class QMetaMethod

The QMetaMethod class provides meta-data about a member function. More…

Synopsis

Methods

Static functions

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description

A QMetaMethod has a methodType() , a methodSignature() , a list of parameterTypes() and parameterNames() , a return typeName() , a tag() , and an access() specifier. You can use invoke() to invoke the method on an arbitrary QObject .

class Access

This enum describes the access level of a method, following the conventions used in C++.

Constant

Description

QMetaMethod.Private

QMetaMethod.Protected

QMetaMethod.Public
class MethodType

Constant

Description

QMetaMethod.Method

The function is a plain member function.

QMetaMethod.Signal

The function is a signal.

QMetaMethod.Slot

The function is a slot.

QMetaMethod.Constructor

The function is a constructor.
__init__()
access()
Return type:

Access

Returns the access specification of this method (private, protected, or public).

Note

Signals are always public, but you should regard that as an implementation detail. It is almost always a bad idea to emit a signal from outside its class.

See also

methodType()

enclosingMetaObject()
Return type:

QMetaObject

static fromSignal(signal)
Parameters:

signal – PySideSignalInstance

Return type:

QMetaMethod

Returns the meta-method that corresponds to the given signal, or an invalid QMetaMethod if signal is not a signal of the class.

invoke(object, val0[, val1=QGenericArgument()[, val2=QGenericArgument()[, val3=QGenericArgument()[, val4=QGenericArgument()[, val5=QGenericArgument()[, val6=QGenericArgument()[, val7=QGenericArgument()[, val8=QGenericArgument()[, val9=QGenericArgument()]]]]]]]]])
Parameters:
Return type:

bool

Please use the variadic overload of this function

This function overloads invoke() .

This overload invokes this method using the connection type AutoConnection and ignores return values.

invoke(object[, val0={}[, val1={}[, val2={}[, val3={}[, val4={}[, val5={}[, val6={}[, val7={}[, val8={}[, val9={}]]]]]]]]]])
Parameters:

  • object – QObject

  • val0 – QGenericArgumentHolder

  • val1 – QGenericArgumentHolder

  • val2 – QGenericArgumentHolder

  • val3 – QGenericArgumentHolder

  • val4 – QGenericArgumentHolder

  • val5 – QGenericArgumentHolder

  • val6 – QGenericArgumentHolder

  • val7 – QGenericArgumentHolder

  • val8 – QGenericArgumentHolder

  • val9 – QGenericArgumentHolder

Return type:

object

invoke(object, returnValue[, val0=QGenericArgument(nullptr)[, val1=QGenericArgument()[, val2=QGenericArgument()[, val3=QGenericArgument()[, val4=QGenericArgument()[, val5=QGenericArgument()[, val6=QGenericArgument()[, val7=QGenericArgument()[, val8=QGenericArgument()[, val9=QGenericArgument()]]]]]]]]]])
Parameters:
Return type:

bool

Please use the variadic overload of this function

This function overloads invoke() .

This overload always invokes this method using the connection type AutoConnection .

invoke(object, connectionType, val0[, val1=QGenericArgument()[, val2=QGenericArgument()[, val3=QGenericArgument()[, val4=QGenericArgument()[, val5=QGenericArgument()[, val6=QGenericArgument()[, val7=QGenericArgument()[, val8=QGenericArgument()[, val9=QGenericArgument()]]]]]]]]])
Parameters:
Return type:

bool

Please use the variadic overload of this function

This function overloads invoke() .

