2006-05-09 Thomas Fitzsimmons <fitzsim@redhat.com>

	* configure.ac: Add --disable-plugin and --with-vm options.  Check
	for plugin support headers and libraries.
	* native/Makefile.am: Recurse into plugin directory.
	* native/plugin/.cvsignore: New file.
	* native/plugin/Makefile.am: New file.
	* native/plugin/gcjwebplugin.cc: New file.
	* tools/Makefile.am: Install appletviewer wrapper script.
	* tools/appletviewer.in: Replace VM location heuristic with
	VM_BINARY configure substitution.

3 files changed, 1430 insertions, 0 deletions

diff --git a/native/plugin/.cvsignore b/native/plugin/.cvsignore
new file mode 100644
index 000000000..70845e08e
--- /dev/null
+++ b/native/plugin/.cvsignore
@@ -0,0 +1 @@
+Makefile.in
diff --git a/native/plugin/Makefile.am b/native/plugin/Makefile.am
new file mode 100644
index 000000000..7358381eb
--- /dev/null
+++ b/native/plugin/Makefile.am
@@ -0,0 +1,18 @@
+lib_LTLIBRARIES = libgcjwebplugin.la
+
+libgcjwebplugin_la_SOURCES = gcjwebplugin.cc
+
+libgcjwebplugin_la_CXXFLAGS = \
+	-Wall -DAPPLETVIEWER_EXECUTABLE="\"$(bindir)/appletviewer\"" \
+	$(MOZILLA_CFLAGS) $(GLIB_CFLAGS)
+
+libgcjwebplugin_la_LDFLAGS = -avoid-version \
+	$(GLIB_LIBS) \
+	-lstdc++
+
+install-libLTLIBRARIES: $(lib_LTLIBRARIES)
+	$(INSTALL) -d -m0755 $(DESTDIR)@PLUGIN_DIR@
+	$(INSTALL) .libs/libgcjwebplugin.so $(DESTDIR)@PLUGIN_DIR@
+
+uninstall-libLTLIBRARIES:
+	rm -f $(DESTDIR)@PLUGIN_DIR@/libgcjwebplugin.so
diff --git a/native/plugin/gcjwebplugin.cc b/native/plugin/gcjwebplugin.cc
new file mode 100644
index 000000000..bbb9809be
--- /dev/null
+++ b/native/plugin/gcjwebplugin.cc
@@ -0,0 +1,1411 @@
+/* gcjwebplugin.cc -- web browser plugin to execute Java applets
+   Copyright (C) 2003, 2004, 2006  Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+// System includes.
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+// Netscape plugin API includes.
+#include <npapi.h>
+#include <npupp.h>
+
+// GLib includes.
+#include <glib.h>
+
+// gcjwebplugin includes.
+#include "config.h"
+
+// Documentbase retrieval includes.
+#include <nsIPluginInstance.h>
+#include <nsIPluginInstancePeer.h>
+#include <nsIPluginTagInfo2.h>
+
+// Debugging macros.
+#define PLUGIN_DEBUG(message)                                           \
+  g_print ("GCJ PLUGIN: thread %p: %s\n", g_thread_self (), message)
+
+#define PLUGIN_DEBUG_TWO(first, second)                                 \
+  g_print ("GCJ PLUGIN: thread %p: %s %s\n", g_thread_self (),          \
+           first, second)
+
+// Error reporting macros.
+#define PLUGIN_ERROR(message)                                       \
+  g_printerr ("%s:%d: thread %p: Error: %s\n", __FILE__, __LINE__,  \
+              g_thread_self (), message)
+
+#define PLUGIN_ERROR_TWO(first, second)                                 \
+  g_printerr ("%s:%d: thread %p: Error: %s: %s\n", __FILE__, __LINE__,  \
+              g_thread_self (), first, second)
+
+// Plugin information passed to about:plugins.
+#define PLUGIN_NAME "GCJ Web Browser Plugin"
+#define PLUGIN_DESC "The " PLUGIN_NAME " executes Java applets."
+#define PLUGIN_MIME_DESC                                           \
+  "application/x-java-vm:class,jar:GCJ;"                           \
+  "application/x-java-applet:class,jar:GCJ;"                       \
+  "application/x-java-applet;version=1.1:class,jar:GCJ;"           \
+  "application/x-java-applet;version=1.1.1:class,jar:GCJ;"         \
+  "application/x-java-applet;version=1.1.2:class,jar:GCJ;"         \
+  "application/x-java-applet;version=1.1.3:class,jar:GCJ;"         \
+  "application/x-java-applet;version=1.2:class,jar:GCJ;"           \
+  "application/x-java-applet;version=1.2.1:class,jar:GCJ;"         \
+  "application/x-java-applet;version=1.2.2:class,jar:GCJ;"         \
+  "application/x-java-applet;version=1.3:class,jar:GCJ;"           \
+  "application/x-java-applet;version=1.3.1:class,jar:GCJ;"         \
+  "application/x-java-applet;version=1.4:class,jar:GCJ;"           \
+  "application/x-java-applet;version=1.4.1:class,jar:GCJ;"         \
+  "application/x-java-applet;version=1.4.2:class,jar:GCJ;"         \
+  "application/x-java-applet;jpi-version=1.4.2_01:class,jar:GCJ;"  \
+  "application/x-java-bean:class,jar:GCJ;"                         \
+  "application/x-java-bean;version=1.1:class,jar:GCJ;"             \
+  "application/x-java-bean;version=1.1.1:class,jar:GCJ;"           \
+  "application/x-java-bean;version=1.1.2:class,jar:GCJ;"           \
+  "application/x-java-bean;version=1.1.3:class,jar:GCJ;"           \
+  "application/x-java-bean;version=1.2:class,jar:GCJ;"             \
+  "application/x-java-bean;version=1.2.1:class,jar:GCJ;"           \
+  "application/x-java-bean;version=1.2.2:class,jar:GCJ;"           \
+  "application/x-java-bean;version=1.3:class,jar:GCJ;"             \
+  "application/x-java-bean;version=1.3.1:class,jar:GCJ;"           \
+  "application/x-java-bean;version=1.4:class,jar:GCJ;"             \
+  "application/x-java-bean;version=1.4.1:class,jar:GCJ;"           \
+  "application/x-java-bean;version=1.4.2:class,jar:GCJ;"           \
+  "application/x-java-bean;jpi-version=1.4.2_01:class,jar:GCJ;"
+#define PLUGIN_URL NS_INLINE_PLUGIN_CONTRACTID_PREFIX NS_JVM_MIME_TYPE
+#define PLUGIN_MIME_TYPE "application/x-java-vm"
+#define PLUGIN_FILE_EXTS "class,jar,zip"
+#define PLUGIN_MIME_COUNT 1
+
+// Directory in which named pipes are created.
