Source code for mytk.progressbar

import tkinter.ttk as ttk
from enum import Enum
from tkinter import DoubleVar

from .base import Base
from .dialog import Dialog
from .labels import Label
from .notificationcenter import NotificationCenter




class ProgressBarNotification(Enum):
    """Notification types for controlling a ProgressBar via NotificationCenter."""

    step = "step"
    start = "start"
    stop = "stop"





class ProgressBar(Base):
    """A determinate or indeterminate progress bar widget."""

    def __init__(self, maximum=100, mode="determinate"):
        Base.__init__(self)
        self.maximum = maximum
        self.mode = mode



    def create_widget(self, master):
        """Create the underlying ttk.Progressbar widget."""
        self.parent = master
        self.value_variable = DoubleVar(value=0)
        self.widget = ttk.Progressbar(
            master,
            variable=self.value_variable,
            orient="horizontal",
            mode=self.mode,
            maximum=self.maximum,
            **self.debug_kwargs,
        )

        nc = NotificationCenter()
        nc.add_observer(self, self.handle_notification, notification_name=ProgressBarNotification.step)
        nc.add_observer(self, self.handle_notification, notification_name=ProgressBarNotification.start)
        nc.add_observer(self, self.handle_notification, notification_name=ProgressBarNotification.stop)


    @property
    def value(self):
        """The current progress value."""
        if self.value_variable is not None:
            return self.value_variable.get()
        return 0

    @value.setter
    def value(self, v):
        if self.value_variable is not None:
            self.value_variable.set(v)



    def handle_notification(self, notification):
        """Respond to step, start, and stop notifications."""
        try:
            if self.widget is None or not self.widget.winfo_exists():
                return
        except Exception:
            return  # entire Tk application was destroyed
        if notification.name == ProgressBarNotification.step:
            if notification.user_info is None:
                return
            step = notification.user_info.get("step", 0)
            self.step(step)
        elif notification.name == ProgressBarNotification.start:
            self.start()
        elif notification.name == ProgressBarNotification.stop:
            self.stop()




    def step(self, delta):
        """Advance the progress bar by delta, wrapping at maximum."""
        # Update value_variable directly so self.value stays consistent.
        # ttk.Progressbar.step() does not reliably sync back to the linked variable.
        new_value = self.value + delta
        if new_value >= self.maximum:
            new_value = new_value % self.maximum
        self.value = new_value




    def start(self, interval=50):
        """Start the indeterminate progress animation."""
        self.widget.start(interval)




    def stop(self):
        """Stop the indeterminate progress animation."""
        self.widget.stop()






class ProgressWindow(Dialog):
    """A modal dialog that displays a message with an embedded progress bar."""

    def __init__(self, title, message, *args, **kwargs):
        super().__init__(title, *args, **kwargs)
        self.message = message
        self.progress_bar = None



    def populate_widget_body(self):
        """Display the message label and progress bar in the dialog body."""
        self.widget.wait_visibility()

        label = Label(
            text=self.message, wrapping=True, width=30, wraplength=300, justify="center"
        )
        label.grid_into(
            widget=self.widget,
            column=0,
            columnspan=2,
            row=0,
            pady=20,
            padx=20,
            sticky="nsew",
        )

        self.progress_bar = ProgressBar()
        self.progress_bar.grid_into(
            widget=self.widget,
            column=0,
            columnspan=2,
            row=1,
            pady=5,
            padx=20,
            sticky="ew",
        )

        self.column_resize_weight(0, 0)
        self.column_resize_weight(1, 1)
        self.widget.resizable(False, False)




    def populate_buttons(self):
        """Create buttons and assign default keyboard shortcuts."""
        super().populate_buttons()
        self.assign_default_key_shortcuts()




    def assign_default_key_shortcuts(self):
        """Bind Return to Ok and Escape to Cancel."""
        if Dialog.Replies.Ok in self.buttons:
            self.widget.bind("<Return>", self.user_clicked_ok)
            self.buttons[Dialog.Replies.Ok].set_as_default()
        self.widget.bind("<Escape>", self.user_clicked_cancel)