DiagramDesigner/PropertyEditor

QDetailsView

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Inspired by the details view of Unreal Engine, QDetailsView leverages Qt's reflection system to easily build property editors for qobject.

Its core features are:

• Create type-based control editors that automatically organize the editor layout according to the reflection structure of the object.
• Utilize QML GPU rendering and control management based on the preview view.

Usage

It is extremely easy to use—simply declare the meta-properties of a QObject using Q_PROPERTY(...):

class QCustomObject : public QObject {
    Q_OBJECT
    Q_PROPERTY(int Int READ getInt WRITE setInt)
    Q_PROPERTY(float Float READ getFloat WRITE setFloat)   
    ...
};

QCustomObject obj;
QDetailsView view;
view.setObject(&obj);
view.show();

You will get the following result:

Customization

About QPropertyHandle

QPropertyHandle serves as the unified entry point for QDetailsView to manipulate properties. It is typically constructed via the following interface:

static QPropertyHandle* QPropertyHandle::FindOrCreate(
    QObject* inParent,      // Parent object that manages the lifecycle of the PropertyHandle
    QMetaType inType,       // Meta-type of the property
    QString inPropertyPath, // Path field of the property
    Getter inGetter,        // Getter function for the property
    Setter inSetter         // Setter function for the property
); 		

To ensure that changes to property values are detected by DetailsView, all value modifications must use the interface provided by PropertyHandle:

QPropertyHandle* handle = QPropertyHandle::Find(object, "propertyName");
if (handle) {
    handle->setVar(QVariant::fromValue(newValue));
}

When creating a QPropertyHandle, you must specify a parent—the handle will be attached to the parent as a child object. Thus, its lifecycle is tied to the parent object. To clean it up, call:

static void QPropertyHandle::Cleanup(QObject* inParent);

Custom Enum

For enum types, they must be defined within a class and declared using Q_ENUM(...):

class QCustomObject : public QObject {
    Q_OBJECT
public:
    enum QCustomEnum {
        One,
        Two,
        Three
    };
    Q_ENUM(QCustomEnum);
};

Custom Type Editor

For custom types that do not inherit from QObject, you first need to declare the type using the macro Q_DECLARE_METATYPE(...) during definition.

For specific types that require only a single editor control, you can directly register the type editor using the following interface:

QQuickDetailsViewManager::Get()->registerTypeEditor(
    metaType,
    [](QPropertyHandle* handle, QQuickItem* parent) -> QQuickItem* {
        // Implementation of the editor creation logic
    }
);

The source code directory QQuickDetailsViewBasicTypeEditor.cpp contains many reference examples, such as the editor for QDir:

registerTypeEditor(
    QMetaType::fromType<QDir>(), 
    [](QPropertyHandle* handle, QQuickItem* parent) -> QQuickItem* {
        QQmlEngine* engine = qmlEngine(parent);
        QQmlContext* context = qmlContext(parent);
        QQmlComponent comp(engine);
        
        comp.setData(R"(
            import QtQuick;
            import QtQuick.Controls;
            import "qrc:/resources/Qml/ValueEditor"
            DirectorySelector {
                anchors.verticalCenter: parent.verticalCenter
                width: parent.width
            }
        )", QUrl());
        
        QVariantMap initialProperties;
        initialProperties["parent"] = QVariant::fromValue(parent);
        auto valueEditor = qobject_cast<QQuickItem*>(comp.createWithInitialProperties(initialProperties, context));
        
        if (!comp.errors().isEmpty()) {
            qDebug() << comp.errorString();
        }
        
        valueEditor->setParentItem(parent);
        valueEditor->setProperty("value", handle->getVar());
        
        connect(valueEditor, SIGNAL(asValueChanged(QVariant)), handle, SLOT(setVar(QVariant)));		
        connect(handle, SIGNAL(asRequestRollback(QVariant)), valueEditor, SLOT(setValue(QVariant)));
        
        return valueEditor;
    }
);

For editor controls that span multiple rows or have complex behaviors, you can extend the property editor by deriving from IPropertyTypeCustomization. This class provides two virtual functions:

class IPropertyTypeCustomization : public QEnableSharedFromThis<IPropertyTypeCustomization>
{
public:
    // Used to assemble the editor for the current property row
    virtual void customizeHeaderRow(QPropertyHandle* inPropertyHandle, QQuickDetailsViewRowBuilder* inBuilder);
    
    // Used to extend child items for the current property row
    virtual void customizeChildren(QPropertyHandle* inPropertyHandle, QQuickDetailsViewLayoutBuilder* inBuilder);
};

After implementing the derived class, register it using the following interface:

QQuickDetailsViewManager::Get()->registerPropertyTypeCustomization<QCustomType, PropertyTypeCustomization_CustomType>();

TODO

• Undo/redo
• Container operations
• Extended meta-data support