qwt_legend_label.cpp

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/******************************************************************************
 * 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
 *****************************************************************************/
 
#include "qwt_legend_label.h"
#include "qwt_legend_data.h"
#include "qwt_graphic.h"
#include "qwt_painter.h"
#include "qwt.h"
 
#include <qpainter.h>
#include <qdrawutil.h>
#include <qstyle.h>
#include <qevent.h>
#include <qstyleoption.h>
 
static const int ButtonFrame = 2;
static const int Margin = 2;
 
static QSize buttonShift( const QwtLegendLabel* w )
{
    QStyleOption option;
    option.initFrom( w );
 
    const int ph = w->style()->pixelMetric(
        QStyle::PM_ButtonShiftHorizontal, &option, w );
    const int pv = w->style()->pixelMetric(
        QStyle::PM_ButtonShiftVertical, &option, w );
    return QSize( ph, pv );
}
 
class QwtLegendLabel::PrivateData
{
  public:
    PrivateData()
        : itemMode( QwtLegendData::ReadOnly )
        , isDown( false )
        , spacing( Margin )
    {
    }
 
    QwtLegendData::Mode itemMode;
    QwtLegendData legendData;
    bool isDown;
 
    QPixmap icon;
 
    int spacing;
};
 
void QwtLegendLabel::setData( const QwtLegendData& legendData )
{
    m_data->legendData = legendData;
 
    const bool doUpdate = updatesEnabled();
    if ( doUpdate )
        setUpdatesEnabled( false );
 
    setText( legendData.title() );
    setIcon( legendData.icon().toPixmap() );
 
    if ( legendData.hasRole( QwtLegendData::ModeRole ) )
        setItemMode( legendData.mode() );
 
    if ( doUpdate )
        setUpdatesEnabled( true );
}
 
const QwtLegendData& QwtLegendLabel::data() const
{
    return m_data->legendData;
}
 
QwtLegendLabel::QwtLegendLabel( QWidget* parent )
    : QwtTextLabel( parent )
{
    m_data = new PrivateData;
    setMargin( Margin );
    setIndent( Margin );
}
 
QwtLegendLabel::~QwtLegendLabel()
{
    delete m_data;
    m_data = NULL;
}
 
void QwtLegendLabel::setText( const QwtText& text )
{
    const int flags = Qt::AlignLeft | Qt::AlignVCenter
        | Qt::TextExpandTabs | Qt::TextWordWrap;
 
    QwtText txt = text;
    txt.setRenderFlags( flags );
 
    QwtTextLabel::setText( txt );
}
 
void QwtLegendLabel::setItemMode( QwtLegendData::Mode mode )
{
    if ( mode != m_data->itemMode )
    {
        m_data->itemMode = mode;
        m_data->isDown = false;
 
        setFocusPolicy( ( mode != QwtLegendData::ReadOnly )
            ? Qt::TabFocus : Qt::NoFocus );
        setMargin( ButtonFrame + Margin );
 
        updateGeometry();
    }
}
 
QwtLegendData::Mode QwtLegendLabel::itemMode() const
{
    return m_data->itemMode;
}
 
void QwtLegendLabel::setIcon( const QPixmap& icon )
{
    m_data->icon = icon;
 
    int indent = margin() + m_data->spacing;
    if ( icon.width() > 0 )
    {
        const qreal devicePixelRatio = QwtPainter::devicePixelRatio( &icon );
        indent += icon.width() / devicePixelRatio + m_data->spacing;
    }
 
    setIndent( indent );
}
 
QPixmap QwtLegendLabel::icon() const
{
    return m_data->icon;
}
 
void QwtLegendLabel::setSpacing( int spacing )
{
    spacing = qMax( spacing, 0 );
    if ( spacing != m_data->spacing )
    {
        m_data->spacing = spacing;
 
        int indent = margin() + m_data->spacing;
        if ( m_data->icon.width() > 0 )
            indent += m_data->icon.width() + m_data->spacing;
 
        setIndent( indent );
    }
}
 
int QwtLegendLabel::spacing() const
{
    return m_data->spacing;
}
 
void QwtLegendLabel::setChecked( bool on )
{
    if ( m_data->itemMode == QwtLegendData::Checkable )
    {
        const bool isBlocked = signalsBlocked();
        blockSignals( true );
 
        setDown( on );
 
        blockSignals( isBlocked );
    }
}
 
bool QwtLegendLabel::isChecked() const
{
    return m_data->itemMode == QwtLegendData::Checkable && isDown();
}
 