+#define PIPE_DIRECTORY "/tmp"
+
+// Documentbase retrieval required definition.
+static NS_DEFINE_IID (kIPluginTagInfo2IID, NS_IPLUGINTAGINFO2_IID);
+
+// Browser function table.
+static NPNetscapeFuncs browserFunctions;
+
+// GCJPluginData stores all the data associated with a single plugin
+// instance.  A separate plugin instance is created for each <APPLET>
+// tag.  For now, each plugin instance spawns its own applet viewer
+// process but this may need to change if we find pages containing
+// multiple applets that expect to be running in the same VM.
+struct GCJPluginData
+{
+  // A unique identifier for this plugin window.
+  gchar* instance_string;
+  // Applet viewer input pipe name.
+  gchar* in_pipe_name;
+  // Applet viewer input channel.
+  GIOChannel* in_from_appletviewer;
+  // Applet viewer input watch source.
+  gint in_watch_source;
+  // Applet viewer output pipe name.
+  gchar* out_pipe_name;
+  // Applet viewer output channel.
+  GIOChannel* out_to_appletviewer;
+  // Applet viewer output watch source.
+  gint out_watch_source;
+  // Mutex to protect appletviewer_alive.
+  GMutex* appletviewer_mutex;
+  // Back-pointer to the plugin instance to which this data belongs.
+  // This should not be freed but instead simply set to NULL.
+  NPP owner;
+  // FALSE if the applet viewer process has died.  All code
+  // communicating with the applet viewer should check this flag
+  // before attempting to read from/write to the applet viewer pipes.
+  gboolean appletviewer_alive;
+  // The address of the plugin window.  This should not be freed but
+  // instead simply set to NULL.
+  gpointer window_handle;
+  // The last plugin window width sent to us by the browser.
+  guint32 window_width;
+  // The last plugin window height sent to us by the browser.
+  guint32 window_height;
+};
+
+// Documentbase retrieval type-punning union.
+typedef union
+{
+  void** void_field;
+  nsIPluginTagInfo2** info_field;
+} info_union;
+
+// Static instance helper functions.
+// Have the browser allocate a new GCJPluginData structure.
+static void plugin_data_new (GCJPluginData** data);
+// Documentbase retrieval.
+static gchar* plugin_get_documentbase (NPP instance);
+// Callback used to monitor input pipe status.
+static gboolean plugin_in_pipe_callback (GIOChannel* source,
+                                         GIOCondition condition,
+                                         gpointer plugin_data);
+// Callback used to monitor output pipe status.
+static gboolean plugin_out_pipe_callback (GIOChannel* source,
+                                          GIOCondition condition,
+                                          gpointer plugin_data);
+static void plugin_start_appletviewer (GCJPluginData* data);
+static gchar* plugin_create_applet_tag (int16 argc, char* argn[],
+                                        char* argv[]);
+static void plugin_send_message_to_appletviewer (GCJPluginData* data,
+                                                 gchar const* message);
+static void plugin_stop_appletviewer (GCJPluginData* data);
+// Uninitialize GCJPluginData structure and delete pipes.
+static void plugin_data_destroy (GCJPluginData** data);
+
+// Global instance counter.
+// Mutex to protect plugin_instance_counter.
+static GMutex* plugin_instance_mutex = NULL;
+// A counter used to create uniquely named pipes.
+static gulong plugin_instance_counter = 0;
+
+// Functions prefixed by GCJ_ are instance functions.  They are called
+// by the browser and operate on instances of GCJPluginData.
+// Functions prefixed by plugin_ are static helper functions.
+// Functions prefixed by NP_ are factory functions.  They are called
+// by the browser and provide functionality needed to create plugin
+// instances.
+
+// INSTANCE FUNCTIONS
+
+// Creates a new gcjwebplugin instance.  This function creates a
+// GCJPluginData* and stores it in instance->pdata.  The following
+// GCJPluginData fiels are initialized: instance_string, in_pipe_name,
+// in_from_appletviewer, in_watch_source, out_pipe_name,
+// out_to_appletviewer, out_watch_source, appletviewer_mutex, owner,
+// appletviewer_alive.  In addition two pipe files are created.  All
+// of those fields must be properly destroyed, and the pipes deleted,
+// by GCJ_Destroy.  If an error occurs during initialization then this
+// function will free anything that's been allocated so far, set
+// instance->pdata to NULL and return an error code.
+NPError
+GCJ_New (NPMIMEType pluginType, NPP instance, uint16 mode,
+         int16 argc, char* argn[], char* argv[],
+         NPSavedData* saved)
+{
+  PLUGIN_DEBUG ("GCJ_New");
+
+  NPError np_error = NPERR_NO_ERROR;
+  GCJPluginData* data = NULL;
+  GError* channel_error = NULL;
+  gchar* documentbase = NULL;
+  gchar* read_message = NULL;
+  gchar* applet_tag = NULL;
+  gchar* tag_message = NULL;
+
+  if (!instance)
+    {
+      PLUGIN_ERROR ("Browser-provided instance pointer is NULL.");
+      np_error = NPERR_INVALID_INSTANCE_ERROR;
+      goto cleanup_done;
+    }
+
+  // Initialize threads (needed for mutexes).
+  if (!g_thread_supported ())
+    g_thread_init (NULL);
+
+  // data
+  plugin_data_new (&data);
+  if (data == NULL)
+    {
+      PLUGIN_ERROR ("Failed to allocate plugin data.");
+      np_error = NPERR_OUT_OF_MEMORY_ERROR;
+      goto cleanup_done;
+    }
+
+  // Initialize data->instance_string.
+  //
+  // instance_string should be unique for this process so we use a
+  // combination of getpid and plugin_instance_counter.
+  //
+  // Critical region.  Reference and increment plugin_instance_counter
+  // global.
+  g_mutex_lock (plugin_instance_mutex);
+
+  // data->instance_string
+  data->instance_string = g_strdup_printf ("instance-%d-%ld",
+                                           getpid (),
+                                           plugin_instance_counter++);
+
+  g_mutex_unlock (plugin_instance_mutex);
+
+  // data->appletviewer_mutex
+  data->appletviewer_mutex = g_mutex_new ();
+
+  // Documentbase retrieval.
+  documentbase = plugin_get_documentbase (instance);
+  if (!documentbase)
+    {
+      PLUGIN_ERROR ("Documentbase retrieval failed."
+                    " Browser not Mozilla-based?");
+      goto cleanup_appletviewer_mutex;
+    }
+
+  // Create appletviewer-to-plugin pipe which we refer to as the input
+  // pipe.
