Nicht blockierende HTTP-Request-Schleife

Question

Ich möchte eine einfache Systray-App schreiben, die den Status einiger Webdienste überprüft und ihr Symbol entsprechend der angegebenen Antwort ändert. Ich bin strangle es non-blocking Weise zu tun, so dass das Programm noch reagiert, wie es http-Anforderungen alle 10 Sekunden abfeuert. Könntest du mir helfen - ich bin ein totaler Anfänger, wenn es um Winapi geht ???

#!/usr/bin/env python 
# Module  : SysTrayIcon.py 
# Synopsis : Windows System tray icon. 
# Programmer : Simon Brunning - simon@brunningonline.net 
# Date  : 11 April 2005 
# Notes  : Based on (i.e. ripped off from) Mark Hammond's 
#    win32gui_taskbar.py and win32gui_menu.py demos from PyWin32 
'''TODO 

For now, the demo at the bottom shows how to use it...''' 

import json 
import time 
import urllib2   
import os 
import sys 
import win32api 
import win32con 
import win32gui_struct 
try: 
    import winxpgui as win32gui 
except ImportError: 
    import win32gui 

class SysTrayIcon(object): 
    '''TODO''' 
    QUIT = 'QUIT' 
    SPECIAL_ACTIONS = [QUIT] 

    FIRST_ID = 1023 

    def __init__(self, 
       icon, 
       hover_text, 
       menu_options, 
       on_quit=None, 
       default_menu_index=None, 
       window_class_name=None,): 

     self.icon = icon 
     self.hover_text = hover_text 
     self.on_quit = on_quit 

     menu_options = menu_options + (('Quit', None, self.QUIT),) 
     self._next_action_id = self.FIRST_ID 
     self.menu_actions_by_id = set() 
     self.menu_options = self._add_ids_to_menu_options(list(menu_options)) 
     self.menu_actions_by_id = dict(self.menu_actions_by_id) 
     del self._next_action_id 


     self.default_menu_index = (default_menu_index or 0) 
     self.window_class_name = window_class_name or "SysTrayIconPy" 

     message_map = {win32gui.RegisterWindowMessage("TaskbarCreated"): self.restart, 
         win32con.WM_DESTROY: self.destroy, 
         win32con.WM_COMMAND: self.command, 
         win32con.WM_USER+20 : self.notify,} 
     # Register the Window class. 
     window_class = win32gui.WNDCLASS() 
     hinst = window_class.hInstance = win32gui.GetModuleHandle(None) 
     window_class.lpszClassName = self.window_class_name 
     window_class.style = win32con.CS_VREDRAW | win32con.CS_HREDRAW; 
     window_class.hCursor = win32gui.LoadCursor(0, win32con.IDC_ARROW) 
     window_class.hbrBackground = win32con.COLOR_WINDOW 
     window_class.lpfnWndProc = message_map # could also specify a wndproc. 
     classAtom = win32gui.RegisterClass(window_class) 
     # Create the Window. 
     style = win32con.WS_OVERLAPPED | win32con.WS_SYSMENU 
     self.hwnd = win32gui.CreateWindow(classAtom, 
              self.window_class_name, 
              style, 
              0, 
              0, 
              win32con.CW_USEDEFAULT, 
              win32con.CW_USEDEFAULT, 
              0, 
              0, 
              hinst, 
              None) 
     win32gui.UpdateWindow(self.hwnd) 
     self.notify_id = None 
     self.refresh_icon() 

     win32gui.PumpMessages() 

    def _add_ids_to_menu_options(self, menu_options): 
     result = [] 
     for menu_option in menu_options: 
      option_text, option_icon, option_action = menu_option 
      if callable(option_action) or option_action in self.SPECIAL_ACTIONS: 
       self.menu_actions_by_id.add((self._next_action_id, option_action)) 
       result.append(menu_option + (self._next_action_id,)) 
      elif non_string_iterable(option_action): 
       result.append((option_text, 
           option_icon, 
           self._add_ids_to_menu_options(option_action), 
           self._next_action_id)) 
      else: 
       print 'Unknown item', option_text, option_icon, option_action 
      self._next_action_id += 1 
     return result 

    def refresh_icon(self): 
     # Try and find a custom icon 
     hinst = win32gui.GetModuleHandle(None) 
     if os.path.isfile(self.icon): 
      icon_flags = win32con.LR_LOADFROMFILE | win32con.LR_DEFAULTSIZE 
      hicon = win32gui.LoadImage(hinst, 
             self.icon, 
             win32con.IMAGE_ICON, 
             0, 
             0, 
             icon_flags) 
     else: 
      print "Can't find icon file - using default." 
      hicon = win32gui.LoadIcon(0, win32con.IDI_APPLICATION) 

     if self.notify_id: message = win32gui.NIM_MODIFY 
     else: message = win32gui.NIM_ADD 
     self.notify_id = (self.hwnd, 
          0, 
          win32gui.NIF_ICON | win32gui.NIF_MESSAGE | win32gui.NIF_TIP, 
          win32con.WM_USER+20, 
          hicon, 
          self.hover_text) 
     win32gui.Shell_NotifyIcon(message, self.notify_id) 

    def restart(self, hwnd, msg, wparam, lparam): 
     self.refresh_icon() 

    def destroy(self, hwnd, msg, wparam, lparam): 
     if self.on_quit: self.on_quit(self) 
     nid = (self.hwnd, 0) 
     win32gui.Shell_NotifyIcon(win32gui.NIM_DELETE, nid) 
     win32gui.PostQuitMessage(0) # Terminate the app. 

