Add option to debug ClipboardTest remote application

Added RemoteClipboard.DEBUG_REMOTE so that ClipboardTest can be
launched as a standalone java application to make it easier
to debug the remote end of the tests.

Part of #2126

Author: jonahgraham

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/RemoteClipboard.java

@@ -35,12 +35,63 @@
 import clipboard.ClipboardCommands;
 
 public class RemoteClipboard implements ClipboardCommands {
+	/**
+	 * Set to true to manually launch the ClipboardTest. This is useful so you can
+	 * debug the Swing side.
+	 */
+	private static boolean DEBUG_REMOTE = false;
 	private ClipboardCommands remote;
 	private Process remoteClipboardProcess;
 	private Path remoteClipboardTempDir;
 
 	public void start() throws Exception {
 		assertNull(remote, "Create a new instance to restart");
+
+		int port = DEBUG_REMOTE ? ClipboardCommands.DEFAULT_PORT : launchRemote();
+		try {
+			Registry reg = LocateRegistry.getRegistry("127.0.0.1", port);
+			long stopTime = System.currentTimeMillis() + 10000;
+			do {
+				try {
+					remote = (ClipboardCommands) reg.lookup(ClipboardCommands.ID);
+					break;
+				} catch (NotBoundException e) {
+					// try again because the remote app probably hasn't bound yet
+				}
+			} while (System.currentTimeMillis() < stopTime);
+		} catch (RemoteException e) {
+
+			Integer exitValue = null;
+			boolean waitFor = false;
+			try {
+				waitFor = remoteClipboardProcess.waitFor(5, TimeUnit.SECONDS);
+				if (waitFor) {
+					exitValue = remoteClipboardProcess.exitValue();
+				}
+			} catch (InterruptedException e1) {
+				Thread.interrupted();
+			}
+
+			String message = "Failed to get remote clipboards command, this seems to happen on macOS on I-build tests. Exception: "
+					+ e.toString() + " waitFor: " + waitFor + " exitValue: " + exitValue;
+
+			// Give some diagnostic information to help track down why this fails on build
+			// machine. We only hard error on Linux, for other platforms we allow test to
+			// just be skipped until we track down what is causing
+			// https://github.com/eclipse-platform/eclipse.platform.swt/issues/2553
+			assumeTrue(SwtTestUtil.isGTK, message);
+			throw new RuntimeException(message, e);
+		}
+		assertNotNull(remote);
+
+		// Run a no-op on the Swing event loop so that we know it is idle
+		// and we can continue startup
+		remote.waitUntilReady();
+		remote.setFocus();
+		remote.waitUntilReady();
+	}
+
+	private int launchRemote() throws IOException {
 		/*
 		 * The below copy using getPath may be redundant (i.e. it may be possible to run
 		 * the class files from where they currently reside in the bin folder or the
@@ -66,7 +117,7 @@ public void start() throws Exception {
 		String javaExe = javaHome + "/bin/java" + (SwtTestUtil.isWindowsOS ? ".exe" : "");
 		assertTrue(Files.exists(Path.of(javaExe)));
 
-		ProcessBuilder pb = new ProcessBuilder(javaExe, "clipboard.ClipboardTest")
+		ProcessBuilder pb = new ProcessBuilder(javaExe, "clipboard.ClipboardTest", "-autoport")
 				.directory(remoteClipboardTempDir.toFile());
 		pb.inheritIO();
 		pb.redirectOutput(Redirect.PIPE);
@@ -85,47 +136,7 @@ public void start() throws Exception {
 			throw new RuntimeException("Failed to get port");
 		});
 		assertNotEquals(0, port);
-		try {
-			Registry reg = LocateRegistry.getRegistry("127.0.0.1", port);
-			long stopTime = System.currentTimeMillis() + 10000;
-			do {
-				try {
-					remote = (ClipboardCommands) reg.lookup(ClipboardCommands.ID);
-					break;
-				} catch (NotBoundException e) {
-					// try again because the remote app probably hasn't bound yet
-				}
-			} while (System.currentTimeMillis() < stopTime);
-		} catch (RemoteException e) {
-
-			Integer exitValue = null;
-			boolean waitFor = false;
-			try {
-				waitFor = remoteClipboardProcess.waitFor(5, TimeUnit.SECONDS);
-				if (waitFor) {
-					exitValue = remoteClipboardProcess.exitValue();
-				}
-			} catch (InterruptedException e1) {
-				Thread.interrupted();
-			}
-
-			String message = "Failed to get remote clipboards command, this seems to happen on macOS on I-build tests. Exception: "
-					+ e.toString() + " waitFor: " + waitFor + " exitValue: " + exitValue;
-
-			// Give some diagnostic information to help track down why this fails on build
-			// machine. We only hard error on Linux, for other platforms we allow test to
-			// just be skipped until we track down what is causing
-			// https://github.com/eclipse-platform/eclipse.platform.swt/issues/2553
-			assumeTrue(SwtTestUtil.isGTK, message);
-			throw new RuntimeException(message, e);
-		}
-		assertNotNull(remote);
-
-		// Run a no-op on the Swing event loop so that we know it is idle
-		// and we can continue startup
-		remote.waitUntilReady();
-		remote.setFocus();
-		remote.waitUntilReady();
+		return port;
 	}
 
 	@Override
@@ -207,7 +218,7 @@ public void waitUntilReady() throws RemoteException {
 	}
 
 	@Override
-	public void waitForButtonPress()  throws RemoteException {
+	public void waitForButtonPress() throws RemoteException {
 		remote.waitForButtonPress();
 	}
 }

tests/org.eclipse.swt.tests/data/clipboard/ClipboardCommands.java

@@ -26,6 +26,10 @@ public interface ClipboardCommands extends Remote {
 	 */
 	int SELECTION_CLIPBOARD = 1 << 1;
 
+	/**
+	 * The port the RMI will listen on by default
+	 */
+	int DEFAULT_PORT = 3456;
 
 	void stop() throws RemoteException;
 

tests/org.eclipse.swt.tests/data/clipboard/ClipboardTest.java

@@ -23,6 +23,7 @@
 import java.rmi.registry.LocateRegistry;
 import java.rmi.registry.Registry;
 import java.rmi.server.RMISocketFactory;
+import java.util.Arrays;
 
 import javax.swing.JButton;
 import javax.swing.JFrame;
@@ -117,9 +118,11 @@ public void log(String log) {
 	public static void main(String[] args) throws IOException {
 		System.setProperty("java.rmi.server.hostname", "127.0.0.1");
 
+		boolean autoPort = Arrays.asList(args).contains("-autoport");
+
 		// Make sure RMI is localhost only
 		RMISocketFactory.setSocketFactory(new LocalHostOnlySocketFactory());
-		int chosenPort = getAvailablePort();
+		int chosenPort = autoPort ? getAvailablePort() : ClipboardCommands.DEFAULT_PORT;
 		rmiRegistry = LocateRegistry.createRegistry(chosenPort);
 		System.out.println(ClipboardCommands.PORT_MESSAGE + chosenPort);