class QMetaProperty#

The QMetaProperty class provides meta-data about a property. More…

Synopsis#

Methods#

def __init__()
def enumerator()
def hasNotifySignal()
def hasStdCppSet()
def isAlias()
def isBindable()
def isConstant()
def isDesignable()
def isEnumType()
def isFinal()
def isFlagType()
def isReadable()
def isRequired()
def isResettable()
def isScriptable()
def isStored()
def isUser()
def isValid()
def isWritable()
def metaType()
def name()
def notifySignal()
def notifySignalIndex()
def propertyIndex()
def read()
def readOnGadget()
def relativePropertyIndex()
def reset()
def resetOnGadget()
def revision()
def typeId()
def typeName()
def userType()
def write()
def writeOnGadget()

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#

Property meta-data is obtained from an object’s meta-object. See property() and propertyCount() for details.

Property Meta-Data#

A property has a name() and a type(), as well as various attributes that specify its behavior: isReadable() , isWritable() , isDesignable() , isScriptable() , revision() , and isStored() .

If the property is an enumeration, isEnumType() returns true; if the property is an enumeration that is also a flag (i.e. its values can be combined using the OR operator), isEnumType() and isFlagType() both return true. The enumerator for these types is available from enumerator() .

The property’s values are set and retrieved with read() , write() , and reset() ; they can also be changed through QObject ‘s set and get functions. See setProperty() and property() for details.

Copying and Assignment#

QMetaProperty objects can be copied by value. However, each copy will refer to the same underlying property meta-data.

See also

QMetaObject QMetaEnum QMetaMethod Qt’s Property System

__init__()#

enumerator()#

Return type:: QMetaEnum

Returns the enumerator if this property’s type is an enumerator type; otherwise the returned value is undefined.

See also

isEnumType() isFlagType()

hasNotifySignal()#

Return type:: bool

Returns true if this property has a corresponding change notify signal; otherwise returns false.

See also

notifySignal()

hasStdCppSet()#

Return type:: bool

isAlias()#

Return type:: bool

isBindable()#

Return type:: bool

Returns true if the Q_PROPERTY() exposes binding functionality; otherwise returns false.

This implies that you can create bindings that use this property as a dependency or install QPropertyObserver objects on this property. Unless the property is readonly, you can also set a binding on this property.

See also

QProperty isWritable() bindable()

isConstant()#

Return type:: bool

Returns true if the property is constant; otherwise returns false.

A property is constant if the Q_PROPERTY()'s CONSTANT attribute is set.

isDesignable()#

Return type:: bool

Returns false if the Q_PROPERTY()'s DESIGNABLE attribute is false; otherwise returns true.

See also

isScriptable() isStored()

isEnumType()#

Return type:: bool

Returns true if the property’s type is an enumeration value; otherwise returns false.

See also

enumerator() isFlagType()

isFinal()#

Return type:: bool

Returns true if the property is final; otherwise returns false.

A property is final if the Q_PROPERTY()'s FINAL attribute is set.

isFlagType()#

Return type:: bool

Returns true if the property’s type is an enumeration value that is used as a flag; otherwise returns false.

Flags can be combined using the OR operator. A flag type is implicitly also an enum type.

See also

isEnumType() enumerator() isFlag()

isReadable()#

Return type:: bool

Returns true if this property is readable; otherwise returns false.

See also

isWritable() read() isValid()

isRequired()#

Return type:: bool

Returns true if the property is required; otherwise returns false.

A property is final if the Q_PROPERTY()'s REQUIRED attribute is set.

isResettable()#

Return type:: bool

Returns true if this property can be reset to a default value; otherwise returns false.

See also

reset()

isScriptable()#

Return type:: bool

Returns false if the Q_PROPERTY()'s SCRIPTABLE attribute is false; otherwise returns true.

See also

isDesignable() isStored()

isStored()#

Return type:: bool

Returns true if the property is stored; otherwise returns false.

The function returns false if the Q_PROPERTY()'s STORED attribute is false; otherwise returns true.

See also

isDesignable() isScriptable()

isUser()#

Return type:: bool

Returns false if the Q_PROPERTY()'s USER attribute is false. Otherwise it returns true, indicating the property is designated as the USER property, i.e., the one that the user can edit or that is significant in some other way.

See also

userProperty() isDesignable() isScriptable()

isValid()#

Return type:: bool

Returns true if this property is valid (readable); otherwise returns false.

See also

isReadable()

isWritable()#

Return type:: bool

Returns true if this property is writable; otherwise returns false.

See also

isReadable() write()

metaType()#

Return type:: QMetaType

Returns this property’s QMetaType .

See also

QMetaType

name()#

Return type:: str

Returns this property’s name.

See also

type() typeName()

notifySignal()#

Return type:: QMetaMethod

Returns the QMetaMethod instance of the property change notifying signal if one was specified, otherwise returns an invalid QMetaMethod .

See also

hasNotifySignal()

notifySignalIndex()#

Return type:: int

Returns the index of the property change notifying signal if one was specified, otherwise returns -1.

See also

hasNotifySignal()

propertyIndex()#

Return type:: int

Returns this property’s index.

read(obj)#

Parameters:: obj – QObject
Return type:: object

Reads the property’s value from the given object. Returns the value if it was able to read it; otherwise returns an invalid variant.

See also

write() reset() isReadable()

readOnGadget(gadget)#

Parameters:: gadget – void
Return type:: object

Reads the property’s value from the given gadget. Returns the value if it was able to read it; otherwise returns an invalid variant.

This function should only be used if this is a property of a Q_GADGET

relativePropertyIndex()#

Return type:: int

Returns this property’s index relative within the enclosing meta object.

reset(obj)#

Parameters:: obj – QObject
Return type:: bool

Resets the property for the given object with a reset method. Returns true if the reset worked; otherwise returns false.

Reset methods are optional; only a few properties support them.

See also

read() write()

resetOnGadget(gadget)#

Parameters:: gadget – void
Return type:: bool

Resets the property for the given gadget with a reset method. Returns true if the reset worked; otherwise returns false.

Reset methods are optional; only a few properties support them.

This function should only be used if this is a property of a Q_GADGET

revision()#

Return type:: int

Returns the property revision if one was specified by REVISION, otherwise returns 0.

typeId()#

Return type:: int

Returns the storage type of the property. This is the same as metaType() .id().

See also

QMetaType typeName() metaType()

typeName()#

Return type:: str

Returns the name of this property’s type.

See also

type() name()

userType()#

Return type:: int

Returns this property’s user type. The return value is one of the values that are registered with QMetaType .

This is equivalent to metaType() .id()

See also

type() QMetaType typeName() metaType()

write(obj, value)#

Parameters:

obj – QObject
value – object

Return type:

bool

Writes value as the property’s value to the given object. Returns true if the write succeeded; otherwise returns false.

If value is not of the same type as the property, a conversion is attempted. An empty QVariant() is equivalent to a call to reset() if this property is resettable, or setting a default-constructed object otherwise.

Note

This function internally makes a copy of value. Prefer to use the rvalue overload when possible.