Qt Toolkit - QKeyEvent Class

# QKeyEvent Class Reference

The QKeyEvent class contains parameters that describe a key event. More...

`#include <qevent.h>`

Inherits QEvent.

List of all member functions.

## Public Members

- QKeyEvent ( int type, int key, int ascii, int state )
- int key () const
- int ascii () const
- int state () const
- bool isAccepted () const
- void accept ()
- void ignore ()

## Detailed Description

The QKeyEvent class contains parameters that describe a key event.

Key events occur when a key is pressed or released when a widget has keyboard input focus.

A key event contains a special accept flag which tells whether the receiver wants the key. You should call QKeyEvent::ignore() if the key press or release event is not handled by your widget.

The QWidget::setEnable() function can be used to enable or disable mouse and keyboard events for a widget.

The event handlers QWidget::keyPressEvent() and QWidget::keyReleaseEvent() receive key events.

See also: QFocusEvent and QWidget::grabKeyboard().

Examples: table/table.cpp picture/picture.cpp

## Member Function Documentation

### QKeyEvent::QKeyEvent ( int type, int key, int ascii, int state )

Constructs a key event object.

The type parameter must be `Event_KeyPress` or `Event_KeyRelease.`

If key is 0, the event is not a result of a known key (e.g. it may be the result of a compose sequence or keyboard macro).

The accept flag is set to TRUE.

### void QKeyEvent::accept ()

Sets the accept flag of the key event object.

Setting the accept parameter indicates that the receiver of the event wants the key event. Unwanted key events are sent to the parent widget.

The accept flag is set by default.

See also: ignore().

### int QKeyEvent::ascii () const

Returns the ASCII code of the key that was pressed or released.

Examples: picture/picture.cpp

### void QKeyEvent::ignore ()

Clears the accept flag parameter of the key event object.

Clearing the accept parameter indicates that the event receiver does not want the key event. Unwanted key events are sent to the parent widget.

The accept flag is set by default.

See also: accept().

Examples: table/table.cpp

### bool QKeyEvent::isAccepted () const

Returns TRUE if the receiver of the event wants to keep the key.

### int QKeyEvent::key () const

Returns the code of the key that was pressed or released.

The header file qkeycode.h lists the possible keyboard codes. These codes are independent of the underlying window system.

Key code 0 means that the event is not a result of a known key (e.g. it may be the result of a compose sequence or keyboard macro).

Examples: table/table.cpp

### int QKeyEvent::state () const

Returns the keyboard modifier flags.

The returned value is `ShiftButton, ControlButton` and `AltButton` OR'ed together.

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This file is part of the Qt toolkit, copyright © 1995-99 Troll Tech, all rights reserved.

It was generated from the following files:

- qevent.h: 1998/10/05
- qdnd_x11.cpp: 1998/12/17
- qevent.cpp: 1999/01/13