Show resolved code language on the left of each block header

tools/chatgui/src/message_text.cpp

@@ -166,18 +166,25 @@ QSharedPointer<const MessageText> formattedMessageText(const QModelIndex& index)
         static const QHash<QString, QString> aliases = {{"cpp", "C++"}, {"c++", "C++"}, {"c", "C"},
             {"py", "Python"}, {"js", "JavaScript"}, {"ts", "TypeScript"}, {"sh", "Bash"}, {"shell", "Bash"},
             {"cs", "C#"}, {"csharp", "C#"}, {"kt", "Kotlin"}, {"rs", "Rust"}, {"php", "PHP/PHP"}, {"yml", "YAML"}};
-        for (const auto& block : message->code) {
-            if (block.language == "text" || block.language == "plain") continue;
+        for (auto& block : message->code) {
+            block.languageName = block.language;
+            if (block.language == "text" || block.language == "plain") { block.languageName = "text"; continue; }
             const QString language = block.language.isEmpty()
                 ? detectCodeLanguage(QStringView(message->text).mid(block.start, block.length)) : block.language;
             if (language.isEmpty()) continue;
+            block.languageName = language;
             auto definition = repository.definitionForName(aliases.value(language, language));
             if (!definition.isValid()) {
                 for (const auto& candidate : repository.definitions()) {
                     if (candidate.name().compare(language, Qt::CaseInsensitive) == 0) { definition = candidate; break; }
                 }
             }
-            if (definition.isValid()) highlighter.highlight(block, definition);
+            if (definition.isValid()) {
+                block.languageName = definition.name() == "PHP/PHP" ? QStringLiteral("PHP") : definition.name();
+                highlighter.highlight(block, definition);
+                GUI_DEBUG("message code: language=%s explicit=%d chars=%d", qPrintable(block.languageName),
+                          !block.language.isEmpty(), block.length);
+            }
             else GUI_DEBUG("message code: unknown language=%s; using plain code", qPrintable(language));
         }
     }

tools/chatgui/src/message_text.h

@@ -12,6 +12,7 @@ struct MessageCodeBlock {
     int start; // Начало кода в видимом тексте, UTF-16.
     int length; // Длина без строк-ограждений; ноль означает пустой блок.
     QString language; // Имя из ограждения: пустое включает автоопределение, неизвестное/text/plain отключает раскраску.
+    QString languageName; // Имя для шапки после подготовки подсветки; пусто означает обычный text.
 };
 
 struct MessageText {

tools/chatgui/src/messagedelegate.cpp

@@ -1624,6 +1624,11 @@ void MessageDelegate::paintBody(QPainter* painter, const QStyleOptionViewItem& o
                 painter->drawRoundedRect(button.adjusted(0.5, 0.5, -0.5, -0.5), 4, 4);
                 painter->setPen(option.palette.buttonText().color());
                 painter->drawText(button, Qt::AlignCenter, QCoreApplication::translate("ChatGui", "Copy"));
+                const QRectF label(L.textRect.x() + 8, button.top(), qMax(0.0, button.left() - L.textRect.x() - 16), button.height());
+                painter->setPen(option.palette.text().color());
+                const QString language = block.languageName.isEmpty() ? QStringLiteral("text") : block.languageName;
+                painter->drawText(label, Qt::AlignLeft | Qt::AlignVCenter,
+                                  painter->fontMetrics().elidedText(language, Qt::ElideRight, int(label.width())));
             }
             painter->restore();
         }