Skip to content

05-property-bindings/main.cpp

An example of how to use makeBoundProperty() to create a KDBindings::Property that is automatically updated once any of its inputs change.

The output of this example is: 

1
2
3
The initial size of the image = 1920000 bytes
The new size of the image = 4608000 bytes
The new size of the image = 8294400 bytes

 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
/*
  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.
*/

#include <kdbindings/binding.h>
#include <kdbindings/property.h>
#include <kdbindings/signal.h>

#include <iostream>

using namespace KDBindings;

class Image
{
public:
    const int bytesPerPixel = 4;
    Property<int> width{ 800 };
    Property<int> height{ 600 };
    const Property<int> byteSize = makeBoundProperty(bytesPerPixel * width * height);
};

int main()
{
    Image img;
    std::cout << "The initial size of the image = " << img.byteSize.get() << " bytes" << std::endl;

    img.byteSize.valueChanged().connect([](const int &newValue) {
        std::cout << "The new size of the image = " << newValue << " bytes" << std::endl;
    });

    img.width = 1920;
    img.height = 1080;

    return 0;
}

Filename: 05-property-bindings/main.cpp

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