use RMI to send images to Swing
Change-Id: I8e294492c6d19a3abf1576cfc7923ab2164eb1c9
diff --git a/projects/syncslidepresenter/src/main/java/io/v/syncslidepresenter/Main.java b/projects/syncslidepresenter/src/main/java/io/v/syncslidepresenter/Main.java
index 4fd4471..e706aaa 100644
--- a/projects/syncslidepresenter/src/main/java/io/v/syncslidepresenter/Main.java
+++ b/projects/syncslidepresenter/src/main/java/io/v/syncslidepresenter/Main.java
@@ -22,14 +22,27 @@
import java.awt.Window;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
-import java.awt.image.BufferedImage;
+import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
+import java.io.InputStreamReader;
import java.lang.reflect.Method;
import java.util.HashSet;
import java.util.Set;
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+import java.rmi.AlreadyBoundException;
+import java.rmi.Naming;
+import java.rmi.NotBoundException;
+import java.rmi.Remote;
+import java.rmi.RemoteException;
+import java.rmi.registry.LocateRegistry;
+import java.rmi.server.UnicastRemoteObject;
import java.util.UUID;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
@@ -80,6 +93,15 @@
* ./gradlew :projects:syncslidepresenter:installDist
* ./projects/syncslidepresenter/build/install/syncslidepresenter/bin/syncslidepresenter
* </pre>
+ *
+ * <p>For reasons not yet fully understood, applications running both Swing and Vanadium freeze
+ * randomly (at least on Mac OS X). We work around this by running two JVMs. The main JVM will
+ * create a sub-JVM in a separate thread, and will then proceed to join a syncgroup and look for
+ * slide data. Once a new slide is detected, the bytes representing the slide will be sent to
+ * the sub-JVM via RMI.
+ *
+ * <p>The sub-JVM simply listens for slide bytes and then, using {@link ImageIO#read}, decodes
+ * those bytes and displays the resulting image in a JFrame.
*/
public class Main {
private static final Logger logger = Logger.getLogger(Main.class.getName());
@@ -87,6 +109,7 @@
private static final String SYNCBASE_DB = "syncslides";
private static final String PRESENTATIONS_TABLE = "Presentations";
private static final String DECKS_TABLE = "Decks";
+ private static final int MAX_PORT_PICKER_ATTEMPTS = 100;
private final Table presentations;
private final Table decks;
private final ImageViewer viewer;
@@ -95,7 +118,9 @@
private VContext context;
- public static void main(String[] args) throws SyncbaseServer.StartException, VException, IOException {
+ public static void main(String[] args)
+ throws SyncbaseServer.StartException, VException, IOException, NotBoundException,
+ AlreadyBoundException {
Options options = new Options();
JCommander commander = new JCommander(options);
try {
@@ -111,13 +136,16 @@
return;
}
- // Make command-Q do the same as closing the main frame (i.e. exit).
- System.setProperty("apple.eawt.quitStrategy", "CLOSE_ALL_WINDOWS");
+ ImageViewer viewer = null;
+ if (options.swing) {
+ // We're just going to be running Swing. Do that and then stop.
+ startSwingServer();
+ return;
+ }
- JFrame frame = new JFrame();
- enableOSXFullscreen(frame);
- frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
- frame.setVisible(true);
+ // Otherwise, we're a Vanadium client. Connect to the swing server and then
+ // set up vanadium.
+ viewer = startAndConnectToSwingServer(options.swingServerTimeoutSeconds);
VContext baseContext = V.init();
@@ -156,17 +184,7 @@
presentations.create(baseContext, permissions);
}
- JPanel panel = new JPanel(new GridBagLayout());
- ScaleToFitJPanel presentationPanel = new ScaleToFitJPanel();
- GridBagConstraints constraints = new GridBagConstraints();
- constraints.weightx = 1;
- constraints.weighty = 1;
- constraints.fill = GridBagConstraints.BOTH;
- panel.add(presentationPanel, constraints);
- frame.getContentPane().add(panel);
- frame.pack();
-
- Main m = new Main(baseContext, presentationPanel, db, decks, presentations);
+ Main m = new Main(baseContext, viewer, db, decks, presentations);
Presentation presentation = new Discovery(
baseContext, options.mountPrefix, options.deckPrefix).getPresentation();
@@ -175,6 +193,36 @@
}
}
+ private static void startSwingServer() throws IOException, AlreadyBoundException {
+ logger.info("inside startSwingServer");
+ // Make command-Q do the same as closing the main frame (i.e. exit).
+ System.setProperty("apple.eawt.quitStrategy", "CLOSE_ALL_WINDOWS");
+
+ JFrame frame = new JFrame();
+ enableOSXFullscreen(frame);
+ frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
+ frame.setVisible(true);
+
+ JPanel panel = new JPanel(new GridBagLayout());
+ ScaleToFitJPanel presentationPanel = new ScaleToFitJPanel();
+ GridBagConstraints constraints = new GridBagConstraints();
+ constraints.weightx = 1;
+ constraints.weighty = 1;
+ constraints.fill = GridBagConstraints.BOTH;
+ panel.add(presentationPanel, constraints);
+ frame.getContentPane().add(panel);
+ frame.pack();
+
+ int port = pickUnusedPort();
+ LocateRegistry.createRegistry(port);
+ String name = "//localhost:" + port + "/" + UUID.randomUUID();
+ logger.info("swing server binding to " + name);
+ Naming.bind(name, new RemoteImageViewer(presentationPanel));
+
+ // The parent JVM will expect to read this value.
