The legend widget. More...

#include <qwt_legend.h>

Collaboration diagram for QwtLegend:

Classes
class	PrivateData
Public Types
enum	LegendDisplayPolicy { NoIdentifier = 0, FixedIdentifier = 1, AutoIdentifier = 2 }
	Display policy. More...
enum	LegendItemMode { ReadOnlyItem, ClickableItem, CheckableItem }
	Interaction mode for the legend items. More...
Public Member Functions
	QwtLegend (QWidget *parent=NULL)
virtual	~QwtLegend ()
	Destructor.
void	setDisplayPolicy (LegendDisplayPolicy policy, int mode)
LegendDisplayPolicy	displayPolicy () const
void	setItemMode (LegendItemMode)
LegendItemMode	itemMode () const
int	identifierMode () const
QWidget *	contentsWidget ()
const QWidget *	contentsWidget () const
void	insert (const QwtLegendItemManager , QWidget )
void	remove (const QwtLegendItemManager *)
QWidget *	find (const QwtLegendItemManager *) const
QwtLegendItemManager *	find (const QWidget *) const
virtual QValueList< QWidget * >	legendItems () const
	Return a list of all legend items.
void	clear ()
	Remove all items.
bool	isEmpty () const
	Return true, if there are no legend items.
uint	itemCount () const
	Return the number of legend items.
virtual bool	eventFilter (QObject , QEvent )
virtual QSize	sizeHint () const
	Return a size hint.
virtual int	heightForWidth (int w) const
QScrollBar *	horizontalScrollBar () const
QScrollBar *	verticalScrollBar () const
Protected Member Functions
virtual void	resizeEvent (QResizeEvent *)
virtual void	layoutContents ()

Detailed Description

The legend widget.

The QwtLegend widget is a tabular arrangement of legend items. Legend items might be any type of widget, but in general they will be a QwtLegendItem.

See also:: QwtLegendItem, QwtLegendItemManager QwtPlot

Definition at line 36 of file qwt_legend.h.

Member Enumeration Documentation

enum QwtLegend::LegendDisplayPolicy

Display policy.

NoIdentifier
The client code is responsible how to display of each legend item. The Qwt library will not interfere.

FixedIdentifier
All legend items are displayed with the QwtLegendItem::IdentifierMode to be passed in 'mode'.

AutoIdentifier
Each legend item is displayed with a mode that is a bitwise or of
- QwtLegendItem::ShowLine (if its curve is drawn with a line) and
- QwtLegendItem::ShowSymbol (if its curve is drawn with symbols) and
- QwtLegendItem::ShowText (if the has a title).

Default is AutoIdentifier.

See also:: setDisplayPolicy(), displayPolicy(), QwtLegendItem::IdentifierMode

Enumerator:

NoIdentifier
FixedIdentifier
AutoIdentifier

Definition at line 62 of file qwt_legend.h.

    {
        NoIdentifier = 0,
        FixedIdentifier = 1,
        AutoIdentifier = 2
    };

enum QwtLegend::LegendItemMode

Interaction mode for the legend items.

ReadOnlyItem
The legend item is not interactive, like a label

ClickableItem
The legend item is clickable, like a push button

CheckableItem
The legend item is checkable, like a checkable button

Default is ReadOnlyItem.

See also:: setItemMode(), itemMode(), QwtLegendItem::IdentifierMode QwtLegendItem::clicked(), QwtLegendItem::checked(), QwtPlot::legendClicked(), QwtPlot::legendChecked()

Enumerator:

ReadOnlyItem
ClickableItem
CheckableItem

Definition at line 87 of file qwt_legend.h.

    {
        ReadOnlyItem,
        ClickableItem,
        CheckableItem
    };

Constructor & Destructor Documentation

QwtLegend::QwtLegend ( QWidget * parent = NULL ) [explicit]

Constructor

Parameters:

parent Parent widget

Definition at line 260 of file qwt_legend.cpp.

References AutoIdentifier, QwtLegend::PrivateData::displayPolicy, QwtLegend::PrivateData::identifierMode, QwtLegend::PrivateData::itemMode, ReadOnlyItem, QwtLegendItem::ShowLine, QwtLegendItem::ShowSymbol, QwtLegendItem::ShowText, and QwtLegend::PrivateData::view.

