Use the Tauri implementation of the DPI-change fix

Cargo.toml

@@ -204,6 +204,7 @@ features = [
 
 [target.'cfg(target_os = "windows")'.dependencies]
 unicode-segmentation = "1.7.1"
+windows-version = "0.1.1"
 
 [target.'cfg(target_os = "windows")'.dependencies.windows-sys]
 version = "0.52.0"

src/platform_impl/windows/event_loop.rs

@@ -18,8 +18,8 @@ use crate::utils::Lazy;
 use windows_sys::Win32::Devices::HumanInterfaceDevice::MOUSE_MOVE_RELATIVE;
 use windows_sys::Win32::Foundation::{HWND, LPARAM, LRESULT, POINT, RECT, WPARAM};
 use windows_sys::Win32::Graphics::Gdi::{
-    MonitorFromRect, RedrawWindow, ScreenToClient, ValidateRect, MONITOR_DEFAULTTONULL,
-    RDW_INTERNALPAINT, SC_SCREENSAVE,
+    GetMonitorInfoW, MonitorFromRect, MonitorFromWindow, RedrawWindow, ScreenToClient,
+    ValidateRect, MONITORINFO, MONITOR_DEFAULTTONULL, RDW_INTERNALPAINT, SC_SCREENSAVE,
 };
 use windows_sys::Win32::System::Ole::RevokeDragDrop;
 use windows_sys::Win32::System::Threading::{GetCurrentThreadId, INFINITE};
@@ -2196,45 +2196,110 @@ unsafe fn public_window_callback_inner(
             }
 
             let new_outer_rect: RECT;
-            {
-                let suggested_ul =
-                    (suggested_rect.left + margin_left, suggested_rect.top + margin_top);
-
-                let mut conservative_rect = RECT {
-                    left: suggested_ul.0,
-                    top: suggested_ul.1,
-                    right: suggested_ul.0 + new_physical_inner_size.width as i32,
-                    bottom: suggested_ul.1 + new_physical_inner_size.height as i32,
-                };
+            if util::WIN_VERSION.build < 22000 {
+                // The window position needs adjustment on Windows 10.
+                {
+                    let suggested_ul =
+                        (suggested_rect.left + margin_left, suggested_rect.top + margin_top);
+
+                    let mut conservative_rect = RECT {
+                        left: suggested_ul.0,
+                        top: suggested_ul.1,
+                        right: suggested_ul.0 + new_physical_inner_size.width as i32,
+                        bottom: suggested_ul.1 + new_physical_inner_size.height as i32,
+                    };
 
