From 00d7430765eba4f0c13f8300515a679a808bc7b1 Mon Sep 17 00:00:00 2001
From: Mathieu Baudier <mbaudier@argeo.org>
Date: Sun, 3 May 2020 12:25:56 +0200
Subject: [PATCH] Introduce lightweight RWT runner.

---
 org.argeo.eclipse.ui.rap/bnd.bnd              |   6 +
 .../org/argeo/eclipse/ui/jetty/RwtRunner.java | 135 ++++++++++++++++++
 2 files changed, 141 insertions(+)
 create mode 100644 org.argeo.eclipse.ui.rap/src/org/argeo/eclipse/ui/jetty/RwtRunner.java

diff --git a/org.argeo.eclipse.ui.rap/bnd.bnd b/org.argeo.eclipse.ui.rap/bnd.bnd
index fb50c88ef..f73a8d019 100644
--- a/org.argeo.eclipse.ui.rap/bnd.bnd
+++ b/org.argeo.eclipse.ui.rap/bnd.bnd
@@ -2,4 +2,10 @@ Import-Package: org.eclipse.swt,\
 org.eclipse.jface.dialogs,\
 org.argeo.eclipse.ui.util,\
 org.eclipse.swt.events,\
+org.eclipse.jetty.util.component;resolution:=optional,\
+org.eclipse.jetty.http;resolution:=optional,\
+org.eclipse.jetty.io;resolution:=optional,\
+org.eclipse.jetty.security;resolution:=optional,\
+org.eclipse.jetty.server.handler;resolution:=optional,\
+org.eclipse.jetty.*;resolution:=optional,\
 *
diff --git a/org.argeo.eclipse.ui.rap/src/org/argeo/eclipse/ui/jetty/RwtRunner.java b/org.argeo.eclipse.ui.rap/src/org/argeo/eclipse/ui/jetty/RwtRunner.java
new file mode 100644
index 000000000..29165a4ef
--- /dev/null
+++ b/org.argeo.eclipse.ui.rap/src/org/argeo/eclipse/ui/jetty/RwtRunner.java
@@ -0,0 +1,135 @@
+package org.argeo.eclipse.ui.jetty;
+
+import java.io.IOException;
+import java.lang.management.ManagementFactory;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import javax.servlet.ServletContextEvent;
+import javax.servlet.ServletContextListener;
+
+import org.eclipse.jetty.server.Connector;
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.server.ServerConnector;
+import org.eclipse.jetty.servlet.DefaultServlet;
+import org.eclipse.jetty.servlet.ServletContextHandler;
+import org.eclipse.jetty.servlet.ServletHolder;
+import org.eclipse.jetty.util.resource.Resource;
+import org.eclipse.jetty.util.thread.QueuedThreadPool;
+import org.eclipse.rap.rwt.application.AbstractEntryPoint;
+import org.eclipse.rap.rwt.application.ApplicationRunner;
+import org.eclipse.rap.rwt.engine.RWTServlet;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Label;
+
+/** A minimal RWT runner based on embedded Jetty. */
+public class RwtRunner {
+
+	private final Server server;
+	private final ServerConnector serverConnector;
+	private Path tempDir;
+
+	public RwtRunner() {
+		server = new Server(new QueuedThreadPool(10, 1));
+		serverConnector = new ServerConnector(server);
+		serverConnector.setPort(0);
+		server.setConnectors(new Connector[] { serverConnector });
+	}
+
+	protected Control createUi(Composite parent, Object context) {
+		return new Label(parent, SWT.NONE);
+	}
+
+	public void init() {
+		ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
+		context.setContextPath("/");
+		server.setHandler(context);
+
+		String entryPoint = "app";
+
+		// rwt-resources requires a file system
+		try {
+			tempDir = Files.createTempDirectory("argeo-rwtRunner");
+			context.setBaseResource(Resource.newResource(tempDir.resolve("www").toString()));
+		} catch (IOException e) {
+			throw new IllegalStateException("Cannot create temporary directory", e);
+		}
+		context.addEventListener(new ServletContextListener() {
+			ApplicationRunner applicationRunner;
+
+			@Override
+			public void contextInitialized(ServletContextEvent sce) {
+				applicationRunner = new ApplicationRunner(
+						(application) -> application.addEntryPoint("/" + entryPoint, () -> new AbstractEntryPoint() {
+							private static final long serialVersionUID = 5678385921969090733L;
+
+							@Override
+							protected void createContents(Composite parent) {
+								createUi(parent, null);
+							}
+						}, null), sce.getServletContext());
+				applicationRunner.start();
+			}
+
+			@Override
+			public void contextDestroyed(ServletContextEvent sce) {
+				applicationRunner.stop();
+			}
+		});
+
+		context.addServlet(new ServletHolder(new RWTServlet()), "/" + entryPoint);
+
+		// Required to serve rwt-resources. It is important that this is last.
+		ServletHolder holderPwd = new ServletHolder("default", DefaultServlet.class);
+		context.addServlet(holderPwd, "/");
+
+		try {
+			server.start();
+		} catch (Exception e) {
+			throw new IllegalStateException("Cannot start Jetty server", e);
+		}
+	}
+
+	public void destroy() {
+		try {
+			serverConnector.close();
+			server.stop();
+			// TODO delete temp dir
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+	}
+
+	public Integer getEffectivePort() {
+		return serverConnector.getLocalPort();
+	}
+
+	public void waitFor() throws InterruptedException {
+		server.join();
+	}
+
+	public static void main(String[] args) throws Exception {
+		RwtRunner rwtRunner = new RwtRunner() {
+
+			@Override
+			protected Control createUi(Composite parent, Object context) {
+				Label label = new Label(parent, SWT.NONE);
+				label.setText("Hello world!");
+				return label;
+			}
+		};
+		rwtRunner.init();
+		Runtime.getRuntime().addShutdownHook(new Thread(() -> rwtRunner.destroy(), "Jetty shutdown"));
+
+		long jvmUptime = ManagementFactory.getRuntimeMXBean().getUptime();
+		System.out.println("App available in " + jvmUptime + " ms, on port " + rwtRunner.getEffectivePort());
+
+		// open browser in app mode
+		Thread.sleep(2000);// wait for RWT to be ready
+		Runtime.getRuntime().exec("google-chrome --app=http://localhost:" + rwtRunner.getEffectivePort() + "/app");
+
+		rwtRunner.waitFor();
+	}
+}
-- 
2.30.2