WebPicDownloader/controller/HomeController.py

from controller.MainController import MainController
from util.AsyncTask import AsyncTask


class HomeController:
    """
        Controller - HomeController

    desc...

    @author     Jérémi Nihart / EndMove
    @link       https://git.endmove.eu/EndMove/WebPicDownloader
    @version    1.0.0
    @since      2022-08-30
    """
    # Variables
    __main_controller = None
    __view = None
    __webpic = None
    __download_task = None

    # Constructor
    def __init__(self, controller: MainController, webpic) -> None:
        """
            Constructor

        * :controller: -> The main application cpntroller.
        * :webpic: -> The webpicdownloader instance.
        """
        # Setub variables
        self.__main_controller = controller
        self.__webpic = webpic

        # Subscribe to events
        controller.subscribe_to_quite_event(self.on_quit)

    # START View methods
    def set_view(self, view) -> None:
        """
            [function for view]
        => Define the view of this controller.
            
        * :view: -> The view that this controller manage.
        """
        self.__view = view
        self.__webpic.set_messenger_callback(view.add_log)
    # END View method

    # START View events
    def on_change_view(self, frame) -> None:
        """
            [event function for view]
        => Call this event method when the user requests to change the window.

        * :frame: -> The frame we want to launch.
        """
        self.__main_controller.change_frame(frame)

    def on_download_requested(self, url: str, name: str) -> None:
        """
            [event function for view]
        => Call this event method when the user requests to download

        * :url: -> The url of the website to use for pic-download.
        * :name: -> The name of the folder in which put pictures.
        """
        if url.strip() and name.strip():
            self.__download_task = AsyncTask(
                rcallback=self.__async_task_start,
                rargs=(url, name),
                qcallback=self.__async_task_stop
            )
            self.__download_task.start()
        else:
            self.__view.show_error_message("Opss, the url or folder name are not valid!")
    # END View events

    # START Controller methods
    def on_quit(self) -> bool:
        """
            [event function for controller]
        => Call this event when a request to exit is thrown.
        """
        if self.__download_task and self.__download_task.is_alive():
            if self.__main_controller.show_question_dialog(
                "Are you sure?",
                "Do you really want to quit while the download is running?\nThis will stop the download."
            ):
                self.__download_task.stop()
                self.__download_task.join()
                return False
            else:
                return True
        print("Quit... homecontroller END") # REMOVE
    # END Controller methods

    # START Task methods
    def __async_task_start(self, url, name) -> None:
        """
            [CallBack start function]
        => Start Callback function for asynctask, be careful once executed in asynctask this
        function will keep its controller context. In short it's as if the thread was
        launched in the controller and the execution never left it.

        * :url: -> Url for webpic.
        * :name: -> Working dir name for webpic.
        """
        print("start callback called")  # REMOVE
        self.__view.clear_logs()
        if self.__webpic.download(url, name):
            self.__view.show_success_message("The download has been successfully completed.")
        else:
            self.__view.show_error_message("A critical error preventing the download occurred, check the logs.")

    def __async_task_stop(self) -> None:
        """
            [CallBack stop function]
        => End Callback function for asynctask, be careful once executed in asynctask this
        function will keep its controller context. In short it's as if the thread was
        launched in the controller and the execution never left it.
        """
        print("stop callback called") # REMOVE
        self.__webpic.stop()
    # END Task methods