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Diffstat (limited to 'src/corelib/doc/src/objectmodel/bindableproperties.qdoc')
-rw-r--r-- | src/corelib/doc/src/objectmodel/bindableproperties.qdoc | 56 |
1 files changed, 30 insertions, 26 deletions
diff --git a/src/corelib/doc/src/objectmodel/bindableproperties.qdoc b/src/corelib/doc/src/objectmodel/bindableproperties.qdoc index dc83c01e3d..9b3ea6ae66 100644 --- a/src/corelib/doc/src/objectmodel/bindableproperties.qdoc +++ b/src/corelib/doc/src/objectmodel/bindableproperties.qdoc @@ -1,29 +1,5 @@ -/**************************************************************************** -** -** Copyright (C) 2021 The Qt Company Ltd. -** Contact: https://www.qt.io/licensing/ -** -** This file is part of the documentation of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:FDL$ -** Commercial License Usage -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and The Qt Company. For licensing terms -** and conditions see https://www.qt.io/terms-conditions. For further -** information use the contact form at https://www.qt.io/contact-us. -** -** GNU Free Documentation License Usage -** Alternatively, this file may be used under the terms of the GNU Free -** Documentation License version 1.3 as published by the Free Software -** Foundation and appearing in the file included in the packaging of -** this file. Please review the following information to ensure -** the GNU Free Documentation License version 1.3 requirements -** will be met: https://www.gnu.org/licenses/fdl-1.3.html. -** $QT_END_LICENSE$ -** -****************************************************************************/ +// Copyright (C) 2021 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only /*! \page bindableproperties.html @@ -45,6 +21,20 @@ uses the encapsulating QObject to store the pointer to the management data structure. + \section1 Why Use Bindable Properties? + + Property bindings are one of the core features of QML. They allow to specify + relationships between different object properties and automatically update + properties' values whenever their dependencies change. Bindable properties + allow to achieve the same not only in QML code, but also in C++. Using + bindable properties can help to simplify your program, by eliminating a lot + of boilerplate code for tracking and reacting to dependency updates of + different objects. + + The \l {Introductory Example} below demonstrates the usage of bindable + properties in C++ code. You can also check \l {Bindable Properties} example + to see how the bindable properties can help to improve your code. + \section1 Introductory Example The binding expression computes the value by reading other QProperty values. @@ -257,4 +247,18 @@ be called for the current value of the property, register your callback using subscribe() instead. + \section1 Interaction with Q_PROPERTYs + + A \l {The Property System}{Q_PROPERTY} that defines \c BINDABLE can be bound and + used in binding expressions. You can implement such properties using \l {QProperty}, + \l {QObjectBindableProperty}, or \l {QObjectComputedProperty}. + + Q_PROPERTYs without \c BINDABLE can also be bound and be used in binding expressions, + as long as they define a \c NOTIFY signal. You must wrap the property in a \l QBindable + using the \c {QBindable(QObject* obj, const char* property)} constructor. Then, the + property can be bound using \l QBindable::setBinding() or used in a binding + expression via \l QBindable::value(). You must use \c QBindable::value() in binding + expressions instead of the normal property \c READ function (or \c MEMBER) to enable + dependency tracking if the property is not \c BINDABLE. + */ |