The QProgressDialog class provides feedback on the progress of a slow operation.. Más...

#include <qprogressdialog.h>

Diagrama de herencias de QProgressDialog

Slots públicos
void	cancel ()
void	reset ()
void	setTotalSteps (int totalSteps)
void	setProgress (int progress)
void	setProgress (int progress, int totalSteps)
void	setLabelText (const QString &)
void	setCancelButtonText (const QString &)
void	setMinimumDuration (int ms)
void	cancel ()
void	reset ()
void	setTotalSteps (int totalSteps)
void	setProgress (int progress)
void	setProgress (int progress, int totalSteps)
void	setLabelText (const QString &)
void	setCancelButtonText (const QString &)
void	setMinimumDuration (int ms)
Señales
void	cancelled ()
void	canceled ()
void	cancelled ()
void	canceled ()
Métodos públicos
	QProgressDialog (QWidget parent=0, const char name=0, bool modal=FALSE, WFlags f=0)
	QProgressDialog (const QString &labelText, const QString &cancelButtonText, int totalSteps, QWidget parent=0, const char name=0, bool modal=FALSE, WFlags f=0)
	~QProgressDialog ()
void	setLabel (QLabel *)
void	setCancelButton (QPushButton *)
void	setBar (QProgressBar *)
bool	wasCancelled () const
bool	wasCanceled () const
int	totalSteps () const
int	progress () const
QSize	sizeHint () const
QString	labelText () const
void	setAutoReset (bool b)
bool	autoReset () const
void	setAutoClose (bool b)
bool	autoClose () const
int	minimumDuration () const
	QProgressDialog (QWidget parent=0, const char name=0, bool modal=FALSE, WFlags f=0)
	QProgressDialog (const QString &labelText, const QString &cancelButtonText, int totalSteps, QWidget parent=0, const char name=0, bool modal=FALSE, WFlags f=0)
	~QProgressDialog ()
void	setLabel (QLabel *)
void	setCancelButton (QPushButton *)
void	setBar (QProgressBar *)
bool	wasCancelled () const
bool	wasCanceled () const
int	totalSteps () const
int	progress () const
QSize	sizeHint () const
QString	labelText () const
void	setAutoReset (bool b)
bool	autoReset () const
void	setAutoClose (bool b)
bool	autoClose () const
int	minimumDuration () const
Slots protegidos
void	forceShow ()
void	forceShow ()
Métodos protegidos
void	resizeEvent (QResizeEvent *)
void	closeEvent (QCloseEvent *)
void	styleChange (QStyle &)
void	showEvent (QShowEvent *e)
void	resizeEvent (QResizeEvent *)
void	closeEvent (QCloseEvent *)
void	styleChange (QStyle &)
void	showEvent (QShowEvent *e)
Propiedades
bool	wasCancelled
	whether the dialog was canceled
bool	wasCanceled
	whether the dialog was canceled
int	totalSteps
	the total number of steps
int	progress
	the current amount of progress made.
bool	autoReset
	whether the progress dialog calls reset() as soon as progress() equals totalSteps()
bool	autoClose
	whether the dialog gets hidden by reset()
int	minimumDuration
	the time that must pass before the dialog appears
QString	labelText
	the label's text

Descripción detallada

The QProgressDialog class provides feedback on the progress of a slow operation.

.

A progress dialog is used to give the user an indication of how long an operation is going to take, and to demonstrate that the application has not frozen. It can also give the user an opportunity to abort the operation.

A common problem with progress dialogs is that it is difficult to know when to use them; operations take different amounts of time on different hardware. QProgressDialog offers a solution to this problem: it estimates the time the operation will take (based on time for steps), and only shows itself if that estimate is beyond minimumDuration() (4 seconds by default).

Use setTotalSteps() (or the constructor) to set the number of "steps" in the operation and call setProgress() as the operation progresses. The step value can be chosen arbitrarily. It can be the number of files copied, the number of bytes received, the number of iterations through the main loop of your algorithm, or some other suitable unit. Progress starts at 0, and the progress dialog shows that the operation has finished when you call setProgress() with totalSteps() as its argument.