                                   : 
    QFrame(parent)
{
    setFrameStyle(NoFrame);

    d_data = new QwtLegend::PrivateData;
    d_data->itemMode = QwtLegend::ReadOnlyItem;
    d_data->displayPolicy = QwtLegend::AutoIdentifier;
    d_data->identifierMode = QwtLegendItem::ShowLine | 
        QwtLegendItem::ShowSymbol | QwtLegendItem::ShowText;

    d_data->view = new QwtLegend::PrivateData::LegendView(this);
    d_data->view->setFrameStyle(NoFrame);

    QwtDynGridLayout *layout = new QwtDynGridLayout(
        d_data->view->contentsWidget);
#if QT_VERSION < 0x040000
    layout->setAutoAdd(true);
#endif
    layout->setAlignment(Qt::AlignHCenter | Qt::AlignTop);

    d_data->view->contentsWidget->installEventFilter(this);
}

QwtLegend::~QwtLegend ( ) [virtual]

Destructor.

Definition at line 285 of file qwt_legend.cpp.

{
    delete d_data;
}

Member Function Documentation

void QwtLegend::clear ( )

Remove all items.

Definition at line 500 of file qwt_legend.cpp.

References QwtLegend::PrivateData::map.

{
#if QT_VERSION < 0x040000
    bool doUpdate = isUpdatesEnabled();
#else
    bool doUpdate = updatesEnabled();
#endif
    setUpdatesEnabled(false);

    d_data->map.clear();

    setUpdatesEnabled(doUpdate);
    update();
}

QWidget * QwtLegend::contentsWidget ( )

The contents widget is the only child of the viewport() and the parent widget of all legend items.

Definition at line 358 of file qwt_legend.cpp.

References QwtLegend::PrivateData::view.

Referenced by insert(), and QwtPlot::printLegend().

{ 
    return d_data->view->contentsWidget; 
}

const QWidget * QwtLegend::contentsWidget ( ) const

The contents widget is the only child of the viewport() and the parent widget of all legend items.

Definition at line 385 of file qwt_legend.cpp.

References QwtLegend::PrivateData::view.

{ 
    return d_data->view->contentsWidget; 
}

QwtLegend::LegendDisplayPolicy QwtLegend::displayPolicy ( ) const

Returns:: the legend display policy. Default is LegendDisplayPolicy::Auto.

See also:: setDisplayPolicy(), LegendDisplayPolicy

Definition at line 326 of file qwt_legend.cpp.

References QwtLegend::PrivateData::displayPolicy.

Referenced by QwtPlotCurve::updateLegend().

{ 
    return d_data->displayPolicy; 
}

bool QwtLegend::eventFilter	(	QObject *	o,
		QEvent *	e
	)		`[virtual]`

Filter layout related events of QwtLegend::contentsWidget().

Parameters:

o	Object to be filtered
e	Event

Definition at line 587 of file qwt_legend.cpp.

References layoutContents(), QwtLegend::PrivateData::map, and QwtLegend::PrivateData::view.

{
    if ( o == d_data->view->contentsWidget )
    {
        switch(e->type())
        {
            case QEvent::ChildRemoved:
            {   
                const QChildEvent *ce = (const QChildEvent *)e;
                if ( ce->child()->isWidgetType() )
                    d_data->map.remove((QWidget *)ce->child());
                break;
            }
#if QT_VERSION < 0x040000
            case QEvent::LayoutHint:
#else
            case QEvent::LayoutRequest:
#endif
            {
                layoutContents();
                break;
            }
#if QT_VERSION < 0x040000
            case QEvent::Resize:
            {
                updateGeometry();
                break;
            }
#endif
            default:
                break;
        }
    }
    
    return QFrame::eventFilter(o, e);
}

QWidget * QwtLegend::find ( const QwtLegendItemManager * plotItem ) const

Find the widget that represents a plot item

Parameters:

plotItem Plot item

Returns:: Widget on the legend, or NULL

Definition at line 470 of file qwt_legend.cpp.

References QwtLegend::PrivateData::map.

Referenced by QwtPlotItem::attach(), QwtPlotPrintFilter::reset(), QwtPlotItem::updateLegend(), and QwtPlotCurve::updateLegend().

{
    return d_data->map.find(plotItem);
}

QwtLegendItemManager * QwtLegend::find ( const QWidget * legendItem ) const

Find the widget that represents a plot item

Parameters:

legendItem Legend item

Returns:: Widget on the legend, or NULL

Definition at line 481 of file qwt_legend.cpp.

References QwtLegend::PrivateData::map.

{
    return d_data->map.find(legendItem);
}

int QwtLegend::heightForWidth ( int width ) const [virtual]

Returns:: The preferred height, for the width w.

Parameters:

width Width

Definition at line 528 of file qwt_legend.cpp.

References QwtLegend::PrivateData::view.

Referenced by QwtPlotLayout::LayoutData::init(), and QwtPlotLayout::minimumSizeHint().

