QProgressBar Class

The QProgressBar widget provides a horizontal or vertical progress bar. More...

Header:	#include <QProgressBar>
qmake:	QT += widgets
Inherits:	QWidget

• List of all members, including inherited members

Public Types

enum	Direction { TopToBottom, BottomToTop }

Properties

alignment : Qt::Alignment format : QString invertedAppearance : bool maximum : int minimum : int

orientation : Qt::Orientation text : const QString textDirection : Direction textVisible : bool value : int

Public Functions

	QProgressBar(QWidget *parent = nullptr)
virtual	~QProgressBar()
Qt::Alignment	alignment() const
QString	format() const
bool	invertedAppearance() const
bool	isTextVisible() const
int	maximum() const
int	minimum() const
Qt::Orientation	orientation() const
void	resetFormat()
void	setAlignment(Qt::Alignment alignment)
void	setFormat(const QString &format)
void	setInvertedAppearance(bool invert)
void	setTextDirection(QProgressBar::Direction textDirection)
void	setTextVisible(bool visible)
virtual QString	text() const
QProgressBar::Direction	textDirection() const
int	value() const

Reimplemented Public Functions

virtual QSize	minimumSizeHint() const override
virtual QSize	sizeHint() const override

Public Slots

void	reset()
void	setMaximum(int maximum)
void	setMinimum(int minimum)
void	setOrientation(Qt::Orientation)
void	setRange(int minimum, int maximum)
void	setValue(int value)

Signals

void	valueChanged(int value)

Protected Functions

void	initStyleOption(QStyleOptionProgressBar *option) const

Reimplemented Protected Functions

virtual bool	event(QEvent *e) override
virtual void	paintEvent(QPaintEvent *) override

Detailed Description

A progress bar is used to give the user an indication of the progress of an operation and to reassure them that the application is still running.

The progress bar uses the concept of steps. You set it up by specifying the minimum and maximum possible step values, and it will display the percentage of steps that have been completed when you later give it the current step value. The percentage is calculated by dividing the progress (value() - minimum()) divided by maximum() - minimum().

You can specify the minimum and maximum number of steps with setMinimum() and setMaximum. The current number of steps is set with setValue(). The progress bar can be rewound to the beginning with reset().

If minimum and maximum both are set to 0, the bar shows a busy indicator instead of a percentage of steps. This is useful, for example, when using QNetworkAccessManager to download items when they are unable to determine the size of the item being downloaded.

See also QProgressDialog and GUI Design Handbook: Progress Indicator.

Member Type Documentation

enum QProgressBar::Direction

Specifies the reading direction of the text for vertical progress bars.

Constant	Value	Description
QProgressBar::TopToBottom	0	The text is rotated 90 degrees clockwise.
QProgressBar::BottomToTop	1	The text is rotated 90 degrees counter-clockwise.

Note that whether or not the text is drawn is dependent on the style. Currently CleanLooks and Plastique draw the text. Mac, Windows and WindowsVista style do not.

This enum was introduced or modified in Qt 4.1.

See also textDirection.

Member Function Documentation

QProgressBar::QProgressBar(QWidget *parent = nullptr)

Constructs a progress bar with the given parent.

By default, the minimum step value is set to 0, and the maximum to 100.

See also setRange().

[slot] void QProgressBar::reset()

Reset the progress bar. The progress bar "rewinds" and shows no progress.

[slot] void QProgressBar::setRange(int minimum, int maximum)

Sets the progress bar's minimum and maximum values to minimum and maximum respectively.

If maximum is smaller than minimum, minimum becomes the only legal value.

If the current value falls outside the new range, the progress bar is reset with reset().

The QProgressBar can be set to undetermined state by using setRange(0, 0).

See also minimum and maximum.

[signal] void QProgressBar::valueChanged(int value)

This signal is emitted when the value shown in the progress bar changes. value is the new value shown by the progress bar.

Note: Notifier signal for property value.

[virtual] QProgressBar::~QProgressBar()

Destructor.

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

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

[protected] void QProgressBar::initStyleOption(QStyleOptionProgressBar *option) const

Initialize option with the values from this QProgressBar. This method is useful for subclasses when they need a QStyleOptionProgressBar, but don't want to fill in all the information themselves.

See also QStyleOption::initFrom().

[override virtual] QSize QProgressBar::minimumSizeHint() const

Reimplements an access function for property: QWidget::minimumSizeHint.

[override virtual protected] void QProgressBar::paintEvent(QPaintEvent *)

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

[override virtual] QSize QProgressBar::sizeHint() const

Reimplements an access function for property: QWidget::sizeHint.