Add mouse wheel support to MouseEventHandler

Author: adazem009

src/mouseeventhandler.cpp

@@ -77,6 +77,18 @@ bool MouseEventHandler::eventFilter(QObject *obj, QEvent *event)
             return true;
         }
 
+        case QEvent::Wheel: {
+            QWheelEvent *wheelEvent = static_cast<QWheelEvent *>(event);
+            const int delta = wheelEvent->angleDelta().y();
+
+            if (delta > 0)
+                emit mouseWheelUp();
+            else if (delta < 0)
+                emit mouseWheelDown();
+
+            break;
+        }
+
         default:
             break;
     }

src/mouseeventhandler.h

@@ -34,6 +34,8 @@ class MouseEventHandler : public QObject
         void mouseMoved(qreal x, qreal y);
         void mousePressed();
         void mouseReleased();
+        void mouseWheelUp();
+        void mouseWheelDown();
 
     private:
         void getSprites();

test/mouseeventhandler/mouseeventhandler_test.cpp

@@ -405,3 +405,25 @@ TEST(MouseEventHandlerTest, MousePressReleaseEvent)
     pressedSpy.clear();
     releasedSpy.clear();
 }
+
+TEST(MouseEventHandlerTest, WheelEvent)
+{
+    MouseEventHandler handler;
+    QSignalSpy upSpy(&handler, &MouseEventHandler::mouseWheelUp);
+    QSignalSpy downSpy(&handler, &MouseEventHandler::mouseWheelDown);
+    QWheelEvent event1(QPointF(), QPointF(), QPoint(2, 3), QPoint(10, 15), Qt::LeftButton, Qt::NoModifier, Qt::NoScrollPhase, false);    // up
+    QWheelEvent event2(QPointF(), QPointF(), QPoint(1, -5), QPoint(10, -50), Qt::LeftButton, Qt::NoModifier, Qt::NoScrollPhase, false);  // down
+    QWheelEvent event3(QPointF(), QPointF(), QPoint(-10, 0), QPoint(-100, 0), Qt::LeftButton, Qt::NoModifier, Qt::NoScrollPhase, false); // none
+
+    handler.eventFilter(nullptr, &event1);
+    ASSERT_EQ(upSpy.count(), 1);
+    ASSERT_EQ(downSpy.count(), 0);
+
+    handler.eventFilter(nullptr, &event2);
+    ASSERT_EQ(upSpy.count(), 1);
+    ASSERT_EQ(downSpy.count(), 1);
+
+    handler.eventFilter(nullptr, &event3);
+    ASSERT_EQ(upSpy.count(), 1);
+    ASSERT_EQ(downSpy.count(), 1);
+}