nwidget2

nwidget is a header-only C++14 library that provides property binding, declarative syntax animation extension for QWidget.

It is designed based on the principle of low invasive, can be integrated without modifying existing code.

How to use

Template Meta-Object System

#include <nwidget/metaobjects.h>

using namespace nwidget;

using MetaObj  = MetaObject<QWidget>;
using MetaProp = decltype(MetaObj().fullScreen());

using Class      = MetaObj::Class;        // QWidget
using SuperClass = MetaObj::Super::Class; // QObject

using Type              = MetaProp::Type;       // bool
constexpr bool readable = MetaProp::isReadable; // true
constexpr bool writable = MetaProp::isWritable; // false

Property Binding

#include <nwidget/binding.h>

using namespace nwidget;

auto label   = MetaObject<>::from(new QLabel);
auto slider1 = MetaObject<>::from(new QSlider);
auto slider2 = MetaObject<>::from(new QSlider);

label.text() = nwidget::asprintf_("%d", slider1.value() + slider2.value());

Animation

#include <nwidget/behavior.h>

using namespace nwidget;

auto rect     = MetaObject<>::from(new QWidget);
auto checkBox = MetaObject<>::from(new QCheckBox);

rect.styleSheet() = "background: #FF0000";

Behavior::on(rect.minimumWidth(),
             new SpringAnimation<int>(
                 spring{2},
                 damping{0.2}));

cond(checkBox.checked(), 300, 50).bindTo(Behavior::animated(rect.minimumWidth()));

Declarative UI Syntax

#include <nwidget/builders.h>

using namespace nwidget;

QLayout* layout = FormLayout {
    {"Label 0" , LineEdit().text("Hello")},
    {"Label 1" , Slider(Qt::Horizontal).range(0, 100).value(25)},
    {"Button 0", GridLayout{
        {0, 0,       PushButton("Button 0")},
        {1, 0,       PushButton("Button 1")},
        {0, 1, 2, 1, PushButton("Button 2").sizePolicy(QSizePolicy::Preferred, QSizePolicy::Expanding),
        },
    }},
    {"Button 1", HBoxLayout {
        ForEach(4, [](int i){ return RadioButton().text(QString::number(i)); })
    }},
};

Header Files

Header File	Description
behavior.h	Animation and Behavior
binding.h	Property Binding
builder.h	Declarative UI Syntax Builder
builders.h	Builder specialization for Qt classes, include after Qt headers
metaobject.h	Template Meta-Object System
metaobjects.h	Template specialization for Qt classes, include after Qt headers

Compatibility

I tested it in the following environment.

OS	Qt	Compiler
Windows	5.12.4, 6.4.3, 6.8.0	MSVC 2017, 2019, 2022

Examples

Gallery: Widget Gallery written with nwidget.

MCDayNightSwitchButton

Special Thanks

• @QuadnucYard for guidance on C++.
• @Niwik for suggestions on the property binding.