/**************************************************************************** ** ** Implementation of QWhatsThis class ** ** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved. ** ** This file is part of the widgets module of the Qt GUI Toolkit. ** ** This file may be used under the terms of the GNU General ** Public License versions 2.0 or 3.0 as published by the Free ** Software Foundation and appearing in the files LICENSE.GPL2 ** and LICENSE.GPL3 included in the packaging of this file. ** Alternatively you may (at your option) use any later version ** of the GNU General Public License if such license has been ** publicly approved by Trolltech ASA (or its successors, if any) ** and the KDE Free Qt Foundation. ** ** Please review the following information to ensure GNU General ** Public Licensing requirements will be met: ** http://trolltech.com/products/qt/licenses/licensing/opensource/. ** If you are unsure which license is appropriate for your use, please ** review the following information: ** http://trolltech.com/products/qt/licenses/licensing/licensingoverview ** or contact the sales department at sales@trolltech.com. ** ** This file may be used under the terms of the Q Public License as ** defined by Trolltech ASA and appearing in the file LICENSE.QPL ** included in the packaging of this file. Licensees holding valid Qt ** Commercial licenses may use this file in accordance with the Qt ** Commercial License Agreement provided with the Software. ** ** This file is provided "AS IS" with NO WARRANTY OF ANY KIND, ** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted ** herein. ** **********************************************************************/ #include "qwhatsthis.h" #ifndef QT_NO_WHATSTHIS #include "qapplication.h" #include "qpaintdevicemetrics.h" #include "qpixmap.h" #include "qpainter.h" #include "qtimer.h" #include "qptrdict.h" #include "qtoolbutton.h" #include "qshared.h" #include "qcursor.h" #include "qbitmap.h" #include "qtooltip.h" #include "qsimplerichtext.h" #include "qstylesheet.h" #if defined(QT_ACCESSIBILITY_SUPPORT) #include "qaccessible.h" #endif #if defined(Q_WS_WIN) #include "qt_windows.h" #ifndef SPI_GETDROPSHADOW #define SPI_GETDROPSHADOW 0x1024 #endif #endif /*! \class QWhatsThis qwhatsthis.h \brief The QWhatsThis class provides a simple description of any widget, i.e. answering the question "What's this?". \ingroup helpsystem \mainclass "What's this?" help is part of an application's online help system that provides users with information about functionality, usage, background etc., in various levels of detail from short tool tips to full text browsing help windows. QWhatsThis provides a single window with an explanatory text that pops up when the user asks "What's this?". The default way to do this is to focus the relevant widget and press Shift+F1. The help text appears immediately; it goes away as soon as the user does something else. (Note that if there is an accelerator for Shift+F1, this mechanism will not work.) To add "What's this?" text to a widget you simply call QWhatsThis::add() for the widget. For example, to assign text to a menu item, call QMenuData::setWhatsThis(); for a global accelerator key, call QAccel::setWhatsThis() and If you're using actions, use QAction::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 possible to embed images. See QStyleSheet::defaultSheet() for details. \quotefile action/application.cpp \skipto fileOpenText \printuntil setWhatsThis An alternative way to enter "What's this?" mode is to use the ready-made tool bar tool button from QWhatsThis::whatsThisButton(). By invoking this context help button (in the picture below the first one from the right) the user switches into "What's this?" mode. If they now click on a widget the appropriate help text is shown. The mode is left when help is given or when the user presses Esc. \img whatsthis.png If you are using QMainWindow you can also use the QMainWindow::whatsThis() slot to invoke the mode from a menu item. 