Is it possible to set only 100 Percent value share limit to all QDoubleSpinBoxes?

Question

I want to share 100 percent value limit to all QDoubleSpinBoxes. If it is possible how to do?

    self.SpinBox_one = QtWidgets.QDoubleSpinBox()
    self.SpinBox_two = QtWidgets.QDoubleSpinBox()
    self.SpinBox_three = QtWidgets.QDoubleSpinBox()
    self.SpinBox_four = QtWidgets.QDoubleSpinBox()
    self.SpinBox_five = QtWidgets.QDoubleSpinBox()

for example i have 5 QDoubleSpinBoxes as above. If i insert 30 in self.SpinBox_one, Remaining is 70, then 70 only should be useful for remaining 4 QDoubleSpinBoxes. And again if i insert 50 in self.SpinBox_two, Remaining should be 20, and it should be useful to remaining QDoubleSpinBoxes. and again if i insert 20 in self.SpinBox_three, remaining is 0. And now remaining QDoubleSpinBoxes are should be 0. Below is my example code:

from PyQt5 import QtWidgets
from PyQt5 import QtCore

class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.SpinBox_one = QtWidgets.QDoubleSpinBox()
        self.SpinBox_two = QtWidgets.QDoubleSpinBox()
        self.SpinBox_three = QtWidgets.QDoubleSpinBox()
        self.SpinBox_four = QtWidgets.QDoubleSpinBox()
        self.SpinBox_five = QtWidgets.QDoubleSpinBox()

        form_widget = QtWidgets.QWidget()
        form_layout = QtWidgets.QFormLayout(form_widget)
        form_layout.addRow("1", self.SpinBox_one)
        form_layout.addRow("2", self.SpinBox_two)
        form_layout.addRow("3", self.SpinBox_three)
        form_layout.addRow("4", self.SpinBox_four)
        form_layout.addRow("5", self.SpinBox_five)

        form_widget.setFixedSize(form_widget.sizeHint())
        central_widget = QtWidgets.QWidget()
        self.setCentralWidget(central_widget)
        hlay1 = QtWidgets.QHBoxLayout()
        hlay1.addWidget(form_widget)
        hlay1.addStretch()

        vboxlayout = QtWidgets.QVBoxLayout(central_widget)
        vboxlayout.addLayout(hlay1)
        self.resize(50, 50)

        ##
        self.SpinBox_one.setMaximum(100.00)
        #self.SpinBox_two.setMaximum(100.00)
        #self.SpinBox_three.setMaximum(100.00)
        #self.SpinBox_four.setMaximum(100.00)
        #self.SpinBox_five.setMaximum(100.00)

        self.SpinBox_one.valueChanged.connect(self.SpinBox_one_changed)
        self.SpinBox_two.valueChanged.connect(self.SpinBox_two_changed)
        self.SpinBox_three.valueChanged.connect(self.SpinBox_three_changed)
        self.SpinBox_four.valueChanged.connect(self.SpinBox_four_changed)
    def SpinBox_one_changed(self):
         self.SpinBox_two.setMaximum(100 - self.SpinBox_one.value())

    def SpinBox_two_changed(self):
         self.SpinBox_three.setMaximum(100-self.SpinBox_one.value() - self.SpinBox_two.value())
         
    def SpinBox_three_changed(self):
         self.SpinBox_four.setMaximum(100-self.SpinBox_one.value() - self.SpinBox_two.value() - self.SpinBox_three.value())

    def SpinBox_four_changed(self):
         self.SpinBox_five.setMaximum(100-self.SpinBox_one.value() - self.SpinBox_two.value() - self.SpinBox_three.value() - self.SpinBox_four.value())

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    sys.exit(app.exec_())

It is working up to fourth but fifth is not working as expect.

alec · Accepted Answer · 2021-04-02T07:20:49.573

It is simpler to operate on a list of spin boxes rather than keep a separate name for each one. Each QDoubleSpinBox's valueChanged signal is connected to the function limit() that limits the maximum values of the remaining boxes. First count the total value up to the spin box that was just changed. Then for the spin boxes after it, set their maximum value to the remaining amount out of 100 and increment the running total.

