Strange border appearing when hovering over Widgets in a QGraphicsScene

[Guigui]

Hi all,

I've got this QGraphicsProxyWidget which is composed of QFrames and QLabels. A stylesheet defines the appearance of the item. Everything works fine, except for a gray border which appears around some labels whenever the mouse passes over them. I unfortunately don't have much useful code to show (not sure posting the whole class would be relevant), and can't send screenshots of the problem from this computer... Not a showstopper for the moment, but a bit annoying and I can't find any clues about what causes this. Any ideas?

Thx in advance!

EDIT:

Wow! I've had no clue about this for the last three months and partially found a solution in about 3 minutes about posting this... Still needs some clarification tough.

I simply overrided the hoverEnterEvent, hoverLeaveEvent and hoverMoveEvent.

@void NodeItem::hoverEnterEvent(QGraphicsSceneHoverEvent *event)
{
Q_UNUSED(event)
qDebug() << "hoverEnterEvent on NodeItem";
}

void NodeItem::hoverLeaveEvent(QGraphicsSceneHoverEvent *event)
{
Q_UNUSED(event)
qDebug() << "hoverLeaveEvent on NodeItem";
}

void NodeItem::hoverMoveEvent(QGraphicsSceneHoverEvent *event)
{
Q_UNUSED(event)
qDebug() << "hoverMoveEvent on NodeItem";
}@

It seems that my QGraphicsProxyWidget ignores setAcceptHoverEvents(false), as debug messages always print.

The problem reappears by adding

@QGraphicsProxyWidget::hover{Enter/Leave/Move}Event(event);@

in the previous functions.

So a clearer question would be: why is setAcceptHoverEvents(false) ignored? Are empty reimplementations of hover events an acceptable solution?

[raven-worx]

i guess the border most probably comes from a definition in your stylesheet.

[Guigui]

Well here's a bit more about how the Item is constructed. It's a node composed of a header, a list of input connectors and a list of output connectors.

@NodeItem::NodeItem(AbstractNode *node, QGraphicsItem *parent)
: QGraphicsProxyWidget(parent),
m_instance(node),
m_zvalue(0)
{
setCacheMode(DeviceCoordinateCache);
setFlag(QGraphicsItem::ItemIsMovable, true);
setFlag(QGraphicsItem::ItemIsSelectable, true);
setFlag(QGraphicsItem::ItemSendsGeometryChanges, true);
setZValue(m_zvalue);
setAcceptHoverEvents(false); // Doesn't seem to do anything

QFrame *m_nodeWidget = new QFrame();
m_nodeWidget->setObjectName("NodeItem");

QLabel *nodeHeader = new QLabel(m_instance->objectName());
nodeHeader->setObjectName("NodeHeaderLabel");

QFrame *innerFrame = new QFrame();
innerFrame->setObjectName("NodeInnerFrame");

QFrame *contentFrame = new QFrame();
contentFrame->setObjectName("NodeContentFrame");

QHBoxLayout *connectorsLayout = new QHBoxLayout();
QVBoxLayout *inputsLayout = new QVBoxLayout();
QVBoxLayout *outputsLayout = new QVBoxLayout();
connectorsLayout->addLayout(inputsLayout);
connectorsLayout->addLayout(outputsLayout);
contentFrame->setLayout(connectorsLayout);

QVBoxLayout *contentLayout = new QVBoxLayout();
contentLayout->addWidget(nodeHeader);
contentLayout->addWidget(contentFrame);
innerFrame->setLayout(contentLayout);

QVBoxLayout *nodeLayout = new QVBoxLayout();
nodeLayout->addWidget(innerFrame);
m_nodeWidget->setLayout(nodeLayout);

inputsLayout->setMargin(0);
outputsLayout->setMargin(0);
connectorsLayout->setMargin(0);
contentLayout->setMargin(0);
nodeLayout->setMargin(0);

/* Add input ports */
input_map_t ins = m_instance->inputs();
for (input_map_t::iterator it = ins.begin(); it != ins.end(); ++it) {
    addConnector(inputsLayout, it.key(), NodeConnectorItem::Input);
}

/* Add output ports */
output_map_t outs = m_instance->outputs();
for (output_map_t::iterator it = outs.begin(); it != outs.end(); ++it) {
    addConnector(outputsLayout, it.key(), NodeConnectorItem::Output);
}

setToolTip(m_instance->getDescription());
setWidget(m_nodeWidget);

}

NodeConnectorItem* NodeItem::addConnector(QBoxLayout *layout, const QString &name, NodeConnectorItem::ConnectorType connectorType)
{
NodeConnectorItem *connector = 0;
QLabel *label = new QLabel(name);

if (connectorType == NodeConnectorItem::Input) {
    label->setObjectName("NodeInput");
    layout->addWidget(label, 0, Qt::AlignLeft);
} else {
    label->setObjectName("NodeOutput");
    layout->addWidget(label, 0, Qt::AlignRight);
}

connector = new NodeConnectorItem(name, connectorType, label, this);
m_connectors.append(connector);

return connector;

}

// Seems like hover events are always enabled and not propagating the event by calling base class event func fixes the problem
void NodeItem::hoverEnterEvent(QGraphicsSceneHoverEvent *event){}
void NodeItem::hoverLeaveEvent(QGraphicsSceneHoverEvent *event){}
void NodeItem::hoverMoveEvent(QGraphicsSceneHoverEvent *event){}
@

And here's the stylesheet, which is pretty simple.

@#NodeItem {
background-color: rgba(0,0,0,0);
border-radius: 4px;
margin: 0px;
padding: 0px;
}

#NodeInnerFrame {
background-color: qlineargradient(x1:0, y1:0, x2:1, y2:1, stop:0.25 rgba(50, 50, 50, 192), stop:1 rgba(160, 160, 160, 192));
border-radius: 4px;
margin: 0px;
padding: 0px;
}

#NodeContentFrame {
background-color: rgba(0,0,0,0);
padding: 4px;
margin: 4px;
}

#NodeHeaderLabel {
background-color: rgba(224,224,224,255);
color: black;
border-radius: 2px;
font: 10px;
font-weight: bold;
padding: 2px;
}

#NodeInput {
background-color: rgba(0,0,0,0);
color: white;
}

#NodeOutput {
background-color: rgba(0,0,0,0);
color: white;
}@