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feat: honor nativeTheme.themeSource = 'dark' before creating BrowserWindow on Windows (electron#25373)
* fix: support 'dark' theme before creating windows.
1 parent d3f32c7 commit f489e30

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‎BUILD.gn‎

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@@ -673,6 +673,14 @@ source_set("electron_lib") {
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}
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sources += get_target_outputs(":electron_fuses")
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if (is_win && enable_win_dark_mode_window_ui) {
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sources += [
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"shell/browser/win/dark_mode.cc",
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"shell/browser/win/dark_mode.h",
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]
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libs += [ "uxtheme.lib" ]
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}
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}
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electron_paks("packed_resources") {

‎buildflags/BUILD.gn‎

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@@ -20,6 +20,7 @@ buildflag_header("buildflags") {
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"ENABLE_ELECTRON_EXTENSIONS=$enable_electron_extensions",
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"ENABLE_BUILTIN_SPELLCHECKER=$enable_builtin_spellchecker",
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"ENABLE_PICTURE_IN_PICTURE=$enable_picture_in_picture",
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"ENABLE_WIN_DARK_MODE_WINDOW_UI=$enable_win_dark_mode_window_ui",
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"OVERRIDE_LOCATION_PROVIDER=$enable_fake_location_provider",
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]
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}

‎buildflags/buildflags.gni‎

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@@ -33,4 +33,7 @@ declare_args() {
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# Enable Spellchecker support
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enable_builtin_spellchecker = true
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# Undocumented Windows dark mode API
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enable_win_dark_mode_window_ui = false
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}

‎shell/browser/ui/win/electron_desktop_window_tree_host_win.cc‎

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@@ -5,9 +5,15 @@
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#include "shell/browser/ui/win/electron_desktop_window_tree_host_win.h"
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#include "base/win/windows_version.h"
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#include "electron/buildflags/buildflags.h"
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#include "shell/browser/ui/views/win_frame_view.h"
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#include "ui/base/win/hwnd_metrics.h"
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#include "ui/base/win/shell.h"
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#if BUILDFLAG(ENABLE_WIN_DARK_MODE_WINDOW_UI)
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#include "shell/browser/win/dark_mode.h"
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#endif
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namespace electron {
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ElectronDesktopWindowTreeHostWin::ElectronDesktopWindowTreeHostWin(
@@ -23,6 +29,15 @@ bool ElectronDesktopWindowTreeHostWin::PreHandleMSG(UINT message,
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WPARAM w_param,
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LPARAM l_param,
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LRESULT* result) {
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#if BUILDFLAG(ENABLE_WIN_DARK_MODE_WINDOW_UI)
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if (message == WM_NCCREATE) {
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HWND const hwnd = GetAcceleratedWidget();
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auto const theme_source =
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ui::NativeTheme::GetInstanceForNativeUi()->theme_source();
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win::SetDarkModeForWindow(hwnd, theme_source);
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}
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#endif
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return native_window_view_->PreHandleMSG(message, w_param, l_param, result);
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}
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‎shell/browser/win/dark_mode.cc‎