{
    width -= 2 * frameWidth();

    int h = d_data->view->contentsWidget->heightForWidth(width);
#if QT_VERSION < 0x040000

    // Asking the layout is the default implementation in Qt4 

    if ( h <= 0 ) 
    {
        QLayout *l = d_data->view->contentsWidget->layout();
        if ( l && l->hasHeightForWidth() )
            h = l->heightForWidth(width);
    }
#endif
    if ( h >= 0 )
        h += 2 * frameWidth();

    return h;
}

QScrollBar * QwtLegend::horizontalScrollBar ( ) const

Returns:: Horizontal scrollbar

See also:: verticalScrollBar()

Definition at line 367 of file qwt_legend.cpp.

References QwtLegend::PrivateData::view.

Referenced by QwtPlotLayout::LayoutData::init().

{
    return d_data->view->horizontalScrollBar();
}

int QwtLegend::identifierMode ( ) const

Returns:: the IdentifierMode to be used in combination with LegendDisplayPolicy::Fixed.

Default is ShowLine | ShowSymbol | ShowText.

Definition at line 349 of file qwt_legend.cpp.

References QwtLegend::PrivateData::identifierMode.

Referenced by QwtPlotCurve::updateLegend().

{
    return d_data->identifierMode;
}

void QwtLegend::insert	(	const QwtLegendItemManager *	plotItem,
		QWidget *	legendItem
	)

Insert a new item for a plot item

Parameters:

plotItem	Plot item
legendItem	New legend item

Note:: The parent of item will be changed to QwtLegend::contentsWidget()

Definition at line 396 of file qwt_legend.cpp.

References contentsWidget(), layoutContents(), QwtLegend::PrivateData::map, and QwtLegend::PrivateData::view.

Referenced by QwtPlotItem::updateLegend().

{
    if ( legendItem == NULL || plotItem == NULL )
        return;

    QWidget *contentsWidget = d_data->view->contentsWidget;

    if ( legendItem->parent() != contentsWidget )
    {
#if QT_VERSION >= 0x040000
        legendItem->setParent(contentsWidget);
#else
        legendItem->reparent(contentsWidget, QPoint(0, 0));
#endif
    }

    legendItem->show();

    d_data->map.insert(plotItem, legendItem);

    layoutContents();

    if ( contentsWidget->layout() )
    {
#if QT_VERSION >= 0x040000
        contentsWidget->layout()->addWidget(legendItem);
#endif

        // set tab focus chain

        QWidget *w = NULL;

#if QT_VERSION < 0x040000
        QLayoutIterator layoutIterator = 
            contentsWidget->layout()->iterator();
        for ( QLayoutItem *item = layoutIterator.current();
            item != 0; item = ++layoutIterator)
        {
#else
        for (int i = 0; i < contentsWidget->layout()->count(); i++)
        {
            QLayoutItem *item = contentsWidget->layout()->itemAt(i);
#endif
            if ( w && item->widget() )
            {
                QWidget::setTabOrder(w, item->widget());
                w = item->widget();
            }
        }
    }
    if ( parentWidget() && parentWidget()->layout() == NULL )
    {
       /*
          updateGeometry() doesn't post LayoutRequest in certain
          situations, like when we are hidden. But we want the
          parent widget notified, so it can show/hide the legend
          depending on its items.
        */
#if QT_VERSION < 0x040000
        QApplication::postEvent(parentWidget(),
            new QEvent(QEvent::LayoutHint));
#else
        QApplication::postEvent(parentWidget(),
            new QEvent(QEvent::LayoutRequest));
#endif
    }
}

bool QwtLegend::isEmpty ( ) const

Return true, if there are no legend items.

Definition at line 626 of file qwt_legend.cpp.

References QwtLegend::PrivateData::map.

Referenced by QwtPlotLayout::activate(), QwtPlotLayout::minimumSizeHint(), and QwtPlot::print().

{
    return d_data->map.count() == 0;
}

uint QwtLegend::itemCount ( ) const

Return the number of legend items.

Definition at line 632 of file qwt_legend.cpp.

References QwtLegend::PrivateData::map.

{
    return d_data->map.count();
}

QwtLegend::LegendItemMode QwtLegend::itemMode ( ) const

See also:: LegendItemMode

Definition at line 338 of file qwt_legend.cpp.

References QwtLegend::PrivateData::itemMode.

Referenced by QwtPlotItem::updateLegend().

{
    return d_data->itemMode;
}

void QwtLegend::layoutContents ( ) [protected, virtual]

Adjust contents widget and item layout to the size of the viewport().

Definition at line 553 of file qwt_legend.cpp.

References QwtDynGridLayout::heightForWidth(), int(), QwtDynGridLayout::maxItemWidth(), qwtMax, and QwtLegend::PrivateData::view.

Referenced by eventFilter(), and insert().