-                conservative_rect = window_flags
-                    .adjust_rect(window, conservative_rect)
-                    .unwrap_or(conservative_rect);
-
-                // If we're dragging the window, offset the window so that the cursor's
-                // relative horizontal position in the title bar is preserved.
-                if dragging_window {
-                    let bias = {
-                        let cursor_pos = {
-                            let mut pos = unsafe { mem::zeroed() };
-                            unsafe { GetCursorPos(&mut pos) };
-                            pos
+                    conservative_rect = window_flags
+                        .adjust_rect(window, conservative_rect)
+                        .unwrap_or(conservative_rect);
+
+                    // If we're dragging the window, offset the window so that the cursor's
+                    // relative horizontal position in the title bar is preserved.
+                    if dragging_window {
+                        let bias = {
+                            let cursor_pos = {
+                                let mut pos = unsafe { mem::zeroed() };
+                                unsafe { GetCursorPos(&mut pos) };
+                                pos
+                            };
+                            let suggested_cursor_horizontal_ratio =
+                                (cursor_pos.x - suggested_rect.left) as f64
+                                    / (suggested_rect.right - suggested_rect.left) as f64;
+
+                            (cursor_pos.x
+                                - (suggested_cursor_horizontal_ratio
+                                    * (conservative_rect.right - conservative_rect.left) as f64)
+                                    as i32)
+                                - conservative_rect.left
                         };
-                        let suggested_cursor_horizontal_ratio = (cursor_pos.x - suggested_rect.left)
-                            as f64
-                            / (suggested_rect.right - suggested_rect.left) as f64;
-
-                        (cursor_pos.x
-                            - (suggested_cursor_horizontal_ratio
-                                * (conservative_rect.right - conservative_rect.left) as f64)
-                                as i32)
-                            - conservative_rect.left
+                        conservative_rect.left += bias;
+                        conservative_rect.right += bias;
+                    }
+
+                    // Check to see if the new window rect is on the monitor with the new DPI factor.
+                    // If it isn't, offset the window so that it is.
+                    let new_dpi_monitor =
+                        unsafe { MonitorFromWindow(window, MONITOR_DEFAULTTONULL) };
+                    let conservative_rect_monitor =
+                        unsafe { MonitorFromRect(&conservative_rect, MONITOR_DEFAULTTONULL) };
+                    new_outer_rect = if conservative_rect_monitor == new_dpi_monitor {
+                        conservative_rect
+                    } else {
+                        let get_monitor_rect = |monitor| {
+                            let mut monitor_info = MONITORINFO {
+                                cbSize: mem::size_of::<MONITORINFO>() as _,
+                                ..unsafe { mem::zeroed() }
+                            };
+                            unsafe { GetMonitorInfoW(monitor, &mut monitor_info) };
+                            monitor_info.rcMonitor
+                        };
+                        let wrong_monitor = conservative_rect_monitor;
+                        let wrong_monitor_rect = get_monitor_rect(wrong_monitor);
+                        let new_monitor_rect = get_monitor_rect(new_dpi_monitor);
+
+                        // The direction to nudge the window in to get the window onto the monitor with
+                        // the new DPI factor. We calculate this by seeing which monitor edges are
+                        // shared and nudging away from the wrong monitor based on those.
+                        #[allow(clippy::bool_to_int_with_if)]
+                        let delta_nudge_to_dpi_monitor = (
+                            if wrong_monitor_rect.left == new_monitor_rect.right {
+                                -1
+                            } else if wrong_monitor_rect.right == new_monitor_rect.left {
+                                1
+                            } else {
+                                0
+                            },
+                            if wrong_monitor_rect.bottom == new_monitor_rect.top {
+                                1
+                            } else if wrong_monitor_rect.top == new_monitor_rect.bottom {
+                                -1
+                            } else {
+                                0
+                            },
+                        );
+
+                        let abort_after_iterations = new_monitor_rect.right - new_monitor_rect.left
+                            + new_monitor_rect.bottom
+                            - new_monitor_rect.top;
+                        for _ in 0..abort_after_iterations {
+                            conservative_rect.left += delta_nudge_to_dpi_monitor.0;
+                            conservative_rect.right += delta_nudge_to_dpi_monitor.0;
+                            conservative_rect.top += delta_nudge_to_dpi_monitor.1;
+                            conservative_rect.bottom += delta_nudge_to_dpi_monitor.1;
+
+                            if unsafe { MonitorFromRect(&conservative_rect, MONITOR_DEFAULTTONULL) }
+                                == new_dpi_monitor
+                            {
+                                break;
+                            }
+                        }
+
+                        conservative_rect
                     };
-                    conservative_rect.left += bias;
-                    conservative_rect.right += bias;
                 }
-
-                new_outer_rect = conservative_rect;
+            } else {
+                // The suggested position is fine w/o adjustment on Windows 11.
+                new_outer_rect = suggested_rect
             }
 
             unsafe {

src/platform_impl/windows/util.rs

@@ -3,6 +3,7 @@ use std::iter::once;
 use std::ops::BitAnd;
 use std::os::windows::prelude::{OsStrExt, OsStringExt};
 use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::LazyLock;
 use std::{io, mem, ptr};
 
 use crate::utils::Lazy;
@@ -26,6 +27,9 @@ use windows_sys::Win32::UI::WindowsAndMessaging::{
 
 use crate::window::CursorIcon;
 
+pub static WIN_VERSION: LazyLock<windows_version::OsVersion> =
+    LazyLock::new(windows_version::OsVersion::current);
+
 pub fn encode_wide(string: impl AsRef<OsStr>) -> Vec<u16> {
     string.as_ref().encode_wide().chain(once(0)).collect()
 }