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@@ -0,0 +1,180 @@
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// Copyright (c) 2020 Microsoft Inc. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE-CHROMIUM file.
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#include "shell/browser/win/dark_mode.h"
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#include <dwmapi.h> // DwmSetWindowAttribute()
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#include "base/files/file_path.h"
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#include "base/scoped_native_library.h"
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#include "base/win/pe_image.h"
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#include "base/win/win_util.h"
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#include "base/win/windows_version.h"
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// This namespace contains code originally from
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// https://github.com/ysc3839/win32-darkmode/
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// governed by the MIT license and (c) Richard Yu
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namespace {
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// 1903 18362
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enum PreferredAppMode { Default, AllowDark, ForceDark, ForceLight, Max };
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bool g_darkModeSupported = false;
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bool g_darkModeEnabled = false;
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DWORD g_buildNumber = 0;
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enum WINDOWCOMPOSITIONATTRIB {
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WCA_USEDARKMODECOLORS = 26 // build 18875+
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};
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struct WINDOWCOMPOSITIONATTRIBDATA {
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WINDOWCOMPOSITIONATTRIB Attrib;
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PVOID pvData;
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SIZE_T cbData;
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};
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using fnSetWindowCompositionAttribute =
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BOOL(WINAPI*)(HWND hWnd, WINDOWCOMPOSITIONATTRIBDATA*);
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fnSetWindowCompositionAttribute _SetWindowCompositionAttribute = nullptr;
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bool IsHighContrast() {
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HIGHCONTRASTW highContrast = {sizeof(highContrast)};
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if (SystemParametersInfoW(SPI_GETHIGHCONTRAST, sizeof(highContrast),
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&highContrast, FALSE))
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return highContrast.dwFlags & HCF_HIGHCONTRASTON;
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return false;
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}
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void RefreshTitleBarThemeColor(HWND hWnd, bool dark) {
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LONG ldark = dark;
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if (g_buildNumber >= 20161) {
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// DWMA_USE_IMMERSIVE_DARK_MODE = 20
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DwmSetWindowAttribute(hWnd, 20, &ldark, sizeof dark);
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return;
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}
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if (g_buildNumber >= 18363) {
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auto data = WINDOWCOMPOSITIONATTRIBDATA{WCA_USEDARKMODECOLORS, &ldark,
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sizeof ldark};
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_SetWindowCompositionAttribute(hWnd, &data);
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return;
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}
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DwmSetWindowAttribute(hWnd, 0x13, &ldark, sizeof ldark);
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}
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void InitDarkMode() {
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// confirm that we're running on a version of Windows
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// where the Dark Mode API is known
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auto* os_info = base::win::OSInfo::GetInstance();
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g_buildNumber = os_info->version_number().build;
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auto const version = os_info->version();
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if ((version < base::win::Version::WIN10_RS5) ||
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(version > base::win::Version::WIN10_20H1)) {
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return;
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}
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// load "SetWindowCompositionAttribute", used in RefreshTitleBarThemeColor()
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_SetWindowCompositionAttribute =
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reinterpret_cast<decltype(_SetWindowCompositionAttribute)>(
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base::win::GetUser32FunctionPointer("SetWindowCompositionAttribute"));
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if (_SetWindowCompositionAttribute == nullptr) {
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return;
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}
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// load the dark mode functions from uxtheme.dll
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// * RefreshImmersiveColorPolicyState()
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// * ShouldAppsUseDarkMode()
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// * AllowDarkModeForApp()
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// * SetPreferredAppMode()
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// * AllowDarkModeForApp() (build < 18362)
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// * SetPreferredAppMode() (build >= 18362)
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base::NativeLibrary uxtheme =
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base::PinSystemLibrary(FILE_PATH_LITERAL("uxtheme.dll"));
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if (!uxtheme) {
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return;
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}
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auto ux_pei = base::win::PEImage(uxtheme);
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auto get_ux_proc_from_ordinal = [&ux_pei](int ordinal, auto* setme) {
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FARPROC proc = ux_pei.GetProcAddress(reinterpret_cast<LPCSTR>(ordinal));
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*setme = reinterpret_cast<decltype(*setme)>(proc);
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};
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// ordinal 104
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using fnRefreshImmersiveColorPolicyState = VOID(WINAPI*)();
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fnRefreshImmersiveColorPolicyState _RefreshImmersiveColorPolicyState = {};
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get_ux_proc_from_ordinal(104, &_RefreshImmersiveColorPolicyState);
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// ordinal 132
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using fnShouldAppsUseDarkMode = BOOL(WINAPI*)();
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fnShouldAppsUseDarkMode _ShouldAppsUseDarkMode = {};
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get_ux_proc_from_ordinal(132, &_ShouldAppsUseDarkMode);
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// ordinal 135, in 1809
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using fnAllowDarkModeForApp = BOOL(WINAPI*)(BOOL allow);
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fnAllowDarkModeForApp _AllowDarkModeForApp = {};
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// ordinal 135, in 1903
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typedef PreferredAppMode(WINAPI *
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fnSetPreferredAppMode)(PreferredAppMode appMode);
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fnSetPreferredAppMode _SetPreferredAppMode = {};
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if (g_buildNumber < 18362) {
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get_ux_proc_from_ordinal(135, &_AllowDarkModeForApp);
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} else {
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get_ux_proc_from_ordinal(135, &_SetPreferredAppMode);
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}
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// dark mode is supported iff we found the functions
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g_darkModeSupported = _RefreshImmersiveColorPolicyState &&
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_ShouldAppsUseDarkMode &&
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(_AllowDarkModeForApp || _SetPreferredAppMode);
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if (!g_darkModeSupported) {
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return;
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}
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// initial setup: allow dark mode to be used
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if (_AllowDarkModeForApp) {
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_AllowDarkModeForApp(true);
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} else if (_SetPreferredAppMode) {
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_SetPreferredAppMode(AllowDark);
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}
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_RefreshImmersiveColorPolicyState();
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// check to see if dark mode is currently enabled
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g_darkModeEnabled = _ShouldAppsUseDarkMode() && !IsHighContrast();
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}
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} // namespace
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namespace electron {
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void EnsureInitialized() {
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static bool initialized = false;
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if (!initialized) {
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initialized = true;
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::InitDarkMode();
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}
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}
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bool IsDarkPreferred(ui::NativeTheme::ThemeSource theme_source) {
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switch (theme_source) {
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case ui::NativeTheme::ThemeSource::kForcedLight:
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return false;
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case ui::NativeTheme::ThemeSource::kForcedDark:
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return g_darkModeSupported;
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case ui::NativeTheme::ThemeSource::kSystem:
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return g_darkModeEnabled;
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}
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}
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namespace win {
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void SetDarkModeForWindow(HWND hWnd,
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ui::NativeTheme::ThemeSource theme_source) {
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EnsureInitialized();
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RefreshTitleBarThemeColor(hWnd, IsDarkPreferred(theme_source));
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}
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} // namespace win
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} // namespace electron

