problem in PyQt4 program

[abhijangda]

Hello everyone, I have started creating a Download Manager for Linux using Python with PyQt4 as GUI toolkit and PycURL as library for downloading files. My problem is that whenever I start a download GUI stops. It works in the background and just keeps on downloading but no response from GUI.
Code is Here.

main.py

    from PyQt4 import QtCore,QtGui
    import downloadclass,winaddnew,treeitem
    import sys

    class Downloader(QtGui.QMainWindow):

        def __init__(self,parent=None):

            QtGui.QMainWindow.__init__(self,parent)

            self.setWindowTitle("Download")
            self.setGeometry(10,10,600,400)
         
            self.tablewidget = QtGui.QTableWidget(self)
            self.setCentralWidget(self.tablewidget)
            self.tablewidget.setColumnCount(6)
            self.tablewidget.setHorizontalHeaderLabels(['File Name','Url','Size','Downloaded','Time Remaining','Speed','Status'])
            self.tablewidget.setRowCount(1)
            self.tablewidgetrowitemarray = []
                                                       
            self.tablewidget.horizontalHeader().setClickable(False)
            self.tablewidget.cellClicked.connect(self.cellclicked)

            menubar = self.menuBar()
            newdownload = QtGui.QAction("Create a new download",self)
            start = QtGui.QAction("Start",self)
            stop = QtGui.QAction("Stop",self)
            pauseresume = QtGui.QAction("Pause/Resume",self)
            startall = QtGui.QAction("Start All",self)
            stopall = QtGui.QAction("Stop All",self)
            pauseresumeall = QtGui.QAction("Pause/Resume All",self)
            restart = QtGui.QAction("Restart Download",self)
           
            downloadmenu = menubar.addMenu("Download")
            downloadmenu.addAction(newdownload)
            downloadmenu.addAction(start)
            downloadmenu.addAction(stop)
            downloadmenu.addAction(pauseresume)
            downloadmenu.addAction(startall)
            downloadmenu.addAction(stopall)
            downloadmenu.addAction(pauseresumeall)
            downloadmenu.addAction(restart)

            self.addwin = winaddnew.addnewwin()
           
            self.url = ''
            self.path = ''
            self.filename = ''
            self.rowselected = 0
           
            self.downloaditem = treeitem.downloaditem
            self.dwlclass = downloadclass.downloadfile
            self.downloaditemarray = []
           
            self.connect(newdownload,QtCore.SIGNAL('triggered()'),self.funcshowaddwin)
            self.connect(start,QtCore.SIGNAL('triggered()'),self.funcstart)
               
            self.Timer = QtCore.QTimer(self)
            self.Timer.setInterval(200)
            self.connect(self.Timer, QtCore.SIGNAL('timeout()'),self.functimer)
           
        def cellclicked(self,row,col):

            self.tablewidget.selectRow(row)
            self.rowselected = row

        def funcshowaddwin(self):

            self.Timer.start()
            self.addwin.show()
       
        def functimer(self):

            self.url,self.path = self.addwin.funcpass()
            if self.url != '':
                if self.path !='':
                    self.Timer.stop()
                    self.adddownload()

        def adddownload(self):

            self.downloaditemarray.append(self.downloaditem(self.getfilename(self.url),self.url,0,'Downloading'))
            self.createrow(self.downloaditemarray[len(self.downloaditemarray)-1])

        def createrow(self,downloaditem):

            for i in range(0,6):
                self.tablewidgetrowitemarray.append(QtGui.QTableWidgetItem(0))
                self.tablewidgetrowitemarray[i].setFlags(QtCore.Qt.ItemIsSelectable)
                self.tablewidget.setItem(0,i,self.tablewidgetrowitemarray[i])

            self.tablewidgetrowitemarray[0].setText(downloaditem.filename)
            self.tablewidgetrowitemarray[1].setText(downloaditem.url)
            self.tablewidgetrowitemarray[2].setText(str(downloaditem.size))
            self.tablewidgetrowitemarray[3].setText("")
            self.tablewidgetrowitemarray[4].setText("")
            self.tablewidgetrowitemarray[5].setText("")
            #self.tablewidgetrowitemarray[6].setText(downloaditem.status)
           
        def getfilename(self,url):

            lst = url.split('/')
            return lst[len(lst)-1]

        def funcstart(self):

            d = self.dwlclass(self.path,str(self.tablewidget.item(self.rowselected,1).text()),self.tablewidget.item(self.rowselected,2).text())
            self.tablewidgetrowitemarray[2].setText(str(d.size))
            d.start()
           
           
    app = QtGui.QApplication(sys.argv)
    d = Downloader()
    d.show()
    app.exec_()

downloadclass.py

    import pycurl,os

    class downloadfile(object):

        def __init__(self,path,url,downloaded):

            self.url = url
            self.path = path
            self.downloaded = downloaded
            self.size = 0
            self.bytesdownloaded = 0
            self.initial = 0
            self.final = 0
           
            self.curl = pycurl.Curl()
            self.curl.setopt(pycurl.URL,self.url)
                   
        def progress(self,download_t,download_d,upload_t,upload_d):

            self.initial = download_d
            self.size = download_t
            self.bytesdownloaded = download_d
            self.speed = self.final - self.initial
            self.final = download_d
           
        def start(self):
           
            f = open(self.path,"wb")
            self.curl.setopt(pycurl.WRITEDATA,f)
            self.curl.setopt(pycurl.NOPROGRESS,0)
            self.curl.setopt(pycurl.PROGRESSFUNCTION,self.progress)
            self.curl.perform()

        def resume(self):

            f = open(self.path,"ab")
            self.curl.setopt(pycurl.RESUME_FROM,os.path.getsize(self.path))
            self.curl.setopt(self.pycurl.WRITEDATA,f)
            self.curl.setopt(pycurl.NOPROGRESS,0)
            self.curl.setopt(pycurl.PROGRESSFUNCTION,self.progress)
            self.curl.perform()

Can anyone solve my problem or atleast give me a hint??

[QwertyManiac]

You're downloading within the application's thread. That would block it, naturally.

Try threading out your downloader operations as a solution, making it report some progress only when required. It would be a good exercise to add to your skill-building.

[abhijangda]

Thanks for reply, are you talking about threads in python??

[QwertyManiac]

Yes, you should be able to use Python's own threads over QThreads. However, the latter supports the whole signals-and-slots concept, if you swing that way.

[gk2k]

You should use threading. I do not know about Python threads, but QThread can do the job very well for you.

[abhijangda]

thanks for reply!!