DropZone.py

import ctypes
import os
import time
import asyncio
import flet as ft
class LoadDLL:
    def __init__(self,page:ft.Page = None,on_entered=None,on_leaved=None,on_dropped=None,is_working:bool = True):
        super().__init__()
        self.page = page
        self.title = page.title
        self.state_active = is_working
        self.is_entered = ctypes.c_bool(False)
        self.is_leaved = ctypes.c_bool(False)
        self.is_over = ctypes.c_bool(False)
        self.is_dropped = ctypes.c_bool(False)

        self.on_entered = on_entered
        self.on_leaved = on_leaved
        self.on_dropped = on_dropped
    
        self.__load_library()
        time.sleep(0.01)
        self.page.run_task(self.__execute)

    
    @property
    def is_working(self):
        return self.state_active
    
    @is_working.setter
    def is_working(self,value:bool = None):
        self.state_active = value


    def __window_exists(self):
        hwnd = ctypes.windll.user32.FindWindowW(None, self.title)
        return hwnd != 0
        
    def __get_file_names(self):
        num = self.dll.GetFilesCount()
        file_names_ptr = self.dll.GetFilesNames()
        file_names = []

        for i in range(num):
            try:
                file_names.append(file_names_ptr[i].decode())
            except:
                pass
        return file_names
        
    def __load_library(self):
        self.dll = ctypes.WinDLL(os.path.abspath("DropZone.dll"))
        self.dll.GetFilesNames.restype = ctypes.POINTER(ctypes.c_char_p)
        self.dll.AttachDLL.argtypes = [
            ctypes.c_char_p,
            ctypes.POINTER(ctypes.c_bool),
            ctypes.POINTER(ctypes.c_bool),
            ctypes.POINTER(ctypes.c_bool),
            ctypes.POINTER(ctypes.c_bool)
        ]


        self.dll.AttachDLL(
            self.title.encode("utf-8"), 
            ctypes.byref(self.is_entered), 
            ctypes.byref(self.is_leaved), 
            ctypes.byref(self.is_over), 
            ctypes.byref(self.is_dropped))
    def __check_state(self):

        if self.is_over.value==True:
            if self.is_entered.value==True:         #ENTERED
                self.is_entered.value = False
                if self.on_entered!=None:
                    self.on_entered("None") 


            if self.is_leaved.value:                #LEAVED
                self.is_leaved.value = False
                if self.on_leaved!=None:
                    self.on_leaved("None")


            if self.is_dropped.value:               #DROPPED
                self.is_dropped.value = False
                if self.on_dropped!=None:
                    paths = self.__get_file_names()
                    self.on_dropped(paths)

            

    async def __execute(self):
        try:
            while self.__window_exists():
                if self.state_active:
                    self.__check_state()
                await asyncio.sleep(0.01)
        except Exception as e:
            print(f"Error occured: {e}")
            raise