The dialog automatically resets and hides itself at the end of the operation. Use setAutoReset() and setAutoClose() to change this behavior.

There are two ways of using QProgressDialog: modal and modeless.

Using a modal QProgressDialog is simpler for the programmer, but you must call QApplication::processEvents() or QEventLoop::processEvents(ExcludeUserInput) to keep the event loop running to ensure that the application doesn't freeze. Do the operation in a loop, call setProgress() at intervals, and check for cancellation with wasCanceled(). For example:

QProgressDialog progress( "Copying files...", "Abort Copy", numFiles,
                          this, "progress", TRUE );
for ( int i = 0; i < numFiles; i++ ) {
    progress.setProgress( i );
    qApp->processEvents();

    if ( progress.wasCanceled() )
        break;
    //... copy one file
}
progress.setProgress( numFiles );

A modeless progress dialog is suitable for operations that take place in the background, where the user is able to interact with the application. Such operations are typically based on QTimer (or QObject::timerEvent()), QSocketNotifier, or QUrlOperator; or performed in a separate thread. A QProgressBar in the status bar of your main window is often an alternative to a modeless progress dialog.

You need to have an event loop to be running, connect the canceled() signal to a slot that stops the operation, and call setProgress() at intervals. For example:

Operation::Operation( QObject *parent = 0 )
    : QObject( parent ), steps( 0 )
{
    pd = new QProgressDialog( "Operation in progress.", "Cancel", 100 );
    connect( pd, SIGNAL(canceled()), this, SLOT(cancel()) );
    t = new QTimer( this );
    connect( t, SIGNAL(timeout()), this, SLOT(perform()) );
    t->start( 0 );
}

void Operation::perform()
{
    pd->setProgress( steps );
    //... perform one percent of the operation
    steps++;
    if ( steps > pd->totalSteps() )
        t->stop();
}

void Operation::cancel()
{
    t->stop();
    //... cleanup
}

In both modes the progress dialog may be customized by replacing the child widgets with custom widgets by using setLabel(), setBar(), and setCancelButton(). The functions setLabelText() and setCancelButtonText() set the texts shown.

Ver también:: QDialog QProgressBar GUI Design Handbook: Progress Indicator

Documentación del constructor y destructor

QProgressDialog::QProgressDialog	(	QWidget *	creator = `0`,
		const char *	name = `0`,
		bool	modal = `FALSE`,
		WFlags	f = `0`
	)

Constructs a progress dialog.

Default settings: The label text is empty. The cancel button text is (translated) "Cancel". The total number of steps is 100.

The creator argument is the widget to use as the dialog's parent. The name, modal, and the widget flags, f, are passed to the QDialog::QDialog() constructor. If modal is FALSE (the default), you must have an event loop proceeding for any redrawing of the dialog to occur. If modal is TRUE, the dialog ensures that events are processed when needed.

Ver también:: setLabelText(), setLabel(), setCancelButtonText(), setCancelButton(), setTotalSteps()

QProgressDialog::QProgressDialog	(	const QString &	labelText,
		const QString &	cancelButtonText,
		int	totalSteps,
		QWidget *	creator = `0`,
		const char *	name = `0`,
		bool	modal = `FALSE`,
		WFlags	f = `0`
	)

Constructs a progress dialog.

The labelText is text used to remind the user what is progressing.

The cancelButtonText is the text to display on the cancel button, or 0 if no cancel button is to be shown.

The totalSteps is the total number of steps in the operation for which this progress dialog shows progress. For example, if the operation is to examine 50 files, this value would be 50. Before examining the first file, call setProgress(0). As each file is processed call setProgress(1), setProgress(2), etc., finally calling setProgress(50) after examining the last file.

The creator argument is the widget to use as the dialog's parent. The name, modal, and widget flags, f, are passed to the QDialog::QDialog() constructor. If modal is FALSE (the default), you will must have an event loop proceeding for any redrawing of the dialog to occur. If modal is TRUE, the dialog ensures that events are processed when needed.

Ver también:: setLabelText(), setLabel(), setCancelButtonText(), setCancelButton(), setTotalSteps()

QProgressDialog::~QProgressDialog ( )

Destroys the progress dialog.

