Add mouse wheel support

src/ProjectPlayer.qml

@@ -191,6 +191,8 @@ ProjectScene {
             onMouseMoved: (x, y)=> root.handleMouseMove(x, y)
             onMousePressed: root.handleMousePress()
             onMouseReleased: root.handleMouseRelease()
+            onMouseWheelUp: root.handleMouseWheelUp()
+            onMouseWheelDown: root.handleMouseWheelDown()
         }
 
         Component {

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();

src/projectscene.cpp

@@ -71,6 +71,19 @@ void ProjectScene::handleMouseRelease()
         m_engine->setMousePressed(false);
 }
 
+void ProjectScene::handleMouseWheelUp()
+{
+    if (m_engine)
+        m_engine->mouseWheelUp();
+}
+
+void ProjectScene::handleMouseWheelDown()
+{
+
+    if (m_engine)
+        m_engine->mouseWheelDown();
+}
+
 void ProjectScene::handleKeyPress(Qt::Key key, const QString &text)
 {
     m_pressedKeys.insert(key);

src/projectscene.h

@@ -34,6 +34,8 @@ class ProjectScene : public QQuickItem
         Q_INVOKABLE void handleMouseMove(qreal x, qreal y);
         Q_INVOKABLE void handleMousePress();
         Q_INVOKABLE void handleMouseRelease();
+        Q_INVOKABLE void handleMouseWheelUp();
+        Q_INVOKABLE void handleMouseWheelDown();
 
         void handleKeyPress(Qt::Key key, const QString &text);
         void handleKeyRelease(Qt::Key key, const QString &text);

src/scenemousearea.cpp

@@ -15,6 +15,8 @@ SceneMouseArea::SceneMouseArea(QQuickItem *parent) :
     connect(m_mouseHandler, &MouseEventHandler::mouseMoved, this, &SceneMouseArea::mouseMoved);
     connect(m_mouseHandler, &MouseEventHandler::mousePressed, this, &SceneMouseArea::mousePressed);
     connect(m_mouseHandler, &MouseEventHandler::mouseReleased, this, &SceneMouseArea::mouseReleased);
+    connect(m_mouseHandler, &MouseEventHandler::mouseWheelUp, this, &SceneMouseArea::mouseWheelUp);
+    connect(m_mouseHandler, &MouseEventHandler::mouseWheelDown, this, &SceneMouseArea::mouseWheelDown);
 
     setAcceptHoverEvents(true);
     setAcceptTouchEvents(true);

src/scenemousearea.h

@@ -34,6 +34,8 @@ class SceneMouseArea : public QQuickItem
         void mouseMoved(qreal x, qreal y);
         void mousePressed();
         void mouseReleased();
+        void mouseWheelUp();
+        void mouseWheelDown();
         void stageChanged();
         void projectLoaderChanged();
 

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);
+}

test/projectscene/projectscene_test.cpp

@@ -67,6 +67,19 @@ TEST(ProjectSceneTest, HandleMouseRelease)
     scene.handleMouseRelease();
 }
 
+TEST(ProjectSceneTest, HandleMouseWheel)
+{
+    ProjectScene scene;
+    EngineMock engine;
+    scene.setEngine(&engine);
+
+    EXPECT_CALL(engine, mouseWheelUp());
+    scene.handleMouseWheelUp();
+
+    EXPECT_CALL(engine, mouseWheelDown());
+    scene.handleMouseWheelDown();
+}
+
 TEST(ProjectSceneTest, HandleKeyPressAndRelease)
 {
     static const std::unordered_map<Qt::Key, KeyEvent::Type> SPECIAL_KEY_MAP = {