From e34040e75a97e5b17d31c6d0f6df007cce5ddfc6 Mon Sep 17 00:00:00 2001
From: Amr Bashir <amr.bashir2015@gmail.com>
Date: Wed, 20 Sep 2023 23:41:59 +0300
Subject: [PATCH] fix(windows): draw over white line below menu (#126)

---
 .changes/windwos-white-line.md             |  5 ++
 examples/wry.rs                            | 18 ++++--
 src/platform_impl/windows/dark_menu_bar.rs | 71 ++++++++++++++++------
 src/platform_impl/windows/mod.rs           | 33 ++++++----
 4 files changed, 93 insertions(+), 34 deletions(-)
 create mode 100644 .changes/windwos-white-line.md
diff --git a/.changes/windwos-white-line.md b/.changes/windwos-white-line.md
new file mode 100644
index 00000000..63257b07
--- /dev/null
+++ b/.changes/windwos-white-line.md
@@ -0,0 +1,5 @@
+---
+"muda": "patch"
+---
+
+On Windows, draw over the white line under the menubar in dark mode.
diff --git a/examples/wry.rs b/examples/wry.rs
index bf24213b..635755cd 100644
--- a/examples/wry.rs
+++ b/examples/wry.rs
@@ -177,15 +177,25 @@ fn main() -> wry::Result<()> {
     <html>
     <body>
         <style>
+            * {{
+                padding: 0;
+                margin: 0;
+                box-sizing: border-box;
+                font-family: Inter, Avenir, Helvetica, Arial, sans-serif;
+            }}
             main {{
-                width: 100vw;
-                height: 100vh;
+                    width: 100vw;
+                    height: 100vh;
+            }}
+            @media (prefers-color-scheme: dark) {{
+                main {{
+                    color: #fff;
+                    background: #2f2f2f;
+                }}
             }}
         </style>
         <main>
             <h4> WRYYYYYYYYYYYYYYYYYYYYYY! </h4>
-            <input />
-            <button> Hi </button>
         </main>
         <script>
             window.addEventListener('contextmenu', (e) => {{
diff --git a/src/platform_impl/windows/dark_menu_bar.rs b/src/platform_impl/windows/dark_menu_bar.rs
index 79ffa1e0..526a338f 100644
--- a/src/platform_impl/windows/dark_menu_bar.rs
+++ b/src/platform_impl/windows/dark_menu_bar.rs
@@ -4,14 +4,17 @@
 
 // this is a port of combination of https://github.com/hrydgard/ppsspp/blob/master/Windows/W32Util/UAHMenuBar.cpp and https://github.com/ysc3839/win32-darkmode/blob/master/win32-darkmode/DarkMode.h
 
-#![allow(non_snake_case)]
+#![allow(non_snake_case, clippy::upper_case_acronyms)]
 
 use once_cell::sync::Lazy;
 use windows_sys::{
     s, w,
     Win32::{
         Foundation::{HMODULE, HWND, LPARAM, RECT, WPARAM},
-        Graphics::Gdi::{OffsetRect, DT_CENTER, DT_HIDEPREFIX, DT_SINGLELINE, DT_VCENTER, HDC},
+        Graphics::Gdi::{
+            GetWindowDC, MapWindowPoints, OffsetRect, ReleaseDC, DT_CENTER, DT_HIDEPREFIX,
+            DT_SINGLELINE, DT_VCENTER, HDC,
+        },
         System::LibraryLoader::{GetProcAddress, LoadLibraryA},
         UI::{
             Accessibility::HIGHCONTRASTA,
@@ -21,8 +24,9 @@ use windows_sys::{
                 ODS_GRAYED, ODS_HOTLIGHT, ODS_INACTIVE, ODS_NOACCEL, ODS_SELECTED,
             },
             WindowsAndMessaging::{
-                GetMenuBarInfo, GetMenuItemInfoW, GetWindowRect, SystemParametersInfoA, HMENU,
-                MENUBARINFO, MENUITEMINFOW, MIIM_STRING, OBJID_MENU, SPI_GETHIGHCONTRAST,
+                GetClientRect, GetMenuBarInfo, GetMenuItemInfoW, GetWindowRect,
+                SystemParametersInfoA, HMENU, MENUBARINFO, MENUITEMINFOW, MIIM_STRING, OBJID_MENU,
+                SPI_GETHIGHCONTRAST, WM_NCACTIVATE, WM_NCPAINT,
             },
         },
     },
@@ -69,12 +73,49 @@ struct UAHDRAWMENUITEM {
 }
 
