLookAndFeel(lookAndFeel);
 		super.run();
 	}
 
 	// -- Initializers --
 
 	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 ArrayList<String> lookAndFeelChoices = new ArrayList<>();
-		for (final LookAndFeelInfo lafInfo : lookAndFeels) {
-			final String lafName = lafInfo.getName();
-			lookAndFeelChoices.add(lafInfo.getName());
-			if (lafClass.equals(lafInfo.getClassName())) {
-				lookAndFeel = lafName;
-			}
-		}
-
-		final MutableModuleItem<String> lookAndFeelItem =
+		final MutableModuleItem<String> lafItem = //
 			getInfo().getMutableInput(LOOK_AND_FEEL, String.class);
-		lookAndFeelItem.setChoices(lookAndFeelChoices);
-	}
-
-	// -- 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
-		// for window retrieval. But does not exist as of this writing.
 
-		final Set<Component> components = new HashSet<>();
+		final LookAndFeel laf = UIManager.getLookAndFeel();
+		lookAndFeel = laf == null ? "<None>" : laf.getName();
 
-		// add Swing UI components from visible UIs
-		for (final UserInterface ui : uiService().getVisibleUIs()) {
-			findComponents(components, ui.getApplicationFrame());
-			findComponents(components, ui.getConsolePane());
+		if (lafService == null) {
+			lafItem.setChoices(Collections.singletonList(lookAndFeel));
 		}
-
-		// add Swing UI components from visible displays
-		for (final Display<?> d : displayService().getDisplays()) {
-			final DisplayViewer<?> viewer = uiService().getDisplayViewer(d);
-			if (viewer == null) continue;
-			findComponents(components, viewer.getWindow());
-		}
-
-		// refresh all discovered components
-		for (final Component c : components) {
-			SwingUtilities.updateComponentTreeUI(c);
-			if (c instanceof Window) ((Window) c).pack();
-		}
-	}
-
-	/**
-	 * Extracts Swing components from the given object, adding them to
-	 * the specified set.
-	 */
-	private void findComponents(final Set<Component> set, final Object o) {
-		if (o == null) return;
-		if (o instanceof UIComponent) {
-			final UIComponent<?> c = (UIComponent<?>) o;
-			findComponents(set, c.getComponent());
-		}
-		if (o instanceof Window) set.add((Window) o);
-		else if (o instanceof Component) {
-			final Component c = (Component) o;
-			final Window w = SwingUtilities.getWindowAncestor(c);
-			set.add(w == null ? c : w);
-		}
-	}
-
-	private UIService uiService() {
-		return getContext().service(UIService.class);
-	}
-
-	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) { // FIXME: should FlatLaf.updateUI() calls be replaced with updateUILater()?
-		case FlatLightLaf.NAME:
-			if (FlatLightLaf.setup()) FlatLaf.updateUI();
-			return;
-		case FlatDarkLaf.NAME:
-			if (FlatDarkLaf.setup()) FlatLaf.updateUI();
-			return;
-		case FlatDarculaLaf.NAME:
-			if (FlatDarculaLaf.setup()) FlatLaf.updateUI();
-			return;
-		case FlatIntelliJLaf.NAME:
-			if (FlatIntelliJLaf.setup()) FlatLaf.updateUI();
-			return;
-		default:
-			try {
-				UIManager.setLookAndFeel(lookAndFeel);
-				FlatLaf.updateUI();
-			} catch (final Exception ex) {
-				ex.printStackTrace();
-				FlatLaf.revalidateAndRepaintAllFramesAndDialogs(); // Recover from possible ill-states
-			}
+		else {
+			final LookAndFeelInfo[] infos = lafService.getLookAndFeels();
+			final List<String> choices = Arrays.stream(infos)//
+				.map(info -> info.getName())//
+				.collect(Collectors.toList());
+			lafItem.setChoices(choices);
 		}
 	}
 }