From 916427a612a93b07d5f1beab58b326f9d0c70b70 Mon Sep 17 00:00:00 2001
From: nerix <nerixdev@outlook.de>
Date: Sun, 1 Oct 2023 07:13:37 +0200
Subject: [PATCH] Fix flickering when running with Direct2D (#4851)

---
 CHANGELOG.md                          | 1 +
 src/widgets/Notebook.cpp              | 1 -
 src/widgets/helper/Button.cpp         | 4 ++++
 src/widgets/helper/Button.hpp         | 8 +++++++-
 src/widgets/helper/NotebookButton.cpp | 2 +-
 src/widgets/helper/TitlebarButton.cpp | 3 +--
 6 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4143892a..e6261d62 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -26,6 +26,7 @@
 - Dev: Add `WindowManager::getLastSelectedWindow()` to replace `getMainWindow()`. (#4816)
 - Dev: Clarify signal connection lifetimes where applicable. (#4818)
 - Dev: Laid the groundwork for advanced input completion strategies. (#4639, #4846)
+- Dev: Fixed flickering when running with Direct2D on Windows. (#4851)
 
 ## 2.4.5
 
diff --git a/src/widgets/Notebook.cpp b/src/widgets/Notebook.cpp
index 3ff3648a..f9f46b76 100644
--- a/src/widgets/Notebook.cpp
+++ b/src/widgets/Notebook.cpp
@@ -1117,7 +1117,6 @@ void Notebook::setTabLocation(NotebookTabLocation location)
 
 void Notebook::paintEvent(QPaintEvent *event)
 {
-    BaseWidget::paintEvent(event);
     auto scale = this->scale();
 
     QPainter painter(this);
diff --git a/src/widgets/helper/Button.cpp b/src/widgets/helper/Button.cpp
index dce0153f..b4caa299 100644
--- a/src/widgets/helper/Button.cpp
+++ b/src/widgets/helper/Button.cpp
@@ -133,7 +133,11 @@ void Button::setMenu(std::unique_ptr<QMenu> menu)
 void Button::paintEvent(QPaintEvent *)
 {
     QPainter painter(this);
+    this->paintButton(painter);
+}
 
+void Button::paintButton(QPainter &painter)
+{
     painter.setRenderHint(QPainter::SmoothPixmapTransform);
 
     if (!this->pixmap_.isNull())
diff --git a/src/widgets/helper/Button.hpp b/src/widgets/helper/Button.hpp
index cac8c532..1bc763a9 100644
--- a/src/widgets/helper/Button.hpp
+++ b/src/widgets/helper/Button.hpp
@@ -56,7 +56,13 @@ signals:
     void leftMousePress();
 
 protected:
-    virtual void paintEvent(QPaintEvent *) override;
+    void paintEvent(QPaintEvent * /*event*/) override;
+
+    /// Paint this button.
+    /// This is intended for child classes that may want to paint the overlay.
+    /// This function should be used after rendering the custom button,
+    /// because the painter's state will be modified by this function.
+    void paintButton(QPainter &painter);
 #if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
     void enterEvent(QEnterEvent * /*event*/) override;
 #else
diff --git a/src/widgets/helper/NotebookButton.cpp b/src/widgets/helper/NotebookButton.cpp
index b7e8315a..510233d1 100644
--- a/src/widgets/helper/NotebookButton.cpp
+++ b/src/widgets/helper/NotebookButton.cpp
@@ -138,7 +138,7 @@ void NotebookButton::paintEvent(QPaintEvent *event)
         default:;
     }
 
-    Button::paintEvent(event);
+    this->paintButton(painter);
 }
 
 void NotebookButton::mouseReleaseEvent(QMouseEvent *event)
diff --git a/src/widgets/helper/TitlebarButton.cpp b/src/widgets/helper/TitlebarButton.cpp
index b4d85939..fa2d6bb2 100644
--- a/src/widgets/helper/TitlebarButton.cpp
+++ b/src/widgets/helper/TitlebarButton.cpp
@@ -121,8 +121,7 @@ void TitleBarButton::paintEvent(QPaintEvent *event)
         default:;
     }
 
-    Button::paintEvent(event);
-    //    this->fancyPaint(painter);
+    this->paintButton(painter);
 }
 
 }  // namespace chatterino