 /// Draws a dark menu bar if needed and returns whether it draws it or not
-pub fn draw(hwnd: HWND, msg: u32, _wparam: WPARAM, lparam: LPARAM) -> bool {
-    if !should_use_dark_mode(hwnd) {
-        return false;
-    }
-
+pub fn draw(hwnd: HWND, msg: u32, _wparam: WPARAM, lparam: LPARAM) {
     match msg {
+        // draw over the annoying white line blow menubar
+        // ref: https://github.com/notepad-plus-plus/notepad-plus-plus/pull/9985
+        WM_NCACTIVATE | WM_NCPAINT => {
+            let mut mbi = MENUBARINFO {
+                cbSize: std::mem::size_of::<MENUBARINFO>() as _,
+                ..unsafe { std::mem::zeroed() }
+            };
+            unsafe { GetMenuBarInfo(hwnd, OBJID_MENU, 0, &mut mbi) };
+
+            let mut client_rc: RECT = unsafe { std::mem::zeroed() };
+            unsafe {
+                GetClientRect(hwnd, &mut client_rc);
+                MapWindowPoints(hwnd, 0, &mut client_rc as *mut _ as *mut _, 2);
+            };
+
+            let mut window_rc: RECT = unsafe { std::mem::zeroed() };
+            unsafe { GetWindowRect(hwnd, &mut window_rc) };
+
+            unsafe { OffsetRect(&mut client_rc, -window_rc.left, -window_rc.top) };
+
+            let mut annoying_rc = client_rc;
+            annoying_rc.bottom = annoying_rc.top;
+            annoying_rc.top -= 1;
+
+            unsafe {
+                let theme = OpenThemeData(hwnd, w!("Menu"));
+                let hdc = GetWindowDC(hwnd);
+                DrawThemeBackground(
+                    theme,
+                    hdc,
+                    MENU_POPUPITEM,
+                    MPI_NORMAL,
+                    &annoying_rc,
+                    std::ptr::null(),
+                );
+                ReleaseDC(hwnd, hdc);
+                CloseThemeData(theme);
+            }
+        }
+
+        // draw menu bar background
         WM_UAHDRAWMENU => {
             let pudm = lparam as *const UAHMENU;
 
@@ -86,9 +127,7 @@ pub fn draw(hwnd: HWND, msg: u32, _wparam: WPARAM, lparam: LPARAM) -> bool {
                 };
                 unsafe { GetMenuBarInfo(hwnd, OBJID_MENU, 0, &mut mbi) };
 
-                let mut window_rc = RECT {
-                    ..unsafe { std::mem::zeroed() }
-                };
+                let mut window_rc: RECT = unsafe { std::mem::zeroed() };
                 unsafe { GetWindowRect(hwnd, &mut window_rc) };
 
                 let mut rc = mbi.rcBar;
@@ -100,7 +139,6 @@ pub fn draw(hwnd: HWND, msg: u32, _wparam: WPARAM, lparam: LPARAM) -> bool {
 
             unsafe {
                 let theme = OpenThemeData(hwnd, w!("Menu"));
-
                 DrawThemeBackground(
                     theme,
                     (*pudm).hdc,
@@ -113,6 +151,7 @@ pub fn draw(hwnd: HWND, msg: u32, _wparam: WPARAM, lparam: LPARAM) -> bool {
             }
         }
 