+
+  // data->in_pipe_name
+  data->in_pipe_name = g_strdup_printf (PIPE_DIRECTORY
+                                        "/gcj-%s-appletviewer-to-plugin",
+                                        data->instance_string);
+  if (!data->in_pipe_name)
+    {
+      PLUGIN_ERROR ("Failed to create input pipe name.");
+      np_error = NPERR_OUT_OF_MEMORY_ERROR;
+      // If data->in_pipe_name is NULL then the g_free at
+      // cleanup_in_pipe_name will simply return.
+      goto cleanup_in_pipe_name;
+    }
+
+  if (mkfifo (data->in_pipe_name, 0700) == -1 && errno != EEXIST)
+    {
+      PLUGIN_ERROR_TWO ("Failed to create input pipe", strerror (errno));
+      np_error = NPERR_GENERIC_ERROR;
+      goto cleanup_in_pipe_name;
+    }
+
+  // Create plugin-to-appletviewer pipe which we refer to as the
+  // output pipe.
+
+  // data->out_pipe_name
+  data->out_pipe_name = g_strdup_printf (PIPE_DIRECTORY
+                                         "/gcj-%s-plugin-to-appletviewer",
+                                         data->instance_string);
+
+  if (!data->out_pipe_name)
+    {
+      PLUGIN_ERROR ("Failed to create output pipe name.");
+      np_error = NPERR_OUT_OF_MEMORY_ERROR;
+      goto cleanup_out_pipe_name;
+    }
+
+  if (mkfifo (data->out_pipe_name, 0700) == -1 && errno != EEXIST)
+    {
+      PLUGIN_ERROR_TWO ("Failed to create output pipe", strerror (errno));
+      np_error = NPERR_GENERIC_ERROR;
+      goto cleanup_out_pipe_name;
+    }
+
+  // Start a separate appletviewer process for each applet, even if
+  // there are multiple applets in the same page.  We may need to
+  // change this behaviour if we find pages with multiple applets that
+  // rely on being run in the same VM.
+
+  // Critical region.  Hold appletviewer_mutex while we start the
+  // appletviewer, create the IO channels and install the channel
+  // watch callbacks.
+  g_mutex_lock (data->appletviewer_mutex);
+
+  plugin_start_appletviewer (data);
+
+  // Create plugin-to-appletviewer channel.  The default encoding for
+  // the file is UTF-8.
+  // data->out_to_appletviewer
+  data->out_to_appletviewer = g_io_channel_new_file (data->out_pipe_name,
+                                                     "w", &channel_error);
+  if (!data->out_to_appletviewer)
+    {
+      PLUGIN_ERROR_TWO ("Failed to create output channel",
+                        channel_error->message);
+      np_error = NPERR_GENERIC_ERROR;
+      goto cleanup_out_to_appletviewer;
+    }
+  if (channel_error)
+    {
+      g_error_free (channel_error);
+      channel_error = NULL;
+    }
+
+  // Watch for hangup and error signals on the output pipe.
+  data->out_watch_source =
+    g_io_add_watch (data->out_to_appletviewer,
+                    (GIOCondition) (G_IO_ERR | G_IO_HUP),
+                    plugin_out_pipe_callback, (gpointer) data);
+
+  // Create appletviewer-to-plugin channel.  The default encoding for
+  // the file is UTF-8.
+  // data->in_from_appletviewer
+  data->in_from_appletviewer = g_io_channel_new_file (data->in_pipe_name,
+                                                      "r", &channel_error);
+  if (!data->in_from_appletviewer)
+    {
+      PLUGIN_ERROR_TWO ("Failed to create input channel",
+                        channel_error->message);
+      np_error = NPERR_GENERIC_ERROR;
+      goto cleanup_in_from_appletviewer;
+    }
+  if (channel_error)
+    {
+      g_error_free (channel_error);
+      channel_error = NULL;
+    }
+
+  // Watch for hangup and error signals on the input pipe.
+  data->in_watch_source =
+    g_io_add_watch (data->in_from_appletviewer,
+                    (GIOCondition) (G_IO_IN | G_IO_ERR | G_IO_HUP),
+                    plugin_in_pipe_callback, (gpointer) data);
+
+  // Wait until we receive confirmation that the appletviewer has
+  // started.
+  if (g_io_channel_read_line (data->in_from_appletviewer,
+                              &read_message, NULL, NULL,
+                              &channel_error)
+      != G_IO_STATUS_NORMAL)
+    {
+      PLUGIN_ERROR_TWO ("Receiving confirmation from appletviewer failed",
+                        channel_error->message);
+      np_error = NPERR_GENERIC_ERROR;
+      goto cleanup_in_watch_source;
+    }
+  if (channel_error)
+    {
+      g_error_free (channel_error);
+      channel_error = NULL;
+    }
+
+  PLUGIN_DEBUG ("GCJ_New: got confirmation that appletviewer is running.");
+  data->appletviewer_alive = TRUE;
+
+  // Send applet tag message to appletviewer.
+  applet_tag = plugin_create_applet_tag (argc, argn, argv);
+  tag_message = g_strconcat ("tag ", documentbase, " ", applet_tag, NULL);
+
+  plugin_send_message_to_appletviewer (data, data->instance_string);
+  plugin_send_message_to_appletviewer (data, tag_message);
+
+  g_mutex_unlock (data->appletviewer_mutex);
+
+  // If initialization succeeded entirely then we store the plugin
+  // data in the instance structure and return.  Otherwise we free the
+  // data we've allocated so far and set instance->pdata to NULL.
+
+  // Set back-pointer to owner instance.
+  data->owner = instance;
+  instance->pdata = data;
+  goto cleanup_done;
+
+  // An error occurred while initializing the plugin data or spawning
+  // the appletviewer so we free the data we've already allocated.
+
+ cleanup_in_watch_source:
+  // Removing a source is harmless if it fails since it just means the
+  // source has already been removed.
+  g_source_remove (data->in_watch_source);
+  data->in_watch_source = 0;
+
+ cleanup_in_from_appletviewer:
+  if (data->in_from_appletviewer)
+    g_io_channel_unref (data->in_from_appletviewer);
+  data->in_from_appletviewer = NULL;
+
+  // cleanup_out_watch_source:
+  g_source_remove (data->out_watch_source);
+  data->out_watch_source = 0;
+
+ cleanup_out_to_appletviewer:
+  if (data->out_to_appletviewer)
+    g_io_channel_unref (data->out_to_appletviewer);
+  data->out_to_appletviewer = NULL;
+
+  // cleanup_out_pipe:
+  // Delete output pipe.