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 help texts, depending on the position of the mouse click. By reimplementing QWhatsThis::clicked() it is possible to have hyperlinks inside the help texts. If you wish to control the "What's this?" behavior of a widget manually see QWidget::customWhatsThis(). The What's This object can be removed using QWhatsThis::remove(), although this is rarely necessary because it is automatically removed when the widget is destroyed. \sa QToolTip */ // a special button class QWhatsThisButton: public QToolButton { Q_OBJECT public: QWhatsThisButton( QWidget * parent, const char * name ); ~QWhatsThisButton(); public slots: void mouseReleased(); }; class QWhatsThat : public QWidget { Q_OBJECT public: QWhatsThat( QWidget* w, const QString& txt, QWidget* parent, const char* name ); ~QWhatsThat() ; public slots: void hide(); inline void widgetDestroyed() { widget = 0; } protected: void mousePressEvent( QMouseEvent* ); void mouseReleaseEvent( QMouseEvent* ); void mouseMoveEvent( QMouseEvent* ); void keyPressEvent( QKeyEvent* ); void paintEvent( QPaintEvent* ); private: QString text; #ifndef QT_NO_RICHTEXT QSimpleRichText* doc; #endif QString anchor; bool pressed; QWidget* widget; }; class QWhatsThisPrivate: public QObject { Q_OBJECT public: // an item for storing texts struct WhatsThisItem: public QShared { WhatsThisItem(): QShared() { whatsthis = 0; } ~WhatsThisItem(); QString s; QWhatsThis* whatsthis; }; // the (these days pretty small) state machine enum State { Inactive, Waiting }; QWhatsThisPrivate(); ~QWhatsThisPrivate(); bool eventFilter( QObject *, QEvent * ); WhatsThisItem* newItem( QWidget * widget ); void add( QWidget * widget, QWhatsThis* special ); void add( QWidget * widget, const QString& text ); // say it. void say( QWidget *, const QString&, const QPoint& ); // setup and teardown static void setUpWhatsThis(); void enterWhatsThisMode(); void leaveWhatsThisMode(); // variables QWhatsThat * whatsThat; QPtrDict * dict; QPtrDict * tlw; QPtrDict * buttons; State state; private slots: void cleanupWidget() { const QObject* o = sender(); if ( o->isWidgetType() ) // sanity QWhatsThis::remove((QWidget*)o); } }; // static, but static the less-typing way static QWhatsThisPrivate * wt = 0; // shadowWidth not const, for XP drop-shadow-fu turns it to 0 static int shadowWidth = 6; // also used as '5' and '6' and even '8' below const int vMargin = 8; const int hMargin = 12; // Lets QPopupMenu destroy the QWhatsThat. void qWhatsThisBDH() { if ( wt && wt->whatsThat ) wt->whatsThat->hide(); } QWhatsThat::QWhatsThat( QWidget* w, const QString& txt, QWidget* parent, const char* name ) : QWidget( parent, name, WType_Popup ), text( txt ), pressed( FALSE ), widget( w ) { setBackgroundMode( NoBackground ); setPalette( QToolTip::palette() ); setMouseTracking( TRUE ); #ifndef QT_NO_CURSOR setCursor( arrowCursor ); #endif if ( widget ) connect( widget, SIGNAL( destroyed() ), this, SLOT( widgetDestroyed() ) ); QRect r; #ifndef QT_NO_RICHTEXT doc = 0; if ( QStyleSheet::mightBeRichText( text ) ) { QFont f = QApplication::font( this ); doc = new QSimpleRichText( text, f ); doc->adjustSize(); r.setRect( 0, 0, doc->width(), doc->height() ); } else #endif { int sw = QApplication::desktop()->width() / 3; if ( sw < 200 ) sw = 200; else if ( sw > 300 ) sw = 300; r = fontMetrics().boundingRect( 0, 0, sw, 1000, AlignAuto + AlignTop + WordBreak + ExpandTabs, text ); } #if defined(Q_WS_WIN) if ( (qWinVersion()&WV_NT_based) > WV_2000 ) { BOOL shadow; SystemParametersInfo( SPI_GETDROPSHADOW, 0, &shadow, 0 ); shadowWidth = shadow ? 