title: Opening a dialog from QMainWindow
body: <p>I have a problem with opening a small dialog window when I press a button from my MainWindow. I know how to make a window that I need to open (let's call it EDIT WINDOW), but calling (opening) it from Main form, and another module is a different story.</p>
  
  <p>Main window is showing, and working. All the imports are fine, with sqlite connection working. Basically, program is finished, only this dialog remains... It should have QMainWindow as it parent.</p>
  
  <pre><code>#!/usr/bin/python
  #encoding=utf8
  import sys
  from PyQt4 import QtCore, QtGui
  from gui import Ui_glavni
  from dialog import Ui_Dialog
  import snimanje #imported modules
  import clear
  import pretraga
  import izmena #this should represent module with custom made dialog.
  
  
  class Prozor(snimanje.Snimi, clear.Brisanje, pretraga.Pretraga,QtGui.QMainWindow):
      def __init__(self,parent=None):
          QtGui.QWidget.__init__(self,parent)
          self.ui=Ui_glavni()
          self.ui.setupUi(self)
          QtCore.QObject.connect(self.ui.dugmeSnimi, QtCore.SIGNAL("clicked()"), self.snimi)
          QtCore.QObject.connect(self.ui.dugmeOtkazi, QtCore.SIGNAL("clicked()"), self.brisanjeUnos)
          QtCore.QObject.connect(self.ui.dugmeOtkazi2, QtCore.SIGNAL("clicked()"), self.brisanjeListanje)
          QtCore.QObject.connect(self.ui.dugmeTrazi, QtCore.SIGNAL("clicked()"), self.pretraga)
          QtCore.QObject.connect(self.ui.checkJedinica, QtCore.SIGNAL("stateChanged(int)"), self.aktivJedinica)
          QtCore.QObject.connect(self.ui.checkVrednost, QtCore.SIGNAL("stateChanged(int)"), self.aktivVrednost)
          QtCore.QObject.connect(self.ui.menjaIme, QtCore.SIGNAL("clicked()"), izmena.dijalog)
          QtCore.QObject.connect(self.ui.dugmeBrisi, QtCore.SIGNAL("clicked()"), self.brisanjeIzBaze)
  #SREDI IZMENU. SREDI PROVERU UNETIH U BAZU PO BROJU PREDMETA
  
  
          def startup():
              self.brisanjeUnos()
              self.brisanjeListanje()
              self.provera()
  
          startup()
  
      def aktivJedinica(self):
          self.ui.lineJedinica.setEnabled(False)
          self.ui.lineJedinica.setText("")
          self.ui.checkJedinica.checkStateSet()
          if self.ui.checkJedinica.isChecked():
              self.ui.lineJedinica.setEnabled(True)
              #self.ui.checkJedinica.setEnabled(False)
  
      def aktivVrednost(self):
          self.ui.vrednost.setEnabled(False)
          self.ui.vrednost.setText("")
          if self.ui.checkVrednost.isChecked():
              self.ui.vrednost.setEnabled(True)
  
      def pretraga(self):
          if self.ui.radioIme.isChecked():
              self.pretragaIme()
          elif self.ui.radioBrPr.isChecked():
              self.pretragaBrPr()
          else:
              self.pretragaSudski()
  
  
  
  if __name__=="__main__":
      program = QtGui.QApplication(sys.argv)
      mojprogram = Prozor()
      mojprogram.show()
      sys.exit(program.exec_())
  </code></pre>