EDIT: There are a number of similar posts on PyQt4 progress bars not updating. They all focus on the issue of threads & where the program actually updates the window. Although helpful, my code was so structured that the replies were not practical. The accepted answer given here is simple, to the point & works.
I am using Python 2.7 and PyQT 4 on a Win 7 x64 machine.
I am trying to clear my window of one widget, an 'Accept' button, see code, and replace it with a progress bar.
Even though I close the 'Accept' button & add the progress bar before the processing loop is entered into. The window is only updated after the loop has finished & the progress bar jumps straight to 100%.
My code,
from PyQt4 import QtCore, QtGui
import sys
import time
class CentralWidget(QtGui.QWidget):
def __init__(self, parent=None):
super(CentralWidget, self).__init__(parent)
# set layouts
self.layout = QtGui.QVBoxLayout(self)
# Poly names
self.pNames = QtGui.QLabel("Import file name", self)
self.polyNameInput = QtGui.QLineEdit(self)
# Polytype selection
self.polyTypeName = QtGui.QLabel("Particle type", self)
polyType = QtGui.QComboBox(self)
polyType.addItem("")
polyType.addItem("Random polyhedra")
polyType.addItem("Spheres")
polyType.addItem("Waterman polyhedra")
polyType.activated[str].connect(self.onActivated)
# Place widgets in layout
self.layout.addWidget(self.pNames)
self.layout.addWidget(self.polyNameInput)
self.layout.addWidget(self.polyTypeName)
self.layout.addWidget(polyType)
self.layout.addStretch()
# Combobox choice
def onActivated(self, text):
if text=="Random polyhedra":
self.randomPolyhedra(text)
if text=="Spheres": # not implementaed yet
self.polyTypeName.setText("Not implemented yet.")
self.polyTypeName.adjustSize()
if text=="Waterman polyhedra": # not implementaed yet
self.polyTypeName.setText("Not implemented yet.")
self.polyTypeName.adjustSize()
# New options for random polyhedra choice
def randomPolyhedra(self, text):
self.polyNumberLbl = QtGui.QLabel("How many: ", self)
self.polyNumber = QtGui.QLineEdit(self)
self.acceptSeed = QtGui.QPushButton('Accept') # Accept button created
self.acceptSeed.clicked.connect(lambda: self.ranPolyGen())
self.layout.addWidget(self.polyNumberLbl)
self.layout.addWidget(self.polyNumber)
self.layout.addWidget(self.acceptSeed) # Accept button in layout
self.randFlag = True
self.polyTypeName.setText(text)
self.polyTypeName.adjustSize()
# Act on option choices for random polyhedra
def ranPolyGen(self):
polyCount = int(self.polyNumber.text())
self.progressBar = QtGui.QProgressBar() # Progress bar created
self.progressBar.setMinimum(1)
self.progressBar.setMaximum(polyCount)
self.acceptSeed.close() # Accept button closed
self.layout.addWidget(self.progressBar) # Add progressbar to layout
for poly in range(1, polyCount+1):
time.sleep(1) # Calls to main polyhedral generating code go here
print poly
self.progressBar.setValue(poly)
self.doneLbl = QtGui.QLabel("Done", self)
self.layout.addWidget(self.doneLbl)
# Creates GUI
class Polyhedra(QtGui.QMainWindow):
def __init__(self):
super(Polyhedra, self).__init__()
# Place central widget in layout
self.central_widget = CentralWidget(self)
self.setCentralWidget(self.central_widget)
# Set up window
self.setGeometry(500, 500, 300, 300)
self.setWindowTitle('Pyticle')
self.show()
# Combo box
def onActivated(self, text):
self.central_widget.onActivated(text)
def main():
app = QtGui.QApplication(sys.argv)
poly = Polyhedra()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
Below is a picture of during loop execution & after completion.
I dont think I have got my head around the addWidget() method. I was under the impression that this would add another widget to the present layout (a vbox layout here) & that the .close() method removed a widget when directed to do so.
What am I missing?
You can add:
Then in your for loop:
Your app is actually becoming unresponsive, you need to call
processEvents()
to process the events and redraw the gui. I am not overly familiar with pyqt but I imagine another alternative is using a thread.