TDE
/
qt3
mirror of https://mirror.git.trinitydesktop.org/gitea/TDE/qt3
0
0
Fork 0
Code Issues Releases Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Branches Tags
${ item.name }
Create tag ${ searchTerm }
Create branch ${ searchTerm }
from 'master'
${ noResults }
qt3/src/widgets/qwhatsthis.cpp

1002 lines
26 KiB
Raw Permalink Blame History

/****************************************************************************
**
** 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<WhatsThisItem> * dict;
QPtrDict<QWidget> * tlw;
QPtrDict<QWhatsThisButton> * 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<QWhatsThisPrivate::WhatsThisItem>;
tlw = new QPtrDict<QWidget>;
wt = this;
buttons = new QPtrDict<QWhatsThisButton>;
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<WhatsThisItem> 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<QWhatsThisButton> 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
View Git Blame Copy Permalink