0 : 6; } #endif resize( r.width() + 2*hMargin + shadowWidth, r.height() + 2*vMargin + shadowWidth ); } QWhatsThat::~QWhatsThat() { if ( wt && wt->whatsThat == this ) wt->whatsThat = 0; #ifndef QT_NO_RICHTEXT if ( doc ) delete doc; #endif } void QWhatsThat::hide() { QWidget::hide(); #if defined(QT_ACCESSIBILITY_SUPPORT) QAccessible::updateAccessibility( this, 0, QAccessible::ContextHelpEnd ); #endif } void QWhatsThat::mousePressEvent( QMouseEvent* e ) { pressed = TRUE; if ( e->button() == LeftButton && rect().contains( e->pos() ) ) { #ifndef QT_NO_RICHTEXT if ( doc ) anchor = doc->anchorAt( e->pos() - QPoint( hMargin, vMargin) ); #endif return; } hide(); } void QWhatsThat::mouseReleaseEvent( QMouseEvent* e ) { if ( !pressed ) return; #ifndef QT_NO_RICHTEXT if ( e->button() == LeftButton && doc && rect().contains( e->pos() ) ) { QString a = doc->anchorAt( e->pos() - QPoint( hMargin, vMargin ) ); QString href; if ( anchor == a ) href = a; anchor = QString::null; if ( widget && wt && wt->dict ) { QWhatsThisPrivate::WhatsThisItem * i = wt->dict->find( widget ); if ( i && i->whatsthis && !i->whatsthis->clicked( href ) ) return; } } #endif hide(); } void QWhatsThat::mouseMoveEvent( QMouseEvent* e) { #ifndef QT_NO_RICHTEXT #ifndef QT_NO_CURSOR if ( !doc ) return; QString a = doc->anchorAt( e->pos() - QPoint( hMargin, vMargin ) ); if ( !a.isEmpty() ) setCursor( pointingHandCursor ); else setCursor( arrowCursor ); #endif #endif } void QWhatsThat::keyPressEvent( QKeyEvent* ) { hide(); } void QWhatsThat::paintEvent( QPaintEvent* ) { bool drawShadow = TRUE; #if defined(Q_WS_WIN) if ( (qWinVersion()&WV_NT_based) > WV_2000 ) { BOOL shadow; SystemParametersInfo( SPI_GETDROPSHADOW, 0, &shadow, 0 ); drawShadow = !shadow; } #elif defined(Q_WS_MACX) drawShadow = FALSE; //never draw it on OS X we get it for free #endif QRect r = rect(); if ( drawShadow ) r.addCoords( 0, 0, -shadowWidth, -shadowWidth ); QPainter p( this); p.setPen( colorGroup().foreground() ); p.drawRect( r ); p.setPen( colorGroup().mid() ); p.setBrush( colorGroup().brush( QColorGroup::Background ) ); int w = r.width(); int h = r.height(); p.drawRect( 1, 1, w-2, h-2 ); if ( drawShadow ) { p.setPen( colorGroup().shadow() ); p.drawPoint( w + 5, 6 ); p.drawLine( w + 3, 6, w + 5, 8 ); p.drawLine( w + 1, 6, w + 5, 10 ); int i; for( i=7; i < h; i += 2 ) p.drawLine( w, i, w + 5, i + 5 ); for( i = w - i + h; i > 6; i -= 2 ) p.drawLine( i, h, i + 5, h + 5 ); for( ; i > 0 ; i -= 2 ) p.drawLine( 6, h + 6 - i, i + 5, h + 5 ); } p.setPen( colorGroup().foreground() ); r.addCoords( hMargin, vMargin, -hMargin, -vMargin ); #ifndef QT_NO_RICHTEXT if ( doc ) { doc->draw( &p, r.x(), r.y(), r, colorGroup(), 0 ); } else #endif { p.drawText( r, AlignAuto + AlignTop + WordBreak + ExpandTabs, text ); } } // the item QWhatsThisPrivate::WhatsThisItem::~WhatsThisItem() { if ( count ) qFatal( "QWhatsThis: Internal error (%d)", count ); delete whatsthis; } static const char * const button_image[] = { "16 16 3 1", " c None", "o c #000000", "a c #000080", "o aaaaa ", "oo aaa aaa ", "ooo aaa aaa", "oooo aa aa", "ooooo aa aa", "oooooo a aaa", "ooooooo aaa ", "oooooooo aaa ", "ooooooooo aaa ", "ooooo aaa ", "oo ooo ", "o ooo aaa ", " ooo aaa ", " ooo ", " ooo ", " ooo "}; // the button class QWhatsThisButton::QWhatsThisButton( QWidget * parent, const char * name ) : QToolButton( parent, name ) { QPixmap p( (const char**)button_image ); setPixmap( p ); setToggleButton( TRUE ); setAutoRaise( TRUE ); setFocusPolicy( NoFocus ); setTextLabel( tr( "What's this?" ) ); wt->buttons->insert( (void *)this, this ); connect( this, SIGNAL( released() ), this, SLOT( mouseReleased() ) ); } QWhatsThisButton::~QWhatsThisButton() { if ( wt && wt->buttons ) wt->buttons->take( (void *)this ); } void QWhatsThisButton::mouseReleased() { if ( wt->state == QWhatsThisPrivate::Inactive && isOn() ) { QWhatsThisPrivate::setUpWhatsThis(); #ifndef QT_NO_CURSOR QApplication::setOverrideCursor( whatsThisCursor, FALSE ); #endif wt->state = QWhatsThisPrivate::Waiting; qApp->installEventFilter( wt ); } } static void qWhatsThisPrivateCleanup() { if( wt ) { delete wt; wt = 0; } } // the what's this manager class QWhatsThisPrivate::QWhatsThisPrivate() : QObject( 0, "global what's this