Unable to use wx.NotificationMessage properly with wxPython

Question

I recently upgraded to the development release of wxPython (wxPython 2.9.2.4) since I needed the functionality of wx.NotificationMessage within my application. I have been t

Answer 1

There is an undocumented hidden method in TaskBarIcon called ShowBalloon which is only implemented for Windows.

From the source:

def ShowBalloon(*args, **kwargs):
    """
    ShowBalloon(self, String title, String text, unsigned int msec=0, int flags=0) -> bool

    Show a balloon notification (the icon must have been already
    initialized using SetIcon).  Only implemented for Windows.

    title and text are limited to 63 and 255 characters respectively, msec
    is the timeout, in milliseconds, before the balloon disappears (will
    be clamped down to the allowed 10-30s range by Windows if it's outside
    it) and flags can include wxICON_ERROR/INFO/WARNING to show a
    corresponding icon

    Returns True if balloon was shown, False on error (incorrect parameters
    or function unsupported by OS)

    """
    return _windows_.TaskBarIcon_ShowBalloon(*args, **kwargs)

I tested it on Windows with wxPython 2.9.4.0 and it works well.

Answer 2

I would not recommend using 2.9 just yet. I have encountered some strange bugs when trying it out.

You can have the same functionality in 2.8. I am using somewhat modified code that I have found some time ago.

import wx, sys

try:
    import win32gui #, win32con
    WIN32 = True
except:
    WIN32 = False

class BalloonTaskBarIcon(wx.TaskBarIcon):
    """
    Base Taskbar Icon Class
    """
    def __init__(self):
        wx.TaskBarIcon.__init__(self)
        self.icon = None
        self.tooltip = ""

    def ShowBalloon(self, title, text, msec = 0, flags = 0):
        """
        Show Balloon tooltip
         @param title - Title for balloon tooltip
         @param msg   - Balloon tooltip text
         @param msec  - Timeout for balloon tooltip, in milliseconds
         @param flags -  one of wx.ICON_INFORMATION, wx.ICON_WARNING, wx.ICON_ERROR
        """
        if WIN32 and self.IsIconInstalled():
            try:
                self.__SetBalloonTip(self.icon.GetHandle(), title, text, msec, flags)
            except Exception:
                pass # print(e) Silent error

    def __SetBalloonTip(self, hicon, title, msg, msec, flags):

        # translate flags
        infoFlags = 0

        if flags & wx.ICON_INFORMATION:
            infoFlags |= win32gui.NIIF_INFO
        elif flags & wx.ICON_WARNING:
            infoFlags |= win32gui.NIIF_WARNING
        elif flags & wx.ICON_ERROR:
            infoFlags |= win32gui.NIIF_ERROR

        # Show balloon
        lpdata = (self.__GetIconHandle(),   # hWnd
                  99,                       # ID
                  win32gui.NIF_MESSAGE|win32gui.NIF_INFO|win32gui.NIF_ICON, # flags: Combination of NIF_* flags
                  0,                        # CallbackMessage: Message id to be pass to hWnd when processing messages
                  hicon,                    # hIcon: Handle to the icon to be displayed
                  '',                       # Tip: Tooltip text
                  msg,                      # Info: Balloon tooltip text
                  msec,                     # Timeout: Timeout for balloon tooltip, in milliseconds
                  title,                    # InfoTitle: Title for balloon tooltip
                  infoFlags                 # InfoFlags: Combination of NIIF_* flags
                  )
        win32gui.Shell_NotifyIcon(win32gui.NIM_MODIFY, lpdata)

        self.SetIcon(self.icon, self.tooltip)   # Hack: because we have no access to the real CallbackMessage value

    def __GetIconHandle(self):
        """
        Find the icon window.
        This is ugly but for now there is no way to find this window directly from wx
        """
        if not hasattr(self, "_chwnd"):
            try:
                for handle in wx.GetTopLevelWindows():
                    if handle.GetWindowStyle():
                        continue
                    handle = handle.GetHandle()
                    if len(win32gui.GetWindowText(handle)) == 0:
                        self._chwnd = handle
                        break
                if not hasattr(self, "_chwnd"):
                    raise Exception
            except:
                raise Exception, "Icon window not found"
        return self._chwnd

    def SetIcon(self, icon, tooltip = ""):
        self.icon = icon
        self.tooltip = tooltip
        wx.TaskBarIcon.SetIcon(self, icon, tooltip)

    def RemoveIcon(self):
        self.icon = None
        self.tooltip = ""
        wx.TaskBarIcon.RemoveIcon(self)

# ===================================================================
app = wx.PySimpleApp()

class TestTaskBarIcon(BalloonTaskBarIcon):

    def __init__(self):
        wx.TaskBarIcon.__init__(self)
        # create a test icon
        bmp = wx.EmptyBitmap(16, 16)
        dc = wx.MemoryDC(bmp)
        dc.SetBrush(wx.RED_BRUSH)
        dc.Clear()
        dc.SelectObject(wx.NullBitmap)

        testicon = wx.EmptyIcon()
        testicon.CopyFromBitmap(bmp)

        self.SetIcon(testicon)
        self.Bind(wx.EVT_TASKBAR_LEFT_UP, lambda e: (self.RemoveIcon(),sys.exit()))

        self.ShowBalloon("", "Hello world!")

icon = TestTaskBarIcon()
app.MainLoop()