COM App Example (ActiveQt)

 
Sélectionnez
class Application : public QObject
{
    Q_OBJECT

    Q_CLASSINFO("ClassID", "{b50a71db-c4a7-4551-8d14-49983566afee}")
    Q_CLASSINFO("InterfaceID", "{4a427759-16ef-4ed8-be79-59ffe5789042}")
    Q_CLASSINFO("RegisterObject", "yes")

    Q_PROPERTY(DocumentList* documents READ documents)
    Q_PROPERTY(QString id READ id)
    Q_PROPERTY(bool visible READ isVisible WRITE setVisible)

public:
    explicit Application(QObject *parent = nullptr);
    DocumentList *documents() const;

    QString id() const { return objectName(); }

    void setVisible(bool on);
    bool isVisible() const;

    QTabWidget *window() const { return m_ui.data(); }

public slots:
    void quit();

private:
    QScopedPointer <DocumentList> m_docs;
    QScopedPointer <QTabWidget> m_ui;
};

The first class Application represents the application object. It exposes read-only properties documents and id to get access to the list of documents, and an identifier. A read/write property visible controls whether the QTabWidget-based user interface of the application should be visible, and a slot quit() terminates the application.

The RegisterObject attribute is set to make sure that instances of this class are registered in COM's running object table (ROT) - this allows COM clients to connect to an already instantiated COM object.

 
Sélectionnez
class DocumentList : public QObject
{
    Q_OBJECT

    Q_CLASSINFO("ClassID", "{496b761d-924b-4554-a18a-8f3704d2a9a6}")
    Q_CLASSINFO("InterfaceID", "{6c9e30e8-3ff6-4e6a-9edc-d219d074a148}")

    Q_PROPERTY(Application* application READ application)
    Q_PROPERTY(int count READ count)

public:
    explicit DocumentList(Application *application);

    int count() const;
    Application *application() const;

public slots:
    Document *addDocument();
    Document *item(int index) const;

private:
    QList<Document *> m_list;
};

The DocumentList class stores a list of documents. It provides an API to read the number of documents, to access each document by index and to create a new document. The application property returns the root object.

 
Sélectionnez
class Document : public QObject
{
    Q_OBJECT

    Q_CLASSINFO("ClassID", "{2b5775cd-72c2-43da-bc3b-b0e8d1e1c4f7}")
    Q_CLASSINFO("InterfaceID", "{2ce1761e-07a3-415c-bd11-0eab2c7283de}")

    Q_PROPERTY(Application *application READ application)
    Q_PROPERTY(QString title READ title WRITE setTitle)

public:
    explicit Document(DocumentList *list);
    virtual ~Document();

    Application *application() const;

    QString title() const;
    void setTitle(const QString &title);

private:
    QScopedPointer <QWidget> m_page;
};

The Document class finally represents a document in the application. Each document is represented by a page in the application's tab widget, and has a title that is readable and writable through the document's API. The application property again returns the root object.

 
Sélectionnez
Document::Document(DocumentList *list)
: QObject(list)
{
    QTabWidget *tabs = list->application()->window();
    m_page.reset(new QWidget(tabs));
    m_page->setWindowTitle(tr("Unnamed"));
    tabs->addTab(m_page.data(), m_page->windowTitle());

    m_page->show();
}

Document::~Document()
{
}

Application *Document::application() const
{
    return qobject_cast<DocumentList *>(parent())->application();
}

QString Document::title() const
{
    return m_page->windowTitle();
}

void Document::setTitle(const QString &t)
{
    m_page->setWindowTitle(t);

    QTabWidget *tabs = application()->window();
    int index = tabs->indexOf(m_page.data());
    tabs->setTabText(index, m_page->windowTitle());
}

The implementation of the Document class creates a new page for the tab widget, and uses the title of that page for the title property. The page is deleted when the document is deleted.

 
Sélectionnez
DocumentList::DocumentList(Application *application)
: QObject(application)
{
}

Application *DocumentList::application() const
{
    return qobject_cast<Application *>(parent());
}

int DocumentList::count() const
{
    return m_list.count();
}

Document *DocumentList::item(int index) const
{
    return m_list.value(index, nullptr);
}

Document *DocumentList::addDocument()
{
    Document *document = new Document(this);
    m_list.append(document);

    return document;
}

The DocumentList implementation is straightforward.

 
Sélectionnez
Application::Application(QObject *parent)
: QObject(parent),
  m_ui(new QTabWidget),
  m_docs(new DocumentList(this))
{
    setObjectName(QStringLiteral("From QAxFactory"));
}

DocumentList *Application::documents() const
{
    return m_docs.data();
}

void Application::setVisible(bool on)
{
    m_ui->setVisible(on);
}

bool Application::isVisible() const
{
    return m_ui->isVisible();
}

void Application::quit()
{
    m_docs.reset();
    m_ui.reset();
    QTimer::singleShot(0 /*ms*/, qApp, &QCoreApplication::quit);
}

#include "main.moc"

The Application class initializes the user interface in the constructor, and shows and hides it in the implementation of setVisible(). The object name (accessible through the id property) is set to "From QAxFactory" to indicate that this COM object has been created by COM. Note that there is no destructor that would delete the QTabWidget - this is instead done in the quit() slot, before calling quit() through a single-shot-timer, which is necessary to ensure that the COM call to the slot is complete.

 
Sélec