Allow for copy and paste of shapes

In the instrument viewer draw tab, the user can copy and paste shapes
using Ctrl+C, Ctrl+V.

qt/widgets/common/inc/MantidQtWidgets/Common/InputController.h

@@ -168,6 +168,10 @@ signals:
   void setSelection(const QRect & /*_t1*/);
   /// Rubber band selection is done
   void finishSelection(const QRect & /*_t1*/);
+  /// Copy the selected shapes.
+  void copySelectedShapes();
+  /// Paste previously copied shapes.
+  void pasteCopiedShapes();
 
 public slots:
   void startCreatingShape2D(const QString &type, const QColor &borderColor,

qt/widgets/common/src/InputController.cpp

@@ -187,6 +187,16 @@ void InputControllerDrawShape::keyPressEvent(QKeyEvent *event) {
   case Qt::Key_Backspace:
     emit removeSelectedShapes();
     break;
+  case Qt::Key_C:
+    if (event->modifiers() == Qt::CTRL) {
+      emit copySelectedShapes();
+    }
+    break;
+  case Qt::Key_V:
+    if (event->modifiers() == Qt::CTRL) {
+      emit pasteCopiedShapes();
+    }
+    break;
   }
 }
 

qt/widgets/instrumentview/inc/MantidQtWidgets/InstrumentView/Shape2DCollection.h

@@ -128,6 +128,8 @@ public slots:
   void restoreOverrideCursor();
   void drawFree(const QPolygonF &polygon);
   void eraseFree(const QPolygonF &polygon);
+  void copySelectedShapes();
+  void pasteCopiedShapes();
 
 protected:
   void drawShape(QPainter & /*painter*/) const override {} // never called
@@ -158,6 +160,8 @@ protected:
   size_t m_currentCP;      ///< control point of m_currentShape selected to edit
   QList<Shape2D *>
       m_selectedShapes; ///< A list of selected shapes (can be moved or deleted)
+  QList<Shape2D *>
+      m_copiedShapes; ///< A list of shapes to be pasted if requiered
   bool m_overridingCursor;
   friend class InstrumentWidgetEncoder;
   friend class InstrumentWidgetDecoder;

qt/widgets/instrumentview/src/ProjectionSurface.cpp

@@ -101,6 +101,10 @@ ProjectionSurface::ProjectionSurface(const InstrumentActor *rootActor)
           SLOT(selectMultipleMasks(QRect)));
   connect(drawController, SIGNAL(finishSelection(QRect)), this,
           SIGNAL(shapeChangeFinished()));
+  connect(drawController, SIGNAL(copySelectedShapes()), &m_maskShapes,
+          SLOT(copySelectedShapes()));
+  connect(drawController, SIGNAL(pasteCopiedShapes()), &m_maskShapes,
+          SLOT(pasteCopiedShapes()));
 
   InputControllerDrawAndErase *freeDrawController =
       new InputControllerDrawAndErase(this);

qt/widgets/instrumentview/src/Shape2DCollection.cpp

@@ -28,7 +28,8 @@ namespace MantidWidgets {
 
 Shape2DCollection::Shape2DCollection()
     : Shape2D(), m_wx(0), m_wy(0), m_h(0), m_currentShape(nullptr),
-      m_currentCP(0), m_overridingCursor(false) {}
+      m_currentCP(0), m_copiedShapes(QList<Shape2D *>()),
+      m_overridingCursor(false) {}
 
 Shape2DCollection::~Shape2DCollection() {
   foreach (Shape2D *shape, m_shapes) { delete shape; }
@@ -532,6 +533,33 @@ void Shape2DCollection::removeSelectedShapes() {
   }
 }
 
+/**
+ * @brief Shape2DCollection::copySelectedShapes
+ * Add the selected shapes to a copy buffer. Remove those previously stored.
+ */
+void Shape2DCollection::copySelectedShapes() {
+  m_copiedShapes.clear();
+  foreach (auto shape, m_selectedShapes) {
+    Shape2D *newShape = shape->clone();
+    newShape->setFillColor(shape->getFillColor());
+    // the fill color is not transmitted by the clone operator
+    m_copiedShapes.push_back(newShape);
+  }
+}
+
+/**
+ * @brief Shape2DCollection::pasteCopiedShapes
+ * Add a copy of the shapes stored in the copy buffer to the collection.
+ */
+void Shape2DCollection::pasteCopiedShapes() {
+  foreach (auto shape, m_copiedShapes) {
+    Shape2D *newShape = shape->clone();
+    newShape->moveBy(QPointF(0.1, 0.1));
+    newShape->setFillColor(shape->getFillColor());
+    addShape(newShape, false);
+  }
+}
+
 /**
  * Restore the cursor image to default.
  */