This overload can be used if the return value of the member is of no interest.

invoke(object, type[, val0={}[, val1={}[, val2={}[, val3={}[, val4={}[, val5={}[, val6={}[, val7={}[, val8={}[, val9={}]]]]]]]]]])
Parameters:

  • object – QObject

  • type – ConnectionType

  • val0 – QGenericArgumentHolder

  • val1 – QGenericArgumentHolder

  • val2 – QGenericArgumentHolder

  • val3 – QGenericArgumentHolder

  • val4 – QGenericArgumentHolder

  • val5 – QGenericArgumentHolder

  • val6 – QGenericArgumentHolder

  • val7 – QGenericArgumentHolder

  • val8 – QGenericArgumentHolder

  • val9 – QGenericArgumentHolder

Return type:

object

invoke(object, ret[, val0={}[, val1={}[, val2={}[, val3={}[, val4={}[, val5={}[, val6={}[, val7={}[, val8={}[, val9={}]]]]]]]]]])
Parameters:

  • object – QObject

  • ret – QGenericReturnArgumentHolder

  • val0 – QGenericArgumentHolder

  • val1 – QGenericArgumentHolder

  • val2 – QGenericArgumentHolder

  • val3 – QGenericArgumentHolder

  • val4 – QGenericArgumentHolder

  • val5 – QGenericArgumentHolder

  • val6 – QGenericArgumentHolder

  • val7 – QGenericArgumentHolder

  • val8 – QGenericArgumentHolder

  • val9 – QGenericArgumentHolder

Return type:

object

invoke(object, connectionType, returnValue[, val0=QGenericArgument(nullptr)[, val1=QGenericArgument()[, val2=QGenericArgument()[, val3=QGenericArgument()[, val4=QGenericArgument()[, val5=QGenericArgument()[, val6=QGenericArgument()[, val7=QGenericArgument()[, val8=QGenericArgument()[, val9=QGenericArgument()]]]]]]]]]])
Parameters:
Return type:

bool

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

Please use the variadic overload of this function

Invokes this method on the object object. Returns true if the member could be invoked. Returns false if there is no such member or the parameters did not match.

See the variadic invokeMethod() function for more information. This function should behave the same way as that one, with the following limitations:

  • The number of parameters is limited to 10.

  • Parameter names may need to be an exact string match.

  • Meta types are not automatically registered.

With asynchronous method invocations, the parameters must be of types that are known to Qt’s meta-object system, because Qt needs to copy the arguments to store them in an event behind the scenes. If you try to use a queued connection and get the error message

QMetaMethod.invoke: Unable to handle unregistered datatype 'MyType'

call qRegisterMetaType() to register the data type before you call invoke() .

Warning

In addition to the limitations of the variadic invoke() overload, the arguments must have the same type as the ones expected by the method, else, the behavior is undefined.

See also

Q_ARG() Q_RETURN_ARG() qRegisterMetaType() invokeMethod()

invoke(object, type, ret[, val0={}[, val1={}[, val2={}[, val3={}[, val4={}[, val5={}[, val6={}[, val7={}[, val8={}[, val9={}]]]]]]]]]])
Parameters:

  • object – QObject

  • type – ConnectionType

  • ret – QGenericReturnArgumentHolder

  • val0 – QGenericArgumentHolder

  • val1 – QGenericArgumentHolder

  • val2 – QGenericArgumentHolder

  • val3 – QGenericArgumentHolder

  • val4 – QGenericArgumentHolder

  • val5 – QGenericArgumentHolder

  • val6 – QGenericArgumentHolder

  • val7 – QGenericArgumentHolder

  • val8 – QGenericArgumentHolder

  • val9 – QGenericArgumentHolder

Return type:

object

invokeOnGadget(gadget, val0[, val1=QGenericArgument()[, val2=QGenericArgument()[, val3=QGenericArgument()[, val4=QGenericArgument()[, val5=QGenericArgument()[, val6=QGenericArgument()[, val7=QGenericArgument()[, val8=QGenericArgument()[, val9=QGenericArgument()]]]]]]]]])
Parameters:
Return type:

bool

This is an overloaded function.

Please use the variadic overload of this function

This overload invokes this method for a gadget and ignores return values.

invokeOnGadget(gadget, returnValue[, val0=QGenericArgument(nullptr)[, val1=QGenericArgument()[, val2=QGenericArgument()[, val3=QGenericArgument()[, val4=QGenericArgument()[, val5=QGenericArgument()[, val6=QGenericArgument()[, val7=QGenericArgument()[, val8=QGenericArgument()[, val9=QGenericArgument()]]]]]]]]]])
Parameters:
Return type:

bool

Please use the variadic overload of this function

Invokes this method on a Q_GADGET . Returns true if the member could be invoked. Returns false if there is no such member or the parameters did not match.

