From 16f7d78035136b8f52e5a06a4078f6cfe694ab5d Mon Sep 17 00:00:00 2001
From: Yuhang Zhao <2546789017@qq.com>
Date: Wed, 31 Mar 2021 20:35:21 +0800
Subject: [PATCH] Win32: Fix the flickering issue when resizing

Signed-off-by: Yuhang Zhao <2546789017@qq.com>
---
 framelesshelper_win32.cpp |  7 +++++++
 qtacryliceffecthelper.cpp | 12 +++++++++---
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/framelesshelper_win32.cpp b/framelesshelper_win32.cpp
index fb7d184..5bf5c0b 100644
--- a/framelesshelper_win32.cpp
+++ b/framelesshelper_win32.cpp
@@ -412,6 +412,13 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
                 }
             }
         }
+        // Fix the flickering issue while resizing.
+        // "clientRect->right += 1;" also works.
+        // The only draw back of this small trick is it will affect
+        // Qt's coordinate system. It makes the "canvas" of the window
+        // larger than it should be. Be careful if you need to paint
+        // something manually either through QPainter or Qt Quick.
+        clientRect->bottom += 1;
         // If the window bounds change, we're going to relayout and repaint
         // anyway. Returning WVR_REDRAW avoids an extra paint before that of
         // the old client pixels in the (now wrong) location, and thus makes
diff --git a/qtacryliceffecthelper.cpp b/qtacryliceffecthelper.cpp
index 1c16d32..40b52c2 100644
--- a/qtacryliceffecthelper.cpp
+++ b/qtacryliceffecthelper.cpp
@@ -250,13 +250,19 @@ void QtAcrylicEffectHelper::paintWindowFrame(QPainter *painter, const QRect &rec
     const int width = rect.isValid() ? rect.width() : m_window->width();
     const int height = rect.isValid() ? rect.height() : m_window->height();
 #if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
-    const QList<QLineF> lines = {
+    using BorderLines = QList<QLineF>;
 #else
-    const QVector<QLineF> lines = {
+    using BorderLines = QVector<QLineF>;
 #endif
+#ifdef Q_OS_WINDOWS
+    const int internalFix = 1;
+#else
+    const int internalFix = 0;
+#endif
+    const BorderLines lines = {
         {0, 0, static_cast<qreal>(width), 0},
         {width - m_frameThickness, 0, width - m_frameThickness, static_cast<qreal>(height)},
-        {static_cast<qreal>(width), height - m_frameThickness, 0, height - m_frameThickness},
+        {static_cast<qreal>(width), height - m_frameThickness - internalFix, 0, height - m_frameThickness - internalFix},
         {0, static_cast<qreal>(height), 0, 0}
     };
     const bool active = m_window->isActive();