void QwtLegendLabel::setDown( bool down )
{
    if ( down == m_data->isDown )
        return;
 
    m_data->isDown = down;
    update();
 
    if ( m_data->itemMode == QwtLegendData::Clickable )
    {
        if ( m_data->isDown )
            Q_EMIT pressed();
        else
        {
            Q_EMIT released();
            Q_EMIT clicked();
        }
    }
 
    if ( m_data->itemMode == QwtLegendData::Checkable )
        Q_EMIT checked( m_data->isDown );
}
 
bool QwtLegendLabel::isDown() const
{
    return m_data->isDown;
}
 
QSize QwtLegendLabel::sizeHint() const
{
    QSize sz = QwtTextLabel::sizeHint();
    sz.setHeight( qMax( sz.height(), m_data->icon.height() + 4 ) );
 
    if ( m_data->itemMode != QwtLegendData::ReadOnly )
    {
        sz += buttonShift( this );
        sz = qwtExpandedToGlobalStrut( sz );
    }
 
    return sz;
}
 
void QwtLegendLabel::paintEvent( QPaintEvent* e )
{
    const QRect cr = contentsRect();
 
    QPainter painter( this );
    painter.setClipRegion( e->region() );
 
    if ( m_data->isDown )
    {
        qDrawWinButton( &painter, 0, 0, width(), height(),
            palette(), true );
    }
 
    painter.save();
 
    if ( m_data->isDown )
    {
        const QSize shiftSize = buttonShift( this );
        painter.translate( shiftSize.width(), shiftSize.height() );
    }
 
    painter.setClipRect( cr );
 
    drawContents( &painter );
 
    if ( !m_data->icon.isNull() )
    {
        QRect iconRect = cr;
        iconRect.setX( iconRect.x() + margin() );
        if ( m_data->itemMode != QwtLegendData::ReadOnly )
            iconRect.setX( iconRect.x() + ButtonFrame );
 
        const qreal devicePixelRatio = QwtPainter::devicePixelRatio( &m_data->icon );
        iconRect.setSize( m_data->icon.size() / devicePixelRatio );
        iconRect.moveCenter( QPoint( iconRect.center().x(), cr.center().y() ) );
 
        painter.drawPixmap( iconRect, m_data->icon );
    }
 
    painter.restore();
}
 
void QwtLegendLabel::mousePressEvent( QMouseEvent* e )
{
    if ( e->button() == Qt::LeftButton )
    {
        switch ( m_data->itemMode )
        {
            case QwtLegendData::Clickable:
            {
                setDown( true );
                return;
            }
            case QwtLegendData::Checkable:
            {
                setDown( !isDown() );
                return;
            }
            default:;
        }
    }
    QwtTextLabel::mousePressEvent( e );
}
 
void QwtLegendLabel::mouseReleaseEvent( QMouseEvent* e )
{
    if ( e->button() == Qt::LeftButton )
    {
        switch ( m_data->itemMode )
        {
            case QwtLegendData::Clickable:
            {
                setDown( false );
                return;
            }
            case QwtLegendData::Checkable:
            {
                return; // do nothing, but accept
            }
            default:;
        }
    }
    QwtTextLabel::mouseReleaseEvent( e );
}
 
void QwtLegendLabel::keyPressEvent( QKeyEvent* e )
{
    if ( e->key() == Qt::Key_Space )
    {
        switch ( m_data->itemMode )
        {
            case QwtLegendData::Clickable:
            {
                if ( !e->isAutoRepeat() )
                    setDown( true );
                return;
            }
            case QwtLegendData::Checkable:
            {
                if ( !e->isAutoRepeat() )
                    setDown( !isDown() );
                return;
            }
            default:;
        }
    }
 
    QwtTextLabel::keyPressEvent( e );
}
 
void QwtLegendLabel::keyReleaseEvent( QKeyEvent* e )
{
    if ( e->key() == Qt::Key_Space )
    {
        switch ( m_data->itemMode )
        {
            case QwtLegendData::Clickable:
            {
                if ( !e->isAutoRepeat() )
                    setDown( false );
                return;
            }
            case QwtLegendData::Checkable:
            {
                return; // do nothing, but accept
            }
            default:;
        }
    }
 
    QwtTextLabel::keyReleaseEvent( e );
}
 
#if QWT_MOC_INCLUDE
#include "moc_qwt_legend_label.cpp"
#endif