QMacNativeWidget Class

The QMacNativeWidget class provides a widget for macOS that provides a way to put Qt widgets into Cocoa hierarchies. More...

Header: #include <QMacNativeWidget>
qmake: QT += widgets
Since: Qt 4.5
Inherits: QWidget

This class is obsolete. It is provided to keep old source code working. We strongly advise against using it in new code.

This class was introduced in Qt 4.5.

Public Functions

QMacNativeWidget(NSView *parentView = nullptr)
virtual ~QMacNativeWidget()
NSView *nativeView() const

Reimplemented Public Functions

virtual QSize sizeHint() const override

Reimplemented Protected Functions

virtual bool event(QEvent *ev) override

Detailed Description

Use QWidget::winId() instead.

On macOS, there is a difference between a window and view; normally expressed as widgets in Qt. Qt makes assumptions about its parent-child hierarchy that make it complex to put an arbitrary Qt widget into a hierarchy of "normal" views from Apple frameworks. QMacNativeWidget bridges the gap between views and windows and makes it possible to put a hierarchy of Qt widgets into a non-Qt window or view.

QMacNativeWidget pretends it is a window (i.e. isWindow() will return true), but it cannot be shown on its own. It needs to be put into a window when it is created or later through a native call.

Here is an example showing how to put a QPushButton into a NSWindow:

    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    NSWindow *window = [[NSWindow alloc] initWithContentRect:NSMakeRect(200, app.desktop()->height() - 200, 239, 200)
                        styleMask:NSTitledWindowMask | NSClosableWindowMask
                                  | NSMiniaturizableWindowMask | NSResizableWindowMask
                        backing:NSBackingStoreBuffered defer:NO];

    QMacNativeWidget *nativeWidget = new QMacNativeWidget();
    nativeWidget->move(0, 0);
    QVBoxLayout *layout = new QVBoxLayout();
    QPushButton *pushButton = new QPushButton("An Embedded Qt Button!", nativeWidget);
    pushButton->setAttribute(Qt::WA_LayoutUsesWidgetRect); // Don't use the layout rect calculated from QMacStyle.

    // Adjust Cocoa layouts
    NSView *nativeWidgetView = reinterpret_cast<NSView *>(nativeWidget->winId());
    NSView *contentView = [window contentView];
    [contentView setAutoresizesSubviews:YES];
    [nativeWidgetView setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];
    [nativeWidgetView setAutoresizesSubviews:YES];
    NSView *pushButtonView = reinterpret_cast<NSView *>(pushButton->winId());
    [pushButtonView setAutoresizingMask:NSViewWidthSizable];

    // Add the nativeWidget to the window.
    [contentView addSubview:nativeWidgetView positioned:NSWindowAbove relativeTo:nil];

    // Show the window.
    [window makeKeyAndOrderFront:window];
    [pool release];

Note that QMacNativeWidget requires knowledge of Cocoa. All it does is get the Qt hierarchy into a window not owned by Qt. It is then up to the programmer to ensure it is placed correctly in the window and responds correctly to events.

Member Function Documentation

QMacNativeWidget::QMacNativeWidget(NSView *parentView = nullptr)

Create a QMacNativeWidget with parentView as its "superview" (i.e., parent). The parentView is a NSView pointer.

[virtual] QMacNativeWidget::~QMacNativeWidget()

Destroy the QMacNativeWidget.

[override virtual protected] bool QMacNativeWidget::event(QEvent *ev)

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

NSView *QMacNativeWidget::nativeView() const

Returns the native view backing the QMacNativeWidget.

[override virtual] QSize QMacNativeWidget::sizeHint() const

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

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