QProgressDialog::QProgressDialog	(	QWidget *	parent = `0`,
		const char *	name = `0`,
		bool	modal = `FALSE`,
		WFlags	f = `0`
	)

QProgressDialog::QProgressDialog	(	const QString &	labelText,
		const QString &	cancelButtonText,
		int	totalSteps,
		QWidget *	parent = `0`,
		const char *	name = `0`,
		bool	modal = `FALSE`,
		WFlags	f = `0`
	)

QProgressDialog::~QProgressDialog ( )

Documentación de las funciones miembro

bool QProgressDialog::autoClose ( ) const

bool QProgressDialog::autoReset ( ) const

void QProgressDialog::cancel ( ) [slot]

Resets the progress dialog. wasCanceled() becomes TRUE until the progress dialog is reset. The progress dialog becomes hidden.

void QProgressDialog::canceled ( ) [signal]

This signal is emitted when the cancel button is clicked. It is connected to the cancel() slot by default.

Ver también:: wasCanceled()

void QProgressDialog::canceled ( ) [signal]

void QProgressDialog::cancelled ( ) [signal]

Use canceled() instead.

void QProgressDialog::cancelled ( ) [signal]

void QProgressDialog::closeEvent ( QCloseEvent * e ) [protected, virtual]

Reimplementado de QDialog.

void QProgressDialog::closeEvent ( QCloseEvent * e ) [protected, virtual]

Reimplementado de QDialog.

void QProgressDialog::forceShow ( ) [protected, slot]

Shows the dialog if it is still hidden after the algorithm has been started and minimumDuration milliseconds have passed.

Ver también:: setMinimumDuration()

void QProgressDialog::forceShow ( ) [protected, slot]

QString QProgressDialog::labelText ( ) const

int QProgressDialog::minimumDuration ( ) const

int QProgressDialog::progress ( ) const

void QProgressDialog::reset ( ) [slot]

void QProgressDialog::reset ( void ) [slot]

Resets the progress dialog. The progress dialog becomes hidden if autoClose() is TRUE.

Ver también:: setAutoClose(), setAutoReset()

void QProgressDialog::resizeEvent ( QResizeEvent * ) [protected, virtual]

Reimplementado de QDialog.

void QProgressDialog::resizeEvent ( QResizeEvent * ) [protected, virtual]

Reimplementado de QDialog.

void QProgressDialog::setAutoClose ( bool b )

void QProgressDialog::setAutoReset ( bool b )

void QProgressDialog::setBar ( QProgressBar * )

void QProgressDialog::setBar ( QProgressBar * bar )

Sets the progress bar widget to bar. The progress dialog resizes to fit. The progress dialog takes ownership of the progress bar which will be deleted when necessary, so do not use a progress bar allocated on the stack.

void QProgressDialog::setCancelButton ( QPushButton * cancelButton )

Sets the cancel button to the push button, cancelButton. The progress dialog takes ownership of this button which will be deleted when necessary, so do not pass the address of an object that is on the stack, i.e. use new() to create the button.

Ver también:: setCancelButtonText()

void QProgressDialog::setCancelButton ( QPushButton * )

void QProgressDialog::setCancelButtonText ( const QString & cancelButtonText ) [slot]

Sets the cancel button's text to cancelButtonText.

Ver también:: setCancelButton()

void QProgressDialog::setCancelButtonText ( const QString & ) [slot]

void QProgressDialog::setLabel ( QLabel * label )

Sets the label to label. The progress dialog resizes to fit. The label becomes owned by the progress dialog and will be deleted when necessary, so do not pass the address of an object on the stack.

Ver también:: setLabelText()

void QProgressDialog::setLabel ( QLabel * )

void QProgressDialog::setLabelText ( const QString & text ) [slot]

void QProgressDialog::setLabelText ( const QString & ) [slot]

void QProgressDialog::setMinimumDuration ( int ms ) [slot]

void QProgressDialog::setProgress ( int progress ) [slot]

void QProgressDialog::setProgress	(	int	progress,
		int	totalSteps
	)		`[slot]`

void QProgressDialog::setProgress ( int progress ) [slot]

void QProgressDialog::setProgress	(	int	progress,
		int	totalSteps
	)		`[slot]`

Esta es una función miembro sobrecargada que se suministra por conveniencia. Difiere de la anterior función solamente en los argumentos que acepta. Sets the current amount of progress to progress and the total number of steps to totalSteps.

