# Demonstrates using a taskbar icon to create and navigate between desktops

import win32api, win32con, win32gui, win32service, win32process
import pywintypes
import traceback, _thread, time
import io

## "Shell_TrayWnd" is class of system tray window, broadcasts "TaskbarCreated" when initialized

def desktop_name_dlgproc(hwnd,msg,wparam,lparam):
    """ Handles messages from the desktop name dialog box """
    if msg in (win32con.WM_CLOSE,win32con.WM_DESTROY):
        win32gui.DestroyWindow(hwnd)
    elif msg == win32con.WM_COMMAND:
        if wparam == win32con.IDOK:
            desktop_name=win32gui.GetDlgItemText(hwnd, 72)
            print('new desktop name: ',desktop_name)
            win32gui.DestroyWindow(hwnd)
            create_desktop(desktop_name)
            
        elif wparam == win32con.IDCANCEL:
            win32gui.DestroyWindow(hwnd)

def get_new_desktop_name(parent_hwnd):
    """ Create a dialog box to ask the user for name of desktop to be created """
    msgs={win32con.WM_COMMAND:desktop_name_dlgproc,
          win32con.WM_CLOSE:desktop_name_dlgproc,
          win32con.WM_DESTROY:desktop_name_dlgproc}
    # dlg item [type, caption, id, (x,y,cx,cy), style, ex style
    style=win32con.WS_BORDER|win32con.WS_VISIBLE|win32con.WS_CAPTION|win32con.WS_SYSMENU  ## |win32con.DS_SYSMODAL
    h=win32gui.CreateDialogIndirect(
        win32api.GetModuleHandle(None),
        [['One ugly dialog box !',(100,100,200,100),style,0],
         ['Button','Create', win32con.IDOK, (10,10,30,20),win32con.WS_VISIBLE|win32con.WS_TABSTOP|win32con.BS_HOLLOW|win32con.BS_DEFPUSHBUTTON],
         ['Button','Never mind', win32con.IDCANCEL, (45,10,50,20),win32con.WS_VISIBLE|win32con.WS_TABSTOP|win32con.BS_HOLLOW],
         ['Static','Desktop name:',71,(10,40,70,10),win32con.WS_VISIBLE],
         ['Edit','',72,(75,40,90,10),win32con.WS_VISIBLE]],
        parent_hwnd, msgs)     ## parent_hwnd, msgs)

    win32gui.EnableWindow(h,True)
    hcontrol=win32gui.GetDlgItem(h,72)
    win32gui.EnableWindow(hcontrol,True)
    win32gui.SetFocus(hcontrol)
    
def new_icon(hdesk,desktop_name):
    """ Runs as a thread on each desktop to create a new tray icon and handle its messages """ 
    global id
    id=id+1
    hdesk.SetThreadDesktop()
    ## apparently the threads can't use same hinst, so each needs its own window class
    windowclassname='PythonDesktopManager'+desktop_name
    wc = win32gui.WNDCLASS()
    wc.hInstance = win32api.GetModuleHandle(None)
    wc.lpszClassName = windowclassname
    wc.style = win32con.CS_VREDRAW | win32con.CS_HREDRAW | win32con.CS_GLOBALCLASS
    wc.hCursor = win32gui.LoadCursor( 0, win32con.IDC_ARROW )
    wc.hbrBackground = win32con.COLOR_WINDOW
    wc.lpfnWndProc = icon_wndproc
    windowclass = win32gui.RegisterClass(wc)
    style = win32con.WS_OVERLAPPED | win32con.WS_SYSMENU
    hwnd = win32gui.CreateWindow(windowclass, 'dm_'+desktop_name, win32con.WS_SYSMENU,
                    0, 0, win32con.CW_USEDEFAULT, win32con.CW_USEDEFAULT,
                    0, 0, wc.hInstance, None)
    win32gui.UpdateWindow(hwnd)
    flags = win32gui.NIF_ICON | win32gui.NIF_MESSAGE | win32gui.NIF_TIP
    notify_info = (hwnd, id, flags, win32con.WM_USER+20, hicon, 'Desktop Manager (%s)' %desktop_name)
    window_info[hwnd]=notify_info
    ## wait for explorer to initialize system tray for new desktop
    tray_found=0
    while not tray_found:
        try:
            tray_found=win32gui.FindWindow("Shell_TrayWnd",None)
        except win32gui.error:
            traceback.print_exc
            time.sleep(.5)
    win32gui.Shell_NotifyIcon(win32gui.NIM_ADD, notify_info)
    win32gui.PumpMessages()

def create_desktop(desktop_name, start_explorer=1):
    """ Creates a new desktop and spawns a thread running on it
        Will also start a new icon thread on an existing desktop
    """
    sa=pywintypes.SECURITY_ATTRIBUTES()
    sa.bInheritHandle=1

    try:
        hdesk=win32service.CreateDesktop(desktop_name, 0, win32con.MAXIMUM_ALLOWED, sa)
    except win32service.error:
        traceback.print_exc()
        errbuf=io.StringIO()
        traceback.print_exc(None,errbuf)
        win32api.MessageBox(0, errbuf.getvalue(), 'Desktop creation failed')
        return
    if start_explorer:
        s=win32process.STARTUPINFO()
        s.lpDesktop=desktop_name
        prc_info=win32process.CreateProcess(None, "Explorer.exe",None,None,True,win32con.CREATE_NEW_CONSOLE,None,'c:\\',s)

    th=_thread.start_new_thread(new_icon,(hdesk,desktop_name))
    hdesk.SwitchDesktop()

def icon_wndproc(hwnd, msg, wp, lp):
    """ Window proc for the tray icons """
    if lp==win32con.WM_LBUTTONDOWN:
        ## popup menu won't disappear if you don't do this
        win32gui.SetForegroundWindow(hwnd)

        curr_desktop=win32service.OpenInputDesktop(0,True,win32con.MAXIMUM_ALLOWED)
        curr_desktop_name=win32service.GetUserObjectInformation(curr_desktop,win32con.UOI_NAME)
        winsta=win32service.GetProcessWindowStation()
        desktops=winsta.EnumDesktops()
        m=win32gui.CreatePopupMenu()
        desktop_cnt=len(desktops)
        ## *don't* create an item 0
        for d in range(1, desktop_cnt+1):
            mf_flags=win32con.MF_STRING
             ## if you switch to winlogon yourself, there's nothing there and you're stuck
            if desktops[d-1].lower() in ('winlogon','disconnect'):
                mf_flags=mf_flags|win32con.MF_GRAYED|win32con.MF_DISABLED
            if desktops[d-1]==curr_desktop_name:
                mf_flags=mf_flags|win32con.MF_CHECKED
            win32gui.AppendMenu(m, mf_flags, d, desktops[d-1])
        win32gui.AppendMenu(m, win32con.MF_STRING, desktop_cnt+1, 'Create new ...')
        win32gui.AppendMenu(m, win32con.MF_STRING, desktop_cnt+2, 'Exit')
            
        x,y=win32gui.GetCursorPos()
        d=win32gui.TrackPopupMenu(m,win32con.TPM_LEFTBUTTON|win32con.TPM_RETURNCMD|win32con.TPM_NONOTIFY,
            x,y, 0, hwnd, None)
        win32gui.PumpWaitingMessages()
        win32gui.DestroyMenu(m)
        if d==desktop_cnt+1:      ## Create new
            get_new_desktop_name(hwnd)
        elif d==desktop_cnt+2:    ## Exit
            win32gui.PostQuitMessage(0)
            win32gui.Shell_NotifyIcon(win32gui.NIM_DELETE, window_info[hwnd])
            del window_info[hwnd]
            origin_desktop.SwitchDesktop()
        elif d>0:
            hdesk=win32service.OpenDesktop(desktops[d-1],0,0,win32con.MAXIMUM_ALLOWED)
            hdesk.SwitchDesktop()
        return 0
    else:
        return win32gui.DefWindowProc(hwnd, msg, wp, lp)

window_info={}
origin_desktop=win32service.OpenInputDesktop(0, True, win32con.MAXIMUM_ALLOWED)
origin_desktop_name=win32service.GetUserObjectInformation(origin_desktop, win32service.UOI_NAME)

hinst=win32api.GetModuleHandle(None)
try:
    hicon=win32gui.LoadIcon(hinst, 1)    ## python.exe and pythonw.exe
except win32gui.error:
    hicon=win32gui.LoadIcon(hinst, 135)  ## pythonwin's icon
id=0

create_desktop(str(origin_desktop_name),0)

## wait for first thread to initialize its icon
while not window_info:
    time.sleep(1)

## exit when last tray icon goes away
while window_info:
    win32gui.PumpWaitingMessages()
    time.sleep(3)