See the variadic invokeMethod() function for more information. This function should behave the same way as that one, with the following limitations:

  • The number of parameters is limited to 10.

  • Parameter names may need to be an exact string match.

  • Meta types are not automatically registered.

Warning

In addition to the limitations of the variadic invoke() overload, the arguments must have the same type as the ones expected by the method, else, the behavior is undefined.

See also

Q_ARG() Q_RETURN_ARG() qRegisterMetaType() invokeMethod()

isConst()
Return type:

bool

Returns whether the method is const qualified.

Note

This method might erroneously return false for a const method if it belongs to a library compiled against an older version of Qt.

isValid()
Return type:

bool

Returns true if this method is valid (can be introspected and invoked), otherwise returns false.

methodIndex()
Return type:

int

Returns this method’s index.

methodSignature()
Return type:

QByteArray

Returns the signature of this method (e.g., setValue(double)).

methodType()
Return type:

MethodType

Returns the type of this method (signal, slot, or method).

See also

access()

name()
Return type:

QByteArray

Returns the name of this method.

__ne__(rhs)
Parameters:

rhs – QMetaMethod

Return type:

bool

This is an overloaded function.

Returns true if method lhs is not equal to method rhs, otherwise returns false.

__eq__(rhs)
Parameters:

rhs – QMetaMethod

Return type:

bool

This is an overloaded function.

Returns true if method lhs is equal to method rhs, otherwise returns false.

parameterCount()
Return type:

int

Returns the number of parameters of this method.

parameterMetaType(index)
Parameters:

index – int

Return type:

QMetaType

Returns the metatype of the parameter at the given index.

If the index is smaller than zero or larger than parameterCount() , an invalid QMetaType is returned.

parameterNames()
Return type:

.list of QByteArray

Returns a list of parameter names.

parameterType(index)
Parameters:

index – int

Return type:

int

Returns the type of the parameter at the given index.

The return value is one of the types that are registered with QMetaType , or UnknownType if the type is not registered.

parameterTypeName(index)
Parameters:

index – int

Return type:

QByteArray

Returns the name of the type at position index If there is no parameter at index, returns an empty QByteArray

See also

parameterNames()

parameterTypes()
Return type:

.list of QByteArray

Returns a list of parameter types.

relativeMethodIndex()
Return type:

int

Returns this method’s local index inside.

returnMetaType()
Return type:

QMetaType

Returns the return type of this method.

returnType()
Return type:

int

Returns the return type of this method.

The return value is one of the types that are registered with QMetaType , or UnknownType if the type is not registered.

revision()
Return type:

int

Returns the method revision if one was specified by Q_REVISION , otherwise returns 0.

tag()
Return type:

str

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

Returns the tag associated with this method.

Tags are special macros recognized by moc that make it possible to add extra information about a method.

Tag information can be added in the following way in the function declaration:

    # In the class MainWindow declaration
    #ifndef Q_MOC_RUN
    # define the tag text as empty, so the compiler doesn't see it
    # define MY_CUSTOM_TAG
    #endif
    ...
#     private slots
        MY_CUSTOM_TAG void testFunc()

and the information can be accessed by using:

win = MainWindow()
win.show()
functionIndex = win.metaObject().indexOfSlot("testFunc()")
mm = win.metaObject().method(functionIndex)
print(mm.tag()) # prints MY_CUSTOM_TAG

For the moment, moc will extract and record all tags, but it will not handle any of them specially. You can use the tags to annotate your methods differently, and treat them according to the specific needs of your application.

Note

moc expands preprocessor macros, so it is necessary to surround the definition with #ifndef Q_MOC_RUN, as shown in the example above.

typeName()
Return type:

str

Returns the return type name of this method.

See also

returnType() type()