Ver también:: setTotalSteps()

void QProgressDialog::setTotalSteps ( int totalSteps ) [slot]

void QProgressDialog::showEvent ( QShowEvent * ) [protected, virtual]

This event handler can be reimplemented in a subclass to receive widget show events.

Non-spontaneous show events are sent to widgets immediately before they are shown. The spontaneous show events of top-level widgets are delivered afterwards.

Ver también:: event(), QShowEvent

Reimplementado de QWidget.

void QProgressDialog::showEvent ( QShowEvent * e ) [protected, virtual]

Reimplementado de QWidget.

QSize QProgressDialog::sizeHint ( ) const [virtual]

Returns a size that fits the contents of the progress dialog. The progress dialog resizes itself as required, so you should not need to call this yourself.

Reimplementado de QDialog.

QSize QProgressDialog::sizeHint ( ) const [virtual]

Reimplementado de QDialog.

void QProgressDialog::styleChange ( QStyle & ) [protected, virtual]

This virtual function is called when the style of the widgets changes. oldStyle is the previous GUI style; you can get the new style from style().

Reimplement this function if your widget needs to know when its GUI style changes. You will almost certainly need to update the widget using update().

The default implementation updates the widget including its geometry.

Ver también:: QApplication::setStyle(), style(), update(), updateGeometry()

Reimplementado de QWidget.

void QProgressDialog::styleChange ( QStyle & s ) [protected, virtual]

Reimplementado de QWidget.

int QProgressDialog::totalSteps ( ) const

bool QProgressDialog::wasCanceled ( ) const [inline]

bool QProgressDialog::wasCancelled ( ) const

Documentación de propiedades

bool QProgressDialog::autoClose [read, write]

whether the dialog gets hidden by reset()

The default is TRUE.

Ver también:: setAutoReset()

bool QProgressDialog::autoReset [read, write]

whether the progress dialog calls reset() as soon as progress() equals totalSteps()

The default is TRUE.

Ver también:: setAutoClose()

QString QProgressDialog::labelText [read, write]

the label's text

The default text is QString::null.

int QProgressDialog::minimumDuration [read, write]

the time that must pass before the dialog appears

If the expected duration of the task is less than the minimumDuration, the dialog will not appear at all. This prevents the dialog popping up for tasks that are quickly over. For tasks that are expected to exceed the minimumDuration, the dialog will pop up after the minimumDuration time or as soon as any progress is set.

If set to 0, the dialog is always shown as soon as any progress is set. The default is 4000 milliseconds.

int QProgressDialog::progress [read, write]

the current amount of progress made.

For the progress dialog to work as expected, you should initially set this property to 0 and finally set it to QProgressDialog::totalSteps(); you can call setProgress() any number of times in-between.

Atención:: If the progress dialog is modal (see QProgressDialog::QProgressDialog()), this function calls QApplication::processEvents(), so take care that this does not cause undesirable re-entrancy in your code. For example, don't use a QProgressDialog inside a paintEvent()!

Ver también:: totalSteps

int QProgressDialog::totalSteps [read, write]

the total number of steps

The default is 0.

bool QProgressDialog::wasCanceled [read]

whether the dialog was canceled

Ver también:: setProgress()

bool QProgressDialog::wasCancelled [read]

whether the dialog was canceled

Use wasCanceled instead.

La documentación para esta clase fue generada a partir de los siguientes ficheros:

src/qt/include/qprogressdialog.h
src/qt/src/dialogs/qprogressdialog.h
src/qt/src/.moc/release-shared-mt/moc_qprogressdialog.cpp
src/qt/src/dialogs/qprogressdialog.cpp

Slots públicos

Señales

Métodos públicos

Slots protegidos

Métodos protegidos

Propiedades

Descripción detallada

Documentación del constructor y destructor

Documentación de las funciones miembro

Documentación de propiedades