QMetaEnum Class
The QMetaEnum class provides meta-data about an enumerator. More...
Header: | #include <QMetaEnum> |
qmake: | QT += core |
Public Functions
const char * | enumName() const |
bool | isFlag() const |
bool | isScoped() const |
bool | isValid() const |
const char * | key(int index) const |
int | keyCount() const |
int | keyToValue(const char *key, bool *ok = nullptr) const |
int | keysToValue(const char *keys, bool *ok = nullptr) const |
const char * | name() const |
const char * | scope() const |
int | value(int index) const |
const char * | valueToKey(int value) const |
QByteArray | valueToKeys(int value) const |
Static Public Members
QMetaEnum | fromType() |
Detailed Description
Use name() for the enumerator's name. The enumerator's keys (names of each enumerated item) are returned by key(); use keyCount() to find the number of keys. isFlag() returns whether the enumerator is meant to be used as a flag, meaning that its values can be combined using the OR operator.
The conversion functions keyToValue(), valueToKey(), keysToValue(), and valueToKeys() allow conversion between the integer representation of an enumeration or set value and its literal representation. The scope() function returns the class scope this enumerator was declared in.
See also QMetaObject, QMetaMethod, and QMetaProperty.
Member Function Documentation
const char *QMetaEnum::enumName() const
Returns the enum name of the flag (without the scope).
For example, the Qt::AlignmentFlag flag has AlignmentFlag
as the enum name, but Alignment
as as the type name. Non flag enums has the same type and enum names.
Enum names have the same scope as the type name.
This function was introduced in Qt 5.12.
See also isValid() and name().
[static]
template <typename T> QMetaEnum QMetaEnum::fromType()
Returns the QMetaEnum corresponding to the type in the template parameter. The enum needs to be declared with Q_ENUM.
This function was introduced in Qt 5.5.
bool QMetaEnum::isFlag() const
Returns true
if this enumerator is used as a flag; otherwise returns false.
When used as flags, enumerators can be combined using the OR operator.
See also keysToValue() and valueToKeys().
bool QMetaEnum::isScoped() const
Returns true
if this enumerator is declared as a C++11 enum class; otherwise returns false.
This function was introduced in Qt 5.8.
bool QMetaEnum::isValid() const
Returns true
if this enum is valid (has a name); otherwise returns false.
See also name().
const char *QMetaEnum::key(int index) const
Returns the key with the given index, or nullptr
if no such key exists.
See also keyCount(), value(), and valueToKey().
int QMetaEnum::keyCount() const
Returns the number of keys.
See also key().
int QMetaEnum::keyToValue(const char *key, bool *ok = nullptr) const
Returns the integer value of the given enumeration key, or -1 if key is not defined.
If key is not defined, *ok is set to false; otherwise *ok is set to true.
For flag types, use keysToValue().
See also valueToKey(), isFlag(), and keysToValue().
int QMetaEnum::keysToValue(const char *keys, bool *ok = nullptr) const
Returns the value derived from combining together the values of the keys using the OR operator, or -1 if keys is not defined. Note that the strings in keys must be '|'-separated.
If keys is not defined, *ok is set to false; otherwise *ok is set to true.
See also isFlag(), valueToKey(), and valueToKeys().
const char *QMetaEnum::name() const
Returns the name of the type (without the scope).
For example, the Qt::Key enumeration has Key
as the type name and Qt as the scope.
For flags this returns the name of the flag type, not the name of the enum type.
See also isValid(), scope(), and enumName().
const char *QMetaEnum::scope() const
Returns the scope this enumerator was declared in.
For example, the Qt::AlignmentFlag enumeration has Qt
as the scope and AlignmentFlag
as the name.
See also name().
int QMetaEnum::value(int index) const
Returns the value with the given index; or returns -1 if there is no such value.
See also keyCount(), key(), and keyToValue().
const char *QMetaEnum::valueToKey(int value) const
Returns the string that is used as the name of the given enumeration value, or nullptr
if value is not defined.
For flag types, use valueToKeys().
See also isFlag() and valueToKeys().
QByteArray QMetaEnum::valueToKeys(int value) const
Returns a byte array of '|'-separated keys that represents the given value.
See also isFlag(), valueToKey(), and keysToValue().