QShortcut Class

The QShortcut class is used to create keyboard shortcuts. More...

• List of all members, including inherited members

Properties

Public Functions

Signals

Detailed Description

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.

On certain widgets, using '&' in front of a character will automatically create a mnemonic (a shortcut) for that character, e.g. "E&xit" will create the shortcut Alt+X (use '&&' to display an actual ampersand). The widget might consume and perform an action on a given shortcut. On X11 the ampersand will not be shown and the character will be underlined. On Windows, shortcuts are normally not displayed until the user presses the Alt key, but this is a setting the user can change. On Mac, shortcuts are disabled by default. Call qt_set_sequence_auto_mnemonic() to enable them. However, because mnemonic shortcuts do not fit in with Aqua's guidelines, Qt will not show the shortcut character underlined.

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 = new 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.

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

Member Function Documentation

QShortcut::QShortcut(const QKeySequence &key, QWidget *parent, const char *member = nullptr, const char *ambiguousMember = nullptr, Qt::ShortcutContext shortcutContext = 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 shortcutContext.

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().

[signal] void QShortcut::activated()

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

See also activatedAmbiguously().

[signal] void QShortcut::activatedAmbiguously()

When a key sequence is being typed at the keyboard, it is said to be ambiguous as long as it matches the start of more than one shortcut.

When a shortcut's key sequence is completed, activatedAmbiguously() is emitted if the key sequence is still ambiguous (i.e., it is the start of one or more other shortcuts). The activated() signal is not emitted in this case.

See also activated().

[virtual] QShortcut::~QShortcut()

Destroys the shortcut.

int QShortcut::id() const

Returns the shortcut's ID.

See also QShortcutEvent::shortcutId().

QWidget *QShortcut::parentWidget() const

Returns the shortcut's parent widget.