+  unlink (data->out_pipe_name);
+
+ cleanup_out_pipe_name:
+  g_free (data->out_pipe_name);
+  data->out_pipe_name = NULL;
+
+  // cleanup_in_pipe:
+  // Delete input pipe.
+  unlink (data->in_pipe_name);
+
+ cleanup_in_pipe_name:
+  g_free (data->in_pipe_name);
+  data->in_pipe_name = NULL;
+
+ cleanup_appletviewer_mutex:
+  g_free (data->appletviewer_mutex);
+  data->appletviewer_mutex = NULL;
+
+  // cleanup_instance_string:
+  g_free (data->instance_string);
+  data->instance_string = NULL;
+
+  // cleanup_data:
+  // Eliminate back-pointer to plugin instance.
+  data->owner = NULL;
+  (*browserFunctions.memfree) (data);
+  data = NULL;
+
+  // Initialization failed so return a NULL pointer for the browser
+  // data.
+  instance->pdata = NULL;
+
+ cleanup_done:
+
+  g_free (tag_message);
+  tag_message = NULL;
+  g_free (applet_tag);
+  applet_tag = NULL;
+  g_free (read_message);
+  read_message = NULL;
+  g_free (documentbase);
+  documentbase = NULL;
+
+  PLUGIN_DEBUG ("GCJ_New return");
+
+  return np_error;
+}
+
+NPError
+GCJ_GetValue (NPP instance, NPPVariable variable, void* value)
+{
+  PLUGIN_DEBUG ("GCJ_GetValue");
+
+  NPError np_error = NPERR_NO_ERROR;
+
+  switch (variable)
+    {
+    // This plugin needs XEmbed support.
+    case NPPVpluginNeedsXEmbed:
+      {
+        PLUGIN_DEBUG ("GCJ_GetValue: returning TRUE for NeedsXEmbed.");
+        PRBool* bool_value = (PRBool*) value;
+        *bool_value = PR_TRUE;
+      }
+      break;
+
+    default:
+      PLUGIN_ERROR ("Unknown plugin value requested.");
+      np_error = NPERR_GENERIC_ERROR;
+      break;
+    }
+
+  PLUGIN_DEBUG ("GCJ_GetValue return");
+
+  return np_error;
+}
+
+NPError
+GCJ_Destroy (NPP instance, NPSavedData** save)
+{
+  PLUGIN_DEBUG ("GCJ_Destroy");
+
+  GCJPluginData* data = (GCJPluginData*) instance->pdata;
+
+  if (data)
+    {
+      // Critical region.  Stop the appletviewer.
+      g_mutex_lock (data->appletviewer_mutex);
+
+      // Tell the appletviewer to destroy its embedded plugin window.
+      plugin_send_message_to_appletviewer (data, "destroy");
+      // Shut down the appletviewer.
+      plugin_stop_appletviewer (data);
+
+      g_mutex_unlock (data->appletviewer_mutex);
+
+      // Free plugin data.
+      plugin_data_destroy (&data);
+    }
+
+  PLUGIN_DEBUG ("GCJ_Destroy return");
+
+  return NPERR_NO_ERROR;
+}
+
+NPError
+GCJ_SetWindow (NPP instance, NPWindow* window)
+{
+  PLUGIN_DEBUG ("GCJ_SetWindow");
+
+  if (instance == NULL)
+    {
+      PLUGIN_ERROR ("Invalid instance.");
+
+      return NPERR_INVALID_INSTANCE_ERROR;
+    }
+
+  GCJPluginData* data = (GCJPluginData*) instance->pdata;
+
+  // Simply return if we receive a NULL window.
+  if ((window == NULL) || (window->window == NULL))
+    {
+      PLUGIN_DEBUG ("GCJ_SetWindow: got NULL window.");
+
+      return NPERR_NO_ERROR;
+    }
+
+  if (data->window_handle)
+    {
+      // The window already exists.
+      if (data->window_handle == window->window)
+	{
+          // The parent window is the same as in previous calls.
+          PLUGIN_DEBUG ("GCJ_SetWindow: window already exists.");
+
+          // Critical region.  Read data->appletviewer_mutex and send
+          // a message to the appletviewer.
+          g_mutex_lock (data->appletviewer_mutex);
+
+	  if (data->appletviewer_alive)
+	    {
+	      // The window is the same as it was for the last
+	      // SetWindow call.
+	      if (window->width != data->window_width)
+		{
+                  PLUGIN_DEBUG ("GCJ_SetWindow: window width changed.");
+		  // The width of the plugin window has changed.
+
+                  // Send the new width to the appletviewer.
+		  plugin_send_message_to_appletviewer (data,
+                                                       data->instance_string);
+                  gchar* width_message = g_strdup_printf ("width %d",
+                                                          window->width);
+		  plugin_send_message_to_appletviewer (data, width_message);
+                  g_free (width_message);
+
+                  // Store the new width.
+                  data->window_width = window->width;
+		}
+
+	      if (window->height != data->window_height)
+		{
+                  PLUGIN_DEBUG ("GCJ_SetWindow: window height changed.");
+		  // The height of the plugin window has changed.
+
+                  // Send the new height to the appletviewer.
+		  plugin_send_message_to_appletviewer (data,
+                                                       data->instance_string);
+                  gchar* height_message = g_strdup_printf ("height %d",
+                                                           window->height);
+		  plugin_send_message_to_appletviewer (data, height_message);
+                  g_free (height_message);
+
+                  // Store the new height.
+                  data->window_height = window->height;
+		}
+	    }
+	  else
+	    {
+              // The appletviewer is not running.
+	      PLUGIN_DEBUG ("GCJ_SetWindow: appletviewer is not running.");
+	    }
+
+          g_mutex_unlock (data->appletviewer_mutex);
+	}
+      else
+	{
+	  // The parent window has changed.  This branch does run but
+	  // doing nothing in response seems to be sufficient.
+	  PLUGIN_DEBUG ("GCJ_SetWindow: parent window changed.");
+	}
+    }
+  else
+    {
+      PLUGIN_DEBUG ("GCJ_SetWindow: setting window.");
+
+      // Critical region.  Send messages to appletviewer.
+      g_mutex_lock (data->appletviewer_mutex);
+
+      plugin_send_message_to_appletviewer (data, data->instance_string);
+      gchar *window_message = g_strdup_printf ("handle %ld",
+                                               (gulong) window->window);
+      plugin_send_message_to_appletviewer (data, window_message);
+      g_free (window_message);
+
+      g_mutex_unlock (data->appletviewer_mutex);
+
+      // Store the window handle.
