From c79d8fa4163faf83796446b330225986ce5db275 Mon Sep 17 00:00:00 2001 From: Vince Salvino Date: Wed, 27 Oct 2021 17:32:09 -0400 Subject: [PATCH] Support system dark mode on Windows 10 version 1809 and higher * src/w32fns.c (DARK_MODE_APP_NAME) (DWMWA_USE_IMMERSIVE_DARK_MODE_OLD) (DWMWA_USE_IMMERSIVE_DARK_MODE): Define. (w32_applytheme): New function. (w32_createvscrollbar, w32_createhscrollbar, w32_createwindow): Call 'w32_applytheme'. (globals_of_w32fns): Load 'DwmSetWindowAttribute' and 'SetWindowTheme' from their DLLs, and initialize 'w32_darkmode'. * src/w32.c (w32_get_resource): Accept an additional argument instead of hard-coding REG_ROOT; callers changed. (Bug#51404) * etc/NEWS: * doc/emacs/msdos.texi (Windows Misc): Document the new feature. --- doc/emacs/msdos.texi | 7 ++++ etc/NEWS | 8 ++++ src/w32.c | 23 +++++++---- src/w32.h | 5 ++- src/w32fns.c | 91 +++++++++++++++++++++++++++++++++++++++++++- 5 files changed, 122 insertions(+), 12 deletions(-) diff --git a/doc/emacs/msdos.texi b/doc/emacs/msdos.texi index 0f8f429b3f8..3c6c61613e2 100644 --- a/doc/emacs/msdos.texi +++ b/doc/emacs/msdos.texi @@ -1181,6 +1181,13 @@ The default is @code{t}, which fits well with the Windows default click-to-focus policy. @end ifnottex + On Windows 10 (version 1809 and higher) and Windows 11, Emacs title +bars and scroll bars will follow the system Light or Dark mode, +similar to other programs such as Explorer and Command Prompt. To +change the color mode: Windows Settings > Personalization > Colors > +Choose your color (or Choose your default app mode); then restart +Emacs. + @ifnottex @include msdos-xtra.texi @end ifnottex diff --git a/etc/NEWS b/etc/NEWS index cc452211b68..51ff53da184 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -73,6 +73,14 @@ Image specifiers can now use ':type webp'. *** 'display-buffer' now can set up the body size of the chosen window. For example, an alist entry as '(window-width . (body-columns . 40))' will make the body of the chosen window 40 columns wide. + +** MS-Windows + ++++ +*** Supports dark mode on Windows 10 (version 1809 and higher) and Windows 11. +Graphical frames now use the appropriate light or dark title bar and +scroll bars, based on the user's Windows color settings. + * Editing Changes in Emacs 29.1 diff --git a/src/w32.c b/src/w32.c index 9fe698d28d7..369e7ee4e1f 100644 --- a/src/w32.c +++ b/src/w32.c @@ -2820,8 +2820,15 @@ sys_putenv (char *str) #define REG_ROOT "SOFTWARE\\GNU\\Emacs" +/* Query a value from the Windows Registry (under HKCU and HKLM), + where `key` is the registry key, `name` is the name, and `lpdwtype` + is a pointer to the return value's type. `lpwdtype` can be NULL if + you do not care about the type. + + Returns: pointer to the value, or null pointer if the key/name does + not exist. */ LPBYTE -w32_get_resource (const char *key, LPDWORD lpdwtype) +w32_get_resource (const char *key, const char *name, LPDWORD lpdwtype) { LPBYTE lpvalue; HKEY hrootkey = NULL; @@ -2830,13 +2837,13 @@ w32_get_resource (const char *key, LPDWORD lpdwtype) /* Check both the current user and the local machine to see if we have any resources. */ - if (RegOpenKeyEx (HKEY_CURRENT_USER, REG_ROOT, 0, KEY_READ, &hrootkey) == ERROR_SUCCESS) + if (RegOpenKeyEx (HKEY_CURRENT_USER, key, 0, KEY_READ, &hrootkey) == ERROR_SUCCESS) { lpvalue = NULL; - if (RegQueryValueEx (hrootkey, key, NULL, NULL, NULL, &cbData) == ERROR_SUCCESS + if (RegQueryValueEx (hrootkey, name, NULL, NULL, NULL, &cbData) == ERROR_SUCCESS && (lpvalue = xmalloc (cbData)) != NULL - && RegQueryValueEx (hrootkey, key, NULL, lpdwtype, lpvalue, &cbData) == ERROR_SUCCESS) + && RegQueryValueEx (hrootkey, name, NULL, lpdwtype, lpvalue, &cbData) == ERROR_SUCCESS) { RegCloseKey (hrootkey); return (lpvalue); @@ -2847,13 +2854,13 @@ w32_get_resource (const char *key, LPDWORD lpdwtype) RegCloseKey (hrootkey); } - if (RegOpenKeyEx (HKEY_LOCAL_MACHINE, REG_ROOT, 0, KEY_READ, &hrootkey) == ERROR_SUCCESS) + if (RegOpenKeyEx (HKEY_LOCAL_MACHINE, key, 0, KEY_READ, &hrootkey) == ERROR_SUCCESS) { lpvalue = NULL; - if (RegQueryValueEx (hrootkey, key, NULL, NULL, NULL, &cbData) == ERROR_SUCCESS + if (RegQueryValueEx (hrootkey, name, NULL, NULL, NULL, &cbData) == ERROR_SUCCESS && (lpvalue = xmalloc (cbData)) != NULL - && RegQueryValueEx (hrootkey, key, NULL, lpdwtype, lpvalue, &cbData) == ERROR_SUCCESS) + && RegQueryValueEx (hrootkey, name, NULL, lpdwtype, lpvalue, &cbData) == ERROR_SUCCESS) { RegCloseKey (hrootkey); return (lpvalue); @@ -3077,7 +3084,7 @@ init_environment (char ** argv) int dont_free = 0; char bufc[SET_ENV_BUF_SIZE]; - if ((lpval = w32_get_resource (env_vars[i].name, &dwType)) == NULL + if ((lpval = w32_get_resource (REG_ROOT, env_vars[i].name, &dwType)) == NULL /* Also ignore empty environment variables. */ || *lpval == 0) { diff --git a/src/w32.h b/src/w32.h index ffa145b1484..ec0f37123e8 100644 --- a/src/w32.h +++ b/src/w32.h @@ -161,8 +161,9 @@ extern void prepare_standard_handles (int in, int out, extern void reset_standard_handles (int in, int out, int err, HANDLE handles[4]); -/* Return the string resource associated with KEY of type TYPE. */ -extern LPBYTE w32_get_resource (const char * key, LPDWORD type); +/* Query Windows Registry and return the resource associated + associated with KEY and NAME of type TYPE. */ +extern LPBYTE w32_get_resource (const char * key, const char * name, LPDWORD type); extern void release_listen_threads (void); extern void init_ntproc (int); diff --git a/src/w32fns.c b/src/w32fns.c index 14d1154a2bc..bcf0f50c6a6 100644 --- a/src/w32fns.c +++ b/src/w32fns.c @@ -73,6 +73,18 @@ along with GNU Emacs. If not, see . */ #include #include +/* + Internal/undocumented constants for Windows Dark mode. + See: https://github.com/microsoft/WindowsAppSDK/issues/41 +*/ +#define DARK_MODE_APP_NAME L"DarkMode_Explorer" +/* For Windows 10 version 1809, 1903, 1909. */ +#define DWMWA_USE_IMMERSIVE_DARK_MODE_OLD 19 +/* For Windows 10 version 2004 and higher, and Windows 11. */ +#ifndef DWMWA_USE_IMMERSIVE_DARK_MODE +#define DWMWA_USE_IMMERSIVE_DARK_MODE 20 +#endif + #ifndef FOF_NO_CONNECTED_ELEMENTS #define FOF_NO_CONNECTED_ELEMENTS 0x2000 #endif @@ -185,6 +197,11 @@ typedef BOOL (WINAPI *IsDebuggerPresent_Proc) (void); typedef HRESULT (WINAPI *SetThreadDescription_Proc) (HANDLE hThread, PCWSTR lpThreadDescription); +typedef HRESULT (WINAPI * SetWindowTheme_Proc) + (IN HWND hwnd, IN LPCWSTR pszSubAppName, IN LPCWSTR pszSubIdList); +typedef HRESULT (WINAPI * DwmSetWindowAttribute_Proc) + (HWND hwnd, DWORD dwAttribute, IN LPCVOID pvAttribute, DWORD cbAttribute); + TrackMouseEvent_Proc track_mouse_event_fn = NULL; ImmGetCompositionString_Proc get_composition_string_fn = NULL; ImmGetContext_Proc get_ime_context_fn = NULL; @@ -199,6 +216,8 @@ EnumDisplayMonitors_Proc enum_display_monitors_fn = NULL; GetTitleBarInfo_Proc get_title_bar_info_fn = NULL; IsDebuggerPresent_Proc is_debugger_present = NULL; SetThreadDescription_Proc set_thread_description = NULL; +SetWindowTheme_Proc SetWindowTheme_fn = NULL; +DwmSetWindowAttribute_Proc DwmSetWindowAttribute_fn = NULL; extern AppendMenuW_Proc unicode_append_menu; @@ -252,6 +271,9 @@ int w32_major_version; int w32_minor_version; int w32_build_number; +/* If the OS is set to use dark mode. */ +BOOL w32_darkmode = FALSE; + /* Distinguish between Windows NT and Windows 95. */ int os_subtype; @@ -2279,10 +2301,36 @@ w32_init_class (HINSTANCE hinst) } } +/* Applies