+        // draw menu bar items
         WM_UAHDRAWMENUITEM => {
             let pudmi = lparam as *const UAHDRAWMENUITEM;
 
@@ -194,13 +233,11 @@ pub fn draw(hwnd: HWND, msg: u32, _wparam: WPARAM, lparam: LPARAM) -> bool {
             }
         }
 
-        _ => return false,
+        _ => {}
     };
-
-    true
 }
 
-fn should_use_dark_mode(hwnd: HWND) -> bool {
+pub fn should_use_dark_mode(hwnd: HWND) -> bool {
     should_apps_use_dark_mode() && !is_high_contrast() && is_dark_mode_allowed_for_window(hwnd)
 }
 
diff --git a/src/platform_impl/windows/mod.rs b/src/platform_impl/windows/mod.rs
index 0beca38a..7033c0ee 100644
--- a/src/platform_impl/windows/mod.rs
+++ b/src/platform_impl/windows/mod.rs
@@ -38,7 +38,7 @@ use windows_sys::Win32::{
             HMENU, MENUITEMINFOW, MFS_CHECKED, MFS_DISABLED, MF_BYCOMMAND, MF_BYPOSITION,
             MF_CHECKED, MF_DISABLED, MF_ENABLED, MF_GRAYED, MF_POPUP, MF_SEPARATOR, MF_STRING,
             MF_UNCHECKED, MIIM_BITMAP, MIIM_STATE, MIIM_STRING, SW_HIDE, SW_MAXIMIZE, SW_MINIMIZE,
-            TPM_LEFTALIGN, WM_CLOSE, WM_COMMAND,
+            TPM_LEFTALIGN, WM_CLOSE, WM_COMMAND, WM_NCACTIVATE, WM_NCPAINT,
         },
     },
 };
@@ -1070,7 +1070,6 @@ unsafe extern "system" fn menu_subclass_proc(
     uidsubclass: usize,
     dwrefdata: usize,
 ) -> LRESULT {
-    let mut ret = None;
     match msg {
         WM_COMMAND => {
             let id = util::LOWORD(wparam as _) as u32;
@@ -1083,8 +1082,6 @@ unsafe extern "system" fn menu_subclass_proc(
             };
 
             if let Some(item) = item {
-                ret = Some(0);
-
                 let (mut dispatch, mut menu_id) = (true, None);
 
                 {
@@ -1149,22 +1146,32 @@ unsafe extern "system" fn menu_subclass_proc(
                         id: menu_id.unwrap(),
                     });
                 }
+
+                0
+            } else {
+                DefSubclassProc(hwnd, msg, wparam, lparam)
             }
         }
 
         WM_UAHDRAWMENUITEM | WM_UAHDRAWMENU => {
-            if dark_menu_bar::draw(hwnd, msg, wparam, lparam) {
-                ret = Some(0);
+            if dark_menu_bar::should_use_dark_mode(hwnd) {
+                dark_menu_bar::draw(hwnd, msg, wparam, lparam);
+                0
+            } else {
+                DefSubclassProc(hwnd, msg, wparam, lparam)
             }
         }
+        WM_NCACTIVATE | WM_NCPAINT => {
+            // DefSubclassProc needs to be called before calling the
+            // custom dark menu redraw
+            let res = DefSubclassProc(hwnd, msg, wparam, lparam);
+            if dark_menu_bar::should_use_dark_mode(hwnd) {
+                dark_menu_bar::draw(hwnd, msg, wparam, lparam);
+            }
+            res
+        }
 
-        _ => {}
-    };
-
-    if let Some(ret) = ret {
-        ret
-    } else {
-        DefSubclassProc(hwnd, msg, wparam, lparam)
+        _ => DefSubclassProc(hwnd, msg, wparam, lparam),
     }
 }
 