{
    const QSize visibleSize = d_data->view->viewport()->size();

    const QLayout *l = d_data->view->contentsWidget->layout();
    if ( l && l->inherits("QwtDynGridLayout") )
    {
        const QwtDynGridLayout *tl = (const QwtDynGridLayout *)l;

        const int minW = int(tl->maxItemWidth()) + 2 * tl->margin();

        int w = qwtMax(visibleSize.width(), minW);
        int h = qwtMax(tl->heightForWidth(w), visibleSize.height());

        const int vpWidth = d_data->view->viewportSize(w, h).width();
        if ( w > vpWidth )
        {
            w = qwtMax(vpWidth, minW);
            h = qwtMax(tl->heightForWidth(w), visibleSize.height());
        }

        d_data->view->contentsWidget->resize(w, h);
#if QT_VERSION < 0x040000
        d_data->view->resizeContents(w, h);
#endif
    }
}

QValueList< QWidget * > QwtLegend::legendItems ( ) const [virtual]

Return a list of all legend items.

Definition at line 639 of file qwt_legend.cpp.

References QwtLegend::PrivateData::map.

Referenced by QwtPlotPrintFilter::apply(), and QwtPlotPrintFilter::reset().

{
    const QMap<QWidget *, const QwtLegendItemManager *> &map = 
        d_data->map.widgetMap();

#if QT_VERSION < 0x040000
    QValueList<QWidget *> list;
#else
    QList<QWidget *> list;
#endif

    QMap<QWidget *, const QwtLegendItemManager *>::const_iterator it;
    for ( it = map.begin(); it != map.end(); ++it ) 
        list += it.key();

    return list;
}

void QwtLegend::remove ( const QwtLegendItemManager * plotItem )

Find the corresponding item for a plotItem and remove it from the item list.

Parameters:

plotItem Plot item

Definition at line 492 of file qwt_legend.cpp.

References QwtLegend::PrivateData::map.

{ 
    QWidget *legendItem = d_data->map.find(plotItem);
    d_data->map.remove(legendItem); 
    delete legendItem;
}

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

Resize event

Parameters:

e	Resize event

Definition at line 664 of file qwt_legend.cpp.

References QwtLegend::PrivateData::view.

{
    QFrame::resizeEvent(e);
    d_data->view->setGeometry(contentsRect());
}

void QwtLegend::setDisplayPolicy	(	LegendDisplayPolicy	policy,
		int	mode
	)

Set the legend display policy to:

Parameters:

policy	Legend display policy
mode	Identifier mode (or'd ShowLine, ShowSymbol, ShowText)

See also:: displayPolicy(), LegendDisplayPolicy

Definition at line 298 of file qwt_legend.cpp.

References QwtLegend::PrivateData::displayPolicy, QwtLegend::PrivateData::identifierMode, QwtLegend::PrivateData::map, and QwtLegendItemManager::updateLegend().

{
    d_data->displayPolicy = policy;
    if (-1 != mode)
       d_data->identifierMode = mode;

    QMap<QWidget *, const QwtLegendItemManager *> &map = 
        d_data->map.widgetMap();

    QMap<QWidget *, const QwtLegendItemManager *>::iterator it;
    for ( it = map.begin(); it != map.end(); ++it ) 
    {
#if QT_VERSION < 0x040000
        QwtLegendItemManager *item = (QwtLegendItemManager *)it.data();
#else
        QwtLegendItemManager *item = (QwtLegendItemManager *)it.value();
#endif
        if ( item )
            item->updateLegend(this);
    }
}

void QwtLegend::setItemMode ( LegendItemMode mode )

See also:: LegendItemMode

Definition at line 332 of file qwt_legend.cpp.

References QwtLegend::PrivateData::itemMode.

{
    d_data->itemMode = mode;
}

QSize QwtLegend::sizeHint ( ) const [virtual]

Return a size hint.

Definition at line 516 of file qwt_legend.cpp.

References QwtLegend::PrivateData::view.

Referenced by QwtPlotLayout::LayoutData::init(), and QwtPlotLayout::minimumSizeHint().

{
    QSize hint = d_data->view->contentsWidget->sizeHint();
    hint += QSize(2 * frameWidth(), 2 * frameWidth());

    return hint;
}

QScrollBar * QwtLegend::verticalScrollBar ( ) const

Returns:: Vertical scrollbar

See also:: horizontalScrollBar()

Definition at line 376 of file qwt_legend.cpp.

References QwtLegend::PrivateData::view.

Referenced by QwtPlotLayout::LayoutData::init(), and QwtPlotLayout::minimumSizeHint().

{
    return d_data->view->verticalScrollBar();
}

The documentation for this class was generated from the following files:

QwtLegend Class Reference

Classes

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation