From 47910161c99677b51745b323a7cc07cf8bc9b00e Mon Sep 17 00:00:00 2001
From: Yuhang Zhao <2546789017@qq.com>
Date: Mon, 19 Oct 2020 18:24:38 +0800
Subject: [PATCH] Fix build for old Qt versions.

Signed-off-by: Yuhang Zhao <2546789017@qq.com>
---
 framelesshelper.cpp         | 8 ++++++++
 framelesswindowsmanager.cpp | 5 +++++
 winnativeeventfilter.cpp    | 7 +++++++
 3 files changed, 20 insertions(+)

diff --git a/framelesshelper.cpp b/framelesshelper.cpp
index f9de5c9..91c9e37 100644
--- a/framelesshelper.cpp
+++ b/framelesshelper.cpp
@@ -127,7 +127,15 @@ void FramelessHelper::moveWindowToDesktopCenter(QObject *obj)
     else if (obj->isWidgetType()) {
         const auto widget = qobject_cast<QWidget *>(obj);
         if (widget && widget->isTopLevel()) {
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0))
             const QSize ss = widget->screen()->size();
+#else
+            QSize ss = {};
+            QWindow *window = widget->windowHandle();
+            if (window) {
+                ss = window->screen()->size();
+            }
+#endif
             const int sw = ss.width();
             const int sh = ss.height();
             const int ww = widget->width();
diff --git a/framelesswindowsmanager.cpp b/framelesswindowsmanager.cpp
index 83961a0..86c2ba4 100644
--- a/framelesswindowsmanager.cpp
+++ b/framelesswindowsmanager.cpp
@@ -57,7 +57,12 @@ QScreen *getCurrentScreenFromWindow(QObject *window)
     }
 #ifdef QT_WIDGETS_LIB
     else if (window->isWidgetType()) {
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0))
         return qobject_cast<QWidget *>(window)->screen();
+#else
+        QWindow *win = qobject_cast<QWidget *>(window)->windowHandle();
+        return win ? win->screen() : nullptr;
+#endif
     }
 #endif
     else {
diff --git a/winnativeeventfilter.cpp b/winnativeeventfilter.cpp
index 9c0fdc4..88e6388 100644
--- a/winnativeeventfilter.cpp
+++ b/winnativeeventfilter.cpp
@@ -1151,7 +1151,14 @@ QString getCurrentScreenIdentifier(const HWND handle)
 #ifdef QT_WIDGETS_LIB
         const QWidget *widget = QWidget::find(reinterpret_cast<WId>(handle));
         if (widget && widget->isTopLevel()) {
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0))
             currentScreen = widget->screen();
+#else
+            QWindow *window = widget->windowHandle();
+            if (window) {
+                currentScreen = window->screen();
+            }
+#endif
         }
 #endif
         if (!currentScreen) {