object" ) { whatsThat = 0; dict = new QPtrDict; tlw = new QPtrDict; wt = this; buttons = new QPtrDict; state = Inactive; } QWhatsThisPrivate::~QWhatsThisPrivate() { #ifndef QT_NO_CURSOR if ( state == Waiting && qApp ) QApplication::restoreOverrideCursor(); #endif // the two straight-and-simple dicts delete tlw; delete buttons; // then delete the complex one. QPtrDictIterator it( *dict ); WhatsThisItem * i; QWidget * w; while( (i=it.current()) != 0 ) { w = (QWidget *)it.currentKey(); ++it; dict->take( w ); if ( i->deref() ) delete i; } delete dict; if ( whatsThat && !whatsThat->parentWidget() ) { delete whatsThat; } // and finally lose wt wt = 0; } bool QWhatsThisPrivate::eventFilter( QObject * o, QEvent * e ) { switch( state ) { case Waiting: if ( e->type() == QEvent::MouseButtonPress && o->isWidgetType() ) { QWidget * w = (QWidget *) o; if ( ( (QMouseEvent*)e)->button() == RightButton ) return FALSE; // ignore RMB if ( w->customWhatsThis() ) return FALSE; QWhatsThisPrivate::WhatsThisItem * i = 0; QMouseEvent* me = (QMouseEvent*) e; QPoint p = me->pos(); while( w && !i ) { i = dict->find( w ); if ( !i ) { p += w->pos(); w = w->parentWidget( TRUE ); } } leaveWhatsThisMode(); if (!i ) { #if defined(QT_ACCESSIBILITY_SUPPORT) QAccessible::updateAccessibility( this, 0, QAccessible::ContextHelpEnd ); #endif return TRUE; } if ( i->whatsthis ) say( w, i->whatsthis->text( p ), me->globalPos() ); else say( w, i->s, me->globalPos() ); return TRUE; } else if ( e->type() == QEvent::MouseButtonRelease ) { if ( ( (QMouseEvent*)e)->button() == RightButton ) return FALSE; // ignore RMB return !o->isWidgetType() || !((QWidget*)o)->customWhatsThis(); } else if ( e->type() == QEvent::MouseMove ) { return !o->isWidgetType() || !((QWidget*)o)->customWhatsThis(); } else if ( e->type() == QEvent::KeyPress ) { QKeyEvent* kev = (QKeyEvent*)e; if ( kev->key() == Qt::Key_Escape ) { leaveWhatsThisMode(); return TRUE; } else if ( o->isWidgetType() && ((QWidget*)o)->customWhatsThis() ) { return FALSE; } else if ( kev->key() == Key_Menu || ( kev->key() == Key_F10 && kev->state() == ShiftButton ) ) { // we don't react to these keys, they are used for context menus return FALSE; } else if ( kev->state() == kev->stateAfter() && kev->key() != Key_Meta ) { // not a modifier key leaveWhatsThisMode(); } } else if ( e->type() == QEvent::MouseButtonDblClick ) { return TRUE; } break; case Inactive: if ( e->type() == QEvent::Accel && ((QKeyEvent *)e)->key() == Key_F1 && o->isWidgetType() && ((QKeyEvent *)e)->state() == ShiftButton ) { QWidget * w = ((QWidget *)o)->focusWidget(); if ( !w ) break; QString s = QWhatsThis::textFor( w, QPoint(0,0), TRUE ); if ( !s.isNull() ) { say ( w, s, w->mapToGlobal( w->rect().center() ) ); ((QKeyEvent *)e)->accept(); return TRUE; } } break; } return FALSE; } void QWhatsThisPrivate::setUpWhatsThis() { if ( !wt ) { wt = new QWhatsThisPrivate(); // It is necessary to use a post routine, because // the destructor deletes pixmaps and other stuff that // needs a working X connection under X11. qAddPostRoutine( qWhatsThisPrivateCleanup ); } } void QWhatsThisPrivate::enterWhatsThisMode() { #if defined(QT_ACCESSIBILITY_SUPPORT) QAccessible::updateAccessibility( this, 0, QAccessible::ContextHelpStart ); #endif } void QWhatsThisPrivate::leaveWhatsThisMode() { if ( state == Waiting ) { QPtrDictIterator it( *(wt->buttons) ); QWhatsThisButton * b; while( (b=it.current()) != 0 ) { ++it; b->setOn( FALSE ); } #ifndef QT_NO_CURSOR QApplication::restoreOverrideCursor(); #endif state = Inactive; qApp->removeEventFilter( this ); } } void QWhatsThisPrivate::say( QWidget * widget, const QString &text, const QPoint& ppos) { if ( text.isEmpty() ) return; // make a fresh widget, and set it up delete whatsThat; whatsThat = new QWhatsThat( widget, text, #if defined(Q_WS_X11) QApplication::desktop()->screen( widget ? widget->x11Screen() : QCursor::x11Screen() ), #else 0, #endif "automatic what's this? widget" ); // okay, now