+      data->window_handle = window->window;
+    }
+
+  PLUGIN_DEBUG ("GCJ_SetWindow return");
+
+  return NPERR_NO_ERROR;
+}
+
+NPError
+GCJ_NewStream (NPP instance, NPMIMEType type, NPStream* stream,
+               NPBool seekable, uint16* stype)
+{
+  PLUGIN_DEBUG ("GCJ_NewStream");
+
+  PLUGIN_DEBUG ("GCJ_NewStream return");
+
+  return NPERR_NO_ERROR;
+}
+
+void
+GCJ_StreamAsFile (NPP instance, NPStream* stream, const char* filename)
+{
+  PLUGIN_DEBUG ("GCJ_StreamAsFile");
+
+  PLUGIN_DEBUG ("GCJ_StreamAsFile return");
+}
+
+NPError
+GCJ_DestroyStream (NPP instance, NPStream* stream, NPReason reason)
+{
+  PLUGIN_DEBUG ("GCJ_DestroyStream");
+
+  PLUGIN_DEBUG ("GCJ_DestroyStream return");
+
+  return NPERR_NO_ERROR;
+}
+
+int32
+GCJ_WriteReady (NPP instance, NPStream* stream)
+{
+  PLUGIN_DEBUG ("GCJ_WriteReady");
+
+  PLUGIN_DEBUG ("GCJ_WriteReady return");
+
+  return 0;
+}
+
+int32
+GCJ_Write (NPP instance, NPStream* stream, int32 offset, int32 len,
+           void* buffer)
+{
+  PLUGIN_DEBUG ("GCJ_Write");
+
+  PLUGIN_DEBUG ("GCJ_Write return");
+
+  return 0;
+}
+
+void
+GCJ_Print (NPP instance, NPPrint* platformPrint)
+{
+  PLUGIN_DEBUG ("GCJ_Print");
+
+  PLUGIN_DEBUG ("GCJ_Print return");
+}
+
+int16
+GCJ_HandleEvent (NPP instance, void* event)
+{
+  PLUGIN_DEBUG ("GCJ_HandleEvent");
+
+  PLUGIN_DEBUG ("GCJ_HandleEvent return");
+
+  return 0;
+}
+
+void
+GCJ_URLNotify (NPP instance, const char* url, NPReason reason,
+               void* notifyData)
+{
+  PLUGIN_DEBUG ("GCJ_URLNotify");
+
+  PLUGIN_DEBUG ("GCJ_URLNotify return");
+}
+
+jref
+GCJ_GetJavaClass (void)
+{
+  PLUGIN_DEBUG ("GCJ_GetJavaClass");
+
+  PLUGIN_DEBUG ("GCJ_GetJavaClass return");
+
+  return 0;
+}
+
+// HELPER FUNCTIONS
+
+static void
+plugin_data_new (GCJPluginData** data)
+{
+  PLUGIN_DEBUG ("plugin_data_new");
+
+  *data = (GCJPluginData*)
+    (*browserFunctions.memalloc) (sizeof (struct GCJPluginData));
+
+  // appletviewer_alive is false until the applet viewer is spawned.
+  if (*data)
+    memset (*data, 0, sizeof (struct GCJPluginData));
+
+  PLUGIN_DEBUG ("plugin_data_new return");
+}
+
+// Documentbase retrieval.  This function gets the current document's
+// documentbase.  This function relies on browser-private data so it
+// will only work when the plugin is loaded in a Mozilla-based
+// browser.  We could not find a way to retrieve the documentbase
+// using the original Netscape plugin API so we use the XPCOM API
+// instead.
+static gchar*
+plugin_get_documentbase (NPP instance)
+{
+  PLUGIN_DEBUG ("plugin_get_documentbase");
+
+  nsIPluginInstance* xpcom_instance = NULL;
+  nsIPluginInstancePeer* peer = NULL;
+  nsresult result = 0;
+  nsIPluginTagInfo2* pluginTagInfo2 = NULL;
+  info_union u = { NULL };
+  char const* documentbase = NULL;
+  gchar* documentbase_copy = NULL;
+
+  xpcom_instance = (nsIPluginInstance*) (instance->ndata);
+  if (!xpcom_instance)
+    {
+      PLUGIN_ERROR ("xpcom_instance is NULL.");
+      goto cleanup_done;
+    }
+
+  xpcom_instance->GetPeer (&peer);
+  if (!peer)
+    {
+      PLUGIN_ERROR ("peer is NULL.");
+      goto cleanup_done;
+    }
+
+  u.info_field = &pluginTagInfo2;
+
+  result = peer->QueryInterface (kIPluginTagInfo2IID,
+                                 u.void_field);
+  if (result || !pluginTagInfo2)
+    {
+      PLUGIN_ERROR ("pluginTagInfo2 retrieval failed.");
+      goto cleanup_peer;
+    }
+
+  pluginTagInfo2->GetDocumentBase (&documentbase);
+
+  if (!documentbase)
+    {
+      PLUGIN_ERROR ("documentbase is NULL.");
+      goto cleanup_plugintaginfo2;
+    }
+
+  documentbase_copy = g_strdup (documentbase);
+
+  // Release references.
+ cleanup_plugintaginfo2:
+  NS_RELEASE (pluginTagInfo2);
+
+ cleanup_peer:
+  NS_RELEASE (peer);
+
+ cleanup_done:
+  PLUGIN_DEBUG ("plugin_get_documentbase return");
+
+  return documentbase_copy;
+}
+
+// plugin_in_pipe_callback is called when data is available on the
+// input pipe, or when the appletviewer crashes or is killed.  It may
+// be called after data has been destroyed in which case it simply
+// returns FALSE to remove itself from the glib main loop.
+static gboolean
+plugin_in_pipe_callback (GIOChannel* source,
+                         GIOCondition condition,
+                         gpointer plugin_data)
+{
+  PLUGIN_DEBUG ("plugin_in_pipe_callback");
+
+  GCJPluginData* data = (GCJPluginData*) plugin_data;
+  gboolean keep_installed = TRUE;
+
+  // If data is NULL then GCJ_Destroy has already been called and
+  // plugin_in_pipe_callback is being called after plugin
+  // destruction.  In that case all we need to do is return FALSE so
+  // that the plugin_in_pipe_callback watch is removed.
+  if (data)
+    {
+      // Critical region. Set or clear data->appletviewer_alive.
+      g_mutex_lock (data->appletviewer_mutex);
+
+      if (condition & G_IO_IN)
+        {
+          GError* channel_error = NULL;
+          gchar* message = NULL;
+
+          if (g_io_channel_read_line (data->in_from_appletviewer,
+                                      &message, NULL, NULL,
+                                      &channel_error)
+              != G_IO_STATUS_NORMAL)
+            {
+              PLUGIN_ERROR_TWO ("Failed to read line from input channel",
+                                channel_error->message);
+            }
+          else
+            {
+              if (g_str_has_prefix (message, "url "))
+                {
+                  gchar** parts = g_strsplit (message, " ", 3);
+                  PLUGIN_DEBUG_TWO ("plugin_in_pipe_callback:"
+                                    " opening URL", parts[1]);
+                  PLUGIN_DEBUG_TWO ("plugin_in_pipe_callback:"
+                                    " URL target", parts[2]);
+                  // Open the URL in a new browser window.