the Windows system theme (light or dark) to a window handle. */ +static void +w32_applytheme (HWND hwnd) +{ + if (w32_darkmode) + { + /* Set window theme to that of a built-in Windows app (Explorer) + because it has dark scroll bars and other UI elements. */ + if (SetWindowTheme_fn) + { + SetWindowTheme_fn (hwnd, DARK_MODE_APP_NAME, NULL); + } + /* Set the titlebar to system dark mode. */ + if (DwmSetWindowAttribute_fn) + { + /* Windows 10 version 2004 and up, Windows 11. */ + DWORD attr = DWMWA_USE_IMMERSIVE_DARK_MODE; + /* Windows 10 older than 2004. */ + if (w32_build_number < 19041) + attr = DWMWA_USE_IMMERSIVE_DARK_MODE_OLD; + DwmSetWindowAttribute_fn + (hwnd, attr, &w32_darkmode, sizeof(w32_darkmode)); + } + } +} + static HWND w32_createvscrollbar (struct frame *f, struct scroll_bar * bar) { - return CreateWindow ("SCROLLBAR", "", + HWND hwnd = CreateWindow ("SCROLLBAR", "", /* Clip siblings so we don't draw over child frames. Apparently this is not always sufficient so we also try to make bar windows @@ -2291,12 +2339,15 @@ w32_createvscrollbar (struct frame *f, struct scroll_bar * bar) /* Position and size of scroll bar. */ bar->left, bar->top, bar->width, bar->height, FRAME_W32_WINDOW (f), NULL, hinst, NULL); + if (hwnd) + w32_applytheme (hwnd); + return hwnd; } static HWND w32_createhscrollbar (struct frame *f, struct scroll_bar * bar) { - return CreateWindow ("SCROLLBAR", "", + HWND hwnd = CreateWindow ("SCROLLBAR", "", /* Clip siblings so we don't draw over child frames. Apparently this is not always sufficient so we also try to make bar windows @@ -2305,6 +2356,9 @@ w32_createhscrollbar (struct frame *f, struct scroll_bar * bar) /* Position and size of scroll bar. */ bar->left, bar->top, bar->width, bar->height, FRAME_W32_WINDOW (f), NULL, hinst, NULL); + if (hwnd) + w32_applytheme (hwnd); + return hwnd; } static void @@ -2390,6 +2444,9 @@ w32_createwindow (struct frame *f, int *coords) /* Enable drag-n-drop. */ DragAcceptFiles (hwnd, TRUE); + /* Enable system light/dark theme. */ + w32_applytheme (hwnd); + /* Do this to discard the default setting specified by our parent. */ ShowWindow (hwnd, SW_HIDE); @@ -11028,6 +11085,36 @@ globals_of_w32fns (void) set_thread_description = (SetThreadDescription_Proc) get_proc_addr (hm_kernel32, "SetThreadDescription"); + /* Support OS dark mode on Windows 10 version 1809 and higher. + See `w32_applytheme` which uses appropriate APIs per version of Windows. + For future wretches who may need to understand Windows build numbers: + https://docs.microsoft.com/en-us/windows/release-health/release-information + */ + if (w32_major_version >= 10 && w32_build_number >= 17763 + && os_subtype == OS_SUBTYPE_NT) + { + /* Load dwmapi and uxtheme, which will be needed to set window themes. */ + HMODULE dwmapi_lib = LoadLibrary("dwmapi.dll"); + DwmSetWindowAttribute_fn = (DwmSetWindowAttribute_Proc) + get_proc_addr (dwmapi_lib, "DwmSetWindowAttribute"); + HMODULE uxtheme_lib = LoadLibrary("uxtheme.dll"); + SetWindowTheme_fn = (SetWindowTheme_Proc) + get_proc_addr (uxtheme_lib, "SetWindowTheme"); + + /* Check Windows Registry for system theme. DWORD set to 0 or 1. + TODO: "Nice to have" would be to create a lisp setting (which + defaults to this Windows Registry value), then read that lisp + value here instead. This would allow the user to forcibly + override the system theme (which is also user-configurable in + Windows settings; see MS-Windows section in Emacs manual). */ + LPBYTE val = w32_get_resource + ("Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize", + "AppsUseLightTheme", + NULL); + if (val && (DWORD)*val == 0) + w32_darkmode = TRUE; + } + except_code = 0; except_addr = 0; #ifndef CYGWIN -- 2.39.2