to find a suitable location int scr = ( widget ? QApplication::desktop()->screenNumber( widget ) : #if defined(Q_WS_X11) QCursor::x11Screen() #else QApplication::desktop()->screenNumber( ppos ) #endif // Q_WS_X11 ); QRect screen = QApplication::desktop()->screenGeometry( scr ); int x; int w = whatsThat->width(); int h = whatsThat->height(); int sx = screen.x(); int sy = screen.y(); // first try locating the widget immediately above/below, // with nice alignment if possible. QPoint pos; if ( widget ) pos = widget->mapToGlobal( QPoint( 0,0 ) ); if ( widget && w > widget->width() + 16 ) x = pos.x() + widget->width()/2 - w/2; else x = ppos.x() - w/2; // squeeze it in if that would result in part of what's this // being only partially visible if ( x + w + shadowWidth > sx+screen.width() ) x = (widget? (QMIN(screen.width(), pos.x() + widget->width()) ) : screen.width() ) - w; if ( x < sx ) x = sx; int y; if ( widget && h > widget->height() + 16 ) { y = pos.y() + widget->height() + 2; // below, two pixels spacing // what's this is above or below, wherever there's most space if ( y + h + 10 > sy+screen.height() ) y = pos.y() + 2 - shadowWidth - h; // above, overlap } y = ppos.y() + 2; // squeeze it in if that would result in part of what's this // being only partially visible if ( y + h + shadowWidth > sy+screen.height() ) y = ( widget ? (QMIN(screen.height(), pos.y() + widget->height()) ) : screen.height() ) - h; if ( y < sy ) y = sy; whatsThat->move( x, y ); whatsThat->show(); } QWhatsThisPrivate::WhatsThisItem* QWhatsThisPrivate::newItem( QWidget * widget ) { WhatsThisItem * i = dict->find( (void *)widget ); if ( i ) QWhatsThis::remove( widget ); i = new WhatsThisItem; dict->insert( (void *)widget, i ); QWidget * t = widget->topLevelWidget(); if ( !tlw->find( (void *)t ) ) { tlw->insert( (void *)t, t ); t->installEventFilter( this ); } connect( widget, SIGNAL(destroyed()), this, SLOT(cleanupWidget()) ); return i; } void QWhatsThisPrivate::add( QWidget * widget, QWhatsThis* special ) { newItem( widget )->whatsthis = special; } void QWhatsThisPrivate::add( QWidget * widget, const QString &text ) { newItem( widget )->s = text; } // and finally the What's This class itself /*! Adds \a text as "What's this" help for \a widget. If the text is rich text formatted (i.e. it contains markup) it will be rendered with the default stylesheet QStyleSheet::defaultSheet(). The text is destroyed if the widget is later destroyed, so it need not be explicitly removed. \sa remove() */ void QWhatsThis::add( QWidget * widget, const QString &text ) { if ( text.isEmpty() ) return; // pointless QWhatsThisPrivate::setUpWhatsThis(); wt->add(widget,text); } /*! Removes the "What's this?" help associated with the \a widget. This happens automatically if the widget is destroyed. \sa add() */ void QWhatsThis::remove( QWidget * widget ) { QWhatsThisPrivate::setUpWhatsThis(); QWhatsThisPrivate::WhatsThisItem * i = wt->dict->find( (void *)widget ); if ( !i ) return; wt->dict->take( (void *)widget ); i->deref(); if ( !i->count ) delete i; } /*! Returns the what's this text for widget \a w or QString::null if there is no "What's this?" help for the widget. \a pos contains the mouse position; this is useful, for example, if you've subclassed to make the text that is displayed position dependent. If \a includeParents is TRUE, parent widgets are taken into consideration as well when looking for what's this help text. \sa add() */ QString QWhatsThis::textFor( QWidget * w, const QPoint& pos, bool includeParents ) { QWhatsThisPrivate::setUpWhatsThis(); QWhatsThisPrivate::WhatsThisItem * i = 0; QPoint p = pos; while( w && !i ) { i = wt->dict->find( w ); if ( !includeParents ) break; if ( !i ) { p += w->pos(); w = w->parentWidget( TRUE ); } } if (!i) return QString::null; if ( i->whatsthis ) return i->whatsthis->text( p ); return i->s; } /*! Creates a QToolButton preconfigured to enter "What's this?" mode when clicked. You will often use this with a tool bar as \a parent: \code (void) QWhatsThis::whatsThisButton( my_help_tool_bar ); \endcode */ QToolButton * QWhatsThis::whatsThisButton( QWidget * parent ) { QWhatsThisPrivate::setUpWhatsThis(); return new QWhatsThisButton( parent, "automatic what's this? button" ); } /*! Constructs a dynamic "What's this?" object for \a widget. The object is deleted when the \a widget is destroyed. 