- Qt 6.9
- Active Qt
- QAxContainer
- QAxWidget
- Qt 6.9.3 Reference Documentation

# QAxWidget Class

The QAxWidget class is a QWidget that wraps an ActiveX control. More...

Header: | `#include <QAxWidget>`
CMake: | `find_package(Qt6 REQUIRED COMPONENTS AxContainer)` `target_link_libraries(mytarget PRIVATE Qt6::AxContainer)`
qmake: | `QT += axcontainer`
Inherits: | QAxBaseWidget and QAxBase

- List of all members, including inherited members

## Public Functions

| QAxWidget(QWidget *parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags())
| QAxWidget(IUnknown *iface, QWidget *parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags())
| QAxWidget(const QString &c, QWidget *parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags())
virtual | ~QAxWidget() override
void | clear()
virtual QAxAggregated * | createAggregate()
bool | doVerb(const QString &verb)

## Reimplemented Public Functions

virtual QSize | minimumSizeHint() const override
virtual void | resetControl() override
virtual QSize | sizeHint() const override

## Protected Functions

virtual bool | createHostWindow(bool initialized)
bool | createHostWindow(bool initialized, const QByteArray &data)
virtual bool | translateKeyEvent(int message, int keycode) const

## Reimplemented Protected Functions

virtual void | changeEvent(QEvent *e) override
virtual void | connectNotify(const QMetaMethod &signal) override
virtual bool | initialize(IUnknown **ptr) override
virtual void | resizeEvent(QResizeEvent *) override

## Detailed Description

A QAxWidget can be instantiated as an empty object, with the name of the ActiveX control it should wrap, or with an existing interface pointer to the ActiveX control. The ActiveX control's properties, methods and events which only use QAxBase supported data types, become available as Qt properties, slots and signals. The base class QAxBase provides an API to access the ActiveX directly through the `IUnknown` pointer.

QAxWidget is a QWidget and can mostly be used as such, e.g. it can be organized in a widget hierarchy and layouts or act as an event filter. Standard widget properties, e.g. enabled are supported, but it depends on the ActiveX control to implement support for ambient properties like e.g. palette or font. QAxWidget tries to provide the necessary hints.

However, you cannot reimplement Qt-specific event handlers like mousePressEvent or keyPressEvent and expect them to be called reliably. The embedded control covers the QAxWidget completely, and usually handles the user interface itself. Use control-specific APIs (i.e. listen to the signals of the control), or use standard COM techniques like window procedure subclassing.

QAxWidget also inherits most of its ActiveX-related functionality from QAxBase, notably dynamicCall() and querySubObject().

Warning: You can subclass QAxWidget, but you cannot use the `Q_OBJECT` macro in the subclass (the generated moc-file will not compile), so you cannot add further signals, slots or properties. This limitation is due to the metaobject information generated in runtime. To work around this problem, aggregate the QAxWidget as a member of the QObject subclass.

See also QAxBase, QAxObject, QAxScript, and ActiveQt Framework.

## Member Function Documentation

### `[explicit]` QAxWidget::QAxWidget(QWidget *parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags())

Creates an empty QAxWidget widget and propagates parent and f to the QWidget constructor. To initialize a control, call setControl().

### `[explicit]` QAxWidget::QAxWidget(IUnknown *iface, QWidget *parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags())

Creates a QAxWidget that wraps the COM object referenced by iface. parent and f are propagated to the QWidget contructor.

### `[explicit]` QAxWidget::QAxWidget(const QString &c, QWidget *parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags())

Creates an QAxWidget widget and initializes the ActiveX control c. parent and f are propagated to the QWidget contructor.

See also setControl().

### `[override virtual noexcept]` QAxWidget::~QAxWidget()

Shuts down the ActiveX control and destroys the QAxWidget widget, cleaning up all allocated resources.

See also clear().

### `[override virtual protected]` void QAxWidget::changeEvent(QEvent *e)

Reimplements: QWidget::changeEvent(QEvent *event).

### void QAxWidget::clear()

Shuts down the ActiveX control.

See also resetControl().

### `[override virtual protected]` void QAxWidget::connectNotify(const QMetaMethod &signal)

Reimplements: QObject::connectNotify(const QMetaMethod &signal).

### `[virtual]` QAxAggregated *QAxWidget::createAggregate()

Reimplement this function when you want to implement additional COM interfaces for the client site of the ActiveX control, or when you want to provide alternative implementations of COM interfaces. Return a new object of a QAxAggregated subclass.

The default implementation returns the null pointer.

### `[virtual protected]` bool QAxWidget::createHostWindow(bool initialized)

Creates the client site for the ActiveX control, and returns true if the control could be embedded successfully, otherwise returns false. If initialized is true the control has already been initialized.

This function is called by initialize(). If you reimplement initialize to customize the actual control instantiation, call this function in your reimplementation to have the control embedded by the default client side. Creates the client site for the ActiveX control, and returns true if the control could be embedded successfully, otherwise returns false.

### `[protected]` bool QAxWidget::createHostWindow(bool initialized, const QByteArray &data)

Creates the client site for the ActiveX control, and returns true if the control could be embedded successfully, otherwise returns false. If initialized is false the control will be initialized using the data. The control will be initialized through either IPersistStreamInit or IPersistStorage interface.

If the control needs to be initialized using custom data, call this function in your reimplementation of initialize(). This function is not called by the default implementation of initialize().

### bool QAxWidget::doVerb(const QString &verb)

Requests the ActiveX control to perform the action verb. The possible verbs are returned by verbs().

The function returns true if the object could perform the action, otherwise returns false.

### `[override virtual protected]` bool QAxWidget::initialize(IUnknown **ptr)

Reimplements: QAxBase::initialize(IUnknown **ptr).

Calls QAxBase::initialize(ptr), and embeds the control in this widget by calling createHostWindow(false) if successful.

To initialize the control before it is activated, reimplement this function and add your initialization code before you call createHostWindow(true).

Returns `true` on success, `false` otherwise.

### `[override virtual]` QSize QAxWidget::minimumSizeHint() const

Reimplements an access function for property: QWidget::minimumSizeHint.

### `[override virtual]` void QAxWidget::resetControl()

Reimplements: QAxObjectInterface::resetControl().

Shuts down the ActiveX control.

### `[override virtual protected]` void QAxWidget::resizeEvent(QResizeEvent *)

Reimplements: QWidget::resizeEvent(QResizeEvent *event).

### `[override virtual]` QSize QAxWidget::sizeHint() const

Reimplements an access function for property: QWidget::sizeHint.

### `[virtual protected]` bool QAxWidget::translateKeyEvent(int message, int keycode) const

Reimplement this function to pass certain key events to the ActiveX control. message is the Window message identifier specifying the message type (ie. WM_KEYDOWN), and keycode is the virtual keycode (ie. VK_TAB).

If the function returns true the key event is passed on to the ActiveX control, which then either processes the event or passes the event on to Qt.

If the function returns false the processing of the key event is ignored by ActiveQt, ie. the ActiveX control might handle it or not.

The default implementation returns true for the following cases:

WM_SYSKEYDOWN | WM_SYSKEYUP | WM_KEYDOWN
--- | --- | ---
All keycodes | VK_MENU | VK_TAB, VK_DELETE and all non-arrow-keys in combination with VK_SHIFT, VK_CONTROL or VK_MENU

This table is the result of experimenting with popular ActiveX controls, ie. Internet Explorer and Microsoft Office applications, but for some controls it might require modification.