From 3bb815d7c46d2bec3b73c1256d89160697c2a15a Mon Sep 17 00:00:00 2001
From: Andy Carlson <2yinyang2@gmail.com>
Date: Fri, 7 Feb 2025 17:34:36 -0500
Subject: [PATCH] prevent incorrect shifting of window when dragging onto
 monitor with different DPI

---
 src/changelog/unreleased.md             |  1 +
 src/platform_impl/windows/event_loop.rs | 64 ++-----------------------
 2 files changed, 4 insertions(+), 61 deletions(-)

diff --git a/src/changelog/unreleased.md b/src/changelog/unreleased.md
index c42c259352..703aafa8e9 100644
--- a/src/changelog/unreleased.md
+++ b/src/changelog/unreleased.md
@@ -182,6 +182,7 @@ changelog entry.
   whilst files are being dragged over the window. It doesn't contain any file paths, just the
   pointer position.
 - Updated `objc2` to `v0.6`.
+- On Windows, prevent incorrect shifting when dragging window onto a monitor with different DPI.
 
 ### Removed
 
diff --git a/src/platform_impl/windows/event_loop.rs b/src/platform_impl/windows/event_loop.rs
index abbaeaa3b9..6b0e1e4a1b 100644
--- a/src/platform_impl/windows/event_loop.rs
+++ b/src/platform_impl/windows/event_loop.rs
@@ -17,8 +17,8 @@ use windows_sys::Win32::Foundation::{
     GetLastError, FALSE, HANDLE, HWND, LPARAM, LRESULT, POINT, RECT, WAIT_FAILED, WPARAM,
 };
 use windows_sys::Win32::Graphics::Gdi::{
-    GetMonitorInfoW, MonitorFromRect, MonitorFromWindow, RedrawWindow, ScreenToClient,
-    ValidateRect, MONITORINFO, MONITOR_DEFAULTTONULL, RDW_INTERNALPAINT, SC_SCREENSAVE,
+    MonitorFromRect, RedrawWindow, ScreenToClient, ValidateRect, MONITOR_DEFAULTTONULL,
+    RDW_INTERNALPAINT, SC_SCREENSAVE,
 };
 use windows_sys::Win32::System::Ole::RevokeDragDrop;
 use windows_sys::Win32::System::Threading::{
@@ -2477,65 +2477,7 @@ unsafe fn public_window_callback_inner(
                     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
-                };
+                new_outer_rect = conservative_rect;
             }
 
             unsafe {