A small native Win32 application in Python; see http://auralbits.blogspot.com/2014/02/a-native-win32-application-in-python.html

win32.py

"""pywin32 native dialog demo

Explanation here: http://auralbits.blogspot.com/2014/02/a-native-win32-application-in-python.html  #noqa

The core of this demo comes from the pywin32 win32gui_dialog demo:

    http://pywin32.hg.sourceforge.net/hgweb/pywin32/pywin32/file/tip/win32/Demos/win32gui_dialog.py  # noqa

"""

import struct

import win32gui_struct
import win32api
import win32con
import winerror
import winxpgui as win32gui


EM_GETEVENTMASK = win32con.WM_USER + 59
EM_SETEVENTMASK = win32con.WM_USER + 69
EM_SETTEXTEX = win32con.WM_USER + 97
EM_EXSETSEL = 1079

IDC_EDIT = 1024


win32gui.InitCommonControls()
hInstance = win32gui.dllhandle

# Load the RichEdit 4.1 control
win32api.LoadLibrary('MSFTEDIT.dll')


class DemoWindow(object):
    class_name = 'Pywin32DialogDemo'
    class_atom = None

    @classmethod
    def _register_wnd_class(cls):
        if cls.class_atom:
            return

        message_map = {}
        wc = win32gui.WNDCLASS()
        wc.SetDialogProc()  # Make it a dialog class.
        wc.hInstance = hInstance
        wc.lpszClassName = cls.class_name
        wc.style = win32con.CS_VREDRAW | win32con.CS_HREDRAW
        wc.hCursor = win32gui.LoadCursor(0, win32con.IDC_ARROW)
        wc.hbrBackground = win32con.COLOR_WINDOW + 1
        wc.lpfnWndProc = message_map  # could also specify a wndproc.
        # C code: wc.cbWndExtra = DLGWINDOWEXTRA + sizeof(HBRUSH)
        #                         + (sizeof(COLORREF));
        wc.cbWndExtra = win32con.DLGWINDOWEXTRA + struct.calcsize('Pi')

        # load icon from python executable
        this_app = win32api.GetModuleHandle(None)
        wc.hIcon = win32gui.LoadIcon(this_app, 1)

        try:
            cls.class_atom = win32gui.RegisterClass(wc)
        except win32gui.error, err_info:
            if err_info.winerror != winerror.ERROR_CLASS_ALREADY_EXISTS:
                raise

    @classmethod
    def _get_dialog_template(cls):
        title = 'pywin32 Dialog Demo'
        style = (win32con.WS_THICKFRAME | win32con.WS_POPUP |
                 win32con.WS_VISIBLE | win32con.WS_CAPTION |
                 win32con.WS_SYSMENU | win32con.DS_SETFONT |
                 win32con.WS_MINIMIZEBOX)

        # These are 'dialog coordinates,' not pixels. Sigh.
        bounds = 0, 0, 250, 210

        # Window frame and title, a PyDLGTEMPLATE object
        dialog = [(title, bounds, style, None, None, None, cls.class_name), ]

        return dialog

    def __init__(self):
        message_map = {
            win32con.WM_SIZE: self.on_size,
            win32con.WM_COMMAND: self.on_command,
            win32con.WM_NOTIFY: self.on_notify,
            win32con.WM_INITDIALOG: self.on_init_dialog,
            win32con.WM_CLOSE: self.on_close,
            win32con.WM_DESTROY: self.on_destroy,
        }

        self._register_wnd_class()
        template = self._get_dialog_template()

        # Create the window via CreateDialogBoxIndirect - it can then
        # work as a 'normal' window, once a message loop is established.
        win32gui.CreateDialogIndirect(hInstance, template, 0, message_map)

