Dark Titlebar in Dark Mode

[16Integer]

I propose that we add a dark titlebar when the dark mode is set or the system theme is dark mode in Flet, using CTypes to set the dark titlebar. I have made a sample code below. This can be done by adding this into the core code of Flet. Or, if you are looking for a dark titlebar in dark mode, you may use this sample code.

import win32gui
import win32process
import psutil
import flet as ft
import ctypes as ct
import darkdetect


def get_process_id_by_name(process_name):
    pids = []
    for proc in psutil.process_iter():
        if process_name in proc.name():
            pids.append(proc.pid)
    return pids


def get_hwnds_for_pid(pid):
    def callback(hwnd, hwnds):
        _, found_pid = win32process.GetWindowThreadProcessId(hwnd)
        if found_pid == pid:
            hwnds.append(hwnd)
        return True

    hwnds = []
    win32gui.EnumWindows(callback, hwnds)
    return hwnds


def get_hwnd_by_path():
    process_name = "flet.exe"
    pids = get_process_id_by_name(process_name)
    for pid in pids:
        hwnds = get_hwnds_for_pid(pid)
        for hwnd in hwnds:
            if win32gui.IsWindowVisible(hwnd):
                return hwnd


def light_mode(page, light_button):
    hwnd = get_hwnd_by_path()
    DWWMA_USE_IMMERSIVE_DARK_MODE = 20
    set_window_attribute = ct.windll.dwmapi.DwmSetWindowAttribute
    renduring_policy = DWWMA_USE_IMMERSIVE_DARK_MODE
    value = 0
    value = ct.c_int(value)
    set_window_attribute(hwnd, renduring_policy, ct.byref(value), ct.sizeof(value))
    page.theme_mode = "light"
    page.remove(light_button)
    dark_button = ft.ElevatedButton(
        "Dark mode", on_click=lambda e: dark_mode(page, dark_button)
    )
    page.add(dark_button)


def dark_mode(page, dark_button):
    hwnd = get_hwnd_by_path()
    DWWMA_USE_IMMERSIVE_DARK_MODE = 20
    set_window_attribute = ct.windll.dwmapi.DwmSetWindowAttribute
    renduring_policy = DWWMA_USE_IMMERSIVE_DARK_MODE
    value = 2
    value = ct.c_int(value)
    set_window_attribute(hwnd, renduring_policy, ct.byref(value), ct.sizeof(value))
    page.theme_mode = "dark"
    page.remove(dark_button)
    light_button = ft.ElevatedButton(
        "Light mode", on_click=lambda e: light_mode(page, light_button)
    )
    page.add(light_button)


def main(page: ft.Page):
    if darkdetect.theme() == "Dark":
        hwnd = get_hwnd_by_path()
        DWWMA_USE_IMMERSIVE_DARK_MODE = 20
        set_window_attribute = ct.windll.dwmapi.DwmSetWindowAttribute
        renduring_policy = DWWMA_USE_IMMERSIVE_DARK_MODE
        value = 2
        value = ct.c_int(value)
        set_window_attribute(hwnd, renduring_policy, ct.byref(value), ct.sizeof(value))
        page.update()
        light_button = ft.ElevatedButton(
            "Light mode", on_click=lambda e: light_mode(page, light_button)
        )
        page.add(light_button)
    else:
        dark_button = ft.ElevatedButton(
            "Dark mode", on_click=lambda e: dark_mode(page, dark_button)
        )
        page.add(dark_button)


if __name__ == "__main__":
    ft.app(target=main)