Add capture help message

src/capture/captureareaselector.cpp

@@ -1,17 +1,22 @@
 #include "captureareaselector.h"
 #include "capturer.h"
+#include "languagecodes.h"
+#include "settings.h"
 #include "task.h"
 
 #include <QMouseEvent>
 #include <QPainter>
 #include <QScreen>
 
-CaptureAreaSelector::CaptureAreaSelector(Capturer &capturer)
+CaptureAreaSelector::CaptureAreaSelector(Capturer &capturer,
+                                         const Settings &settings)
   : capturer_(capturer)
+  , settings_(settings)
 {
   setWindowFlags(Qt::FramelessWindowHint | Qt::NoDropShadowWindowHint |
                  Qt::WindowStaysOnTopHint | Qt::X11BypassWindowManagerHint);
   setCursor(Qt::CrossCursor);
+  setMouseTracking(true);
 }
 
 void CaptureAreaSelector::setScreen(QScreen &screen)
@@ -30,6 +35,31 @@ void CaptureAreaSelector::setScreen(QScreen &screen)
   palette.setBrush(backgroundRole(), pixmap);
   setPalette(palette);
   setGeometry(geometry);
+
+  updateHelp();
+}
+
+void CaptureAreaSelector::updateHelp()
+{
+  LanguageCodes languages;
+  const auto source = languages.findById(settings_.sourceLanguage);
+  const auto sourceName =
+      source ? QObject::tr(source->name) : settings_.sourceLanguage;
+  const auto target = languages.findById(settings_.targetLanguage);
+  const auto targetName =
+      target ? QObject::tr(target->name) : settings_.targetLanguage;
+
+  help_ = tr(R"(Recognition language: %1
+Translation language: %2)")
+              .arg(sourceName, targetName);
+
+  const auto rect = this->rect();
+  auto helpRect = fontMetrics().boundingRect({}, 0, help_);
+  helpRect.setSize(helpRect.size() * 1.4);
+  helpRects_ = std::vector<QRect>(2, helpRect);
+  helpRects_[0].moveTopLeft(rect.topLeft());
+  helpRects_[1].moveTopRight(rect.topRight());
+  currentHelpRect_ = helpRects_[0];
 }
 
 void CaptureAreaSelector::showEvent(QShowEvent * /*event*/)
@@ -45,11 +75,30 @@ void CaptureAreaSelector::keyPressEvent(QKeyEvent *event)
 
 void CaptureAreaSelector::paintEvent(QPaintEvent * /*event*/)
 {
+  QPainter painter(this);
+
+  const auto cursor = mapFromGlobal(QCursor::pos());
+  if (currentHelpRect_.contains(cursor)) {
+    for (const auto &rect : helpRects_) {
+      if (!rect.contains(cursor)) {
+        currentHelpRect_ = rect;
+        break;
+      }
+    }
+  }
+
+  painter.setBrush(QBrush(QColor(200, 200, 200, 200)));
+  painter.setPen(Qt::NoPen);
+  painter.drawRect(currentHelpRect_);
+  painter.setBrush({});
+  painter.setPen(Qt::black);
+  painter.drawText(currentHelpRect_, Qt::AlignCenter, help_);
+
   auto selection = QRect(startSelectPos_, currentSelectPos_).normalized();
   if (!selection.isValid())
     return;
 
-  QPainter painter(this);
+  painter.setBrush({});
   painter.setPen(Qt::red);
   painter.drawRect(selection);
 }
@@ -62,11 +111,14 @@ void CaptureAreaSelector::mousePressEvent(QMouseEvent *event)
 
 void CaptureAreaSelector::mouseMoveEvent(QMouseEvent *event)
 {
-  if (startSelectPos_.isNull())
+  if (startSelectPos_.isNull()) {
+    if (currentHelpRect_.contains(event->pos()))
+      update();
     return;
+  }
 
   currentSelectPos_ = event->pos();
-  repaint();
+  update();
 }
 
 void CaptureAreaSelector::mouseReleaseEvent(QMouseEvent *event)

src/capture/captureareaselector.h

@@ -11,7 +11,7 @@ class CaptureAreaSelector : public QWidget
   Q_OBJECT
 
 public:
-  explicit CaptureAreaSelector(Capturer &capturer);
+  CaptureAreaSelector(Capturer &capturer, const Settings &settings);
 
   void setScreen(QScreen &screen);
 
@@ -24,8 +24,14 @@ protected:
   void paintEvent(QPaintEvent *event) override;
 
 private:
+  void updateHelp();
+
   Capturer &capturer_;
+  const Settings &settings_;
   QPixmap pixmap_;
   QPoint startSelectPos_;
   QPoint currentSelectPos_;
+  QString help_;
+  QRect currentHelpRect_;
+  std::vector<QRect> helpRects_;
 };

src/capture/capturer.cpp

@@ -54,7 +54,7 @@ void Capturer::showOverlays(bool capturePixmap)
 
   for (auto i = 0, end = screensSize; i < end; ++i) {
     if (i == overlaysSize) {
-      selectors_.push_back(new CaptureAreaSelector(*this));
+      selectors_.push_back(new CaptureAreaSelector(*this, settings_));
       ++overlaysSize;
     }