panofish panofish - 5 months ago 30
Python Question

Python PyQt4 functions to save and restore UI widget values?

Before I attempt to write my own Python PyQt4 module functions... I wanted to ask if anyone has such a function to share.

In many of my python programs where I have a GUI built using PyQt4 and qtDesigner, I use the QSettings method to save and restore UI states and values of all widgets during close and startup.

This example shows how I save and restore some lineEdit, checkBox, and radioButton fields.

Does anyone have a function that can traverse the UI and find ALL widgets/controls and their states and save them (e.g. guisave()) and another function that can restore them (e.g. guirestore())?

My closeEvent looks something like this:

#---------------------------------------------
# close by x OR call to self.close
#---------------------------------------------

def closeEvent(self, event): # user clicked the x or pressed alt-F4...

UI_VERSION = 1 # increment this whenever the UI changes significantly

programname = os.path.basename(__file__)
programbase, ext = os.path.splitext(programname) # extract basename and ext from filename
settings = QtCore.QSettings("company", programbase)
settings.setValue("geometry", self.saveGeometry()) # save window geometry
settings.setValue("state", self.saveState(UI_VERSION)) # save settings (UI_VERSION is a constant you should increment when your UI changes significantly to prevent attempts to restore an invalid state.)

# save ui values, so they can be restored next time
settings.setValue("lineEditUser", self.lineEditUser.text());
settings.setValue("lineEditPass", self.lineEditPass.text());

settings.setValue("checkBoxReplace", self.checkBoxReplace.checkState());
settings.setValue("checkBoxFirst", self.checkBoxFirst.checkState());

settings.setValue("radioButton1", self.radioButton1.isChecked());

sys.exit() # prevents second call


My MainWindow init looks something like this:

def __init__(self, parent = None):
# initialization of the superclass
super(QtDesignerMainWindow, self).__init__(parent)
# setup the GUI --> function generated by pyuic4
self.setupUi(self)

#---------------------------------------------
# restore gui position and restore fields
#---------------------------------------------

UI_VERSION = 1

settings = QtCore.QSettings("company", programbase) # http://pyqt.sourceforge.net/Docs/PyQt4/pyqt_qsettings.html

self.restoreGeometry(settings.value("geometry"))
self.restoreState(settings.value("state"),UI_VERSION)

self.lineEditUser.setText(str(settings.value("lineEditUser"))) # restore lineEditFile
self.lineEditPass.setText(str(settings.value("lineEditPass"))) # restore lineEditFile

if settings.value("checkBoxReplace") != None:
self.checkBoxReplace.setCheckState(settings.value("checkBoxReplace")) # restore checkbox
if settings.value("checkBoxFirst") != None:
self.checkBoxFirst.setCheckState(settings.value("checkBoxFirst")) # restore checkbox

value = settings.value("radioButton1").toBool()
self.ui.radioButton1.setChecked(value)

Answer

OK, I wrote a module with 2 functions to do what I was asking for. Not really that complicated, once I figured it out, but it sure does save a lot of time whenever you create new pyqt gui programs where you want to save widget field values between sessions. I currently only have lineEdit, checkBox and combobox fields coded. If anyone else wants to add or improve (e.g. radio buttons...etc) ... I'm sure others, including myself, will appreciate it.

#===================================================================
# Module with functions to save & restore qt widget values
# Written by: Alan Lilly 
# Website: http://panofish.net
#===================================================================

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
import inspect

#===================================================================
# save "ui" controls and values to registry "setting"
# currently only handles comboboxes editlines & checkboxes
# ui = qmainwindow object
# settings = qsettings object
#===================================================================

def guisave(ui, settings):

    #for child in ui.children():  # works like getmembers, but because it traverses the hierarachy, you would have to call guisave recursively to traverse down the tree

    for name, obj in inspect.getmembers(ui):
        #if type(obj) is QComboBox:  # this works similar to isinstance, but missed some field... not sure why?
        if isinstance(obj, QComboBox):
            name   = obj.objectName()      # get combobox name
            index  = obj.currentIndex()    # get current index from combobox
            text   = obj.itemText(index)   # get the text for current index
            settings.setValue(name, text)   # save combobox selection to registry

        if isinstance(obj, QLineEdit):
            name = obj.objectName()
            value = obj.text()
            settings.setValue(name, value)    # save ui values, so they can be restored next time

        if isinstance(obj, QCheckBox):
            name = obj.objectName()
            state = obj.checkState()
            settings.setValue(name, state)

#===================================================================
# restore "ui" controls with values stored in registry "settings"
# currently only handles comboboxes, editlines &checkboxes
# ui = QMainWindow object
# settings = QSettings object
#===================================================================

def guirestore(ui, settings):

    for name, obj in inspect.getmembers(ui):
        if isinstance(obj, QComboBox):
            index  = obj.currentIndex()    # get current region from combobox
            #text   = obj.itemText(index)   # get the text for new selected index
            name   = obj.objectName()

            value = unicode(settings.value(name))  

            if value == "":
                continue

            index = obj.findText(value)   # get the corresponding index for specified string in combobox

            if index == -1:  # add to list if not found
                obj.insertItems(0,[value])
                index = obj.findText(value)
                obj.setCurrentIndex(index)
            else:
                obj.setCurrentIndex(index)   # preselect a combobox value by index    

        if isinstance(obj, QLineEdit):
            name = obj.objectName()
            value = unicode(settings.value(name))  # get stored value from registry
            obj.setText(value)  # restore lineEditFile

        if isinstance(obj, QCheckBox):
            name = obj.objectName()
            value = settings.value(name)   # get stored value from registry
            if value != None:
                obj.setCheckState(value)   # restore checkbox

        #if isinstance(obj, QRadioButton):                

################################################################

if __name__ == "__main__":

    # execute when run directly, but not when called as a module.
    # therefore this section allows for testing this module!

    #print "running directly, not as a module!"

    sys.exit()