Incremental saves in text editor make updates to textarea.

This is accomplished by extending the communication protocol between
the extension and the edit server.  The edit server watches for
changes to the temp file it creates.  When a change is discovered, the
edit server responds as normal, except that it adds two new headers,
'x-file' and 'x-open'.  The value for 'x-file' is the name of the
temporary file.  The value for 'x-open' is set to 'true'.  When the
extension receives a response with 'x-open' set to 'true', it
immediately makes another request to the edit server, adding a header,
'x-file', whose value is the same as the value in the preceding
response.  If the edit server gets a request with a valid 'x-file'
header, it does not create a new temp file and spawn a new text editor
instance.  Instead, it watches the given file for changes.  The
process of the text editor is also monitored for termination.  A
terminated editor instance also triggers a response by the edit
server.

The Python edit server was the only one modified to handle the
changes.  It shouldn't be too difficult to update the Emacs-based edit
server in the future.

pycl.py

@@ -1,4 +1,7 @@
+#!/usr/bin/env python
+
 # Copyright (C) 2009  David Hilley <davidhi@cc.gatech.edu>
+# Copyright (C) 2010  Matt DeVuyst <mdevuyst@gmail.com>
 #
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU General Public License
@@ -18,9 +21,11 @@ import cgi, urlparse
 import subprocess
 import tempfile, time
 import os, sys, re
+import stat
 from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
 
 temp_has_delete=True
+processes = {}
 
 class Handler(BaseHTTPRequestHandler):
     global temp_has_delete
@@ -35,6 +40,7 @@ class Handler(BaseHTTPRequestHandler):
         self.send_error(404, "GET Not Found: %s" % self.path)
 
     def do_POST(self):
+        global processes
         try:
             (content, params) = cgi.parse_header(self.headers.
                                                  getheader('content-type'))
@@ -55,37 +61,60 @@ class Handler(BaseHTTPRequestHandler):
             l = [s for s in self.path.split('/') if s]
             print l
 
+            existing_file = self.headers.getheader('x-file')
+
             # write text into file
-            url = self.headers.getheader('x-url')
-            print "url:", url
-            prefix = "chrome_"
-            if url:
-                prefix += re.sub("[^.\w]", "_", re.sub("^.*?//","",url))
-            prefix += "_"
-            if temp_has_delete==True:
-                f = tempfile.NamedTemporaryFile(
-                        delete=False, prefix=prefix, suffix='.txt')
-                fname = f.name
+            if not existing_file or existing_file == "undefined":
+                existing = False
+                url = self.headers.getheader('x-url')
+                print "url:", url
+                prefix = "chrome_"
+                if url:
+                    prefix += re.sub("[^.\w]", "_", re.sub("^.*?//","",url))
+                prefix += "_"
+                if temp_has_delete==True:
+                    f = tempfile.NamedTemporaryFile(
+                            delete=False, prefix=prefix, suffix='.txt')
+                    fname = f.name
+                else:
+                    tf = tempfile.mkstemp(prefix=prefix, suffix='.txt')
+                    f = os.fdopen(tf[0],"w")
+                    fname = tf[1]
+                print "Opening new file ", fname
             else:
-                tf = tempfile.mkstemp(prefix=prefix, suffix='.txt')
-                f = os.fdopen(tf[0],"w")
-                fname = tf[1]
+                existing = True
+                p = processes[existing_file]
+                print "Opening existing file ", existing_file
+                f = open(existing_file, "w")
+                fname = existing_file
 
             f.write(body)
             f.close()
-
-            # spawn editor...
-            print "Spawning editor... ", fname
-
-            p = subprocess.Popen(["/usr/bin/emacsclient", "-c", fname], close_fds=True)
-            #p = subprocess.Popen(["/usr/local/bin/mvim", "--remote-wait", fname], close_fds=True)
-
-            # hold connection open until editor finishes
-            rc = p.wait()
-
-            if not rc:
+            last_mod_time = os.stat(fname)[stat.ST_MTIME]
+
+            if not existing:
+                # spawn editor...
+                print "Spawning editor... ", fname
+
+                p = subprocess.Popen(["/usr/bin/emacsclient", fname], close_fds=True)
+                #p = subprocess.Popen(["/usr/local/bin/mvim", "--remote-wait", fname], close_fds=True)
+                processes[fname] = p
+
+            saved = False
+            rc = None
+            while (True):
+                time.sleep(1)
+                rc = p.poll()
+                if rc != None: break
+                mod_time = os.stat(fname)[stat.ST_MTIME]
+                if mod_time != last_mod_time:
+                    print "new mod time:", mod_time, " last:", last_mod_time
+                    last_mod_time = mod_time
+                    saved = True
+                if saved: break
+
+            if saved or not rc:
                     self.send_response(200)
-                    self.end_headers()
 
                     f = file(fname, 'r')
                     s = f.read()
@@ -97,12 +126,17 @@ class Handler(BaseHTTPRequestHandler):
                             msg = 'text editor died on signal %d' % -rc
                     self.send_error(404, msg)
 
-            try:
-                os.unlink(fname)
-            except :
-                print "Unable to unlink:", fname
-                pass
-
+            if saved:
+                self.send_header('x-open', "true")
+            else:
+                try:
+                    os.unlink(fname)
+                except :
+                    print "Unable to unlink:", fname
+                    pass
+
+            self.send_header('x-file', fname)
+            self.end_headers()
             self.wfile.write(s)
         except :
             print "Error: ", sys.exc_info()[0]