+                  NPError np_error =
+                    (*browserFunctions.geturl) (data->owner, parts[1], parts[2]);
+                  if (np_error != NPERR_NO_ERROR)
+                    PLUGIN_ERROR ("Failed to load URL.");
+                  g_strfreev (parts);
+                  parts = NULL;
+                }
+              else if (g_str_has_prefix (message, "status "))
+                {
+                  gchar** parts = g_strsplit (message, " ", 2);
+
+                  PLUGIN_DEBUG_TWO ("plugin_in_pipe_callback:"
+                                    " setting status", parts[1]);
+                  (*browserFunctions.status) (data->owner, parts[1]);
+                  g_strfreev (parts);
+                  parts = NULL;
+                }
+              g_print ("  PIPE: plugin read %s\n", message);
+            }
+
+          if (channel_error)
+            {
+              g_error_free (channel_error);
+              channel_error = NULL;
+            }
+
+          g_free (message);
+          message = NULL;
+
+          keep_installed = TRUE;
+        }
+
+      if (condition & (G_IO_ERR | G_IO_HUP))
+        {
+          PLUGIN_DEBUG ("appletviewer has stopped.");
+          data->appletviewer_alive = FALSE;
+          keep_installed = FALSE;
+        }
+      g_mutex_unlock (data->appletviewer_mutex);
+    }
+
+  PLUGIN_DEBUG ("plugin_in_pipe_callback return");
+
+  return keep_installed;
+}
+
+// plugin_out_pipe_callback is called when the appletviewer crashes or
+// is killed.  It may be called after data has been destroyed in which
+// case it simply returns FALSE to remove itself from the glib main
+// loop.
+static gboolean
+plugin_out_pipe_callback (GIOChannel* source,
+                          GIOCondition condition,
+                          gpointer plugin_data)
+{
+  PLUGIN_DEBUG ("plugin_out_pipe_callback");
+
+  GCJPluginData* data = (GCJPluginData*) plugin_data;
+
+  // If data is NULL then GCJ_Destroy has already been called and
+  // plugin_out_pipe_callback is being called after plugin
+  // destruction.  In that case all we need to do is return FALSE so
+  // that the plugin_out_pipe_callback watch is removed.
+  if (data)
+    {
+      // Critical region.  Clear data->appletviewer_alive.
+      g_mutex_lock (data->appletviewer_mutex);
+
+      PLUGIN_DEBUG ("plugin_out_pipe_callback: appletviewer has stopped.");
+      data->appletviewer_alive = FALSE;
+
+      g_mutex_unlock (data->appletviewer_mutex);
+    }
+
+  PLUGIN_DEBUG ("plugin_out_pipe_callback return");
+
+  return FALSE;
+}
+
+static void
+plugin_start_appletviewer (GCJPluginData* data)
+{
+  PLUGIN_DEBUG ("plugin_start_appletviewer");
+
+  if (!data->appletviewer_alive)
+    {
+      GError* spawn_error = NULL;
+      gchar* command_line[3] = { NULL, NULL, NULL };
+
+      command_line[0] = g_strdup (APPLETVIEWER_EXECUTABLE);
+      // Output from plugin's perspective is appletviewer's input.
+      // Input from plugin's perspective is appletviewer's output.
+      command_line[1] = g_strdup_printf ("--plugin=%s,%s",
+                                         data->out_pipe_name,
+                                         data->in_pipe_name);
+      command_line[2] = NULL;
+
+      if (!g_spawn_async (NULL, command_line, NULL, (GSpawnFlags) 0,
+                          NULL, NULL, NULL, &spawn_error))
+        {
+          PLUGIN_ERROR_TWO ("Failed to spawn applet viewer",
+                            spawn_error->message);
+          goto cleanup;
+        }
+
+    cleanup:
+      g_free (command_line[0]);
+      g_free (command_line[1]);
+      g_free (command_line[2]);
+      if (spawn_error)
+        {
+          g_error_free (spawn_error);
+          spawn_error = NULL;
+        }
+    }
+
+  PLUGIN_DEBUG ("plugin_start_appletviewer return");
+}
+
+// Build up the applet tag string that we'll send to the applet
+// viewer.
+static gchar*
+plugin_create_applet_tag (int16 argc, char* argn[], char* argv[])
+{
+  PLUGIN_DEBUG ("plugin_create_applet_tag");
+
+  gchar* applet_tag = g_strdup ("<EMBED ");
+  gchar* parameters = g_strdup ("");
+
+  for (int16 i = 0; i < argc; i++)
+    {
+      if (!g_ascii_strcasecmp (argn[i], "code"))
+        {
+          gchar* code = g_strdup_printf ("CODE=\"%s\" ", argv[i]);
+	  applet_tag = g_strconcat (applet_tag, code, NULL);
+          g_free (code);
+	}
+      else if (!g_ascii_strcasecmp (argn[i], "codebase"))
+	{
+          gchar* codebase = g_strdup_printf ("CODEBASE=\"%s\" ", argv[i]);
+	  applet_tag = g_strconcat (applet_tag, codebase, NULL);
+          g_free (codebase);
+	}
+      else if (!g_ascii_strcasecmp (argn[i], "archive"))
+	{
+          gchar* archive = g_strdup_printf ("ARCHIVE=\"%s\" ", argv[i]);
+	  applet_tag = g_strconcat (applet_tag, archive, NULL);
+          g_free (archive);
+	}
+      else if (!g_ascii_strcasecmp (argn[i], "width"))
+	{
+          gchar* width = g_strdup_printf ("WIDTH=\"%s\" ", argv[i]);
+	  applet_tag = g_strconcat (applet_tag, width, NULL);
+          g_free (width);
+	}
+      else if (!g_ascii_strcasecmp (argn[i], "height"))
+	{
+          gchar* height = g_strdup_printf ("HEIGHT=\"%s\" ", argv[i]);
+	  applet_tag = g_strconcat (applet_tag, height, NULL);
+          g_free (height);
+	}
+      else
+        {
+          // Escape the parameter value so that line termination
+          // characters will pass through the pipe.