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 the text assigned by add(). */ QWhatsThis::QWhatsThis( QWidget * widget) { QWhatsThisPrivate::setUpWhatsThis(); wt->add(widget,this); } /*! Destroys the object and frees any allocated resources. */ QWhatsThis::~QWhatsThis() { } /*! This virtual function returns the text for position \e p in the widget that this "What's this?" object documents. If there is no "What's this?" text for the position, QString::null is returned. The default implementation returns QString::null. */ QString QWhatsThis::text( const QPoint & ) { return QString::null; } /*! \fn bool QWhatsThis::clicked( const QString& href ) This virtual function is called when the user clicks inside the "What's this?" window. \a href is the link the user clicked on, or QString::null if there was no link. If the function returns TRUE (the default), the "What's this?" window is closed, otherwise it remains visible. The default implementation ignores \a href and returns TRUE. */ bool QWhatsThis::clicked( const QString& ) { return TRUE; } /*! Enters "What's this?" mode and returns immediately. Qt will install a special cursor and take over mouse input until the user clicks somewhere. It then shows any help available and ends "What's this?" mode. Finally, Qt removes the special cursor and help window and then restores ordinary event processing, at which point the left mouse button is no longer pressed. The user can also use the Esc key to leave "What's this?" mode. \sa inWhatsThisMode(), leaveWhatsThisMode() */ void QWhatsThis::enterWhatsThisMode() { QWhatsThisPrivate::setUpWhatsThis(); if ( wt->state == QWhatsThisPrivate::Inactive ) { wt->enterWhatsThisMode(); #ifndef QT_NO_CURSOR QApplication::setOverrideCursor( whatsThisCursor, FALSE ); #endif wt->state = QWhatsThisPrivate::Waiting; qApp->installEventFilter( wt ); } } /*! Returns TRUE if the application is in "What's this?" mode; otherwise returns FALSE. \sa enterWhatsThisMode(), leaveWhatsThisMode() */ bool QWhatsThis::inWhatsThisMode() { if (!wt) return FALSE; return wt->state == QWhatsThisPrivate::Waiting; } /*! 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 of such a widget is QPopupMenu: menus still work normally in "What's this?" mode but also provide help texts for individual menu items. If \a text is not QString::null, a "What's this?" help window is displayed at the global screen position \a pos. If widget \a w is not 0 and has its own dedicated QWhatsThis object, this object will receive clicked() messages when the user clicks on hyperlinks inside the help text. \sa inWhatsThisMode(), enterWhatsThisMode(), QWhatsThis::clicked() */ void QWhatsThis::leaveWhatsThisMode( const QString& text, const QPoint& pos, QWidget* w ) { if ( !inWhatsThisMode() ) return; wt->leaveWhatsThisMode(); if ( !text.isNull() ) wt->say( w, text, pos ); } /*! Display \a text in a help window at the global screen position \a pos. If widget \a w is not 0 and has its own dedicated QWhatsThis object, this object will receive clicked() messages when the user clicks on hyperlinks inside the help text. \sa QWhatsThis::clicked() */ void QWhatsThis::display( const QString& text, const QPoint& pos, QWidget* w ) { if ( inWhatsThisMode() ) { leaveWhatsThisMode( text, pos, w ); return; } QWhatsThisPrivate::setUpWhatsThis(); wt->say( w, text, pos ); } /*! Sets the font for all "What's this?" helps to \a font. */ void QWhatsThis::setFont( const QFont &font ) { QApplication::setFont( font, TRUE, "QWhatsThat" ); } #include "qwhatsthis.moc" #endif