opt: add system font configuration (#1125)

* opt: add system font configuration

* [autofix.ci] apply automated fixes

* opt: add option to change the interface font

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

src/config.cc

@@ -856,6 +856,7 @@ Class load()
   if ( !preferences.isNull() ) {
     c.preferences.interfaceLanguage = preferences.namedItem( "interfaceLanguage" ).toElement().text();
     c.preferences.displayStyle      = preferences.namedItem( "displayStyle" ).toElement().text();
+    c.preferences.interfaceFont     = preferences.namedItem( "interfaceFont" ).toElement().text();
 #if !defined( Q_OS_WIN )
     c.preferences.interfaceStyle = preferences.namedItem( "interfaceStyle" ).toElement().text();
 #endif
@@ -1702,6 +1703,10 @@ void save( Class const & c )
     opt.appendChild( dd.createTextNode( c.preferences.interfaceLanguage ) );
     preferences.appendChild( opt );
 
+    opt = dd.createElement( "interfaceFont" );
+    opt.appendChild( dd.createTextNode( c.preferences.interfaceFont ) );
+    preferences.appendChild( opt );
+
     opt             = dd.createElement( "customFonts" );
     auto customFont = c.preferences.customFonts.toElement( dd );
     preferences.appendChild( customFont );

src/config.hh

@@ -345,6 +345,7 @@ ScanPopupWindowFlags spwfFromInt( int id );
 struct Preferences
 {
   QString interfaceLanguage; // Empty value corresponds to system default
+  QString interfaceFont;     //Empty as default value.
 
   CustomFonts customFonts;
   bool newTabsOpenAfterCurrentOne;

src/main.cc

@@ -508,6 +508,12 @@ int main( int argc, char ** argv )
     localeName = cfg.preferences.interfaceLanguage;
   }
 
+  //System Font
+  auto font = QApplication::font();
+  if ( !cfg.preferences.interfaceFont.isEmpty() && font.family() != cfg.preferences.interfaceFont ) {
+    app.setFont( QFont( cfg.preferences.interfaceFont ) );
+  }
+
   QLocale locale( localeName );
   QLocale::setDefault( locale );
   if ( !qtTranslator.load( "qt_extra_" + localeName, Config::getLocDir() ) ) {

src/ui/preferences.cc

@@ -97,7 +97,14 @@ Preferences::Preferences( QWidget * parent, Config::Class & cfg_ ):
     }
   }
 
+  //System Font
+  if ( !p.interfaceFont.isEmpty() ) {
+    ui.systemFont->setCurrentText( p.interfaceFont );
+  }
+
+
   prevWebFontFamily = p.customFonts;
+  prevSysFont       = p.interfaceFont;
 
   if ( !p.customFonts.standard.isEmpty() )
     ui.font_standard->setCurrentText( p.customFonts.standard );
@@ -397,6 +404,8 @@ Config::Preferences Preferences::getPreferences()
 
   p.interfaceLanguage = ui.interfaceLanguage->itemData( ui.interfaceLanguage->currentIndex() ).toString();
 
+  p.interfaceFont = ui.systemFont->currentText();
+
   Config::CustomFonts c;
   c.standard    = ui.font_standard->currentText();
   c.serif       = ui.font_serif->currentText();
@@ -602,17 +611,27 @@ void Preferences::on_enableClipboardHotkey_toggled( bool checked )
 
 void Preferences::on_buttonBox_accepted()
 {
-  if ( prevInterfaceLanguage != ui.interfaceLanguage->currentIndex() )
-    QMessageBox::information( this,
-                              tr( "Changing Language" ),
-                              tr( "Restart the program to apply the language change." ) );
+  QString promptText;
+
+  if ( prevInterfaceLanguage != ui.interfaceLanguage->currentIndex() ) {
+    promptText = tr( "Restart the program to apply the language change." );
+    promptText += "\n";
+  }
 
 #if !defined( Q_OS_WIN )
   if ( prevInterfaceStyle != ui.InterfaceStyle->currentIndex() ) {
-    QMessageBox::information( this, tr( "Restart needed" ), tr( "Restart to apply the interface style change." ) );
+    promptText += tr( "Restart to apply the interface style change." );
+    promptText += "\n";
   }
 #endif
 
+  if ( ui.systemFont->currentText() != prevSysFont ) {
+    promptText += tr( "Restart to apply the interface font change." );
+  }
+
+  if ( !promptText.isEmpty() ) {
+    QMessageBox::information( this, tr( "Restart needed" ), promptText );
+  }
 
   auto c = getPreferences();
   if ( c.customFonts != prevWebFontFamily ) {
@@ -625,6 +644,11 @@ void Preferences::on_buttonBox_accepted()
     QWebEngineProfile::defaultProfile()->settings()->setFontFamily( QWebEngineSettings::FixedFont,
                                                                     c.customFonts.monospace );
   }
+
+  //change interface font.
+  if ( ui.systemFont->currentText() != prevSysFont ) {
+    QApplication::setFont( QFont( ui.systemFont->currentText() ) );
+  }
 }
 
 void Preferences::on_useExternalPlayer_toggled( bool enabled )

src/ui/preferences.hh

@@ -19,6 +19,7 @@ class Preferences: public QDialog
 
 
   Config::CustomFonts prevWebFontFamily;
+  QString prevSysFont;
 
   Config::Class & cfg;
   QAction helpAction;

src/ui/preferences.ui

@@ -284,6 +284,20 @@ the application.</string>
           <string>Appearance</string>
          </property>
          <layout class="QVBoxLayout" name="verticalLayout_16">
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_17">
+            <item>
+             <widget class="QLabel" name="label_29">
+              <property name="text">
+               <string>Interface Font</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QFontComboBox" name="systemFont"/>
+            </item>
+           </layout>
+          </item>
           <item>
            <layout class="QHBoxLayout" name="horizontalLayout_4">
             <item>