From 04f31f7b42f7de920ba1cb60073bb5be811837d2 Mon Sep 17 00:00:00 2001
From: Yuhang Zhao <2546789017@qq.com>
Date: Mon, 7 Mar 2022 10:26:16 +0800
Subject: [PATCH] Win32: update the internal margin when DPI changes

Make the internal margin sync with the latest DPI.

Signed-off-by: Yuhang Zhao <2546789017@qq.com>
---
 framelesshelper_win32.cpp | 8 +++++++-
 framelesshelper_windows.h | 4 ++++
 framelessquickhelper.cpp  | 3 +++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/framelesshelper_win32.cpp b/framelesshelper_win32.cpp
index 483757a..48096cb 100644
--- a/framelesshelper_win32.cpp
+++ b/framelesshelper_win32.cpp
@@ -154,7 +154,7 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
         // Anyway, we should skip it in this case.
         return false;
     }
-    const QWindow *window = Utilities::findWindow(reinterpret_cast<WId>(msg->hwnd));
+    const QWindow * const window = Utilities::findWindow(reinterpret_cast<WId>(msg->hwnd));
     if (!window || !window->property(Constants::kFramelessModeFlag).toBool()) {
         return false;
     }
@@ -675,6 +675,12 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
         windowPos->flags |= SWP_NOCOPYBITS;
     } break;
 #endif
+    case WM_DPICHANGED: {
+        // The DPI has changed, we need to update the internal window frame
+        // recorded in Windows QPA.
+        Utilities::updateQtFrameMargins(const_cast<QWindow *>(window), true);
+        Utilities::triggerFrameChange(reinterpret_cast<WId>(msg->hwnd));
+    } break;
     default:
         break;
     }
diff --git a/framelesshelper_windows.h b/framelesshelper_windows.h
index 6d53db4..a32e725 100644
--- a/framelesshelper_windows.h
+++ b/framelesshelper_windows.h
@@ -90,6 +90,10 @@
 #define WM_DWMCOLORIZATIONCOLORCHANGED (0x0320)
 #endif
 
+#ifndef WM_DPICHANGED
+#define WM_DPICHANGED (0x02E0)
+#endif
+
 #ifndef SM_CXPADDEDBORDER
 #define SM_CXPADDEDBORDER (92)
 #endif
diff --git a/framelessquickhelper.cpp b/framelessquickhelper.cpp
index 59a4732..00d37f1 100644
--- a/framelessquickhelper.cpp
+++ b/framelessquickhelper.cpp
@@ -96,6 +96,9 @@ void FramelessQuickHelper::showMinimized()
 {
 #ifdef Q_OS_WINDOWS
     // Work-around a QtQuick bug: https://bugreports.qt.io/browse/QTBUG-69711
+    // Don't use "SW_SHOWMINIMIZED" because it will activate the current
+    // window instead of the next window in the Z order, that's not the
+    // native behavior of Windows applications.
     ShowWindow(reinterpret_cast<HWND>(window()->winId()), SW_MINIMIZE);
 #else
     window()->showMinimized();