Model/View mapping to dynamically-generated widgets?

[Alabaster]

Hello,

The model/view concept is fairly new to me and I'm trying to understand it. Most of the examples I can find online involve the QListView, QTableView, QTreeView, etc., but for my application I would prefer to map to labels & buttons. The labels & buttons are dynamically generated so there is no fixed layout.

From some initial research it looks like I need to work with QDataWidgetMapper, but I'm having trouble finding helpful examples.

Below is an example of some of the convoluted steps I often take (without model/view approach). My impression is that a model/view approach will greatly simplify this.

If someone could either a.) point me in the direction of some clear examples/tutorials for mapping model data to (non Q?View) widgets, and/or b.) give me some suggestions for re-writing the code below in a model/view paradigm, I wouild appreciate it.

Thanks

@from PySide.QtGui import *
from PySide.QtCore import *
from random import choice
import sys

class MainWindow(QMainWindow):
def init(self, thingList):
super(MainWindow, self).init()
self.initUI(thingList)

def initUI(self, thingList):
    cw = centralWidget(thingList)
    self.setCentralWidget(cw)
    self.setWindowTitle("How can I do the same with model/view (& QDataWidgetMapper?)")
    self.show()

class centralWidget(QWidget):
def init(self, thingList):
super(centralWidget, self).init()
self.initUI()
self.thingList = thingList

def initUI(self):
    self.vbox = QVBoxLayout()
    self.actionLabel = QLabel("No Buttons have been Clicked")
    self.vbox.addWidget(self.actionLabel)

    self.g = QGridLayout()

    col=0
    row=0
    columnBreak = len(thingList) / 2
    for index, thing in enumerate(thingList):
        newHBox = QHBoxLayout()


        newLabel = thing[4]

        newHBox.addWidget(newLabel)
        for button in thing[2]:
            newHBox.addWidget(button)
            button.clicked.connect(self.somethingChanged)

        newComboBox = thing[3]
        newComboBox.currentIndexChanged.connect(self.somethingChanged)
        newHBox.addWidget(newComboBox)
        newHBox.addStretch(1)
        self.g.addLayout(newHBox, row, col)
        row += 1
        if row >= columnBreak:
            row = 0
            col += 1

    self.setMinimumWidth(500)
    self.vbox.addLayout(self.g)
    self.setLayout(self.vbox)
    self.show()
    
###########################################
# Needlessly complicated series of methods
# used for translating user input into 
# property changes of "thing."
# I assume that model/view will simplify this?
############################################

def changeValue(self, sender, thing, index):
    bools = thing[1]
    comboBox = thing[3]
    thingLabel = thing[4]
    originalThingName = thing[5]

    if comboBox.currentText() == "":
        thingName = originalThingName
    else:
        thingName = "{0}_{1}".format(thing[0], comboBox.currentText().replace(" ", ""))

    thingLabel.setText(thingName)


    if type(sender) == QPushButton:
        if sender.isChecked():
            bools[index] = True
        else:
            bools[index] = False

    message = "{0}: New Values: {1} - {2} - {3} - {4}.  New Name: {5}".format(thing[0], bools[0], bools[1], bools[2], bools[3], thingName)
    self.actionLabel.setText(message)
    newData = [thingName, [bools[0], bools[1], bools[2], bools[3]], originalThingName]
    self.setThingValues(newData)


def findSenderThing(self, sender):
    for thing in self.thingList:
        if sender == thing[3]:
            index = None
            return thing, index
        if sender in thing[2]:
            index = thing[2].index(sender)
            return thing, index


def setThingValues(self, newData):
    print("\n\nADJUSTED THINGLIST:\n")
    for thing in thingList:
        newThingName = newData[0]
        newBoolsList = newData[1]
        originalThingName = newData[2]

        if thing[5] == originalThingName:
            thing[0] = newThingName
            thing[1] = newBoolsList

        print("\t{0}\t{1}\t(Originally: {2})".format(thing[0], thing[1], thing[5]))


def somethingChanged(self):
    sender = self.sender()
    thing, index = self.findSenderThing(sender)
    self.changeValue(sender, thing, index)

def generateDummyData():
rnd = choice(range(15, 40))
thingList = []

for x in range(rnd):
    thingName = "Thing {0}".format(str(x))
    originalThingName = thingName

    newLabel = QLabel(thingName)
    newLabel.setFixedWidth(80)

    boolList = []
    buttonList = []
    while len(boolList) < 4:
        randBool = choice([True, False])
        boolList.append(randBool)
        newButton = QPushButton(str(len(boolList)))
        newButton.setCheckable(True)
        newButton.setFixedSize(20,20)
        buttonList.append(newButton)

        newComboBox = QComboBox()
        newComboBox.addItems(['', 'ABC', 'DEF', 'GHI', ' OCD', 'MNO'])

    newThing = [thingName, boolList, buttonList, newComboBox, newLabel, originalThingName]
    for bool in boolList:
        if bool:
            buttonList[boolList.index(bool)].setChecked(True)
    thingList.append(newThing)
return thingList

if name == 'main':
app = QApplication(sys.argv)
thingList = generateDummyData()
win = MainWindow(thingList)
sys.exit(app.exec_())@

[dheerendra]

It is not completely clear on what is required here. Do you want to use your own widgets to display the data present in model ? If that is the case, please try to use the Delegates for this. You need to write custom delegates for this. I'm not familiar with pyqt. I have examples to share using Qt C++ for custom delegates.

[Alabaster]

Thanks for your response. To clarify my question:

Basically I'm looking to make the jump into the model/view paradigm, but the only useful information I can find is on using QListView, QTableView, and QTreeView. None of which exactly fit my needs (I'm looking to create more of a button/combobox GUI).

My research has pointed me in the direction of QDataWidgetMapper but any information I've found has been over my head, and I wondered if someone could explain, show some examples, or point me in the direction of some decent tutorials.

The sample code I provided is an example of how I often find myself doing things (sans model/view) -- which, I believe, is convoluted and error-prone. I suspect that I could eliminate a lot of my "middle-man" methods/functions if I used a model/view approach. I figure someone who knows what they're doing might be able to suggest how I could accomplish the same (in fewer lines of code) .

Thanks

[dheerendra]

ok. My suggestion is not get into ModelView directly. If your intent is to create simple UI with button and combo box, just create the UI using buttons/combobox and layouts. This will help you.

[Alabaster]

That is what I have been doing so far, but my code seems very inefficient. Notice all of the methods of my centralWidget class. (My actual application is much more complex than the example I posted).

Is there any way to set "thingList" as a model and map each item's True/False values directly to the buttons?

I think your first response (to use custom delegates) may be what I'm looking for but I don't understand it -- can you point me in the direction of some simple examples?

[SGaist]

Hi,

Search for "Simple Widget Mapper Example" in Qt's documentation. It should give you the basics to start your code the right way.

Hope it helps