feat: apply tabular number formatting to timestamp (#6062)

src/messages/MessageElement.cpp

@@ -1026,7 +1026,7 @@ TextElement *TimestampElement::formatTime(const QTime &time)
     QString format = locale.toString(time, getSettings()->timestampFormat);
 
     return new TextElement(format, MessageElementFlag::Timestamp,
-                           MessageColor::System, FontStyle::ChatMedium);
+                           MessageColor::System, FontStyle::TimestampMedium);
 }
 
 QJsonObject TimestampElement::toJson() const

src/singletons/Fonts.cpp

@@ -70,6 +70,7 @@ float fontSize(FontStyle style)
         case FontStyle::ChatMedium:
         case FontStyle::ChatMediumBold:
         case FontStyle::ChatMediumItalic:
+        case FontStyle::TimestampMedium:
             return chatSize();
         case FontStyle::ChatLarge:
             return 1.2F * chatSize();
@@ -99,6 +100,7 @@ int fontWeight(FontStyle style)
         case FontStyle::ChatMediumItalic:
         case FontStyle::ChatLarge:
         case FontStyle::ChatVeryLarge:
+        case FontStyle::TimestampMedium:
             return getSettings()->chatFontWeight.getValue();
 
         case FontStyle::ChatMediumBold:
@@ -129,6 +131,7 @@ bool isItalic(FontStyle style)
         case FontStyle::ChatMediumBold:
         case FontStyle::ChatLarge:
         case FontStyle::ChatVeryLarge:
+        case FontStyle::TimestampMedium:
         case FontStyle::UiMedium:
         case FontStyle::UiMediumBold:
         case FontStyle::UiTabs:
@@ -157,6 +160,7 @@ QString fontFamily(FontStyle style)
         case FontStyle::ChatMediumItalic:
         case FontStyle::ChatLarge:
         case FontStyle::ChatVeryLarge:
+        case FontStyle::TimestampMedium:
             return getSettings()->chatFontFamily.getValue();
 
         case FontStyle::UiMedium:
@@ -229,12 +233,27 @@ Fonts::FontData &Fonts::getOrCreateFontData(FontStyle type, float scale)
 
 Fonts::FontData Fonts::createFontData(FontStyle type, float scale)
 {
-    return QFont{
+    QFont font{
         fontFamily(type),
         static_cast<int>(fontSize(type) * scale),
         fontWeight(type),
         isItalic(type),
     };
+
+    switch (type)
+    {
+        case FontStyle::TimestampMedium: {
+#if QT_VERSION >= QT_VERSION_CHECK(6, 7, 0)
+            // Apply the OpenType feature `tnum` to timestamp fonts
+            // https://sparanoid.com/lab/opentype-features/#tnum
+            auto tag = QFont::Tag("tnum");
+            font.setFeature(tag, 1);
+#endif
+        }
+        break;
+    }
+
+    return font;
 }
 
 }  // namespace chatterino

src/singletons/Fonts.hpp

@@ -24,6 +24,8 @@ enum class FontStyle : uint8_t {
     ChatLarge,
     ChatVeryLarge,
 
+    TimestampMedium,
+
     UiMedium,
     UiMediumBold,
     UiTabs,