diff options
Diffstat (limited to 'src/corelib/doc/snippets/code/src_corelib_kernel_qproperty.cpp')
-rw-r--r-- | src/corelib/doc/snippets/code/src_corelib_kernel_qproperty.cpp | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/src/corelib/doc/snippets/code/src_corelib_kernel_qproperty.cpp b/src/corelib/doc/snippets/code/src_corelib_kernel_qproperty.cpp new file mode 100644 index 0000000000..c2b55c9684 --- /dev/null +++ b/src/corelib/doc/snippets/code/src_corelib_kernel_qproperty.cpp @@ -0,0 +1,152 @@ +// Copyright (C) 2020 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause + +#include <QObject> +#include <QDebug> + +//! [0] +class MyClass : public QObject +{ + Q_OBJECT + Q_PROPERTY(int x READ x WRITE setX NOTIFY xChanged BINDABLE bindableX) +public: + int x() const { return xProp; } + void setX(int x) { xProp = x; } + QBindable<int> bindableX() { return QBindable<int>(&xProp); } + +signals: + void xChanged(); + +private: + // Declare the instance of the bindable property data. + Q_OBJECT_BINDABLE_PROPERTY(MyClass, int, xProp, &MyClass::xChanged) +}; +//! [0] + +//! [1] +class MyClass : public QObject +{ + Q_OBJECT + Q_PROPERTY(int x READ x WRITE setX NOTIFY xChanged BINDABLE bindableX) +public: + int x() const { return xProp; } + void setX(int x) { xProp = x; } + QBindable<int> bindableX() { return QBindable<int>(&xProp); } + +signals: + void xChanged(); + +private: + // Declare the instance of int bindable property data and + // initialize it with the value 5. + // This is similar to declaring + // int xProp = 5; + // without using the new QObjectBindableProperty class. + Q_OBJECT_BINDABLE_PROPERTY_WITH_ARGS(MyClass, int, xProp, 5, &MyClass::xChanged) +}; +//! [1] + +//! [2] +class CustomType +{ +public: + CustomType(int val, int otherVal) : value(val), anotherValue(otherVal) { } + +private: + int value = 0; + int anotherValue = 0; +}; + +// later when using CustomType as a property +Q_OBJECT_BINDABLE_PROPERTY_WITH_ARGS(MyClass, CustomType xProp, CustomType(5, 10), + &MyClass::xChanged) +//! [2] + +void usage_QBindable() { + //! [3] + MyClass *myObject; + QBindable<int> bindableX = myObject->bindableX(); + qDebug() << bindableX.hasBinding(); // prints false + QProperty<int> y {42}; + bindableX.setBinding([&](){ return 2*y.value(); }); + qDebug() << bindableX.hasBinding() << myObject->x(); // prints true 84 + //! [3] +} + +//! [4] +#include <QObject> +#include <QProperty> +#include <QDebug> + +class Foo : public QObject +{ + Q_OBJECT + Q_PROPERTY(int myVal READ myVal WRITE setMyVal BINDABLE bindableMyVal) +public: + int myVal() { return myValMember.value(); } + void setMyVal(int newvalue) { myValMember = newvalue; } + QBindable<int> bindableMyVal() { return &myValMember; } +signals: + void myValChanged(); + +private: + Q_OBJECT_BINDABLE_PROPERTY(Foo, int, myValMember, &Foo::myValChanged); +}; + +int main() +{ + bool debugout(true); // enable debug log + Foo myfoo; + QProperty<int> prop(42); + QObject::connect(&myfoo, &Foo::myValChanged, [&]() { + if (debugout) + qDebug() << myfoo.myVal(); + }); + myfoo.bindableMyVal().setBinding([&]() { return prop.value(); }); // prints "42" + + prop = 5; // prints "5" + debugout = false; + prop = 6; // prints nothing + debugout = true; + prop = 7; // prints "7" +} + +#include "main.moc" +//! [4] + +//! [5] +class Client{}; + +class MyClassPrivate : public QObjectPrivate +{ +public: + QList<Client> clients; + bool hasClientsActualCalculation() const { return clients.size() > 0; } + Q_OBJECT_COMPUTED_PROPERTY(MyClassPrivate, bool, hasClientsData, + &MyClassPrivate::hasClientsActualCalculation) +}; + +class MyClass : public QObject +{ + Q_OBJECT + Q_PROPERTY(bool hasClients READ hasClients STORED false BINDABLE bindableHasClients) +public: + QBindable<bool> bindableHasClients() + { + return QBindable<bool>(&d_func()->hasClientsData); + } + bool hasClients() const + { + return d_func()->hasClientsData.value(); + } + void addClient(const Client &c) + { + Q_D(MyClass); + d->clients.push_back(c); + // notify that the value could have changed + d->hasClientsData.notify(); + } +private: + Q_DECLARE_PRIVATE(MyClass) +}; +//! [5] |