Fixed issues when running JavaFX or SWT on the swing EDT.

src/dorkbox/systemTray/SystemTray.java

@@ -26,6 +26,8 @@ import java.io.PrintStream;
 import java.net.URL;
 import java.util.concurrent.atomic.AtomicReference;
 
+import javax.swing.SwingUtilities;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -573,10 +575,26 @@ class SystemTray implements Menu {
                     }
                 }
 
+                if (isJavaFxLoaded) {
+                    // This will initialize javaFX dispatch methods
+                    JavaFX.init();
+                }
+                else if (isSwtLoaded) {
+                    // This will initialize swt dispatch methods
+                    Swt.init();
+                }
 
-                // if it's native + linux, have to do GTK instead. Don't need to be on the dispatch thread though.
+                if ((isJavaFxLoaded || isSwtLoaded) && SwingUtilities.isEventDispatchThread()) {
-                // _AwtTray must be constructed on the EDT...
+                    // oh boy! This WILL NOT WORK. Let the dev know
-                if (OS.isLinux() && NativeUI.class.isAssignableFrom(trayType) && trayType == _AwtTray.class) {
+                    throw new RuntimeException("SystemTray initialization can not occur on the swing Event Dispatch Thread (EDT)");
+                }
+
+                // javaFX and SWT should not start on the EDT!!
+
+                // if it's linux + native menus must not start on the EDT!
+                // _AwtTray must be constructed on the EDT however...
+                if (isJavaFxLoaded || isSwtLoaded ||
+                    (OS.isLinux() && NativeUI.class.isAssignableFrom(trayType) && trayType == _AwtTray.class)) {
                     try {
                         reference.set((Menu) trayType.getConstructors()[0].newInstance(systemTray));
                         logger.info("Successfully Loaded: {}", trayType.getSimpleName());
@@ -619,7 +637,6 @@ class SystemTray implements Menu {
                              "configuration");
             }
 
-
             // These install a shutdown hook in JavaFX/SWT, so that when the main window is closed -- the system tray is ALSO closed.
             if (ENABLE_SHUTDOWN_HOOK) {
                 if (isJavaFxLoaded) {

src/dorkbox/systemTray/util/JavaFX.java

@@ -29,24 +29,47 @@ public
 class JavaFX {
 
     // Methods are cached for performance
-    private static Method isEventThread;
+    private static final Method dispatchMethod;
-    private static Method dispatchMethod;
+    private static final Method isEventThreadMethod;
 
-    public static
+    static {
-    void dispatch(final Runnable runnable) {
+        Method _isEventThreadMethod = null;
-        // javafx.application.Platform.runLater(runnable);
+        Method _dispatchMethod = null;
 
         try {
-            if (dispatchMethod == null) {
+            Class<?> clazz = Class.forName("javafx.application.Platform");
-                Class<?> clazz = Class.forName("javafx.application.Platform");
+            _dispatchMethod = clazz.getMethod("runLater", Runnable.class);
-                dispatchMethod = clazz.getMethod("runLater");
-            }
 
-            dispatchMethod.invoke(null, runnable);
+            clazz = Class.forName("javafx.application.Platform");
+            _isEventThreadMethod = clazz.getMethod("isFxApplicationThread");
         } catch (Throwable e) {
             if (SystemTray.DEBUG) {
                 SystemTray.logger.error("Cannot initialize JavaFX", e);
             }
+        }
+
+        dispatchMethod = _dispatchMethod;
+        isEventThreadMethod = _isEventThreadMethod;
+    }
+
+    public static
+    void init() {
+        // empty method to initialize class
+
+        if (dispatchMethod == null || isEventThreadMethod == null) {
+            SystemTray.logger.error("Unable to initialize JavaFX! Please create an issue with your OS and Java " +
+                                    "version so we may further investigate this issue.");
+        }
+    }
+
+
+    public static
+    void dispatch(final Runnable runnable) {
+//         javafx.application.Platform.runLater(runnable);
+
+        try {
+            dispatchMethod.invoke(null, runnable);
+        } catch (Throwable e) {
             SystemTray.logger.error("Unable to execute JavaFX runLater(). Please create an issue with your OS and Java " +
                                     "version so we may further investigate this issue.");
         }
@@ -57,15 +80,8 @@ class JavaFX {
         // javafx.application.Platform.isFxApplicationThread();
 
         try {
-            if (isEventThread == null) {
+            return (Boolean) isEventThreadMethod.invoke(null);
-                Class<?> clazz = Class.forName("javafx.application.Platform");
-                isEventThread = clazz.getMethod("isFxApplicationThread");
-            }
-            return (Boolean) isEventThread.invoke(null);
         } catch (Throwable e) {
-            if (SystemTray.DEBUG) {
-                SystemTray.logger.error("Cannot initialize JavaFX", e);
-            }
             SystemTray.logger.error("Unable to check if JavaFX is in the event thread. Please create an issue with your OS and Java " +
                                     "version so we may further investigate this issue.");
         }

src/dorkbox/systemTray/util/Swt.java

@@ -15,6 +15,10 @@
  */
 package dorkbox.systemTray.util;
 
+import static dorkbox.systemTray.SystemTray.logger;
+
+import org.eclipse.swt.widgets.Display;
+
 /**
  * Utility methods for SWT.
  * <p>
@@ -22,16 +26,31 @@ package dorkbox.systemTray.util;
  */
 public
 class Swt {
+    private static final Display currentDisplay;
+
+    static {
+        // we have to save this, otherwise it is "null" when methods are run from the swing EDT.
+        currentDisplay = Display.getCurrent();
+    }
+
+
+    public static
+    void init() {
+        // empty method to initialize class
+        if (currentDisplay == null) {
+            logger.error("Unable to get the current display for SWT. Please create an issue with your OS and Java " +
+                         "version so we may further investigate this issue.");
+        };
+    }
+
     public static
     void dispatch(final Runnable runnable) {
-         org.eclipse.swt.widgets.Display.getCurrent()
+        currentDisplay.syncExec(runnable);
-                                        .syncExec(runnable);
     }
 
     public static
     void onShutdown(final Runnable runnable) {
-        org.eclipse.swt.widgets.Display.getCurrent()
+        currentDisplay.getShells()[0].addListener(org.eclipse.swt.SWT.Close, new org.eclipse.swt.widgets.Listener() {
-                                       .getShells()[0].addListener(org.eclipse.swt.SWT.Close, new org.eclipse.swt.widgets.Listener() {
             @Override
             public
             void handleEvent(final org.eclipse.swt.widgets.Event event) {