#!/usr/bin/env python
from PyQt4.QtCore import *
from PyQt4.QtGui import *
import psycopg2
 
class ListWidgetTest(QDialog):
    def __init__(self, parent=None):
     super(ListWidgetTest, self).__init__(parent)

     self.listWidget = QListWidget()
     self.button= QPushButton()
     self.checkBox = QCheckBox()
     self.checkBox.setChecked(False)
     layout = QVBoxLayout()
     layout.addWidget(self.listWidget)
     layout.addWidget(self.button)
     layout.addWidget(self.checkBox)
     self.setLayout(layout)
     self._list = []
     self.booolean= False

     self.listWidget.itemClicked.connect(self.on_list_selected)
     self.button.clicked.connect(self.on_button_clicked)
     self.checkBox.stateChanged.connect(self.on_all_selected)
   
     try:
            conn = psycopg2.connect("dbname='qgis_db' user='postgres' host='localhost' password='postgresql'")
     except Exception as e:
            print "I am unable to connect to the database", e
     cur = conn.cursor()
     conn.set_isolation_level(0)
     try:
        cur.execute("select  pt_projname from point group by pt_projname")
     except psycopg2.ProgrammingError as e:
        print e
     self.project =cur.fetchall()
     self.item = QListWidgetItem()
     proj=['2','3','4']
     #cur.execute("insert into  point (pt_projname)values ('TEST')")
     for i in self.project:
         self.item = QListWidgetItem((i[0]))
         self.item.setFlags(Qt.ItemIsUserCheckable | Qt.ItemIsEnabled)
         self.item.setCheckState(Qt.Unchecked)
         self.item.setSelected(True)          
         self.listWidget.insertItem(0,self.item)

    def on_list_selected(self,item):
        if item.checkState() == Qt.Checked:
            print('"%s" Checked' % item.text())
            self._list.append(item.text())
            
    def on_button_clicked(self,item):
        print self._list
            
    def on_all_selected(self,state):       
        self.boolean= (state == Qt.Checked)
        if self.boolean == True:
            for i in self.project:
                 item = self.listWidget.takeItem(self.listWidget.currentRow())
                 self.item = QListWidgetItem((i[0]))
                 self.item.setFlags(Qt.ItemIsUserCheckable | Qt.ItemIsEnabled)
                 self.item.setCheckState(Qt.Checked)
                 self.item.setSelected(False)          
                 self.listWidget.insertItem(0,self.item)
                 self._list.append(item.text())
        else :
            for i in self.project:
                 item = self.listWidget.takeItem(self.listWidget.currentRow())
                 self.item = QListWidgetItem((i[0]))
                 self.item.setFlags(Qt.ItemIsUserCheckable | Qt.ItemIsEnabled)
                 self.item.setCheckState(Qt.Unchecked)
                 self.item.setSelected(True)          
                 self.listWidget.insertItem(0,self.item)
                 self._list.remove(item.text())
            
 
if __name__ == "__main__":
 import sys
 app = QApplication(sys.argv)
 dialog = ListWidgetTest()
 dialog.show()
 app.exec_()