#---------------------------------------------------------------------
# 
# Threading - A QGIS plugin to show an example of running code in 
#             a thread from QGIS
#
# Copyright (C) 2009  Aaron Racicot
#
# EMAIL: aaronr (at) z-pulley.com
# WEB  : www.reprojected.com
#
#---------------------------------------------------------------------
# 
# licensed under the terms of GNU GPL 2
# 
# This program 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 of the License, or
# (at your option) any later version.
# 
# This program 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 this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
# 
#---------------------------------------------------------------------

from PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.core import *
from qgis.gui import *

import resources
from threading_gui import Ui_Dialog

import os
import time

class TestThread(QThread):
    def __init__(self, parentThread,parentObject):
        QThread.__init__(self, parentThread)
        self.parent = parentObject
        self.running = False
        self.total = 0
        self.currentCount = 0

    def loop(self):
        for i in xrange(0,10,1):
            self.emit(SIGNAL("runStatus(PyQt_PyObject)"),i)
            time.sleep(1)
            if self.running == False:
                print "(Printed from thread) Stop requested from QGIS"
                return False
        return True

    def run(self):
        self.running = True
        while (True):
            if not self.loop():
                break
        self.emit(SIGNAL("runFinished(PyQt_PyObject)"),"Pass")

    def stop(self):
        self.running = False
        
    def getUpdate(self):
        return self.currentCount
            
class ThreadingPlugin(QObject):
    def __init__(self, iface):
        QObject.__init__(self)
        # Save a reference to the QGIS iface
        self.iface = iface
        self.canvas = iface.mapCanvas()
    
    def initGui(self):
        # Create action
        self.action = QAction(QIcon(":/threading.png"),
                              "Threading Example", self.iface.mainWindow())
        self.action.setWhatsThis("Threading Example")
        QObject.connect(self.action, SIGNAL("activated()"), self.run)
        self.helpaction = QAction(QIcon(":/threadinghelp.png"),
                                  "About", self.iface.mainWindow())
        self.helpaction.setWhatsThis("Threading Example Help")
        QObject.connect(self.helpaction, SIGNAL("activated()"), self.helprun)
        
        # Add to the main toolbar
        self.iface.addToolBarIcon(self.action)
        self.iface.addPluginToMenu("&Threading", self.action)
        self.iface.addPluginToMenu("&Threading", self.helpaction)
        
    def unload(self):
        # Remove the plugin
        self.iface.removePluginMenu("&Threading",self.action)
        self.iface.removePluginMenu("&Threading",self.helpaction)
        self.iface.removeToolBarIcon(self.action)
    
    def helprun(self):
        # print "Help pressed..."
        infoString = QString("Written by Aaron Racicot\naaronr@z-pulley.com\n")
        infoString = infoString.append("Company - http://www.z-pulley.com\n\n")
        infoString = infoString.append("Blog - http://www.reprojected.com\n\n")
        infoString = infoString.append("Source: http://svn.reprojected.com/")
        infoString = infoString.append("qgisplugins/trunk/threading_demo\n")
        infoString = infoString.append("TRAC: http://trac.reprojected.com/")
        infoString = infoString.append("qgisplugins\n")
        QMessageBox.information(self.iface.mainWindow(),
                                "Threading Plugin About",infoString)
        
    def run(self):
        print "Run Pressed"
        flags = Qt.WindowTitleHint | Qt.WindowSystemMenuHint | Qt.WindowMaximizeButtonHint 
        self.gui = ThreadingGui(self.iface,flags)
        self.gui.show()

    def finished(self,xy):
        pass

class ThreadingGui(QDialog, Ui_Dialog):
    def __init__(self, iface, fl):
        QDialog.__init__(self, iface.mainWindow(), fl)
        self.iface = iface
        self.setupUi(self)
        self.progressBar.setRange(0,10)
        self.progressBar.setValue(0)
        self.running = False
        self.runThread = None
        
    def on_btnCancel_released(self):
        print "Shutting down thread - ", self.runThread
        if self.runThread:
            self.runThread.stop()
        self.running = False
        self.close()
        
    def on_pushButton_released(self):
        if self.running == True:
            print "Shutting down thread - ", self.runThread
            self.running = False
            # Stop everything
            self.runThread.stop()
            self.pushButton.setText(QString("Start"))
            self.progressBar.setValue(0)
        else:
            self.running = True
            self.pushButton.setText(QString("Stop"))
            # Start it up...
            self.runThread = TestThread(self.iface.mainWindow(),self)
            print "Starting up thread - ", self.runThread
            
            # Use this signal from the thread to indicate the thread exited
            QObject.connect(self.runThread, SIGNAL("runFinished(PyQt_PyObject)"),
                            self.runFinishedFromThread)
            QObject.connect(self.runThread, SIGNAL("runStatus(PyQt_PyObject)"),
                            self.runStatusFromThread)
            QObject.connect(self.runThread, SIGNAL("runError(PyQt_PyObject)"),
                            self.runErrorFromThread)
            self.runThread.start()
            
            # Testing code
            #print "Current priority is - ", self.thread().priority()
            #print "Current thread priority is - ", self.runThread.priority()
            #print "Current mainwindow priority is - ", self.iface.getMainWindow().thread().priority()

            print "Starting up a timer to let the thread run"
            self.timer = QTimer()
            QObject.connect(self.timer, SIGNAL("timeout()"),
                            self.runStatus)
            self.timer.start(10)

    def runStatus(self):
        # print "runStatus recieved"
        self.runThread.msleep(1)
    
    def runFinishedFromThread(self,success):
        # print "Thread Finished with success = ", success
        self.timer.stop()

    def runStatusFromThread(self,statusMessage):
        # Fill in the updates to the progress bar and number display
        self.progressBar.setValue(statusMessage)
        
    def runErrorFromThread(self,errorMessage):
        print "Error recieved from thread = ", errorMessage