    def notify(self, hwnd, msg, wparam, lparam): 
     if lparam==win32con.WM_LBUTTONDBLCLK: 
      self.execute_menu_option(self.default_menu_index + self.FIRST_ID) 
     elif lparam==win32con.WM_RBUTTONUP: 
      self.show_menu() 
     elif lparam==win32con.WM_LBUTTONUP: 
      pass 
     return True 

    def show_menu(self): 
     menu = win32gui.CreatePopupMenu() 
     self.create_menu(menu, self.menu_options) 
     #win32gui.SetMenuDefaultItem(menu, 1000, 0) 

     pos = win32gui.GetCursorPos() 
     # See http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/menus_0hdi.asp 
     win32gui.SetForegroundWindow(self.hwnd) 
     win32gui.TrackPopupMenu(menu, 
           win32con.TPM_LEFTALIGN, 
           pos[0], 
           pos[1], 
           0, 
           self.hwnd, 
           None) 
     win32gui.PostMessage(self.hwnd, win32con.WM_NULL, 0, 0) 

    def create_menu(self, menu, menu_options): 
     for option_text, option_icon, option_action, option_id in menu_options[::-1]: 
      if option_icon: 
       option_icon = self.prep_menu_icon(option_icon) 

      if option_id in self.menu_actions_by_id:     
       item, extras = win32gui_struct.PackMENUITEMINFO(text=option_text, 
                   hbmpItem=option_icon, 
                   wID=option_id) 
       win32gui.InsertMenuItem(menu, 0, 1, item) 
      else: 
       submenu = win32gui.CreatePopupMenu() 
       self.create_menu(submenu, option_action) 
       item, extras = win32gui_struct.PackMENUITEMINFO(text=option_text, 
                   hbmpItem=option_icon, 
                   hSubMenu=submenu) 
       win32gui.InsertMenuItem(menu, 0, 1, item) 

    def prep_menu_icon(self, icon): 
     # First load the icon. 
     ico_x = win32api.GetSystemMetrics(win32con.SM_CXSMICON) 
     ico_y = win32api.GetSystemMetrics(win32con.SM_CYSMICON) 
     hicon = win32gui.LoadImage(0, icon, win32con.IMAGE_ICON, ico_x, ico_y, win32con.LR_LOADFROMFILE) 

     hdcBitmap = win32gui.CreateCompatibleDC(0) 
     hdcScreen = win32gui.GetDC(0) 
     hbm = win32gui.CreateCompatibleBitmap(hdcScreen, ico_x, ico_y) 
     hbmOld = win32gui.SelectObject(hdcBitmap, hbm) 
     # Fill the background. 
     brush = win32gui.GetSysColorBrush(win32con.COLOR_MENU) 
     win32gui.FillRect(hdcBitmap, (0, 0, 16, 16), brush) 
     # unclear if brush needs to be feed. Best clue I can find is: 
     # "GetSysColorBrush returns a cached brush instead of allocating a new 
     # one." - implies no DeleteObject 
     # draw the icon 
     win32gui.DrawIconEx(hdcBitmap, 0, 0, hicon, ico_x, ico_y, 0, 0, win32con.DI_NORMAL) 
     win32gui.SelectObject(hdcBitmap, hbmOld) 
     win32gui.DeleteDC(hdcBitmap) 

     return hbm 

    def command(self, hwnd, msg, wparam, lparam): 
     id = win32gui.LOWORD(wparam) 
     self.execute_menu_option(id) 

    def execute_menu_option(self, id): 
     menu_action = self.menu_actions_by_id[id]  
     if menu_action == self.QUIT: 
      win32gui.DestroyWindow(self.hwnd) 
     else: 
      menu_action(self) 

def non_string_iterable(obj): 
    try: 
     iter(obj) 
    except TypeError: 
     return False 
    else: 
     return not isinstance(obj, basestring) 

# Minimal self test. You'll need a bunch of ICO files in the current working 
# directory in order for this to work... 
if __name__ == '__main__': 
    import itertools, glob 

    icons = itertools.cycle(glob.glob('*.ico')) 
    hover_text = "SysTrayIcon.py Demo" 

    # -------------changed --------- 
    def ping_server(sysTrayIcon): 
     while True: 
      request = urllib2.urlopen('http://localhost:8080/api/some_end_point') 
      data = json.loads(request) 
      if data and data['some_value']: 
       #change icon 
       sysTrayIcon.icon = icons.next() 
       sysTrayIcon.refresh_icon() 
      time.sleep(10) 
      # TODO: how do i do this non - blocking way ??????????? 


    menu_options = (('Ping server', icons.next(), ping_server)) 
    def bye(sysTrayIcon): print 'Bye, then.' 

    SysTrayIcon(icons.next(), hover_text, menu_options, on_quit=bye, default_menu_index=1) 

Answer 1

Folgende @enhzflep Beratung Ich habe Faden abgeschnitten und gewünschten Effekt erreicht. Dies ist, was ich SysTrayClass hinzugefügt habe