Detailed Description
The QProgressBar widget provides a horizontal progress bar.
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 give it the
total number of steps and the number of steps completed so far and
it will display the percentage of steps that have been completed.
You can specify the total number of steps in the constructor or
later with setTotalSteps(). The current number of steps is set
with setProgress(). The progress bar can be rewound to the
beginning with reset().
If the total is given as 0 the progress bar shows a busy indicator
instead of a percentage of steps. This is useful, for example,
when using QFtp or QHttp to download items when they are unable to
determine the size of the item being downloaded.
See also QProgressDialog, GUI Design Handbook: Progress Indicator, and Advanced Widgets.
See also QProgressDialog, GUI Design Handbook: Progress Indicator, and Advanced Widgets.
Member Function Documentation
QProgressBar::QProgressBar ( QWidget * parent = 0, const char * name = 0, WFlags f = 0 )
Constructs a progress bar.
The total number of steps is set to 100 by default.
The parent, name and widget flags, f, are passed on to
the QFrame::QFrame() constructor.
See also totalSteps.
QProgressBar::QProgressBar ( int totalSteps, QWidget * parent = 0, const char * name = 0, WFlags f = 0 )
Constructs a progress bar.
The totalSteps is the total number of steps that need to be
completed for the operation which this progress bar represents.
For example, if the operation is to examine 50 files, this value
would be 50. Before examining the first file, call setProgress(0);
call setProgress(50) after examining the last file.
The parent, name and widget flags, f, are passed to the
QFrame::QFrame() constructor.
See also totalSteps and progress.
bool QProgressBar::centerIndicator () const
Returns TRUE if the indicator string should be centered; otherwise returns FALSE.
See the "centerIndicator" property for details.
bool QProgressBar::indicatorFollowsStyle () const
Returns TRUE if the display of the indicator string should follow the GUI style; otherwise returns FALSE.
See the "indicatorFollowsStyle" property for details.
bool QProgressBar::percentageVisible () const
Returns TRUE if the current progress value is displayed; otherwise returns FALSE.
See the "percentageVisible" property for details.
int QProgressBar::progress () const
Returns the current amount of progress.
See the "progress" property for details.
const QString & QProgressBar::progressString () const
Returns the amount of progress as a string.
See the "progressString" property for details.
void QProgressBar::reset () [slot]
Reset the progress bar. The progress bar "rewinds" and shows no
progress.
Examples: fileiconview/mainwindow.cpp and progressbar/progressbar.cpp.
void QProgressBar::setCenterIndicator ( bool on )
Sets whether the indicator string should be centered to on.
See the "centerIndicator" property for details.
bool QProgressBar::setIndicator ( QString & indicator, int progress, int totalSteps ) [virtual protected]
This method is called to generate the text displayed in the center
(or in some styles, to the left) of the progress bar.
The progress may be negative, indicating that the progress bar
is in the "reset" state before any progress is set.
The default implementation is the percentage of completion or
blank in the reset state. The percentage is calculated based on
the progress and totalSteps. You can set the indicator
text if you wish.
To allow efficient repainting of the progress bar, this method
should return FALSE if the string is unchanged from the last call
to this function.
void QProgressBar::setIndicatorFollowsStyle ( bool )
Sets whether the display of the indicator string should follow the GUI style.
See the "indicatorFollowsStyle" property for details.
void QProgressBar::setPercentageVisible ( bool )
Sets whether the current progress value is displayed.
See the "percentageVisible" property for details.
void QProgressBar::setProgress ( int progress ) [virtual slot]
Sets the current amount of progress to progress.
See the "progress" property for details.
void QProgressBar::setProgress ( int progress, int totalSteps ) [slot]
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
Sets the amount of progress to progress and the total number of
steps to totalSteps.
See also totalSteps.
void QProgressBar::setTotalSteps ( int totalSteps ) [virtual slot]
Sets the total number of steps to totalSteps.
See the "totalSteps" property for details.
int QProgressBar::totalSteps () const
Returns the total number of steps.
See the "totalSteps" property for details.
Property Documentation
bool centerIndicator
This property holds whether the indicator string should be centered.
Changing this property sets QProgressBar::indicatorFollowsStyle
to FALSE. The default is TRUE.
Set this property's value with setCenterIndicator() and get this property's value with centerIndicator().
bool indicatorFollowsStyle
This property holds whether the display of the indicator string should follow the GUI style.
The default is TRUE.
See also centerIndicator.
Set this property's value with setIndicatorFollowsStyle() and get this property's value with indicatorFollowsStyle().
bool percentageVisible
This property holds whether the current progress value is displayed.
The default is TRUE.
See also centerIndicator and indicatorFollowsStyle.
Set this property's value with setPercentageVisible() and get this property's value with percentageVisible().
int progress
This property holds the current amount of progress.
This property is -1 if progress counting has not started.
Set this property's value with setProgress() and get this property's value with progress().
QString progressString
This property holds the amount of progress as a string.
This property is QString::null if progress counting has not started.
Get this property's value with progressString().
int totalSteps
This property holds the total number of steps.
If totalSteps is 0, the progress bar will display a busy
indicator.
See also
Set this property's value with setTotalSteps() and get this property's value with totalSteps().
This file is part of the Qt toolkit.
Copyright © 1995-2005
Trolltech. All Rights Reserved.
