MainWindow: decide DPI on the screen where vnote starts

src/main.cpp

@@ -8,6 +8,8 @@
 #include <QDateTime>
 #include <QSysInfo>
 #include <QProcess>
+#include <QWebEngineSettings>
+#include <QWindow>
 
 #include <core/configmgr.h>
 #include <core/mainconfig.h>
@@ -17,8 +19,8 @@
 #include <core/vnotex.h>
 #include <core/logger.h>
 #include <widgets/mainwindow.h>
-#include <QWebEngineSettings>
 #include <core/exception.h>
+#include <utils/widgetutils.h>
 #include <widgets/messageboxhelper.h>
 #include "commandlineoptions.h"
 #include "application.h"
@@ -145,17 +147,8 @@ int main(int argc, char *argv[])
     // Should set the correct locale before VNoteX::getInst().
     loadTranslators(app);
 
-    if (app.styleSheet().isEmpty()) {
-        auto style = VNoteX::getInst().getThemeMgr().fetchQtStyleSheet();
-        if (!style.isEmpty()) {
-            app.setStyleSheet(style);
-        }
-    }
-
     MainWindow window;
-
     window.show();
-    VNoteX::getInst().getThemeMgr().setBaseBackground(window.palette().color(QPalette::Base));
 
     QObject::connect(&guard, &SingleInstanceGuard::showRequested,
                      &window, &MainWindow::showMainWindow);
@@ -167,6 +160,19 @@ int main(int argc, char *argv[])
                          window.openFiles(QStringList() << p_filePath);
                      });
 
+    // Let MainWindow show first to decide the screen on which app is running.
+    WidgetUtils::calculateScaleFactor(window.windowHandle()->screen());
+
+    if (app.styleSheet().isEmpty()) {
+        auto style = VNoteX::getInst().getThemeMgr().fetchQtStyleSheet();
+        if (!style.isEmpty()) {
+            app.setStyleSheet(style);
+            WidgetUtils::updateStyle(&window);
+        }
+    }
+
+    VNoteX::getInst().getThemeMgr().setBaseBackground(window.palette().color(QPalette::Base));
+
     window.kickOffOnStart(cmdOptions.m_pathsToOpen);
 
     int ret = app.exec();

src/utils/widgetutils.cpp

@@ -45,12 +45,14 @@ void WidgetUtils::updateStyle(QWidget *p_widget)
     p_widget->update();
 }
 
-qreal WidgetUtils::calculateScaleFactor(bool p_update)
+qreal WidgetUtils::calculateScaleFactor(const QScreen *p_screen)
 {
     static qreal factor = -1;
 
-    if (factor < 0 || p_update) {
-        factor =  QGuiApplication::primaryScreen()->devicePixelRatio();
+    if (factor < 0 || p_screen) {
+        auto screen = p_screen ? p_screen : QGuiApplication::primaryScreen();
+        factor =  screen->devicePixelRatio();
+        qDebug() << screen->name() << "dpi" << factor;
     }
 
     return factor;

src/utils/widgetutils.h

@@ -21,6 +21,7 @@ class QLineEdit;
 class QLayout;
 class QPushButton;
 class QSplitter;
+class QScreen;
 
 namespace vnotex
 {
@@ -35,7 +36,7 @@ namespace vnotex
 
         static void updateStyle(QWidget *p_widget);
 
-        static qreal calculateScaleFactor(bool p_update = false);
+        static qreal calculateScaleFactor(const QScreen *p_screen = nullptr);
 
         static bool isScrollBarVisible(QAbstractScrollArea *p_widget, bool p_horizontal);