CLI/GUI Progress Bar

progressbar.py

# stdlib modules
import sys
import time

# third party modules
from PySide2 import QtCore, QtWidgets


class AbstractProgressBar(QtCore.QObject):
    # signals
    start_changed = QtCore.Signal(int)
    end_changed = QtCore.Signal(int)
    step_changed = QtCore.Signal(int)
    value_changed = QtCore.Signal(int)
    title_changed = QtCore.Signal(str)
    message_changed = QtCore.Signal(str)

    def __init__(self):
        super(AbstractProgressBar, self).__init__()
        self._start = 0
        self._end = 1
        self._step = 1
        self._value = 0
        self._title = ""
        self._message = ""

    @property
    def start(self):
        return self._start

    @start.setter
    def start(self, value):
        self._start = value
        self.start_changed.emit(value)

    @property
    def end(self):
        return self._end

    @end.setter
    def end(self, value):
        self._end = value
        self.end_changed.emit(value)

    @property
    def step(self):
        return self._step

    @step.setter
    def step(self, value):
        self._step = value
        self.step_changed.emit(value)

    @property
    def value(self):
        return self._value

    @value.setter
    def value(self, value):
        self._value = value
        self.value_changed.emit(value)

    @property
    def title(self):
        return self._title

    @title.setter
    def title(self, value):
        self._title = value
        self.title_changed.emit(value)

    @property
    def message(self):
        return self._message

    @message.setter
    def message(self, value):
        self._message = value
        self.message_changed.emit(value)

    def advance(self):
        self.value = self.value + self.step


class ProgressBarCLI(AbstractProgressBar):
    def __init__(self):
        super(ProgressBarCLI, self).__init__()
        self.width = 10
        self.char_fill = "#"
        self.char_empty = " "
        self._previous_line = ""
        self.value_changed.connect(self._print_value)

    @property
    def width(self):
        return self._width

    @width.setter
    def width(self, value):
        self._width = value

    def _print_value(self, value):
        if self._previous_line:
            sys.stdout.write(len(self._previous_line) * " " + "\r")
            sys.stdout.flush()

        step = (self.width / self.end) * self.step
        value = int(self.value * step)

        fill_str = value * self.char_fill
        empty_str = (self.width - len(fill_str)) * self.char_empty
        bar = "{} {} [{}{}]".format(self.title, self.message, fill_str, empty_str)

        # store previous
        self._previous_line = bar

        bar += "\r"
        if self.value >= self.end:
            bar += "\n"

        sys.stdout.write(bar)
        sys.stdout.flush()


class ProgressBarGUI(QtWidgets.QWidget):
    def __init__(self, pbar):
        self._pbar = pbar
        super(ProgressBarGUI, self).__init__()
        self._build_ui()
        self._connect_signals()
        self._refresh()

    def _build_ui(self):
        self._title = QtWidgets.QLabel()
        self._message = QtWidgets.QLabel()
        self._pbar_widget = QtWidgets.QProgressBar()
        self.setLayout(QtWidgets.QHBoxLayout())
        self.layout().addWidget(self._title)
        self.layout().addWidget(self._message)
        self.layout().addWidget(self._pbar_widget)

    def _connect_signals(self):
        self._pbar.title_changed.connect(self._title.setText)
        self._pbar.message_changed.connect(self._message.setText)
        self._pbar.start_changed.connect(self._pbar_widget.setMinimum)
        self._pbar.end_changed.connect(self._pbar_widget.setMaximum)
        self._pbar.value_changed.connect(self._pbar_widget.setValue)

        self._pbar.start_changed.connect(self._refresh)
        self._pbar.end_changed.connect(self._refresh)
        self._pbar.value_changed.connect(self._refresh)

    def _refresh(self, *args, **kwargs):
        QtCore.QCoreApplication.processEvents()


if __name__ == "__main__":
    # cli
    pbar = ProgressBarCLI()

    # gui
    app = QtWidgets.QApplication.instance() or QtWidgets.QApplication()
    widget = ProgressBarGUI(pbar)
    dialog = QtWidgets.QDialog()
    dialog.setLayout(QtWidgets.QVBoxLayout())
    dialog.layout().addWidget(widget)
    dialog.show()

    # action iterable
    l = list(range(10))

    # settings
    pbar.title = "iteration:"
    pbar.end = len(l)
    pbar.width = 20

    for i in l:
        pbar.message = str(i + 1)
        time.sleep(0.5)  # action
        pbar.advance()

    sys.exit(dialog.exec_())