    #
    # edit control

    def edit_proc(self, hwnd, msg, wparam, lparam):
        print 'edit_proc', hwnd, msg, wparam, lparam

        if msg == EM_SETTEXTEX:
            print 'EM_SETTEXTEX'
        elif msg == win32con.WM_SETTEXT:
            print 'WM_SETTEXT'
        elif msg == win32con.EM_REPLACESEL:
            print 'EM_REPLACESEL'

        # I'm not sure why this is needed (i.e. not handled by the default
        # handler), but without it the process hangs when you close the window.
        elif msg == win32con.WM_DESTROY:
            win32gui.DestroyWindow(hwnd)
            return

        # 'super' call to the overridden WndProc
        return win32gui.CallWindowProc(self.old_edit_proc, hwnd, msg, wparam,
                                       lparam)

    def _setup_edit(self):
        class_name = 'RICHEDIT50W'
        initial_text = ''
        child_style = (win32con.WS_CHILD | win32con.WS_VISIBLE |
                       win32con.WS_HSCROLL | win32con.WS_VSCROLL |
                       win32con.WS_TABSTOP | win32con.WS_VSCROLL |
                       win32con.ES_MULTILINE | win32con.ES_WANTRETURN)
        parent = self.hwnd

        self.edit_hwnd = win32gui.CreateWindow(
            class_name, initial_text, child_style,

            # bounds for the control. Since they are required, we will pass in
            # 0, but the size of the edit control is dictated by the resize
            # handler below
            0, 0, 0, 0,
            parent, IDC_EDIT, hInstance, None)

        message_mask = (win32con.ENM_KEYEVENTS | win32con.ENM_SELCHANGE |
                        win32con.ENM_CHANGE | win32con.ENM_UPDATE)
        win32gui.SendMessage(self.edit_hwnd, EM_SETEVENTMASK, 0, message_mask)

        self.old_edit_proc = win32gui.SetWindowLong(self.edit_hwnd,
                                                    win32con.GWL_WNDPROC,
                                                    self.edit_proc)

    #
    # dialog window notification handlers

    def on_init_dialog(self, hwnd, msg, wparam, lparam):
        self.hwnd = hwnd
        self._setup_edit()
        l, t, r, b = win32gui.GetWindowRect(self.hwnd)
        self._do_size(r, b, 1)

    def _do_size(self, cx, cy, repaint=1):
        # expand the textbox to fill the window
        win32gui.MoveWindow(self.edit_hwnd, 0, 0, cx, cy, repaint)

    def on_size(self, hwnd, msg, wparam, lparam):
        x = win32api.LOWORD(lparam)
        y = win32api.HIWORD(lparam)
        self._do_size(x, y)
        return 1

    def on_command(self, hwnd, msg, wparam, lparam):
        print 'on_command', hwnd, msg, wparam, lparam

        msg_id = win32api.HIWORD(wparam)
        print msg_id

        if lparam != self.edit_hwnd:
            print 'origin not edit, skipping'
            return 1

        if msg_id == win32con.EN_CHANGE:
            print 'EN_CHANGE'
        elif msg_id == win32con.EN_UPDATE:
            print 'EN_UPDATE'

        return 1

    def on_notify(self, hwnd, msg, wparam, lparam):
        print 'on_notify', hwnd, msg, wparam, lparam

        info = win32gui_struct.UnpackNMITEMACTIVATE(lparam)

        if wparam != IDC_EDIT:
            print 'origin not edit, skipping'
            return 1

        if info.code == win32con.EN_MSGFILTER:
            print 'EN_MSGFILTER'
        elif info.code == win32con.EN_SELCHANGE:
            print 'EN_SELCHANGE'

        print info.code

        return 1

    def on_close(self, hwnd, msg, wparam, lparam):
        win32gui.DestroyWindow(hwnd)

    def on_destroy(self, hwnd, msg, wparam, lparam):
        # Terminate the app
        win32gui.PostQuitMessage(0)


def main():
    DemoWindow()
    # PumpMessages runs until PostQuitMessage() is called by someone.
    win32gui.PumpMessages()


if __name__ == '__main__':
    main()