feat: change application style

- change default dark theme to light
- disable dark mode on windows 10 because Qt's windows 11 theme has bad support on windows 10 (icon display error)
- level required minimum qt version up to 6.5 for color schema.

app/graphicsview.cpp

@@ -7,6 +7,8 @@
 #include "graphicsscene.h"
 #include "settings.h"
 
+#include <QStyleHints>
+#include <QOperatingSystemVersion>
 #include <QDebug>
 #include <QColorSpace>
 #include <QMouseEvent>
@@ -23,11 +25,12 @@ GraphicsView::GraphicsView(QWidget *parent)
     setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
     setResizeAnchor(QGraphicsView::AnchorUnderMouse);
     setTransformationAnchor(QGraphicsView::AnchorUnderMouse);
-    setStyleSheet("background-color: rgba(0, 0, 0, 220);"
-                  "border-radius: 3px;");
     setAcceptDrops(false);
     setCheckerboardEnabled(false);
 
+    updateStyle(qGuiApp->styleHints()->colorScheme());
+    connect(qGuiApp->styleHints(), &QStyleHints::colorSchemeChanged, this, &GraphicsView::updateStyle);
+
     connect(horizontalScrollBar(), &QScrollBar::valueChanged, this, &GraphicsView::viewportRectChanged);
     connect(verticalScrollBar(), &QScrollBar::valueChanged, this, &GraphicsView::viewportRectChanged);
 }
@@ -344,6 +347,39 @@ void GraphicsView::toggleCheckerboard(bool invertCheckerboardColor)
     setCheckerboardEnabled(!m_checkerboardEnabled, invertCheckerboardColor);
 }
 
+void GraphicsView::updateStyle(Qt::ColorScheme colorScheme) {
+    // YYC MARK:
+    // If we are using Windows 10 and lower system or Qt which do not support "Windows 11"
+    // theme (lower than Qt 6.7), we should only support light mode.
+    // Because Qt's dark-mode-aware "Windows 11" theme is only well-supported on Windows 11.
+#if defined(Q_OS_WIN)
+#if QT_VERSION < QT_VERSION_CHECK(6, 7, 0)
+    colorScheme = Qt::ColorScheme::Light;
+#else
+    if (QOperatingSystemVersion::current() < QOperatingSystemVersion::Windows11) {
+        colorScheme = Qt::ColorScheme::Light;
+    }
+#endif // QT_VERSION < QT_VERSION_CHECK(6, 7, 0)
+#endif // defined(Q_OS_WIN)
+
+    switch (colorScheme) {
+    case Qt::ColorScheme::Dark:
+        setStyleSheet(R"#(
+border-style: none;
+background-color: black;
+)#");
+        break;
+    case Qt::ColorScheme::Light:
+    case Qt::ColorScheme::Unknown:
+    default:
+        setStyleSheet(R"#(
+border-style: none;
+background-color: white;
+)#");
+        break;
+    }
+}
+
 void GraphicsView::mousePressEvent(QMouseEvent *event)
 {
     if (shouldIgnoreMousePressMoveEvent(event)) {