QJniArray Class

Member Function Documentation

Returns an STL-style const iterator pointing to the first item in the array.

If the array is invalid, then this will return the same iterator as the corresponding end() function.

See also end() and rbegin().

Returns an STL-style iterator pointing just after the last item in the list.

See also begin() and rend().

Returns an STL-style reverse iterator pointing to the first item in the array, in reverse order.

If the array is invalid, then this will return the same iterator as the corresponding rend() function.

See also rend() and begin().

Returns an STL-style reverse iterator pointing just after the last item in the list, in reverse order.

See also rbegin() and end().

Returns the value at position i in the wrapped Java array.

i must be a valid index position in the list (i.e., 0 <= i < size()).

See also size().

QJniArray::QJniArray()

Default constructor of QJniArray. This does not create a Java-side array, and the instance will be invalid.

See also isValid.

[explicit] template <typename Container, QJniArrayBase::if_compatible_source_container<Container> = true> QJniArray::QJniArray(Container &&container)

Constructs a QJniArray that wraps a newly-created Java array for elements of type Container::value_type, and populates the Java array with the data from container.

This function only participates in overload resolution if Container is a container that stores elements of a JNI type or equivalent C++ type, and provides a forward iterator.

The specialization of the constructed QJniArray depends on the value type of the container. For a Container<T> (such as e.g. QList<T>) it will typically be QJniArray<T>, with the following exceptions:

See also QJniArrayBase::fromContainer() and toContainer().

[noexcept] template <typename Other, QJniArrayBase::if_convertible<Other, T> = true> QJniArray::QJniArray(QJniArray<Other> &&other)

Constructs a QJniArray by moving from other. The other array becomes invalid.

This constructor only participates in overload resolution if the element type Other of other is convertible to the element type T of the QJniArray being constructed. However, no actual conversion takes place.

[explicit, since 6.9] QJniArray::QJniArray(QJniArrayBase::size_type size)

Constructs an empty QJniArray of size size. The elements in the array do not get initialized.

This function was introduced in Qt 6.9.

[explicit noexcept] QJniArray::QJniArray(QJniObject &&object)

Constructs a QJniArray by moving from object. The QJniObject becomes invalid.

template <typename Other, QJniArrayBase::if_convertible<Other, T> = true> QJniArray::QJniArray(const QJniArray<Other> &other)

Constructs a QJniArray by copying other. Both QJniArray objects will reference the same Java array object.

This constructor only participates in overload resolution if the element type Other of other is convertible to the element type T of the QJniArray being constructed. However, no actual conversion takes place.

[explicit] QJniArray::QJniArray(const QJniObject &object)

Constructs a QJniArray that wraps the same Java array as object, creating a new global reference. To construct a QJniArray from an existing local reference, use a QJniObject constructed via fromLocalRef().

[explicit] QJniArray::QJniArray(jarray array)

Constructs a QJniArray that wraps the Java-side array array, creating a new global reference to array.

[default] QJniArray::QJniArray(std::initializer_list<T> &list)

Constructs a QJniArray that wraps a newly-created Java array for elements of type T, and populates the Java array with the data from list.

See also QJniArrayBase::fromContainer() and toContainer().

QJniArray::~QJniArray()

Destroys the QJniArray object and releases any references held to the wrapped Java array.

auto QJniArray::arrayObject() const

Returns the wrapped Java object as the suitable jarray type that matches the element type T of this QJniArray object.

template <typename Container = QJniArrayBase::ToContainerType<T>, QJniArrayBase::if_compatible_target_container<T, Container> = true> Container QJniArray::toContainer(Container &&container = {}) const

Returns a container populated with the data in the wrapped Java array.

If no container is provided, then the type of the container returned depends on the element type of this QJniArray. For QJniArray<T> this will typically be QList<T>, with the following exceptions:

If you pass in a named container (an lvalue) for container, then that container is filled, and a reference to it is returned. If you pass in a temporary container (an rvalue, incl. the default argument), then that container is filled, and returned by value.

This function returns immediately if the array is invalid.

See also QJniArrayBase::fromContainer().

[noexcept] template <typename Other, QJniArrayBase::if_convertible<Other, T> = true> QJniArray<T> &QJniArray::operator=(QJniArray<Other> &&other)

Moves other into this QJniArray, and returns a reference to this. The other array becomes invalid.

This operator only participates in overload resolution if the element type Other of other is convertible to the element type T of this QJniArray. However, no actual conversion takes place.

template <typename Other, QJniArrayBase::if_convertible<Other, T> = true> QJniArray<T> &QJniArray::operator=(const QJniArray<Other> &other)

Assigns other to this QJniArray, and returns a reference to this. Both QJniArray objects will reference the same Java array object.

This operator only participates in overload resolution if the element type Other of other is convertible to the element type T of this QJniArray. However, no actual conversion takes place.

[since 6.9] QJniArray<T>::reference QJniArray::operator[](QJniArrayBase::size_type i)

Returns a reference object for value at position i in the wrapped Java array.

i must be a valid index position in the list (i.e., 0 <= i < size()).

The returned reference object holds the value at position i, and in most cases will convert implicitly to the value. Assigning to the returned reference will overwrite the entry in the Java array. However, calling mutating member functions on the object will not modify the entry in the array. To call member function on the result of this operator, dereference the reference object:

QJniArray<QString> strings = object.callMethod<QString[]>("getStrings");
if (!strings.isEmpty()) {
    if (!(*array[0]).isEmpty()) {
        // ...
    }
}

However, if modifying the value in the array itself is not intended, make the array const, or use at() instead.

This function was introduced in Qt 6.9.

See also at() and size().