From 886f31d0c0df89e4e71bcfe3e175248fe800d868 Mon Sep 17 00:00:00 2001
From: Yuhang Zhao <2546789017@qq.com>
Date: Mon, 19 Oct 2020 22:07:12 +0800
Subject: [PATCH] Fix two issues.

1. The border line may disappear when resizing: fixed by change the line width to 2px.
2. Some part of the window become totally transparent after DPI changes: fixed by calling update() after DPI changes.

Signed-off-by: Yuhang Zhao <2546789017@qq.com>
---
 examples/Win32Demo/widget.cpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/examples/Win32Demo/widget.cpp b/examples/Win32Demo/widget.cpp
index 748dea2..3cd6cae 100644
--- a/examples/Win32Demo/widget.cpp
+++ b/examples/Win32Demo/widget.cpp
@@ -32,6 +32,11 @@
 #include <QSettings>
 #include <qt_windows.h>
 
+// Some old SDK doesn't have this value.
+#ifndef WM_DPICHANGED
+#define WM_DPICHANGED 0x02E0
+#endif
+
 // Copied from windowsx.h
 #define GET_X_LPARAM(lp) ((int) (short) LOWORD(lp))
 #define GET_Y_LPARAM(lp) ((int) (short) HIWORD(lp))
@@ -289,6 +294,7 @@ bool Widget::eventFilter(QObject *object, QEvent *event)
 {
     Q_ASSERT(object);
     Q_ASSERT(event);
+    Q_ASSERT(object == this);
     switch (event->type()) {
     case QEvent::WindowStateChange: {
         if (shouldDrawBorder(true)) {
@@ -349,6 +355,9 @@ bool Widget::nativeEvent(const QByteArray &eventType, void *message, long *resul
             }
             break;
         }
+        case WM_DPICHANGED:
+            update();
+            break;
         default:
             break;
         }
@@ -362,7 +371,7 @@ void Widget::paintEvent(QPaintEvent *event)
     if (shouldDrawBorder()) {
         QPainter painter(this);
         painter.save();
-        painter.setPen(borderColor());
+        painter.setPen({borderColor(), 2.0});
         painter.drawLine(0, 0, width(), 0);
         painter.drawLine(0, height(), width(), height());
         painter.drawLine(0, 0, 0, height());