event handling of balloon tip with win32gui
<p>I'm currently using a slightly modified version of the <a href="http://www.brunningonline.net/simon/blog/archives/SysTrayIcon.py.html" rel="nofollow">common example of the systemtray</a>.</p>

<pre><code>#!/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 os
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
            self.hicon = win32gui.LoadImage(hinst,
                                       self.icon,
                                       win32con.IMAGE_ICON,
                                       0,
                                       0,
                                       icon_flags)
        else:
            print "Can't find icon file - using default."
            self.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,
                          self.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 show_notification(self, title, msg):
        """
        show the shell notification with the title and message

        :param title:
        :param msg:
        :return:
        """
        win32gui.Shell_NotifyIcon(win32gui.NIM_MODIFY,
                                  (self.hwnd, 0, win32gui.NIF_INFO, win32con.WM_USER + 20,
                                   self.hicon, "", msg, 200, title))

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"


    def hello(sysTrayIcon): print "Hello World."


    def simon(sysTrayIcon): print "Hello Simon."


    def switch_icon(sysTrayIcon):
        sysTrayIcon.icon = icons.next()
        sysTrayIcon.refresh_icon()



    menu_options = (('Say Hello', icons.next(), hello),
                    ('Show balloon tip', None, lambda x: x.show_notification("title", "message")),
                    ('A sub-menu', icons.next(), (('Say Hello to Simon', icons.next(), simon),
                                                  ('Switch Icon', icons.next(), switch_icon),
                                                  ))
                    )


    def bye(sysTrayIcon): print 'Bye, then.'


    SysTrayIcon(icons.next(), hover_text, menu_options, on_quit=bye, default_menu_index=1)
</code></pre>

<p>I made the hicon variable accessible for the whole class and added the function show_notification.
What I'm currently trying to do is calling a function if the notification is clicked.
I found in the <a href="http://perl-win32-gui.sourceforge.net/cgi-bin/docs.cgi?doc=notifyicon" rel="nofollow">win32gui perl documentation</a>(which should be essentially the same from the functionality) that there are certain common events like Click or MouseEvent, but so far I couldn't find any way to add an event handler to the Shell_NotifyIcon.</p>

<p>I've checked the <a href="https://msdn.microsoft.com/en-us/library/windows/desktop/bb773352(v=vs.85).aspx" rel="nofollow">NOTIFYICONDATA structure from Microsoft</a> and found this interesting part:</p>

<blockquote>
  <p>When the uVersion member is NOTIFYICON_VERSION_4, applications
  continue to receive notification events in the form of
  application-defined messages through the uCallbackMessage member</p>
</blockquote>

<p>But I couldn't find any way to put this to any use.
Lastly I tried to add an eventhandler with win32com.client.DispatchWithEvents but I'm failing here with the clsid already.</p>