Display message being replied to above input box (#4350)

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

src/widgets/helper/MessageView.cpp

@@ -0,0 +1,134 @@
+#include "widgets/helper/MessageView.hpp"
+
+#include "Application.hpp"
+#include "messages/layouts/MessageLayout.hpp"
+#include "messages/MessageElement.hpp"
+#include "messages/Selection.hpp"
+#include "providers/colors/ColorProvider.hpp"
+#include "singletons/Theme.hpp"
+#include "singletons/WindowManager.hpp"
+
+#include <QApplication>
+#include <QPainter>
+
+namespace {
+
+using namespace chatterino;
+
+const Selection EMPTY_SELECTION;
+
+const MessageElementFlags MESSAGE_FLAGS{
+    MessageElementFlag::Text,
+    MessageElementFlag::EmojiAll,
+    MessageElementFlag::EmoteText,
+};
+
+}  // namespace
+
+namespace chatterino {
+
+MessageView::MessageView() = default;
+MessageView::~MessageView() = default;
+
+void MessageView::createMessageLayout()
+{
+    if (this->message_ == nullptr)
+    {
+        this->messageLayout_.reset();
+        return;
+    }
+
+    this->messageLayout_ = std::make_unique<MessageLayout>(this->message_);
+}
+
+void MessageView::setMessage(const MessagePtr &message)
+{
+    if (!message)
+    {
+        return;
+    }
+
+    auto singleLineMessage = std::make_shared<Message>();
+    singleLineMessage->elements.emplace_back(
+        std::make_unique<SingleLineTextElement>(
+            message->messageText, MESSAGE_FLAGS, MessageColor::Type::System,
+            FontStyle::ChatMediumSmall));
+    this->message_ = std::move(singleLineMessage);
+    this->createMessageLayout();
+    this->layoutMessage();
+}
+
+void MessageView::clearMessage()
+{
+    this->setMessage(nullptr);
+}
+
+void MessageView::setWidth(int width)
+{
+    if (this->width_ != width)
+    {
+        this->width_ = width;
+        this->layoutMessage();
+    }
+}
+
+void MessageView::paintEvent(QPaintEvent * /*event*/)
+{
+    QPainter painter(this);
+
+    auto ctx = MessagePaintContext{
+        .painter = painter,
+        .selection = EMPTY_SELECTION,
+        .colorProvider = ColorProvider::instance(),
+        .messageColors = this->messageColors_,
+        .preferences = this->messagePreferences_,
+
+        .canvasWidth = this->width_,
+        .isWindowFocused = this->window() == QApplication::activeWindow(),
+        .isMentions = false,
+
+        .y = 0,
+        .messageIndex = 0,
+        .isLastReadMessage = false,
+    };
+
+    this->messageLayout_->paint(ctx);
+}
+
+void MessageView::themeChangedEvent()
+{
+    this->messageColors_.applyTheme(getTheme());
+    this->messageColors_.regular = getTheme()->splits.input.background;
+    if (this->messageLayout_)
+    {
+        this->messageLayout_->invalidateBuffer();
+    }
+}
+
+void MessageView::scaleChangedEvent(float newScale)
+{
+    (void)newScale;
+
+    this->layoutMessage();
+}
+
+void MessageView::layoutMessage()
+{
+    if (this->messageLayout_ == nullptr)
+    {
+        return;
+    }
+
+    bool updateRequired = this->messageLayout_->layout(
+        this->width_, this->scale(),
+        this->scale() * static_cast<float>(this->devicePixelRatio()),
+        MESSAGE_FLAGS, false);
+
+    if (updateRequired)
+    {
+        this->setFixedSize(this->width_, this->messageLayout_->getHeight());
+        this->update();
+    }
+}
+
+}  // namespace chatterino