+          if (argv[i] != '\0')
+            {
+              gchar* escaped = g_strescape (argv[i], NULL);
+              parameters = g_strconcat (parameters, "<PARAM NAME=\"", argn[i],
+                                        "\" VALUE=\"", escaped, "\">", NULL);
+              g_free (escaped);
+            }
+        }
+    }
+
+  applet_tag = g_strconcat (applet_tag, ">", parameters, "</EMBED>", NULL);
+
+  g_free (parameters);
+  parameters = NULL;
+
+  PLUGIN_DEBUG ("plugin_create_applet_tag return");
+
+  return applet_tag;
+}
+
+// plugin_send_message_to_appletviewer must be called while holding
+// data->appletviewer_mutex.
+static void
+plugin_send_message_to_appletviewer (GCJPluginData* data, gchar const* message)
+{
+  PLUGIN_DEBUG ("plugin_send_message_to_appletviewer");
+
+  if (data->appletviewer_alive)
+    {
+      GError* channel_error = NULL;
+      gchar* newline_message = NULL;
+      gsize bytes_written = 0;
+
+      // Send message to appletviewer.
+      newline_message = g_strdup_printf ("%s\n", message);
+
+      // g_io_channel_write_chars will return something other than
+      // G_IO_STATUS_NORMAL if not all the data is written.  In that
+      // case we fail rather than retrying.
+      if (g_io_channel_write_chars (data->out_to_appletviewer,
+                                    newline_message, -1, &bytes_written,
+                                    &channel_error)
+          != G_IO_STATUS_NORMAL)
+        PLUGIN_ERROR_TWO ("Failed to write bytes to output channel",
+                          channel_error->message);
+
+      if (channel_error)
+        {
+          g_error_free (channel_error);
+          channel_error = NULL;
+        }
+
+      if (g_io_channel_flush (data->out_to_appletviewer, &channel_error)
+          != G_IO_STATUS_NORMAL)
+        PLUGIN_ERROR_TWO ("Failed to flush bytes to output channel",
+                          channel_error->message);
+
+      if (channel_error)
+        {
+          g_error_free (channel_error);
+          channel_error = NULL;
+        }
+      g_free (newline_message);
+
+      g_print ("  PIPE: plugin wrote %s\n", message);
+    }
+
+  PLUGIN_DEBUG ("plugin_send_message_to_appletviewer return");
+}
+
+// Stop the appletviewer process.  When this is called the
+// appletviewer can be in any of three states: running, crashed or
+// hung.  If the appletviewer is running then sending it "shutdown"
+// will cause it to exit.  This will cause
+// plugin_out_pipe_callback/plugin_in_pipe_callback to be called and
+// the input and output channels to be shut down.  If the appletviewer
+// has crashed then plugin_out_pipe_callback/plugin_in_pipe_callback
+// would already have been called and data->appletviewer_alive cleared
+// in which case this function simply returns.  If the appletviewer is
+// hung then this function will be successful and the input and output
+// watches will be removed by plugin_data_destroy.
+// plugin_stop_appletviewer must be called with
+// data->appletviewer_mutex held.
+static void
+plugin_stop_appletviewer (GCJPluginData* data)
+{
+  PLUGIN_DEBUG ("plugin_stop_appletviewer");
+
+  if (data->appletviewer_alive)
+    {
+      // Shut down the appletviewer.
+      GError* channel_error = NULL;
+      gsize bytes_written = 0;
+
+      if (data->out_to_appletviewer)
+        {
+          if (g_io_channel_write_chars (data->out_to_appletviewer, "shutdown",
+                                        -1, &bytes_written, &channel_error)
+              != G_IO_STATUS_NORMAL)
+            PLUGIN_ERROR_TWO ("Failed to write shutdown message to"
+                              " appletviewer", channel_error->message);
+
+          if (channel_error)
+            {
+              g_error_free (channel_error);
+              channel_error = NULL;
+            }
+
+          if (g_io_channel_flush (data->out_to_appletviewer, &channel_error)
+              != G_IO_STATUS_NORMAL)
+            PLUGIN_ERROR_TWO ("Failed to write shutdown message to"
+                              " appletviewer", channel_error->message);
+
+          if (channel_error)
+            {
+              g_error_free (channel_error);
+              channel_error = NULL;
+            }
+
+          if (g_io_channel_shutdown (data->out_to_appletviewer,
+                                     TRUE, &channel_error)
+              != G_IO_STATUS_NORMAL)
+            PLUGIN_ERROR_TWO ("Failed to shut down appletviewer"
+                              " output channel", channel_error->message);
+
+          if (channel_error)
+            {
+              g_error_free (channel_error);
+              channel_error = NULL;
+            }
+        }
+
+      if (data->in_from_appletviewer)
+        {
+          if (g_io_channel_shutdown (data->in_from_appletviewer,
+                                     TRUE, &channel_error)
+              != G_IO_STATUS_NORMAL)
+            PLUGIN_ERROR_TWO ("Failed to shut down appletviewer"
+                              " input channel", channel_error->message);
+
+          if (channel_error)
+            {
+              g_error_free (channel_error);
+              channel_error = NULL;
+            }
+        }
+    }
+
+  PLUGIN_DEBUG ("plugin_stop_appletviewer return");
+}
+
+static void
+plugin_data_destroy (GCJPluginData** data)
+{
+  PLUGIN_DEBUG ("plugin_data_destroy");
+
+  GCJPluginData* tofree = *data;
+
+  tofree->window_handle = NULL;
+  tofree->window_height = 0;
+  tofree->window_width = 0;
+
+  // Copied from GCJ_New.
+
+  // cleanup_in_watch_source:
+  // Removing a source is harmless if it fails since it just means the
+  // source has already been removed.
+  g_source_remove (tofree->in_watch_source);
+  tofree->in_watch_source = 0;
+
+  // cleanup_in_from_appletviewer:
+  if (tofree->in_from_appletviewer)
+    g_io_channel_unref (tofree->in_from_appletviewer);
+  tofree->in_from_appletviewer = NULL;
+
+  // cleanup_out_watch_source:
+  g_source_remove (tofree->out_watch_source);
+  tofree->out_watch_source = 0;
+
+  // cleanup_out_to_appletviewer:
+  if (tofree->out_to_appletviewer)
+    g_io_channel_unref (tofree->out_to_appletviewer);
+  tofree->out_to_appletviewer = NULL;
+
+  // cleanup_out_pipe:
+  // Delete output pipe.
+  unlink (tofree->out_pipe_name);
+
+  // cleanup_out_pipe_name:
+  g_free (tofree->out_pipe_name);
+  tofree->out_pipe_name = NULL;
+
+  // cleanup_in_pipe:
+  // Delete input pipe.
