connect() of signal passing parameters not wanted by slot
-
Stylistic opinion/what you do wanted, please.
When I have a signal which passes some parameters and I want to
connect()it to a slot of mine which is not interested in/does not use the parameters, for clarity I end up writing a stub lambda just to received but ignore the parameters, e.g.connect(spinBox, &QSpinBox::valueChanged, this, [this](int /*i*/) { existingMethodWithNoParameters(); }); // or (something like) connect(model, &QAbstractItemModel::dataChanged, this, [this](const QModelIndex &/*topLeft*/, const QModelIndex &/*bottomRight*/, const QVector<int> &/*roles*/ = QVector<int>()) { existingMethodWithNoParameters(); });Is this what you would do? I am getting a bit fed up with quite a lot of these, I would prefer to write these as direct slot calls:
connect(spinBox, &QSpinBox::valueChanged, this, &ThisClass::existingMethodWithNoParameters); // or connect(model, &QAbstractItemModel::dataChanged, this, &ThisClass::existingMethodWithNoParameters);connect()seems to be quite happy attaching a slot without these matching parameters, as shown, no compiler complaint. (And I equally don't fancy writing a fully matching slot just to call the desired non-parameter method.) Would you be happy abbreviating like this? Or do you think that is "bad form" and I should spell out the passed-in parameters and write a lambda each time? -
Stylistic opinion/what you do wanted, please.
When I have a signal which passes some parameters and I want to
connect()it to a slot of mine which is not interested in/does not use the parameters, for clarity I end up writing a stub lambda just to received but ignore the parameters, e.g.connect(spinBox, &QSpinBox::valueChanged, this, [this](int /*i*/) { existingMethodWithNoParameters(); }); // or (something like) connect(model, &QAbstractItemModel::dataChanged, this, [this](const QModelIndex &/*topLeft*/, const QModelIndex &/*bottomRight*/, const QVector<int> &/*roles*/ = QVector<int>()) { existingMethodWithNoParameters(); });Is this what you would do? I am getting a bit fed up with quite a lot of these, I would prefer to write these as direct slot calls:
connect(spinBox, &QSpinBox::valueChanged, this, &ThisClass::existingMethodWithNoParameters); // or connect(model, &QAbstractItemModel::dataChanged, this, &ThisClass::existingMethodWithNoParameters);connect()seems to be quite happy attaching a slot without these matching parameters, as shown, no compiler complaint. (And I equally don't fancy writing a fully matching slot just to call the desired non-parameter method.) Would you be happy abbreviating like this? Or do you think that is "bad form" and I should spell out the passed-in parameters and write a lambda each time?@JonB A slot does not have to have parameters. You can for example connect a slot without parameters to a signal with parameters. What is not allowed is the other way around. So, in my opinion it is perfectly fine to omit the parameters in the slot.
-
@JonB A slot does not have to have parameters. You can for example connect a slot without parameters to a signal with parameters. What is not allowed is the other way around. So, in my opinion it is perfectly fine to omit the parameters in the slot.
