Skip to content

kdbindings/binding.h

Namespaces

Name
KDBindings
The main namespace of the KDBindings library.

Classes

Name
class KDBindings::Binding
A combination of a root Node with an evaluator.
class KDBindings::Binding< T, ImmediateBindingEvaluator >
Provides a convenience for old-school, immediate mode Bindings.

Source code

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
/*
  This file is part of KDBindings.

  SPDX-FileCopyrightText: 2021 Klarälvdalens Datakonsult AB, a KDAB Group company <info@kdab.com>
  Author: Sean Harmer <sean.harmer@kdab.com>

  SPDX-License-Identifier: MIT

  Contact KDAB at <info@kdab.com> for commercial licensing options.
*/

#pragma once

#include <kdbindings/node.h>
#include <kdbindings/node_operators.h>
#include <kdbindings/node_functions.h>
#include <kdbindings/make_node.h>
#include <kdbindings/binding_evaluator.h>
#include <kdbindings/property_updater.h>

namespace KDBindings {

template<typename T, typename EvaluatorT = BindingEvaluator>
class Binding : public PropertyUpdater<T>, public Private::Dirtyable
{
    static_assert(
            std::is_base_of<BindingEvaluator, EvaluatorT>::value,
            "The EvaluatorT type must inherit from BindingEvaluator.");

public:
    explicit Binding(Private::Node<T> &&rootNode, EvaluatorT const &evaluator)
        : m_rootNode{ std::move(rootNode) }
        , m_evaluator{ evaluator }
    {
        m_bindingId = m_evaluator.insert(this);
        m_rootNode.setParent(this);
    }

    ~Binding() override
    {
        m_evaluator.remove(m_bindingId);
    }

    Binding() = delete;

    Binding(Binding const &other) = delete;
    Binding &operator=(Binding const &other) = delete;

    // Move construction would invalidate the this pointer passed to the evaluator
    // in the constructor
    Binding(Binding &&other) = delete;
    Binding &operator=(Binding &&other) = delete;

    void setUpdateFunction(std::function<void(T &&)> const &updateFunction) override
    {
        m_propertyUpdateFunction = updateFunction;
    }

    T get() const override { return m_rootNode.evaluate(); }

    void evaluate()
    {
        T value = m_rootNode.evaluate();

        // Use this to update any associated property via the PropertyUpdater's update function
        m_propertyUpdateFunction(std::move(value));
    }

protected:
    Private::Dirtyable **parentVariable() override { return nullptr; }
    const bool *dirtyVariable() const override { return nullptr; }

    Private::Node<T> m_rootNode;
    EvaluatorT m_evaluator;
    std::function<void(T &&)> m_propertyUpdateFunction = [](T &&) {};
    int m_bindingId = -1;
};

template<typename T, typename EvaluatorT>
inline std::unique_ptr<Binding<T, EvaluatorT>> makeBinding(EvaluatorT &evaluator, Property<T> &property)
{
    return std::make_unique<Binding<T, EvaluatorT>>(Private::makeNode(property), evaluator);
}

template<typename T, typename EvaluatorT>
inline std::unique_ptr<Binding<T, EvaluatorT>> makeBinding(EvaluatorT &evaluator, Private::Node<T> &&rootNode)
{
    return std::make_unique<Binding<T, EvaluatorT>>(std::move(rootNode), evaluator);
}

template<typename EvaluatorT, typename Func, typename... Args, typename = std::enable_if_t<sizeof...(Args) != 0>, typename ResultType = Private::operator_node_result_t<Func, Args...>>
inline std::unique_ptr<Binding<ResultType, EvaluatorT>> makeBinding(EvaluatorT &evaluator, Func &&func, Args &&...args)
{
    return std::make_unique<Binding<ResultType, EvaluatorT>>(Private::makeNode(std::forward<Func>(func), std::forward<Args>(args)...), evaluator);
}

template<typename T>
class Binding<T, ImmediateBindingEvaluator> : public Binding<T, BindingEvaluator>
{
public:
    explicit Binding(Private::Node<T> &&rootNode)
        : Binding<T, BindingEvaluator>(std::move(rootNode), ImmediateBindingEvaluator::instance())
    {
    }

    Binding() = delete;

    virtual ~Binding() = default;

    Binding(Binding const &other) = delete;
    Binding &operator=(Binding const &other) = delete;

    Binding(Binding &&other) = delete;
    Binding &operator=(Binding &&other) = delete;

    void markDirty() override
    {
        Binding::evaluate();
    }
};

template<typename T>
inline std::unique_ptr<Binding<T, ImmediateBindingEvaluator>> makeBinding(Property<T> &property)
{
    return std::make_unique<Binding<T, ImmediateBindingEvaluator>>(Private::makeNode(property));
}

template<typename T>
inline std::unique_ptr<Binding<T, ImmediateBindingEvaluator>> makeBinding(Private::Node<T> &&rootNode)
{
    return std::make_unique<Binding<T, ImmediateBindingEvaluator>>(std::move(rootNode));
}

template<typename Func, typename... Args, typename = std::enable_if_t<sizeof...(Args) != 0>, typename ResultType = Private::operator_node_result_t<Func, Args...>>
inline std::unique_ptr<Binding<ResultType, ImmediateBindingEvaluator>> makeBinding(Func &&func, Args &&...args)
{
    return std::make_unique<Binding<ResultType, ImmediateBindingEvaluator>>(Private::makeNode(std::forward<Func>(func), std::forward<Args>(args)...));
}

template<typename... T>
inline auto makeBoundProperty(T &&...args)
{
    auto binding = makeBinding(std::forward<T>(args)...);
    return Property<decltype(binding->get())>(std::move(binding));
}

} // namespace KDBindings

Updated on 2024-04-14 at 00:00:43 +0000