From 6b3f555a95330f6211058e4497ca12349f9f21b5 Mon Sep 17 00:00:00 2001
From: Yuhang Zhao <2546789017@qq.com>
Date: Fri, 3 Apr 2020 09:57:00 +0800
Subject: [PATCH] Update.

Signed-off-by: Yuhang Zhao <2546789017@qq.com>
---
 winnativeeventfilter.cpp | 85 ++++++++++++++++++++++++----------------
 winnativeeventfilter.h   |  1 +
 2 files changed, 53 insertions(+), 33 deletions(-)

diff --git a/winnativeeventfilter.cpp b/winnativeeventfilter.cpp
index bc26dbf..486b0ae 100644
--- a/winnativeeventfilter.cpp
+++ b/winnativeeventfilter.cpp
@@ -16,6 +16,11 @@
 
 Q_DECLARE_METATYPE(QMargins)
 
+#ifndef USER_DEFAULT_SCREEN_DPI
+// FIXME: Since which version?
+#define USER_DEFAULT_SCREEN_DPI 96
+#endif
+
 #ifndef SM_CXPADDEDBORDER
 // Only available since Windows Vista
 #define SM_CXPADDEDBORDER 92
@@ -104,39 +109,7 @@ QVector<HWND> m_framelessWindows;
 
 } // namespace
 
-WinNativeEventFilter::WinNativeEventFilter() {
-    QLibrary user32Lib(QString::fromUtf8("User32")),
-        shcoreLib(QString::fromUtf8("SHCore"));
-    if (QOperatingSystemVersion::current() >=
-        QOperatingSystemVersion::Windows7) {
-        m_SetWindowCompositionAttribute =
-            reinterpret_cast<lpSetWindowCompositionAttribute>(
-                user32Lib.resolve("SetWindowCompositionAttribute"));
-    }
-    if (QOperatingSystemVersion::current() >=
-        QOperatingSystemVersion::Windows8_1) {
-        m_GetDpiForMonitor = reinterpret_cast<lpGetDpiForMonitor>(
-            shcoreLib.resolve("GetDpiForMonitor"));
-    }
-    // Windows 10, version 1607 (10.0.14393)
-    if (QOperatingSystemVersion::current() >=
-        QOperatingSystemVersion(QOperatingSystemVersion::Windows, 10, 0,
-                                14393)) {
-        m_GetDpiForWindow = reinterpret_cast<lpGetDpiForWindow>(
-            user32Lib.resolve("GetDpiForWindow"));
-        m_GetDpiForSystem = reinterpret_cast<lpGetDpiForSystem>(
-            user32Lib.resolve("GetDpiForSystem"));
-        m_GetSystemMetricsForDpi = reinterpret_cast<lpGetSystemMetricsForDpi>(
-            user32Lib.resolve("GetSystemMetricsForDpi"));
-    }
-    // Windows 10, version 1803 (10.0.17134)
-    if (QOperatingSystemVersion::current() >=
-        QOperatingSystemVersion(QOperatingSystemVersion::Windows, 10, 0,
-                                17134)) {
-        m_GetSystemDpiForProcess = reinterpret_cast<lpGetSystemDpiForProcess>(
-            user32Lib.resolve("GetSystemDpiForProcess"));
-    }
-}
+WinNativeEventFilter::WinNativeEventFilter() { initDLLs(); }
 
 WinNativeEventFilter::~WinNativeEventFilter() = default;
 
@@ -874,3 +847,49 @@ void WinNativeEventFilter::updateQtFrame(QWindow *window) {
         }
     }
 }
+
+void WinNativeEventFilter::initDLLs() {
+    QLibrary user32Lib(QString::fromUtf8("User32")),
+        shcoreLib(QString::fromUtf8("SHCore"));
+    if (QOperatingSystemVersion::current() >=
+        QOperatingSystemVersion::Windows7) {
+        if (!m_SetWindowCompositionAttribute) {
+            m_SetWindowCompositionAttribute =
+                reinterpret_cast<lpSetWindowCompositionAttribute>(
+                    user32Lib.resolve("SetWindowCompositionAttribute"));
+        }
+    }
+    if (QOperatingSystemVersion::current() >=
+        QOperatingSystemVersion::Windows8_1) {
+        if (!m_GetDpiForMonitor) {
+            m_GetDpiForMonitor = reinterpret_cast<lpGetDpiForMonitor>(
+                shcoreLib.resolve("GetDpiForMonitor"));
+        }
+    }
+    // Windows 10, version 1607 (10.0.14393)
+    if (QOperatingSystemVersion::current() >=
+        QOperatingSystemVersion(QOperatingSystemVersion::Windows, 10, 0,
+                                14393)) {
+        if (!m_GetDpiForWindow) {
+            m_GetDpiForWindow = reinterpret_cast<lpGetDpiForWindow>(
+                user32Lib.resolve("GetDpiForWindow"));
+        }
+        if (!m_GetDpiForSystem) {
+            m_GetDpiForSystem = reinterpret_cast<lpGetDpiForSystem>(
+                user32Lib.resolve("GetDpiForSystem"));
+        }
+        if (!m_GetSystemMetricsForDpi) {
+            m_GetSystemMetricsForDpi = reinterpret_cast<lpGetSystemMetricsForDpi>(
+                user32Lib.resolve("GetSystemMetricsForDpi"));
+        }
+    }
+    // Windows 10, version 1803 (10.0.17134)
+    if (QOperatingSystemVersion::current() >=
+        QOperatingSystemVersion(QOperatingSystemVersion::Windows, 10, 0,
+                                17134)) {
+        if (!m_GetSystemDpiForProcess) {
+            m_GetSystemDpiForProcess = reinterpret_cast<lpGetSystemDpiForProcess>(
+                user32Lib.resolve("GetSystemDpiForProcess"));
+        }
+    }
+}
diff --git a/winnativeeventfilter.h b/winnativeeventfilter.h
index 576da3f..c99449d 100644
--- a/winnativeeventfilter.h
+++ b/winnativeeventfilter.h
@@ -66,6 +66,7 @@ public:
 
 private:
     void init(LPWINDOW data);
+    void initDLLs();
     static void createUserData(HWND handle, WINDOWDATA *data = nullptr);
     void handleDwmCompositionChanged(LPWINDOW data);
     void handleThemeChanged(LPWINDOW data);