Use Segoe UI font on Windows.

Qt uses "MS Shell Dlg 2" as the default font, which resolves to Tahoma and not Segoe UI, which is the actual Windows 10 default font.
keepassxreboot · May 21, 2020 · 0c800b6 · 0c800b6
1 parent a1b4a3f
commit 0c800b6
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diff --git a/src/core/Bootstrap.cpp b/src/core/Bootstrap.cpp
@@ -22,6 +22,8 @@
 #include "gui/MessageBox.h"
 
 #ifdef Q_OS_WIN
+#include "gui/osutils/OSUtils.h"
+
 #include <aclapi.h> // for createWindowsDACL()
 #include <windows.h> // for Sleep(), SetDllDirectoryA(), SetSearchPathMode(), ...
 #undef MessageBox
@@ -74,6 +76,10 @@ namespace Bootstrap
         setupSearchPaths();
         applyEarlyQNetworkAccessManagerWorkaround();
         Translator::installTranslators();
+
+#ifdef Q_OS_WIN
+        winUtils()->fixDefaultUIFont();
+#endif
     }
 
     /**

diff --git a/src/gui/osutils/winutils/WinUtils.cpp b/src/gui/osutils/winutils/WinUtils.cpp
@@ -18,10 +18,13 @@
 #include "WinUtils.h"
 #include <QAbstractNativeEventFilter>
 #include <QApplication>
+#include <QFontDatabase>
 #include <QSettings>
 
 #include <windows.h>
 
+#include <cmath>
+
 QPointer<WinUtils> WinUtils::m_instance = nullptr;
 QScopedPointer<WinUtils::DWMEventFilter> WinUtils::m_eventFilter;
 
@@ -105,3 +108,42 @@ bool WinUtils::isCapslockEnabled()
 {
     return GetKeyState(VK_CAPITAL) == 1;
 }
+
+/**
+ * Convert binary UTF-16 string to QByteArray.
+ *
+ * This is useful for reading REG_BINARY registry keys, which are incorrectly
+ * read as UTF16-encoded QStrings. See QTBUG-98.
+ *
+ * @param binaryString UTF-16 REG_BINARY string
+ * @return properly encoded QByteArray
+ */
+QByteArray WinUtils::convertRegBinary(const QString& binaryString) const
+{
+    return QByteArray(reinterpret_cast<const char*>(binaryString.utf16()), binaryString.length() * 2);
+}
+
+
+/**
+ * Replace application default font with Window's actual default UI font.
+ *
+ * The default app font retrieved by Qt on Windows is "MS Shell Dlg 2", which translates to Tahoma
+ * even though the default Windows 10 font is actually Segoe UI.
+ * @return default font
+ */
+void WinUtils::fixDefaultUIFont() const
+{
+    QSettings windowMetrics(R"(HKEY_CURRENT_USER\Control Panel\Desktop\WindowMetrics)", QSettings::NativeFormat);
+    auto captionFont = winUtils()->convertRegBinary(windowMetrics.value("CaptionFont").toString());
+    if (captionFont.size() > 0x1C && captionFont[captionFont.size() - 1] == '\0') {
+        // Font size is the inverted first byte as device-dependent pixels
+        int pointSize = std::ceil(~captionFont[0] * 72.0 / windowMetrics.value("AppliedDPI", 96.0).toDouble());
+
+        // Font name starts at 0x1C and is a null-terminated UTF-16 string
+        auto font = QString::fromUtf16(reinterpret_cast<const ushort*>(captionFont.constData() + 0x1C));
+
+        qApp->setFont(QFontDatabase().font(font, "Regular", pointSize));
+    }
+
+    // If we're here, then something or somebody messed with WindowMetrics, do nothing.
+}
diff --git a/src/gui/osutils/winutils/WinUtils.h b/src/gui/osutils/winutils/WinUtils.h
@@ -21,6 +21,7 @@
 #include "gui/osutils/OSUtilsBase.h"
 
 #include <QAbstractNativeEventFilter>
+#include <QFont>
 #include <QPointer>
 #include <QScopedPointer>
 
@@ -37,6 +38,9 @@ class WinUtils : public OSUtilsBase
     void setLaunchAtStartup(bool enable) override;
     bool isCapslockEnabled() override;
 
+    QByteArray convertRegBinary(const QString& binaryString) const;
+    void fixDefaultUIFont() const;
+
 protected:
     explicit WinUtils(QObject* parent = nullptr);
     ~WinUtils() override;