QAbstractButton Class

Member Function Documentation

[explicit] QAbstractButton::QAbstractButton(QWidget *parent = nullptr)

Constructs an abstract button with a parent.

[virtual noexcept] QAbstractButton::~QAbstractButton()

Destroys the button.

[slot] void QAbstractButton::animateClick()

Performs an animated click: the button is pressed immediately, and released 100ms later.

Calling this function again before the button is released resets the release timer.

All signals associated with a click are emitted as appropriate.

This function does nothing if the button is disabled.

See also click().

[override virtual protected] void QAbstractButton::changeEvent(QEvent *e)

Reimplements: QWidget::changeEvent(QEvent *event).

[virtual protected] void QAbstractButton::checkStateSet()

This virtual handler is called when setChecked() is used, unless it is called from within nextCheckState(). It allows subclasses to reset their intermediate button states.

See also nextCheckState().

[slot] void QAbstractButton::click()

Performs a click.

All the usual signals associated with a click are emitted as appropriate. If the button is checkable, the state of the button is toggled.

This function does nothing if the button is disabled.

See also animateClick().

[signal] void QAbstractButton::clicked(bool checked = false)

This signal is emitted when the button is activated (i.e., pressed down then released while the mouse cursor is inside the button), when the shortcut key is typed, or when click() or animateClick() is called. Notably, this signal is not emitted if you call setDown(), setChecked() or toggle().

If the button is checkable, checked is true if the button is checked, or false if the button is unchecked.

See also pressed(), released(), and toggled().

[override virtual protected] bool QAbstractButton::event(QEvent *e)

Reimplements: QWidget::event(QEvent *event).

[override virtual protected] void QAbstractButton::focusInEvent(QFocusEvent *e)

Reimplements: QWidget::focusInEvent(QFocusEvent *event).

[override virtual protected] void QAbstractButton::focusOutEvent(QFocusEvent *e)

Reimplements: QWidget::focusOutEvent(QFocusEvent *event).

QButtonGroup *QAbstractButton::group() const

Returns the group that this button belongs to.

If the button is not a member of any QButtonGroup, this function returns nullptr.

See also QButtonGroup.

[virtual protected] bool QAbstractButton::hitButton(const QPoint &pos) const

Returns true if pos is inside the clickable button rectangle; otherwise returns false.

By default, the clickable area is the entire widget. Subclasses may reimplement this function to provide support for clickable areas of different shapes and sizes.

[override virtual protected] void QAbstractButton::keyPressEvent(QKeyEvent *e)

Reimplements: QWidget::keyPressEvent(QKeyEvent *event).

[override virtual protected] void QAbstractButton::keyReleaseEvent(QKeyEvent *e)

Reimplements: QWidget::keyReleaseEvent(QKeyEvent *event).

[override virtual protected] void QAbstractButton::mouseMoveEvent(QMouseEvent *e)

Reimplements: QWidget::mouseMoveEvent(QMouseEvent *event).

[override virtual protected] void QAbstractButton::mousePressEvent(QMouseEvent *e)

Reimplements: QWidget::mousePressEvent(QMouseEvent *event).

[override virtual protected] void QAbstractButton::mouseReleaseEvent(QMouseEvent *e)

Reimplements: QWidget::mouseReleaseEvent(QMouseEvent *event).

[virtual protected] void QAbstractButton::nextCheckState()

This virtual handler is called when a button is clicked. The default implementation calls setChecked(!isChecked()) if the button isCheckable(). It allows subclasses to implement intermediate button states.

See also checkStateSet().

[override pure virtual protected] void QAbstractButton::paintEvent(QPaintEvent *e)

Reimplements: QWidget::paintEvent(QPaintEvent *event).

[signal] void QAbstractButton::pressed()

This signal is emitted when the button is pressed down.

See also released() and clicked().

[signal] void QAbstractButton::released()

This signal is emitted when the button is released.

See also pressed(), clicked(), and toggled().

[override virtual protected] void QAbstractButton::timerEvent(QTimerEvent *e)

Reimplements: QObject::timerEvent(QTimerEvent *event).

[slot] void QAbstractButton::toggle()

Toggles the state of a checkable button.

See also checked.

[signal] void QAbstractButton::toggled(bool checked)

This signal is emitted whenever a checkable button changes its state. checked is true if the button is checked, or false if the button is unchecked.

This may be the result of a user action, click() slot activation, or because setChecked() is called.

The states of buttons in exclusive button groups are updated before this signal is emitted. This means that slots can act on either the "off" signal or the "on" signal emitted by the buttons in the group whose states have changed.

For example, a slot that reacts to signals emitted by newly checked buttons but which ignores signals from buttons that have been unchecked can be implemented using the following pattern:

void MyWidget::reactToToggle(bool checked)
{
   if (checked) {
      // Examine the new button states.
      ...
   }
}

Button groups can be created using the QButtonGroup class, and updates to the button states monitored with the QButtonGroup::buttonClicked() signal.

See also checked and clicked().