QWhatsThis(3qt)QWhatsThis(3qt)NAMEQWhatsThis - Simple description of any widget, e.g.
answering the question "what's this?"
#include <qwhatsthis.h>
Inherits Qt.
Public Members
QWhatsThis ( QWidget * )
virtual ~QWhatsThis ()
virtual QString text ( const QPoint & )
Static Public Members
void add ( QWidget *, const QString & )
void remove ( QWidget * )
QString textFor ( QWidget *, const QPoint & pos = QPoint
())
QToolButton* whatsThisButton ( QWidget * parent )
void enterWhatsThisMode ()
bool inWhatsThisMode ()
void leaveWhatsThisMode ( const QString & = QString::null,
const QPoint & pos = QCursor::pos ())
DESCRIPTION
The QWhatsThis class provides a simple description of any
widget, e.g. answering the question "what's this?"
What's This help is part of an application's online help
systems, offering users a level of detail between tool
tips and full text browsing windows.
QWhatsThis provides a single window with a single
explanatory text, which pops up quickly when the user asks
"what's this?", and goes away as soon as the user does
something else.
To assign What's This? text to a widget, you simply call
QWhatsThis::add() for the widget. To assign text to a menu
item, call QMenuData::setWhatsThis(), and for a global
accelerator key, call QAccel::setWhatsThis().
The text can be either rich text or plain text. If you
specify a rich text formatted string, it will be rendered
using the default stylesheet. This makes it also possible
to embed images. See QStyleSheet::defaultSheet() for
details.
By default, the user will be able to view the text for a
widget by pressing Shift-F1 while the widget has focus. On
window systems where a context help button is provided in
the window decorations, that button enters What's This?
mode. In this mode, if the user clicks on a widget, help
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will be given for the widget. The mode is left when help
is given or when the user presses the Escape key.
An alternative way to enter What's This? mode is to use
the ready-made toolbar tool button from
QWhatsThis::whatsThisButton(). If you are using
QMainWindow, you can also use the QMainWindow::whatsThis()
slot to invoke the mode from a menu item.
[Image Omitted]
For more control, you can create a dedicated QWhatsThis
object for a special widget. By subclassing and
reimplementing QWhatsThis::text() it is possible to have
different explanatory texts depending on the position of
the mouse click.
If your widget needs even more control, see
QWidget::customWhatsThis().
To remove added text, you can use QWhatsThis::remove(),
but since the text is automatically removed when the
widget is destroyed, this is rarely needed.
See also QToolTip.
MEMBER FUNCTION DOCUMENTATIONQWhatsThis::QWhatsThis ( QWidget * widget )
Constructs a dynamic What's This object for widget.
When the widget is queried by the user, the text()
function of this QWhatsThis will be called to provide the
appropriate text, rather than using text assigned by
add().
QWhatsThis::~QWhatsThis () [virtual]
Destructs the object and frees any allocated resources.
void QWhatsThis::add ( QWidget * widget, const QString & text )
[static]
Adds text as What's This help for widget. If the text is
rich text formatted (ie. it contains markup), it will be
rendered with the default stylesheet
QStyleSheet::defaultSheet().
The text is destroyed if the widget is later destroyed and
so need not be explicitly removed.
See also remove().
void QWhatsThis::enterWhatsThisMode () [static]
Enters What's This? mode and returns immediately.
Qt will install a special cursor and take over mouse input
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until the user clicks somewhere, then show any help
available and switch out of What's This mode. Finally, Qt
removes the special cursor and help window then restores
ordinary event processing, at which point the left mouse
button is not pressed.
The user can also use the Escape key to leave What's This?
mode.
See also inWhatsThisMode() and leaveWhatsThisMode().
bool QWhatsThis::inWhatsThisMode () [static]
Returns whether the application is in What's This mode.
See also enterWhatsThisMode() and leaveWhatsThisMode().
void QWhatsThis::leaveWhatsThisMode ( const QString & text =
QString::null, const QPoint & pos = QCursor::pos ())
[static]
Leaves What's This? question mode
This function is used internally by widgets that support
QWidget::customWhatsThis(), applications do not usually
call it. An example for such a kind of widget is
QPopupMenu: Menus still work normally in What's This mode,
but provide help texts for single menu items instead.
If text is not a null string, then a What's This help
window is displayed at the global screen position pos.
See also inWhatsThisMode() and enterWhatsThisMode().
void QWhatsThis::remove ( QWidget * widget ) [static]
Removes the What's This help for widget. This happens
automatically if the widget is destroyed.
See also add().
QString QWhatsThis::text ( const QPoint & ) [virtual]
This virtual functions returns the text for position p in
the widget that this What's This object documents. If
there is no What's This text for a position, QString::null
is returned.
The default implementation returns QString::null.
QString QWhatsThis::textFor ( QWidget * widget, const QPoint &
pos = QPoint ()) [static]
Returns the text for widget, or a null string if there is
no What's This help for widget.
See also add().
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QWhatsThis(3qt)QWhatsThis(3qt)QToolButton * QWhatsThis::whatsThisButton ( QWidget * parent )
[static]
Creates a QToolButton pre-configured to enter What's This
mode when clicked. You will often use this with a toolbar:
(void)QWhatsThis::whatsThisButton( my_help_tool_bar );
SEE ALSO
http://doc.trolltech.com/qwhatsthis.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2001 Trolltech AS,
http://www.trolltech.com. See the license file included
in the distribution for a complete license statement.
AUTHOR
Generated automatically from the source code.
BUGS
If you find a bug in Qt, please report it as described in
http://doc.trolltech.com/bughowto.html. Good bug reports
make our job much simpler. Thank you.
In case of content or formattting problems with this
manual page, please report them to qt-bugs@trolltech.com.
Please include the name of the manual page
(qwhatsthis.3qt) and the Qt version (2.3.1).
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