QShortcut Class Reference
^{[QtGui module]}

Detailed Description

The QShortcut class is used to create keyboard shortcuts.

The QShortcut class provides a way of connecting keyboard shortcuts to Qt's signals and slots mechanism, so that objects can be informed when a shortcut is executed. The shortcut can be set up to contain all the key presses necessary to describe a keyboard shortcut, including the states of modifier keys such as Shift, Ctrl, and Alt.

For applications that use menus, it may be more convenient to use the convenience functions provided in the QMenu class to assign keyboard shortcuts to menu items as they are created. Alternatively, shortcuts may be associated with other types of actions in the QAction class.

The simplest way to create a shortcut for a particular widget is to construct the shortcut with a key sequence. For example:

    shortcut = QShortcut(QKeySequence(tr("Ctrl+O", "File|Open")),
                         parent);

When the user types the key sequence for a given shortcut, the shortcut's activated() signal is emitted. (In the case of ambiguity, the activatedAmbiguously() signal is emitted.) A shortcut is "listened for" by Qt's event loop when the shortcut's parent widget is receiving events.

A shortcut's key sequence can be set with setKey() and retrieved with key(). A shortcut can be enabled or disabled with setEnabled(), and can have "What's This?" help text set with setWhatsThis().

See also QShortcutEvent, QKeySequence, and QAction.

Property Documentation

context : Qt::ShortcutContext

This property holds the context in which the shortcut is valid.

A shortcut's context decides in which circumstances a shortcut is allowed to be triggered. The normal context is Qt::WindowShortcut, which allows the shortcut to trigger if the parent (the widget containing the shortcut) is a subwidget of the active top-level window.

Access functions:

• Qt::ShortcutContext context ()
• void setContext ( Qt::ShortcutContext context )

enabled : bool

This property holds whether the shortcut is enabled.

An enabled shortcut emits the activated() or activatedAmbiguously() signal when a QShortcutEvent occurs that matches the shortcut's key() sequence.

If the application is in WhatsThis mode the shortcut will not emit the signals, but will show the "What's This?" text instead.

Access functions:

• bool isEnabled () const
• void setEnabled ( bool enable )

See also whatsThis.

key : QKeySequence

This property holds the shortcut's key sequence.

This is a key sequence with an optional combination of Shift, Ctrl, and Alt. The key sequence may be supplied in a number of ways:

    setKey(0);                  // no signal emitted
    setKey(QKeySequence());     // no signal emitted
    setKey(0x3b1);              // Greek letter alpha
    setKey(Qt::Key_D);              // 'd', e.g. to delete
    setKey('q');                // 'q', e.g. to quit
    setKey(Qt::CTRL + Qt::Key_P);       // Ctrl+P, e.g. to print document
    setKey("Ctrl+P");           // Ctrl+P, e.g. to print document

Access functions:

• QKeySequence key () const
• void setKey ( const QKeySequence & key )

whatsThis : QString

This property holds the shortcut's "What's This?" help text.

The text will be shown when the application is in "What's This?" mode and the user types the shortcut key() sequence.

To set "What's This?" help on a menu item (with or without a shortcut key), set the help on the item's action.

Access functions:

• QString whatsThis () const
• void setWhatsThis ( const QString & text )

See also QWhatsThis::inWhatsThisMode() and QAction::setWhatsThis().

Member Function Documentation

QShortcut::QShortcut ( QWidget * parent )

Constructs a QShortcut object for the parent widget. Since no shortcut key sequence is specified, the shortcut will not emit any signals.

See also setKey().

QShortcut::QShortcut ( const QKeySequence & key, QWidget * parent, const char * member = 0, const char * ambiguousMember = 0, Qt::ShortcutContext context = Qt::WindowShortcut )

Constructs a QShortcut object for the parent widget. The shortcut operates on its parent, listening for QShortcutEvents that match the key sequence. Depending on the ambiguity of the event, the shortcut will call the member function, or the ambiguousMember function, if the key press was in the shortcut's context.

QShortcut::~QShortcut ()

Destroys the shortcut.

void QShortcut::activated ()   [signal]

This signal is emitted when the user types the shortcut's key sequence.

See also activatedAmbiguously().

void QShortcut::activatedAmbiguously ()   [signal]

This signal is emitted when the user types a shortcut key sequence that is ambiguous. For example, if one key sequence is a "prefix" for another and the user types these keys it isn't clear if they want the shorter key sequence, or if they're about to type more to complete the longer key sequence.

See also activated().

int QShortcut::id () const

Returns the shortcut's ID.

See also QShortcutEvent::shortcutId().

QWidget * QShortcut::parentWidget () const

Returns the shortcut's parent widget.