Place editor respecting available space

screen-translator.pro

@@ -44,6 +44,7 @@ HEADERS += \
   src/represent/resultwidget.h \
   src/service/apptranslator.h \
   src/service/debug.h \
+  src/service/geometryutils.h \
   src/service/globalaction.h \
   src/service/runatsystemstart.h \
   src/service/singleapplication.h \
@@ -75,6 +76,7 @@ SOURCES += \
   src/represent/resultwidget.cpp \
   src/service/apptranslator.cpp \
   src/service/debug.cpp \
+  src/service/geometryutils.cpp \
   src/service/globalaction.cpp \
   src/service/runatsystemstart.cpp \
   src/service/singleapplication.cpp \

src/capture/captureareaselector.cpp

@@ -3,6 +3,7 @@
 #include "captureareaeditor.h"
 #include "capturer.h"
 #include "debug.h"
+#include "geometryutils.h"
 #include "languagecodes.h"
 #include "settings.h"
 
@@ -219,8 +220,10 @@ void CaptureAreaSelector::customize(const CaptureArea &area)
 {
   SOFT_ASSERT(editor_, return );
   editor_->set(area);
-  editor_->move(QCursor::pos());
   editor_->show();
+  const auto topLeft = service::geometry::cornerAtPoint(
+      area.rect().center(), editor_->size(), geometry());
+  editor_->move(topLeft);
   update();
 }
 

src/service/geometryutils.cpp

@@ -0,0 +1,50 @@
+#include "geometryutils.h"
+
+#include <QRect>
+
+namespace service
+{
+namespace geometry
+{
+QPoint cornerAtPoint(const QPoint &corner, const QSize &size,
+                     const QRect &boundRect)
+{
+  auto clamped = corner;
+  if (!boundRect.contains(clamped)) {
+    const auto x = std::clamp(clamped.x(), boundRect.left(), boundRect.right());
+    const auto y = std::clamp(clamped.y(), boundRect.top(), boundRect.bottom());
+    clamped = QPoint(x, y);
+  }
+
+  const auto zeroCorner = clamped - boundRect.topLeft();
+  const auto boundWidth = boundRect.width();
+  const auto boundHeight = boundRect.height();
+
+  QPoint result;
+  if (boundWidth <= size.width()) {  // not fits
+    result.rx() = 0;
+  } else if (boundWidth - zeroCorner.x() >= size.width()) {  // enough on right
+    result.rx() = zeroCorner.x();
+  } else if (zeroCorner.x() >= size.width()) {  // enough on left
+    result.rx() = zeroCorner.x() - size.width() + 1;
+  } else {  // not enough on both sides
+    result.rx() =
+        zeroCorner.x() >= boundWidth / 2 ? 0 : boundWidth - size.width() + 1;
+  }
+
+  if (boundHeight <= size.height()) {
+    result.ry() = 0;
+  } else if (boundHeight - zeroCorner.y() >= size.height()) {
+    result.ry() = zeroCorner.y();
+  } else if (zeroCorner.y() >= size.height()) {
+    result.ry() = zeroCorner.y() - size.height() + 1;
+  } else {
+    result.ry() =
+        zeroCorner.y() >= boundHeight / 2 ? 0 : boundHeight - size.height() + 1;
+  }
+
+  return result + boundRect.topLeft();
+}
+
+}  // namespace geometry
+}  // namespace service

src/service/geometryutils.h

@@ -0,0 +1,14 @@
+#pragma once
+
+class QRect;
+class QPoint;
+class QSize;
+
+namespace service
+{
+namespace geometry
+{
+QPoint cornerAtPoint(const QPoint& corner, const QSize& size,
+                     const QRect& boundRect);
+}
+}  // namespace service