Struct qt_core::QAbstractNativeEventFilter

#[repr(C)]pub struct QAbstractNativeEventFilter { /* fields omitted */ }

The QAbstractNativeEventFilter class provides an interface for receiving native events, such as MSG or XCB event structs.

C++ class: QAbstractNativeEventFilter.

C++ documentation:

The QAbstractNativeEventFilter class provides an interface for receiving native events, such as MSG or XCB event structs.

Methods

impl QAbstractNativeEventFilter

pub unsafe fn native_event_filter(
    &self,
    event_type: impl CastInto<Ref<QByteArray>>,
    message: *mut c_void,
    result: *mut c_long
) -> bool

This method is called for every native event.

Calls C++ function: pure virtual bool QAbstractNativeEventFilter::nativeEventFilter(const QByteArray& eventType, void* message, long* result).

C++ documentation:

This method is called for every native event.

Note: The filter function here receives native messages, for example, MSG or XCB event structs.

It is called by the QPA platform plugin. On Windows, it is called by the event dispatcher.

The type of event eventType is specific to the platform plugin chosen at run-time, and can be used to cast message to the right type.

On X11, eventType is set to "xcb_generic_event_t", and the message can be casted to a xcb_generic_event_t pointer.

On Windows, eventType is set to "windows_generic_MSG" for messages sent to toplevel windows, and "windows_dispatcher_MSG" for system-wide messages such as messages from a registered hot key. In both cases, the message can be casted to a MSG pointer. The result pointer is only used on Windows, and corresponds to the LRESULT pointer.

On macOS, eventType is set to "mac_generic_NSEvent", and the message can be casted to an NSEvent pointer.

In your reimplementation of this function, if you want to filter the message out, i.e. stop it being handled further, return true; otherwise return false.

Linux example

class MyXcbEventFilter : public QAbstractNativeEventFilter
{
public:
      bool nativeEventFilter(const QByteArray &eventType, void message, long ) override
      {
          if (eventType == "xcb_generic_event_t") {
              xcb_generic_event_t ev = static_cast<xcb_generic_event_t >(message);
              // ...
          }
          return false;
      }
};

macOS example

mycocoaeventfilter.h:

#include <QAbstractNativeEventFilter>
class MyCocoaEventFilter : public QAbstractNativeEventFilter
{
public:
      bool nativeEventFilter(const QByteArray &eventType, void message, long ) override;
};

mycocoaeventfilter.mm:

#include "mycocoaeventfilter.h"
#import <AppKit/AppKit.h>
bool CocoaNativeEventFilter::nativeEventFilter(const QByteArray &eventType, void *message, long *)
{
      if (eventType == "mac_generic_NSEvent") {
          NSEvent *event = static_cast<NSEvent *>(message);
          if ([event type] == NSKeyDown) {
              // Handle key event
              qDebug() << QString::fromNSString([event characters]);
          }
      }
      return false;
}

myapp.pro:

HEADERS += mycocoaeventfilter.h
OBJECTIVE_SOURCES += mycocoaeventfilter.mm
LIBS += -framework AppKit

Trait Implementations

impl CppDeletable for QAbstractNativeEventFilter

unsafe fn delete(&self)

Destroys the native event filter.

Calls C++ function: virtual [destructor] void QAbstractNativeEventFilter::~QAbstractNativeEventFilter().

C++ documentation:

Destroys the native event filter.

This automatically removes it from the application.