‎shell/browser/win/dark_mode.h‎

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@@ -0,0 +1,28 @@
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// Copyright (c) 2020 Microsoft Inc. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE-CHROMIUM file.
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#ifndef SHELL_BROWSER_WIN_DARK_MODE_H_
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#define SHELL_BROWSER_WIN_DARK_MODE_H_
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#ifdef WIN32_LEAN_AND_MEAN
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#include <Windows.h>
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#else
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#define WIN32_LEAN_AND_MEAN
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#include <Windows.h>
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#undef WIN32_LEAN_AND_MEAN
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#endif
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#include "ui/native_theme/native_theme.h"
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namespace electron {
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namespace win {
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void SetDarkModeForWindow(HWND hWnd, ui::NativeTheme::ThemeSource theme_source);
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} // namespace win
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} // namespace electron
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#endif // SHELL_BROWSER_WIN_DARK_MODE_H_

‎shell/common/api/features.cc‎

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@@ -58,6 +58,10 @@ bool IsPictureInPictureEnabled() {
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return BUILDFLAG(ENABLE_PICTURE_IN_PICTURE);
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}
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bool IsWinDarkModeWindowUiEnabled() {
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return BUILDFLAG(ENABLE_WIN_DARK_MODE_WINDOW_UI);
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}
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bool IsComponentBuild() {
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#if defined(COMPONENT_BUILD)
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return true;
@@ -85,6 +89,7 @@ void Initialize(v8::Local<v8::Object> exports,
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dict.SetMethod("isPictureInPictureEnabled", &IsPictureInPictureEnabled);
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dict.SetMethod("isComponentBuild", &IsComponentBuild);
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dict.SetMethod("isExtensionsEnabled", &IsExtensionsEnabled);
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dict.SetMethod("isWinDarkModeWindowUiEnabled", &IsWinDarkModeWindowUiEnabled);
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}
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} // namespace

‎typings/internal-ambient.d.ts‎

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@@ -24,6 +24,7 @@ declare namespace NodeJS {
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isPictureInPictureEnabled(): boolean;
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isExtensionsEnabled(): boolean;
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isComponentBuild(): boolean;
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isWinDarkModeWindowUiEnabled(): boolean;
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}
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interface IpcRendererBinding {

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