PyQt5 StringSpinBox - Looping the strings - GeeksforGeeks

17 May, 2020
In this article we will see how we can make the string values repeat themselves when the last value reaches it should go back to the first value similarly when value is decremented after first value it should go back to the last value. In order to do this we have to change the custom class code of the StringSpinBox.
Below is the code for the custom StringSpinBox class
# custom class for String Spin Box
class StringBox(QSpinBox):

    # constructor
    def __init__(self, parent=None):
        super(StringBox, self).__init__(parent)

        # list of strings
        strings = ["a", "b", "c", "d", "e", "f", "g"]


        # calling set Strings method with
        # adding blank value in front and in end
        self.setStrings(["BLANK"] + strings + ["BLANK"])

        # show first value from index 1
        self.setValue(1)

    def reset_spin(self):
        if self.value() == len(self.strings()) - 1:
            self.setValue(0)

    # method setString
    # similar to set value method
    def setStrings(self, strings):

        # making strings list
        strings = list(strings)

        # making tuple from the string list
        self._strings = tuple(strings)

        # creating a dictionary
        self._values = dict(zip(strings, range(len(strings))))

        # setting range to it the spin box
        self.setRange(0, len(strings)-1)

    # overwriting the textFromValue method
    def textFromValue(self, value):

        # returning string from index
        # _string = tuple
        return self._strings[value]

    # overwriting the stepBy method
    # method that get called when values get incremented or decremented
    def stepBy(self, step):

        # checking if current value is 1 and step is -1
        # step = -1 means decrement
        if self.value() == 1 and step == -1:

            # set current value to maximum
            self.setValue(self.maximum())

        # checking if current value is maximum -1 and step is 1
        # step = 1 means Increment
        elif self.value() == self.maximum() - 1 and step == 1:

            # setting current value to 0
            self.setValue(0)
        
        # calling stepBy method of QSpinBox
        QSpinBox.stepBy(self, step)


Explanation : Inside the String spin box custom class overwrite the stepBy method which get called when increment or decrement takes place there check the that if there is decrement and current value is minimum then change its value to maximum similarly if there is increment and it is currently at maximum value then change its value to minimum -1 value.
Below is the implementation
# importing librariesfrom PyQt5.QtWidgets import * from PyQt5 import QtCore, QtGuifrom PyQt5.QtGui import * from PyQt5.QtCore import * import sys  # custom class for String Spin Boxclass StringBox(QSpinBox):      # constructor    def __init__(self, parent = None):        super(StringBox, self).__init__(parent)          # list of strings        strings = ["a", "b", "c", "d", "e", "f", "g"]            # calling set Strings method with        # adding blank value in front and in end        self.setStrings(["BLANK"] + strings + ["BLANK"])          # show first value from index 1        self.setValue(1)      def reset_spin(self):        if self.value() == len(self.strings()) - 1:            self.setValue(0)      # method setString    # similar to set value method    def setStrings(self, strings):          # making strings list        strings = list(strings)          # making tuple from the string list        self._strings = tuple(strings)          # creating a dictionary        self._values = dict(zip(strings, range(len(strings))))          # setting range to it the spin box        self.setRange(0, len(strings)-1)      # overwriting the textFromValue method    def textFromValue(self, value):          # returning string from index        # _string = tuple        return self._strings[value]      # overwriting the stepBy method    # method that get called when values incremented    def stepBy(self, step):          # checking if current value is 1 and step is -1        # step = -1 means decrement        if self.value() == 1 and step == -1:              # set current value to maximum            self.setValue(self.maximum())          # checking if current value is maximum -1 and step is 1        # step = 1 means Increment        elif self.value() == self.maximum() - 1 and step == 1:              # setting current value to 0            self.setValue(0)          # calling stepBy method by QSpinBox        QSpinBox.stepBy(self, step)  class Window(QMainWindow):      def __init__(self):        super().__init__()          # setting title        self.setWindowTitle("Python ")          # setting geometry        self.setGeometry(100, 100, 600, 400)          # calling method        self.UiComponents()          # showing all the widgets        self.show()          # method for widgets    def UiComponents(self):          # creating a string spin box        string_spin_box = StringBox(self)          # setting geometry to the spin box        string_spin_box.setGeometry(100, 100, 200, 40)    # create pyqt5 appApp = QApplication(sys.argv)  # create the instance of our Windowwindow = Window()  # start the appsys.exit(App.exec())
Output :
Python PyQt-SpinBox
Python-gui
Python-PyQt
Python
Writing code in comment?
Please use ide.geeksforgeeks.org,
generate link and share the link here.
Comments
Old Comments
How to Install PIP on Windows ?
How to drop one or multiple columns in Pandas Dataframe
Python OOPs Concepts
Python | Get unique values from a list
Check if element exists in list in Python
Python Classes and Objects
Python | os.path.join() method
How To Convert Python Dictionary To JSON?
Python | Pandas dataframe.groupby()
Create a directory in Python