QActionGroup Class Reference

The QActionGroup class groups actions together. More...

 #include <QActionGroup>

Inherits: QObject.

Properties

Public Functions

QActionGroup ( QObject * parent )
~QActionGroup ()
QList<QAction *> actions () const
QAction * addAction ( QAction * action )
QAction * addAction ( const QString & text )
QAction * addAction ( const QIcon & icon, const QString & text )
QAction * checkedAction () const
bool isEnabled () const
bool isExclusive () const
bool isVisible () const
void removeAction ( QAction * action )
  • 29 public functions inherited from QObject

Public Slots

void setDisabled ( bool b )
void setEnabled ( bool )
void setExclusive ( bool )
void setVisible ( bool )
  • 1 public slot inherited from QObject

Signals

void hovered ( QAction * action )
void triggered ( QAction * action )

Additional Inherited Members

  • 7 static public members inherited from QObject
  • 8 protected functions inherited from QObject

Detailed Description

The QActionGroup class groups actions together.

In some situations it is useful to group QAction objects together. For example, if you have a Left Align action, a Right Align action, a Justify action, and a Center action, only one of these actions should be active at any one time. One simple way of achieving this is to group the actions together in an action group.

Here's a example (from the Menus example):

     alignmentGroup = new QActionGroup(this);
     alignmentGroup->addAction(leftAlignAct);
     alignmentGroup->addAction(rightAlignAct);
     alignmentGroup->addAction(justifyAct);
     alignmentGroup->addAction(centerAct);
     leftAlignAct->setChecked(true);

Here we create a new action group. Since the action group is exclusive by default, only one of the actions in the group is checked at any one time.

Alignment options in a QMenu

A QActionGroup emits an triggered() signal when one of its actions is chosen. Each action in an action group emits its triggered() signal as usual.

As stated above, an action group is exclusive by default; it ensures that only one checkable action is active at any one time. If you want to group checkable actions without making them exclusive, you can turn of exclusiveness by calling setExclusive(false).

Actions can be added to an action group using addAction(), but it is usually more convenient to specify a group when creating actions; this ensures that actions are automatically created with a parent. Actions can be visually separated from each other by adding a separator action to the group; create an action and use QAction's setSeparator() function to make it considered a separator. Action groups are added to widgets with the QWidget::addActions() function.

See also QAction.

Property Documentation

enabled : bool

This property holds whether the action group is enabled.

Each action in the group will be enabled or disabled unless it has been explicitly disabled.

Access functions:

bool isEnabled () const
void setEnabled ( bool )

See also QAction::setEnabled().

exclusive : bool

This property holds whether the action group does exclusive checking.

If exclusive is true, only one checkable action in the action group can ever be active at any time. If the user chooses another checkable action in the group, the one they chose becomes active and the one that was active becomes inactive.

Access functions:

bool isExclusive () const
void setExclusive ( bool )

See also QAction::checkable.

visible : bool

This property holds whether the action group is visible.

Each action in the action group will match the visible state of this group unless it has been explicitly hidden.

Access functions:

bool isVisible () const
void setVisible ( bool )

See also QAction::setEnabled().

Member Function Documentation

QActionGroup::QActionGroup ( QObject * parent )

Constructs an action group for the parent object.

The action group is exclusive by default. Call setExclusive(false) to make the action group non-exclusive.

QActionGroup::~QActionGroup ()

Destroys the action group.

QList<QAction *> QActionGroup::actions () const

Returns the list of this groups's actions. This may be empty.

QAction * QActionGroup::addAction ( QAction * action )

Adds the action to this group, and returns it.

Normally an action is added to a group by creating it with the group as its parent, so this function is not usually used.

See also QAction::setActionGroup().

QAction * QActionGroup::addAction ( const QString & text )

Creates and returns an action with text. The newly created action is a child of this action group.

Normally an action is added to a group by creating it with the group as parent, so this function is not usually used.

See also QAction::setActionGroup().

QAction * QActionGroup::addAction ( const QIcon & icon, const QString & text )

Creates and returns an action with text and an icon. The newly created action is a child of this action group.

Normally an action is added to a group by creating it with the group as its parent, so this function is not usually used.

See also QAction::setActionGroup().

QAction * QActionGroup::checkedAction () const

Returns the currently checked action in the group, or 0 if none are checked.

void QActionGroup::hovered ( QAction * action ) [signal]

This signal is emitted when the given action in the action group is highlighted by the user; for example, when the user pauses with the cursor over a menu option, toolbar button, or presses an action's shortcut key combination.

See also QAction::activate().

void QActionGroup::removeAction ( QAction * action )

Removes the action from this group. The action will have no parent as a result.

See also QAction::setActionGroup().

void QActionGroup::setDisabled ( bool b ) [slot]

This is a convenience function for the enabled property, that is useful for signals--slots connections. If b is true the action group is disabled; otherwise it is enabled.

void QActionGroup::triggered ( QAction * action ) [signal]

This signal is emitted when the given action in the action group is activated by the user; for example, when the user clicks a menu option, toolbar button, or presses an action's shortcut key combination.

Connect to this signal for command actions.

See also QAction::activate().

Notes provided by the Qt Community
Informative
  • 5

Votes: 3

Coverage: Qt library 4.7, 4.8, 5.0

Picture of Volker Volker

Ant Farmer
35 notes

Nokia Certified Qt Developer

Actions not checkable by default

For some reason the actions added to a QActionGroup are not checkable by default. To make the group fully working, just call

  1. setCheckable(true)

on the actions you wish to add to the group.

[Revisions]