+  unlink (tofree->in_pipe_name);
+
+  // cleanup_in_pipe_name:
+  g_free (tofree->in_pipe_name);
+  tofree->in_pipe_name = NULL;
+
+  // cleanup_appletviewer_mutex:
+  g_free (tofree->appletviewer_mutex);
+  tofree->appletviewer_mutex = NULL;
+
+  // cleanup_instance_string:
+  g_free (tofree->instance_string);
+  tofree->instance_string = NULL;
+
+  // cleanup_data:
+  // Eliminate back-pointer to plugin instance.
+  tofree->owner = NULL;
+  (*browserFunctions.memfree) (tofree);
+  tofree = NULL;
+
+  PLUGIN_DEBUG ("plugin_data_destroy return");
+}
+
+// FACTORY FUNCTIONS
+
+// Provides the browser with pointers to the plugin functions that we
+// implement and initializes a local table with browser functions that
+// we may wish to call.  Called once, after browser startup and before
+// the first plugin instance is created.
+NPError
+NP_Initialize (NPNetscapeFuncs* browserTable, NPPluginFuncs* pluginTable)
+{
+  PLUGIN_DEBUG ("NP_Initialize");
+
+  if ((browserTable == NULL) || (pluginTable == NULL))
+    {
+      PLUGIN_ERROR ("Browser or plugin function table is NULL.");
+
+      return NPERR_INVALID_FUNCTABLE_ERROR;
+    }
+
+  // Ensure that the major version of the plugin API that the browser
+  // expects is not more recent than the major version of the API that
+  // we've implemented.
+  if ((browserTable->version >> 8) > NP_VERSION_MAJOR)
+    {
+      PLUGIN_ERROR ("Incompatible version.");
+
+      return NPERR_INCOMPATIBLE_VERSION_ERROR;
+    }
+
+  // Ensure that the plugin function table we've received is large
+  // enough to store the number of functions that we may provide.
+  if (pluginTable->size < sizeof (NPPluginFuncs))      
+    {
+      PLUGIN_ERROR ("Invalid plugin function table.");
+
+      return NPERR_INVALID_FUNCTABLE_ERROR;
+    }
+
+  // Ensure that the browser function table is large enough to store
+  // the number of browser functions that we may use.
+  if (browserTable->size < sizeof (NPNetscapeFuncs))
+    {
+      PLUGIN_ERROR ("Invalid browser function table.");
+
+      return NPERR_INVALID_FUNCTABLE_ERROR;
+    }
+
+  // Store in a local table the browser functions that we may use.
+  browserFunctions.version = browserTable->version;
+  browserFunctions.size = browserTable->size;
+  browserFunctions.posturl = browserTable->posturl;
+  browserFunctions.geturl = browserTable->geturl;
+  browserFunctions.geturlnotify = browserTable->geturlnotify;
+  browserFunctions.requestread = browserTable->requestread;
+  browserFunctions.newstream = browserTable->newstream;
+  browserFunctions.write = browserTable->write;
+  browserFunctions.destroystream = browserTable->destroystream;
+  browserFunctions.status = browserTable->status;
+  browserFunctions.uagent = browserTable->uagent;
+  browserFunctions.memalloc = browserTable->memalloc;
+  browserFunctions.memfree = browserTable->memfree;
+  browserFunctions.memflush = browserTable->memflush;
+  browserFunctions.reloadplugins = browserTable->reloadplugins;
+  browserFunctions.getvalue = browserTable->getvalue;
+
+  // Return to the browser the plugin functions that we implement.
+  pluginTable->version = (NP_VERSION_MAJOR << 8) + NP_VERSION_MINOR;
+  pluginTable->size = sizeof (NPPluginFuncs);
+  pluginTable->newp = NewNPP_NewProc (GCJ_New);
+  pluginTable->destroy = NewNPP_DestroyProc (GCJ_Destroy);
+  pluginTable->setwindow = NewNPP_SetWindowProc (GCJ_SetWindow);
+  pluginTable->newstream = NewNPP_NewStreamProc (GCJ_NewStream);
+  pluginTable->destroystream = NewNPP_DestroyStreamProc (GCJ_DestroyStream);
+  pluginTable->asfile = NewNPP_StreamAsFileProc (GCJ_StreamAsFile);
+  pluginTable->writeready = NewNPP_WriteReadyProc (GCJ_WriteReady);
+  pluginTable->write = NewNPP_WriteProc (GCJ_Write);
+  pluginTable->print = NewNPP_PrintProc (GCJ_Print);
+  pluginTable->urlnotify = NewNPP_URLNotifyProc (GCJ_URLNotify);
+  pluginTable->getvalue = NewNPP_GetValueProc (GCJ_GetValue);
+
+  plugin_instance_mutex = g_mutex_new ();
+
+  PLUGIN_DEBUG ("NP_Initialize: using " APPLETVIEWER_EXECUTABLE ".");
+
+  PLUGIN_DEBUG ("NP_Initialize return");
+
+  return NPERR_NO_ERROR;
+}
+
+// Returns a string describing the MIME type that this plugin
+// handles.
+char*
+NP_GetMIMEDescription (void)
+{
+  PLUGIN_DEBUG ("NP_GetMIMEDescription");
+
+  PLUGIN_DEBUG ("NP_GetMIMEDescription return");
+
+  return (char*) PLUGIN_MIME_DESC;
+}
+
+// Returns a value relevant to the plugin as a whole.  The browser
+// calls this function to obtain information about the plugin.
+NPError
+NP_GetValue (void* future, NPPVariable variable, void* value)
+{
+  PLUGIN_DEBUG ("NP_GetValue");
+
+  NPError result = NPERR_NO_ERROR;
+  gchar** char_value = (gchar**) value;
+
+  switch (variable)
+    {
+    case NPPVpluginNameString:
+      PLUGIN_DEBUG ("NP_GetValue: returning plugin name.");
+      *char_value = g_strdup (PLUGIN_NAME " " PACKAGE_VERSION);
+      break;
+
+    case NPPVpluginDescriptionString:
+      PLUGIN_DEBUG ("NP_GetValue: returning plugin description.");
+      *char_value = g_strdup (PLUGIN_DESC);
+      break;
+
+    default:
+      PLUGIN_ERROR ("Unknown plugin value requested.");
+      result = NPERR_GENERIC_ERROR;
+      break;
+    }
+
+  PLUGIN_DEBUG ("NP_GetValue return");
+
+  return result;
+}
+
+// Shuts down the plugin.  Called after the last plugin instance is
+// destroyed.
+NPError
+NP_Shutdown (void)
+{
+  PLUGIN_DEBUG ("NP_Shutdown");
+
+  // Free mutex.
+  g_mutex_free (plugin_instance_mutex);
+  plugin_instance_mutex = NULL;
+
+  PLUGIN_DEBUG ("NP_Shutdown return");
+
+  return NPERR_NO_ERROR;
+}