Mouse Tracking not working with QOpenGLWidget as MainWindow's' central widget in Qt 5.12

[feistykittykat]

Hey folks, I'm trying to track mouse move events in my GLWidget, which inherits from QOpenGLWidget. I have this widget set as the central widget of my main window. I have NO custom event filters or anything, and the widget correctly receives mouse move events when a mouse button is pressed. I've seen a lot of threads discussing similar issues, but so far no solutions that are relevant for me.

I am calling setMouseTracking(true); in the constructor of my widget, and am verifying that this is set correctly via hasMouseTracking after setting the widget as the central widget. I don't have any widgets occluding this widget, so I'm really at a loss. I don't want to have to implement my own thread that captures mouse events, since that defeats the point of using Qt.

[SGaist]

Hi,

Which OS ?
Which version of Qt ?
Can you provide a minimal compilable example that shows that behaviour ?

[feistykittykat]

@SGaist I'm on windows, and I mentioned that I'm using Qt 5.12. I can try to put together a working example, but I'm not doing much besides what I described. My GLWidget looks like this:

GLWidget.h

class GLWidget : public QOpenGLWidget, public Object 
{
    Q_OBJECT
public:
    //-----------------------------------------------------------------------------------------------------------------
    /// @name Constructors and Destructors
    /// @{
    GLWidget(const QString& name, QWidget *parent);
    ~GLWidget();
    /// @}

    //-----------------------------------------------------------------------------------------------------------------
    /// @name Methods
    /// @{

    virtual const char* className() const override { return "GLWidget"; }

    /// @}

    //-----------------------------------------------------------------------------------------------------------------
    /// @name QWidget Overrides
    /// @{

    /// @brief Override resize event to send out signal
    virtual void resizeEvent(QResizeEvent* event) override;

    /// @}
signals:
    /// @brief Sent on resize
    void resized(int width, int height);

    /// @brief Send on initialization
    void initializedContext();

protected:
    //---------------------------------------------------------------------------------------------
    /// @name Protected Methods
    /// @{

    /// @brief Override contextMenuEvent
    void contextMenuEvent(QContextMenuEvent *event) override;

    /// @brief Input handlers
    void keyPressEvent(QKeyEvent *event) override;
    void keyReleaseEvent(QKeyEvent *event) override;
    void wheelEvent(QWheelEvent *event) override;
    void mouseDoubleClickEvent(QMouseEvent *event) override;
    void mouseMoveEvent(QMouseEvent *event) override;
    void mousePressEvent(QMouseEvent *event) override;
    void mouseReleaseEvent(QMouseEvent *event) override;

    /// @brief GL-specific overrides
	void initializeGL() override;
	void resizeGL(int w, int h) override;
	void paintGL() override;

    /// @brief set up signal/slot connections to render manager
    void initializeConnections();

    /// @}

    // Input handler, processes key and mouse inputs
    InputHandler m_inputHandler;

};

GLWidget.cpp

GLWidget::GLWidget(const QString& name, QWidget * parent) :
    QOpenGLWidget(parent),
    Object(name), // My own Object class 
    m_inputHandler(this)
{
    // Initialize all signal/slot connections
    initializeConnections();

    // Ensure that mouse is tracked even when button is not clicked
    setMouseTracking(true);

    // Ensure that widget accepts keyboard focus
    setFocusPolicy(Qt::StrongFocus);
}
/////////////////////////////////////////////////////////////////////////////////////////////
GLWidget::~GLWidget()
{
    // Make context current for cleanup
    makeCurrent();
}
/////////////////////////////////////////////////////////////////////////////////////////////
void GLWidget::clear()
{
    m_renderProjections.clear();
    m_renderer->requestResize();
}
/////////////////////////////////////////////////////////////////////////////////////////////
void GLWidget::resizeEvent(QResizeEvent * event)
{
    // Perform base class resize event
    QOpenGLWidget::resizeEvent(event);

    // Emit resize signal (connects to RenderProjection class)
    emit resized(width(), height());

#ifdef DEBUG_MODE
    //int w = width();
    //int h = height();
#endif
}
/////////////////////////////////////////////////////////////////////////////////////////////
void GLWidget::initializeGL()
{
	// Needed to checkValidity GL
	m_renderer = std::make_shared<MainRenderer>(m_engine, this);
	m_renderer->initialize();

    // Emit signal that GL context is initialized
    emit initializedContext();
}
/////////////////////////////////////////////////////////////////////////////////////////////
void GLWidget::resizeGL(int w, int h)
{
    Q_UNUSED(w);
    Q_UNUSED(h);
    resizeProjections(w, h);
    if (m_engine->scenario()) {
        m_renderer->requestResize();
        m_renderer->render();
    }
}
/////////////////////////////////////////////////////////////////////////////////////////////
void GLWidget::paintGL()
{
    if (m_engine->scenario()) {
        // This is called from the main simloop's update routine (GLWidget::update())
        // TODO: Separate processScenes and render logic into different loops
        m_renderer->processScenes(); 
        m_renderer->render();
    }
}

void GLWidget::keyPressEvent(QKeyEvent * event)
{
    m_inputHandler.handleEvent(event);
    QOpenGLWidget::keyPressEvent(event);
}

void GLWidget::keyReleaseEvent(QKeyEvent * event)
{
    m_inputHandler.handleEvent(event);
    QOpenGLWidget::keyReleaseEvent(event);
}

void GLWidget::wheelEvent(QWheelEvent * event)
{
    m_inputHandler.handleEvent(event);
    QOpenGLWidget::wheelEvent(event);
}

void GLWidget::mouseDoubleClickEvent(QMouseEvent * event)
{
    m_inputHandler.handleEvent(event);
    //QOpenGLWidget::mouseDoubleClickEvent(event); // Don't send another press event
}

void GLWidget::mouseMoveEvent(QMouseEvent * event)
{
    m_inputHandler.handleEvent(event);
    //event->ignore();
    QOpenGLWidget::mouseMoveEvent(event);
}

void GLWidget::mousePressEvent(QMouseEvent * event)
{
    m_inputHandler.handleEvent(event);
    QOpenGLWidget::mousePressEvent(event);
}

void GLWidget::mouseReleaseEvent(QMouseEvent * event)
{
    m_inputHandler.handleEvent(event);
    QOpenGLWidget::mouseReleaseEvent(event);
}

void GLWidget::initializeConnections()
{
    connect(m_engine, &CoreEngine::scenarioNeedsRedraw, this, static_cast<void (GLWidget::*)()>(&GLWidget::resizeProjections));
}

[SGaist]

@feistykittykat said in Mouse Tracking not working with QOpenGLWidget as MainWindow's' central widget in Qt 5.12:

and I mentioned that I'm using Qt 5.12.

Not in this thread.

That class does not show anything obviously wrong hoe we there are missing pieces like the custom input handler that does not allow to guess what might be happening.