Squash: Single instance and pop up old instance

src/bitmessagemain.py

@@ -144,7 +144,7 @@ class Main:
 
         shared.daemon = daemon
         # is the application already running?  If yes then exit.
-        thisapp = singleton.singleinstance()
+        thisapp = singleton.singleinstance("", daemon)
 
         import upnp
         upnp.createPortMapping()

src/bitmessageqt/__init__.py

@@ -56,10 +56,23 @@ import subprocess
 import datetime
 from helper_sql import *
 import l10n
-import types
-from utils import *
-from collections import OrderedDict
-from account import *
+
+try:
+    from PyQt4 import QtCore, QtGui
+    from PyQt4.QtCore import *
+    from PyQt4.QtGui import *
+    from PyQt4.QtNetwork import QLocalSocket, QLocalServer
+
+except Exception as err:
+    print 'PyBitmessage requires PyQt unless you want to run it as a daemon and interact with it using the API. You can download it from http://www.riverbankcomputing.com/software/pyqt/download or by searching Google for \'PyQt Download\' (without quotes).'
+    print 'Error message:', err
+    sys.exit()
+
+try:
+    _encoding = QtGui.QApplication.UnicodeUTF8
+except AttributeError:
+    print 'QtGui.QApplication.UnicodeUTF8 error:', err
+
 
 def _translate(context, text):
     return QtGui.QApplication.translate(context, text)
@@ -4483,8 +4496,70 @@ class UISignaler(QThread):
                 sys.stderr.write(
                     'Command sent to UISignaler not recognized: %s\n' % command)
 
+
+app = None
+myapp = None
+
+class MySingleApplication(QApplication):
+    """
+    Listener to allow our Qt form to get focus when another instance of the
+    application is open.
+
+    Based off this nice reimplmentation of MySingleApplication:
+    http://stackoverflow.com/a/12712362/2679626
+    """
+
+    # Unique identifier for this application
+    uuid = '6ec0149b-96e1-4be1-93ab-1465fb3ebf7c'
+
+    def __init__(self, *argv):
+        super(MySingleApplication, self).__init__(*argv)
+        id = MySingleApplication.uuid
+
+        self.server = None
+        self.is_running = False
+
+        socket = QLocalSocket()
+        socket.connectToServer(id)
+        self.is_running = socket.waitForConnected()
+
+        # Cleanup past crashed servers
+        if not self.is_running:
+            if socket.error() == QLocalSocket.ConnectionRefusedError:
+                socket.disconnectFromServer()
+                QLocalServer.removeServer(id)
+
+        socket.abort()
+
+        # Checks if there's an instance of the local server id running
+        if self.is_running:
+            # This should be ignored, singleton.py will take care of exiting me.
+            pass
+        else:
+            # Nope, create a local server with this id and assign on_new_connection
+            # for whenever a second instance tries to run focus the application.
+            self.server = QLocalServer()
+            self.server.listen(id)
+            self.server.newConnection.connect(self.on_new_connection)
+
+    def __del__(self):
+        if self.server:
+            self.server.close()
+
+    def on_new_connection(self):
+        global myapp
+        if myapp:
+            myapp.appIndicatorShow()
+
+def init():
+    global app
+    if not app:
+        app = MySingleApplication(sys.argv)
+    return app
+
 def run():
-    app = QtGui.QApplication(sys.argv)
+    global myapp
+    app = init()
     change_translation(l10n.getTranslationLanguage())
     app.setStyleSheet("QStatusBar::item { border: 0px solid black }")
     myapp = MyForm()

src/singleton.py

@@ -3,22 +3,26 @@
 import sys
 import os
 import errno
-import tempfile
+import shared
 from multiprocessing import Process
 
-
 class singleinstance:
     """
-    Implements a single instance application by creating a lock file based on the full path to the script file.
+    Implements a single instance application by creating a lock file at appdata.
 
     This is based upon the singleton class from tendo https://github.com/pycontribs/tendo
     which is under the Python Software Foundation License version 2    
     """
-    def __init__(self, flavor_id=""):
+    def __init__(self, flavor_id="", daemon=False):
         import sys
         self.initialized = False
-        basename = os.path.splitext(os.path.abspath(sys.argv[0]))[0].replace("/", "-").replace(":", "").replace("\\", "-") + '-%s' % flavor_id + '.lock'
-        self.lockfile = os.path.normpath(tempfile.gettempdir() + '/' + basename)
+        self.daemon = daemon;
+        self.lockfile = os.path.normpath(os.path.join(shared.appdata, 'singleton%s.lock' % flavor_id))
+
+        if not self.daemon:
+            # Tells the already running (if any) application to get focus.
+            import bitmessageqt
+            bitmessageqt.init()
 
         if sys.platform == 'win32':
             try: