systray without explorer.exe (huge cpu usage 30%)

[MaximKiselev]

hi, thanks for tool.
is it possible to use widget systray without explorer.exe ? i mean, create fake system tray.

import sys
import logging
from ctypes import windll, byref, sizeof, Structure, c_uint, c_int, c_wchar
from ctypes.wintypes import HWND, UINT, WPARAM, LPARAM, DWORD
import win32gui
import win32con
import win32api
from PyQt6.QtWidgets import QApplication, QSystemTrayIcon, QMenu
from PyQt6.QtGui import QIcon
from PyQt6.QtCore import Qt

# Logging setup
logging.basicConfig(level=logging.DEBUG)
logger = logging.getLogger("CustomTray")

# Win32 API constants
NIM_ADD = 0
NIM_MODIFY = 1
NIM_DELETE = 2
NIF_MESSAGE = 0x00000001
NIF_ICON = 0x00000002
NIF_TIP = 0x00000004
WM_COPYDATA = 0x004A
WM_USER = 0x0400
HWND_BROADCAST = 0xFFFF

# Simplified NOTIFYICONDATA structure
class NOTIFYICONDATA(Structure):
    _fields_ = [
        ("cbSize", DWORD),
        ("hWnd", HWND),
        ("uID", UINT),
        ("uFlags", UINT),
        ("uCallbackMessage", UINT),
        ("hIcon", c_int),
        ("szTip", c_wchar * 128),
    ]

# COPYDATASTRUCT structure
class COPYDATASTRUCT(Structure):
    _fields_ = [
        ("dwData", c_uint),
        ("cbData", DWORD),
        ("lpData", c_int),
    ]

# Custom tray class
class CustomTray:
    def __init__(self):
        self.app = QApplication(sys.argv)
        self.icons = {}  # Dict to store icons: {uID: QSystemTrayIcon}
        self.hwnd = None
        self.taskbar_created_msg = None

    def create_tray_window(self):
        # Register window class
        wc = win32gui.WNDCLASS()
        wc.lpszClassName = "Shell_TrayWnd"
        wc.lpfnWndProc = self.wnd_proc
        wc.hInstance = win32api.GetModuleHandle(None)
        win32gui.RegisterClass(wc)

        # Create window
        self.hwnd = win32gui.CreateWindowEx(
            win32con.WS_EX_TOOLWINDOW,
            "Shell_TrayWnd",
            "Custom System Tray",
            win32con.WS_POPUP,
            0, 0, 0, 0,
            0, 0, wc.hInstance, None
        )
        win32gui.SetWindowPos(self.hwnd, win32con.HWND_TOPMOST, 0, 0, 0, 0,
                              win32con.SWP_NOMOVE | win32con.SWP_NOSIZE | win32con.SWP_NOACTIVATE)

        # Send TaskbarCreated message
        self.taskbar_created_msg = win32gui.RegisterWindowMessage("TaskbarCreated")
        win32gui.SendMessage(HWND_BROADCAST, self.taskbar_created_msg, 0, 0)
        logger.debug(f"Sent TaskbarCreated message: {self.taskbar_created_msg}")

    def wnd_proc(self, hwnd, msg, wparam, lparam):
        if msg == WM_COPYDATA:
            copy_data = COPYDATASTRUCT.from_address(lparam)
            if copy_data.dwData == 1:  # Tray message
                nid = NOTIFYICONDATA.from_address(copy_data.lpData)
                return self.handle_tray_message(nid)
        elif msg == win32con.WM_DESTROY:
            win32gui.PostQuitMessage(0)
            return 0
        return win32gui.DefWindowProc(hwnd, msg, wparam, lparam)

    def handle_tray_message(self, nid):
        tray_id = nid.uID
        if nid.uFlags & NIF_MESSAGE:
            callback_msg = nid.uCallbackMessage
        else:
            callback_msg = None

        if nid.cbSize == 0:
            return 0

        # Handle tooltip
        tooltip = nid.szTip if nid.uFlags & NIF_TIP else ""

        # Handle icon (simplified)
        if nid.uFlags & NIF_ICON and nid.hIcon:
            hicon = nid.hIcon
            bitmap = win32gui.CreateCompatibleBitmap(win32gui.GetDC(0), 32, 32)
            hdc = win32gui.CreateCompatibleDC(0)
            win32gui.SelectObject(hdc, bitmap)
            win32gui.DrawIconEx(hdc, 0, 0, hicon, 32, 32, 0, 0, win32con.DI_NORMAL)
            icon = QIcon()  # Simplified; needs proper HICON to QIcon conversion
        else:
            icon = None

        # Manage tray icon
        if tray_id not in self.icons:
            tray_icon = QSystemTrayIcon(self.app)
            self.icons[tray_id] = tray_icon
        else:
            tray_icon = self.icons[tray_id]

        if tooltip:
            tray_icon.setToolTip(tooltip)
        if icon:
            tray_icon.setIcon(icon)

        # Handle tray message types
        if nid.cbSize in {NIM_ADD, NIM_MODIFY}:
            tray_icon.show()
            logger.debug(f"Added/Modified icon: {tray_id}, tooltip: {tooltip}")
            return 1  # Fake success response
        elif nid.cbSize == NIM_DELETE:
            tray_icon.hide()
            del self.icons[tray_id]
            logger.debug(f"Deleted icon: {tray_id}")
            return 1  # Fake success response

        return 1  # Default fake response

    def run(self):
        self.create_tray_window()
        win32gui.PumpMessages()

    def cleanup(self):
        for tray_icon in self.icons.values():
            tray_icon.hide()
        if self.hwnd:
            win32gui.DestroyWindow(self.hwnd)

if __name__ == "__main__":
    tray = CustomTray()
    try:
        tray.run()
    finally:
        tray.cleanup()```

[Video-Nomad]

This is exactly what systray widget is doing right now. However, "no explorer.exe" mode is not supported at the moment.

Right now, the systray monitor searches for the real systray/taskbar as fast as possible to not miss any messages it should pass to it. That's why you see high CPU usage if explorer.exe is not running as it hangs on that task. This can be modified to not forward any messages and just consume them if there's no explorer.exe detected, but then this will cause issues if the user just restarts the explorer (or it crashes and restarts for whatever reason).

Furthermore, some applications will have issues without explorer process and might just not run or crash. I already fixed some of them with tasks service but there might be even more hidden problems.

TL;DR - this adds an unnecessary complexity to already "hacky" systray solution. If there's any reason to not have explorer.exe on the background other than saving 100 MB of RAM I'm interested to hear it.

[MaximKiselev]

yes, I just meant to disable forwarding messages to the real explorer.
why do we need two system bars on the screen? (taskbar). That is, the system dock can be removed from the screen if you hide it or kill the explorer process. It turns out to be a duplication of functionality and a decrease in speed (the processor spends time on forwarding).
thanks.

[Video-Nomad]

It's not a duplication of functionality because YASB is not a fully functional shell replacement. We only take icons from the systray and events from the taskbar. That's it. Besides, some people do not use it as dock. Some people do not like the systray or taskbar widgets and prefer something like Windhawk to mod the native one. Some people use both + native taskbar. Forwarding messages is the only way to ensure that even when people use both - they still have all the icons in the native systray and they are fully functional. If YASB to consume all the messages, native systray would be empty or won't update already existing icons.

As I said, it is possible to simply ignore the native systray when explorer.exe is not running, but it's not something YASB is planning to support. Not unless we move to full shell replacement like ManagedShell or CairoShell.

[MaximKiselev]

Hi, thank you very much. I created a small app to improve the user experience using yasb TaskbarHider. I also checked out Windhawk hooks. As far as I understand, it injects itself into system processes, and we can, for example, set the taskbar height to zero. But completely disabling Explorer in Windows 11 without breaking something is difficult. 😰