class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)

        form_widget = QtWidgets.QWidget()
        form_layout = QtWidgets.QFormLayout(form_widget)

        self.boxes = []
        for i in range(5):
            box = QtWidgets.QDoubleSpinBox(maximum=100, valueChanged=self.limit)
            form_layout.addRow(str(i + 1), box)
            self.boxes.append(box)

        form_widget.setFixedSize(form_widget.sizeHint())
        central_widget = QtWidgets.QWidget()
        self.setCentralWidget(central_widget)
        hlay1 = QtWidgets.QHBoxLayout()
        hlay1.addWidget(form_widget)
        hlay1.addStretch()

        vboxlayout = QtWidgets.QVBoxLayout(central_widget)
        vboxlayout.addLayout(hlay1)
        self.resize(50, 50)

    def limit(self, value):
        i = self.boxes.index(self.sender())
        total = value + sum(box.value() for box in self.boxes[:i])
        for box in self.boxes[i + 1:]:
            box.blockSignals(True) # Avoid extra calls to limit()
            box.setMaximum(100 - total)
            box.blockSignals(False)
            total += box.value()

Edit, keeping the original __init__ code:

class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.SpinBox_one = QtWidgets.QDoubleSpinBox()
        self.SpinBox_two = QtWidgets.QDoubleSpinBox()
        self.SpinBox_three = QtWidgets.QDoubleSpinBox()
        self.SpinBox_four = QtWidgets.QDoubleSpinBox()
        self.SpinBox_five = QtWidgets.QDoubleSpinBox()

        form_widget = QtWidgets.QWidget()
        form_layout = QtWidgets.QFormLayout(form_widget)
        form_layout.addRow("1", self.SpinBox_one)
        form_layout.addRow("2", self.SpinBox_two)
        form_layout.addRow("3", self.SpinBox_three)
        form_layout.addRow("4", self.SpinBox_four)
        form_layout.addRow("5", self.SpinBox_five)
        
        form_widget.setFixedSize(form_widget.sizeHint())
        central_widget = QtWidgets.QWidget()
        self.setCentralWidget(central_widget)
        hlay1 = QtWidgets.QHBoxLayout()
        hlay1.addWidget(form_widget)
        hlay1.addStretch()

        vboxlayout = QtWidgets.QVBoxLayout(central_widget)
        vboxlayout.addLayout(hlay1)
        self.resize(50, 50)

        ##
        self.SpinBox_one.setMaximum(100.00)
        #self.SpinBox_two.setMaximum(100.00)
        #self.SpinBox_three.setMaximum(100.00)
        #self.SpinBox_four.setMaximum(100.00)
        #self.SpinBox_five.setMaximum(100.00)

        self.SpinBox_one.valueChanged.connect(self.limit)
        self.SpinBox_two.valueChanged.connect(self.limit)
        self.SpinBox_three.valueChanged.connect(self.limit)
        self.SpinBox_four.valueChanged.connect(self.limit)
        
        self.boxes = [self.SpinBox_one, self.SpinBox_two, self.SpinBox_three, self.SpinBox_four, self.SpinBox_five]

Thank you for your answer. And is it possible to specify separate names to five QDoubleSpinBoxes as per my example code. Because i need to use them for other purposes also. — user3030327, Apr 02 '21 at 05:55
@user3030327 Yes of course it's possible, I've added that in. — alec, Apr 02 '21 at 06:04
Actually i created as self.SpinBox_one = QtWidgets.QDoubleSpinBox() self.SpinBox_two = QtWidgets.QDoubleSpinBox() self.SpinBox_three = QtWidgets.QDoubleSpinBox() self.SpinBox_four = QtWidgets.QDoubleSpinBox() self.SpinBox_five = QtWidgets.QDoubleSpinBox() And i did not use range for create boxes. Can you please create as per my example. — user3030327, Apr 02 '21 at 06:23
@user3030327 creating instance attributes like that is discouraged, as relying on "spoken language" to set attributes is really not a good practice. I'm under the impression that you're trying to solve an [XY problem](https://meta.stackexchange.com/questions/66377/what-is-the-xy-problem), as trying to access objects using the "written" index is certainly not a good idea. Access to indexed objects should always be done through *integer* based indexing (`self.spinBox_1`, ...) or through data models; any other way will most certainly lead to issues and is usually due to simple *bad* practice. — musicamante, Apr 02 '21 at 06:34
@alec I mean if i do like this - `self.boxes = [self.SpinBox_one, self.SpinBox_two, self.SpinBox_three, self.SpinBox_four, self.SpinBox_five]` and is it possible to call these boxes and set maximum value(100) and valueChanged=self.limit — user3030327, Apr 02 '21 at 06:50
@musicamante I mean if i do like this - self.boxes = [self.SpinBox_one, self.SpinBox_two, self.SpinBox_three, self.SpinBox_four, self.SpinBox_five] and is it possible to call these boxes and set maximum value(100) and valueChanged=self.limit — user3030327, Apr 02 '21 at 07:10

Is it possible to set only 100 Percent value share limit to all QDoubleSpinBoxes?

1 Answers1