+ System.out.println(name);
+ }
+
public Main(VContext context, ImageViewer viewer, Database db, Table decks,
Table presentations) throws VException {
this.context = context;
@@ -216,9 +264,7 @@
String row = String.format(slideRowFormat, presentation.getDeckId(),
currentSlide.getNum());
VSlide slide = (VSlide) decks.getRow(row).get(context, VSlide.class);
- final BufferedImage image = ImageIO.read(
- new ByteArrayInputStream(slide.getThumbnail()));
- viewer.setImage(image);
+ viewer.setImage(slide.getThumbnail());
} catch (IOException | VException e) {
logger.log(Level.WARNING, "exception encountered while handling change event", e);
}
@@ -253,6 +299,9 @@
description = "mounttable prefix for live presentations.")
private String deckPrefix = "happyDeck";
+ @Parameter(names = {"--swing"})
+ private boolean swing = false;
+
@Parameter(names = {"-m", "--mountPrefix"}, description = "the base path in the namespace"
+ " where the syncbase service will be mounted")
private String mountPrefix = "/192.168.86.254:8101";
@@ -267,6 +316,10 @@
@Parameter(names = {"-h", "--help"}, description = "display this help message", help = true)
private boolean help = false;
+
+ @Parameter(names = {"--swingServerTimeoutSeconds"},
+ description = "the amount of time to wait for the swing server to start")
+ private int swingServerTimeoutSeconds = 10;
}
private static class ScaleToFitJPanel extends JPanel implements ImageViewer {
@@ -310,15 +363,111 @@
}
@Override
- public void setImage(Image image) {
- this.image = image;
- setPreferredSize(new Dimension(image.getWidth(null), image.getHeight(null)));
- repaint();
+ public void setImage(byte[] imageData) throws RemoteException {
+ try {
+ this.image = ImageIO.read(new ByteArrayInputStream(imageData));
+ setPreferredSize(new Dimension(image.getWidth(null), image.getHeight(null)));
+ repaint();
+ } catch (IOException e) {
+ throw new RemoteException("Could not set image", e);
+ }
}
}
- private interface ImageViewer {
- void setImage(Image image);
+ private interface ImageViewer extends Remote {
+ void setImage(byte[] imageData) throws RemoteException;
+ }
+
+ private static class RemoteImageViewer extends UnicastRemoteObject implements ImageViewer {
+ private final ImageViewer viewer;
+
+ protected RemoteImageViewer(ImageViewer viewer) throws RemoteException {
+ super();
+
+ this.viewer = viewer;
+ }
+
+ @Override
+ public void setImage(byte[] imageData) throws RemoteException {
+ viewer.setImage(imageData);
+ }
+ }
+
+ private static ImageViewer startAndConnectToSwingServer(int timeoutSeconds) throws IOException,
+ NotBoundException {
+ String javaHome = System.getProperty("java.home");
+ if (javaHome == null) {
+ throw new IllegalStateException("System property java.home is not set");
+ }
+ File javaBin = new File(javaHome, Joiner.on(File.separator).join("bin", "java"));
+ if (!javaBin.exists() || !javaBin.canExecute()) {
+ throw new IllegalStateException("Java binary " + javaBin
+ + " does not exist or is not executable");
+ }
+ ProcessBuilder builder = new ProcessBuilder(javaBin.getAbsolutePath(),
+ "-classpath", System.getProperty("java.class.path"),
+ Main.class.getCanonicalName(), "--swing");
+ builder.redirectError(ProcessBuilder.Redirect.INHERIT);
+ logger.info("starting " + builder.command());
+ // The first line of output should be the address to which we should connect.
+ final Process process = builder.start();
+ logger.info("started " + process);
+
+ // Get a timeout timer going.
+ ScheduledExecutorService service = Executors.newSingleThreadScheduledExecutor();
+ service.schedule(new Runnable() {
+ @Override
+ public void run() {
+ process.destroyForcibly();
+ }
+ }, timeoutSeconds, TimeUnit.SECONDS);
+ BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
+ String name = reader.readLine();
+ // If the timeout didn't fire, we don't want it killing our process now!
+ service.shutdownNow();
+ if (name != null) {
+ logger.info("vanadium listener sending slide images to " + name);
+ ImageViewer viewer = (ImageViewer) Naming.lookup(name);
+ // Hack: when the swing viewer exits, terminate our main app.
+ new Thread(new Runnable() {
+ @Override
+ public void run() {
+ do {
+ try {
+ process.waitFor();
+ break;
+ } catch (InterruptedException e) {
+ // Ignored.
+ }
+ } while (true);
+ System.exit(0);
+ }
+ }, "SwingServerTerminationWatcher").start();
+ return viewer;
+ } else {
+ throw new IOException("could not read slide name");
+ }
+ }
+
+ private static int pickUnusedPort() throws IOException {
+ for (int i = 0; i < MAX_PORT_PICKER_ATTEMPTS; i++) {
+ ServerSocket socket = new ServerSocket();
+ try {
+ socket.bind(new InetSocketAddress(0));
+ int port = ((InetSocketAddress) socket.getLocalSocketAddress()).getPort();
+ return port;
+ } catch (IOException e) {
+ // Couldn't bind, try again.
+ } finally {
+ try {
+ socket.close();
+ } catch (IOException closeException) {
+ logger.log(Level.WARNING, "Exception caught during close", closeException);
+ }
+ }
+ }
+
+ throw new IOException("Couldn't locate unused port");
}
private static class Discovery {
