qwt_legend.cpp

QWT5.01用于Qt开发的二维图形库程序

/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2002   Uwe Rathmann
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *****************************************************************************/

// vim: expandtab

#include <qapplication.h> 
#include <qmap.h> 
#if QT_VERSION >= 0x040000
#include <qscrollbar.h> 
#endif
#include "qwt_math.h"
#include "qwt_dyngrid_layout.h"
#include "qwt_plot_item.h"
#include "qwt_legend_item.h"
#include "qwt_legend.h"

class QwtLegend::PrivateData
{
public:
    class LegendMap
    {
    public:
        void insert(const QwtPlotItem *, QWidget *);

        void remove(const QwtPlotItem *);
        void remove(QWidget *);

        void clear();

        uint count() const;

        inline const QWidget *find(const QwtPlotItem *) const;
        inline QWidget *find(const QwtPlotItem *);

        inline const QwtPlotItem *find(const QWidget *) const;
        inline QwtPlotItem *find(const QWidget *);

        const QMap<QWidget *, const QwtPlotItem *> &widgetMap() const;
        QMap<QWidget *, const QwtPlotItem *> &widgetMap();

    private:
        QMap<QWidget *, const QwtPlotItem *> d_widgetMap;
        QMap<const QwtPlotItem *, QWidget *> d_itemMap;
    };

    QwtLegend::LegendItemMode itemMode;
    QwtLegend::LegendDisplayPolicy displayPolicy;
    int identifierMode;

    LegendMap map;

    class LegendView;
    LegendView *view;
};

#if QT_VERSION < 0x040000
#include <qscrollview.h>

class QwtLegend::PrivateData::LegendView: public QScrollView
{
public:
    LegendView(QWidget *parent):
        QScrollView(parent)
    {
        setResizePolicy(Manual);

        viewport()->setBackgroundMode(Qt::NoBackground); // Avoid flicker

        contentsWidget = new QWidget(viewport());

        addChild(contentsWidget);
    }

    void viewportResizeEvent(QResizeEvent *e)
    {
        QScrollView::viewportResizeEvent(e);

        // It's not safe to update the layout now, because
        // we are in an internal update of the scrollview framework.
        // So we delay the update by posting a LayoutHint.

        QApplication::postEvent(contentsWidget, 
            new QEvent(QEvent::LayoutHint));
    }

    QWidget *contentsWidget;
};

#else // QT_VERSION >= 0x040000

#include <qscrollarea.h>

class QwtLegend::PrivateData::LegendView: public QScrollArea
{
public:
    LegendView(QWidget *parent):
        QScrollArea(parent)
    {
        contentsWidget = new QWidget(this);

        setWidget(contentsWidget);
        setWidgetResizable(false);
        setFocusPolicy(Qt::NoFocus);
    }

    virtual bool viewportEvent(QEvent *e) 
    {
        bool ok = QScrollArea::viewportEvent(e);

        if ( e->type() == QEvent::Resize )
        {
            QApplication::sendEvent(contentsWidget, 
                new QEvent(QEvent::LayoutRequest));
        }
        return ok;
    }

    QSize viewportSize(int w, int h) const
    {
        const int sbHeight = horizontalScrollBar()->sizeHint().height();
        const int sbWidth = verticalScrollBar()->sizeHint().width();
    
        const int cw = contentsRect().width();
        const int ch = contentsRect().height();

        int vw = cw;
        int vh = ch;

        if ( w > vw )
            vh -= sbHeight;

        if ( h > vh )
        {
            vw -= sbWidth;
            if ( w > vw && vh == ch )
                vh -= sbHeight;
        }
        return QSize(vw, vh);
    }

    QWidget *contentsWidget;
};

#endif


void QwtLegend::PrivateData::LegendMap::insert(
    const QwtPlotItem *item, QWidget *widget)
{
    d_itemMap.insert(item, widget);
    d_widgetMap.insert(widget, item);
}

void QwtLegend::PrivateData::LegendMap::remove(const QwtPlotItem *item)
{
    QWidget *widget = d_itemMap[item];
    d_itemMap.remove(item);
    d_widgetMap.remove(widget);
}

void QwtLegend::PrivateData::LegendMap::remove(QWidget *widget)
{
    const QwtPlotItem *item = d_widgetMap[widget];
    d_itemMap.remove(item);
    d_widgetMap.remove(widget);
}

void QwtLegend::PrivateData::LegendMap::clear()
{
    
    /*
       We can't delete the widgets in the following loop, because
       we would get ChildRemoved events, changing d_itemMap, while
       we are iterating.
     */

#if QT_VERSION < 0x040000
    QValueList<QWidget *> widgets;

    QMap<const QwtPlotItem *, QWidget *>::const_iterator it;
    for ( it = d_itemMap.begin(); it != d_itemMap.end(); ++it ) 
        widgets.append(it.data());
#else
    QList<QWidget *> widgets;

    QMap<const QwtPlotItem *, QWidget *>::const_iterator it;
    for ( it = d_itemMap.begin(); it != d_itemMap.end(); ++it ) 
        widgets.append(it.value());
#endif

    d_itemMap.clear();
    d_widgetMap.clear();

    for ( int i = 0; i < (int)widgets.size(); i++ )
        delete widgets[i];
}

uint QwtLegend::PrivateData::LegendMap::count() const
{
    return d_itemMap.count();
}

inline const QWidget *QwtLegend::PrivateData::LegendMap::find(const QwtPlotItem *item) const
{
    if ( !d_itemMap.contains((QwtPlotItem *)item) )
        return NULL;

    return d_itemMap[(QwtPlotItem *)item];
}

inline QWidget *QwtLegend::PrivateData::LegendMap::find(const QwtPlotItem *item)
{
    if ( !d_itemMap.contains((QwtPlotItem *)item) )
        return NULL;

    return d_itemMap[(QwtPlotItem *)item];
}

inline const QwtPlotItem *QwtLegend::PrivateData::LegendMap::find(
    const QWidget *widget) const
{
    if ( !d_widgetMap.contains((QWidget *)widget) )
        return NULL;

    return d_widgetMap[(QWidget *)widget];
}

inline QwtPlotItem *QwtLegend::PrivateData::LegendMap::find(
    const QWidget *widget)
{
    if ( !d_widgetMap.contains((QWidget *)widget) )
        return NULL;

    return (QwtPlotItem *)d_widgetMap[(QWidget *)widget];
}

inline const QMap<QWidget *, const QwtPlotItem *> &
    QwtLegend::PrivateData::LegendMap::widgetMap() const
{
    return d_widgetMap;
} 

inline QMap<QWidget *, const QwtPlotItem *> &
    QwtLegend::PrivateData::LegendMap::widgetMap() 
{
    return d_widgetMap;
} 

/*!
  \param parent Parent widget
*/
QwtLegend::QwtLegend(QWidget *parent): 
    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);
}

//! Destructor
QwtLegend::~QwtLegend()
{
    delete d_data;
}

/*!
  Set the legend display policy to:

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

  \sa displayPolicy, LegendDisplayPolicy
*/
void QwtLegend::setDisplayPolicy(LegendDisplayPolicy policy, int mode)
{
    d_data->displayPolicy = policy;
    if (-1 != mode)
       d_data->identifierMode = mode;

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

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

/*! 
  \return the legend display policy.
  Default is LegendDisplayPolicy::Auto.
  \sa setDisplayPolicy, LegendDisplayPolicy
*/ 

QwtLegend::LegendDisplayPolicy QwtLegend::displayPolicy() const 
{ 
    return d_data->displayPolicy; 
}

void QwtLegend::setItemMode(LegendItemMode mode)
{