A class which draws a scale inside the plot canvas. More...

#include <qwt_plot_scaleitem.h>

Inheritance diagram for QwtPlotScaleItem:

Collaboration diagram for QwtPlotScaleItem:

Classes
class	PrivateData
Public Member Functions
	QwtPlotScaleItem (QwtScaleDraw::Alignment=QwtScaleDraw::BottomScale, const double pos=0.0)
	Constructor for scale item at the position pos.
virtual	~QwtPlotScaleItem ()
	Destructor.
virtual int	rtti () const
void	setScaleDiv (const QwtScaleDiv &)
	Assign a scale division.
const QwtScaleDiv &	scaleDiv () const
void	setScaleDivFromAxis (bool on)
bool	isScaleDivFromAxis () const
void	setColorGroup (const QColorGroup &)
QColorGroup	colorGroup () const
void	setFont (const QFont &)
QFont	font () const
void	setScaleDraw (QwtScaleDraw *)
	Set a scale draw.
const QwtScaleDraw *	scaleDraw () const
QwtScaleDraw *	scaleDraw ()
void	setPosition (double pos)
double	position () const
void	setBorderDistance (int numPixels)
	Align the scale to the canvas.
int	borderDistance () const
void	setAlignment (QwtScaleDraw::Alignment)
virtual void	draw (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRect &rect) const
	Draw the scale.
virtual void	updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &)
	Update the item to changes of the axes scale division.

Detailed Description

A class which draws a scale inside the plot canvas.

QwtPlotScaleItem can be used to draw an axis inside the plot canvas. It might by synchronized to one of the axis of the plot, but can also display its own ticks and labels.

It is allowed to synchronize the scale item with a disabled axis. In plots with vertical and horizontal scale items, it might be necessary to remove ticks at the intersections, by overloading updateScaleDiv().

The scale might be at a specific position (f.e 0.0) or it might be aligned to a canvas border.

Example

The following example shows how to replace the left axis, by a scale item at the x position 0.0.

QwtPlotScaleItem *scaleItem = 
    new QwtPlotScaleItem(QwtScaleDraw::RightScale, 0.0);
scaleItem->setFont(plot->axisWidget(QwtPlot::yLeft)->font());
scaleItem->attach(plot);

plot->enableAxis(QwtPlot::yLeft, false);

Definition at line 51 of file qwt_plot_scaleitem.h.

Constructor & Destructor Documentation

QwtPlotScaleItem::QwtPlotScaleItem	(	QwtScaleDraw::Alignment	alignment = `QwtScaleDraw::BottomScale`,
		const double	pos = `0.0`
	)		`[explicit]`

Constructor for scale item at the position pos.

Parameters:

alignment	In case of QwtScaleDraw::BottomScale/QwtScaleDrawTopScale the scale item is corresponding to the xAxis(), otherwise it corresponds to the yAxis().
pos	x or y position, depending on the corresponding axis.

See also:: setPosition(), setAlignment()

Definition at line 58 of file qwt_plot_scaleitem.cpp.

References QwtPlotScaleItem::PrivateData::position, QwtPlotScaleItem::PrivateData::scaleDraw, QwtScaleDraw::setAlignment(), and QwtPlotItem::setZ().

                                                          :
    QwtPlotItem(QwtText("Scale"))
{
    d_data = new PrivateData;
    d_data->position = pos;
    d_data->scaleDraw->setAlignment(alignment);

    setZ(11.0);
}

QwtPlotScaleItem::~QwtPlotScaleItem ( ) [virtual]

Destructor.

Definition at line 70 of file qwt_plot_scaleitem.cpp.

{
    delete d_data;
}

Member Function Documentation

int QwtPlotScaleItem::borderDistance ( ) const

Returns:: Distance from a canvas border

See also:: setBorderDistance(), setPosition()

Definition at line 320 of file qwt_plot_scaleitem.cpp.

References QwtPlotScaleItem::PrivateData::borderDistance.

{
    return d_data->borderDistance;
}

QColorGroup QwtPlotScaleItem::colorGroup ( ) const

Returns:: color group

See also:: setColorGroup()

Definition at line 156 of file qwt_plot_scaleitem.cpp.

References QwtPlotScaleItem::PrivateData::colorGroup.

Referenced by setColorGroup().

{
    return d_data->colorGroup;
}

void QwtPlotScaleItem::draw	(	QPainter *	p,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRect &	rect
	)		const `[virtual]`

Draw the scale.

Implements QwtPlotItem.

Definition at line 354 of file qwt_plot_scaleitem.cpp.

References QwtScaleDraw::alignment(), QwtPlotScaleItem::PrivateData::borderDistance, QwtScaleDraw::BottomScale, QwtPlotScaleItem::PrivateData::canvasRectCache, QwtPlotScaleItem::PrivateData::colorGroup, QwtScaleTransformation::copy(), QwtAbstractScaleDraw::draw(), QwtPlotScaleItem::PrivateData::font, QwtScaleDraw::move(), QwtScaleDraw::orientation(), QwtPlotScaleItem::PrivateData::position, QwtScaleDraw::RightScale, QwtPlotScaleItem::PrivateData::scaleDraw, QwtScaleDraw::setLength(), QwtAbstractScaleDraw::setTransformation(), QwtScaleMap::transform(), and QwtScaleMap::transformation().

{
    if ( canvasRect != d_data->canvasRectCache )
    {
        QwtPlotScaleItem* that = (QwtPlotScaleItem*)this;
        that->updateBorders();
    }

    QPen pen = painter->pen();
    pen.setStyle(Qt::SolidLine);
    painter->setPen(pen);

    int pw = painter->pen().width();
    if ( pw == 0 )
        pw = 1;

    QwtScaleDraw *sd = d_data->scaleDraw;
    if ( sd->orientation() == Qt::Horizontal )
    {
        int y;
        if ( d_data->borderDistance >= 0 )
        {
            if ( sd->alignment() == QwtScaleDraw::BottomScale )
                y = canvasRect.top() + d_data->borderDistance;
            else
            {
                y = canvasRect.bottom() - d_data->borderDistance - pw + 1;
            }

        }
        else
        {
            y = yMap.transform(d_data->position);
        }

        if ( y < canvasRect.top() || y > canvasRect.bottom() )
            return;

        sd->move(canvasRect.left(), y);
        sd->setLength(canvasRect.width() - 1);
        sd->setTransformation(xMap.transformation()->copy());
    }
    else // == Qt::Vertical
    {
        int x;
        if ( d_data->borderDistance >= 0 )
        {
            if ( sd->alignment() == QwtScaleDraw::RightScale )
                x = canvasRect.left() + d_data->borderDistance;
            else
            {
                x = canvasRect.right() - d_data->borderDistance - pw + 1;
            }
        }
        else
        {
            x = xMap.transform(d_data->position);
        }
        if ( x < canvasRect.left() || x > canvasRect.right() )
            return;

        sd->move(x, canvasRect.top());
        sd->setLength(canvasRect.height() - 1);
        sd->setTransformation(yMap.transformation()->copy());
    }

    painter->setFont(d_data->font);

#if QT_VERSION < 0x040000
    sd->draw(painter, d_data->colorGroup);
#else
    sd->draw(painter, d_data->palette);
#endif
    
}

QFont QwtPlotScaleItem::font ( ) const

Returns:: tick label font

See also:: setFont()

Definition at line 204 of file qwt_plot_scaleitem.cpp.

References QwtPlotScaleItem::PrivateData::font.

Referenced by setFont().

{
    return d_data->font;
}

bool QwtPlotScaleItem::isScaleDivFromAxis ( ) const

Returns:: True, if the synchronization of the scale division with the corresponding axis is enabled.

See also:: setScaleDiv(), setScaleDivFromAxis()

Definition at line 132 of file qwt_plot_scaleitem.cpp.

References QwtPlotScaleItem::PrivateData::scaleDivFromAxis.

{
    return d_data->scaleDivFromAxis;
}

double QwtPlotScaleItem::position ( ) const

Returns:: Position of the scale

See also:: setPosition(), setAlignment()

Definition at line 283 of file qwt_plot_scaleitem.cpp.

References QwtPlotScaleItem::PrivateData::position.

{
    return d_data->position;
}

int QwtPlotScaleItem::rtti ( ) const [virtual]

Returns:: QwtPlotItem::Rtti_PlotScale

Reimplemented from QwtPlotItem.

Definition at line 76 of file qwt_plot_scaleitem.cpp.

References QwtPlotItem::Rtti_PlotScale.

{
    return QwtPlotItem::Rtti_PlotScale;
}

const QwtScaleDiv & QwtPlotScaleItem::scaleDiv ( ) const

Returns:: Scale division

Definition at line 97 of file qwt_plot_scaleitem.cpp.

References QwtAbstractScaleDraw::scaleDiv(), and QwtPlotScaleItem::PrivateData::scaleDraw.

{
    return d_data->scaleDraw->scaleDiv();
}

const QwtScaleDraw * QwtPlotScaleItem::scaleDraw ( ) const

Returns:: Scale draw

See also:: setScaleDraw()

Definition at line 244 of file qwt_plot_scaleitem.cpp.

References QwtPlotScaleItem::PrivateData::scaleDraw.

Referenced by setScaleDraw().

{
    return d_data->scaleDraw;
}

QwtScaleDraw * QwtPlotScaleItem::scaleDraw ( )

Returns:: Scale draw

See also:: setScaleDraw()

Definition at line 253 of file qwt_plot_scaleitem.cpp.

References QwtPlotScaleItem::PrivateData::scaleDraw.

{
    return d_data->scaleDraw;
}

void QwtPlotScaleItem::setAlignment ( QwtScaleDraw::Alignment alignment )

Change the alignment of the scale

The alignment sets the orientation of the scale and the position of the ticks:

QwtScaleDraw::BottomScale: horizontal, ticks below
QwtScaleDraw::TopScale: horizontal, ticks above
QwtScaleDraw::LeftScale: vertical, ticks left
QwtScaleDraw::RightScale: vertical, ticks right

For horizontal scales the position corresponds to QwtPlotItem::yAxis(), otherwise to QwtPlotItem::xAxis().

See also:: scaleDraw(), QwtScaleDraw::alignment(), setPosition()

Definition at line 341 of file qwt_plot_scaleitem.cpp.

References QwtScaleDraw::alignment(), QwtPlotItem::itemChanged(), QwtPlotScaleItem::PrivateData::scaleDraw, and QwtScaleDraw::setAlignment().

{
    QwtScaleDraw *sd = d_data->scaleDraw;
    if ( sd->alignment() != alignment )
    {
        sd->setAlignment(alignment);
        itemChanged();
    }
}

void QwtPlotScaleItem::setBorderDistance ( int distance )

Align the scale to the canvas.

If distance is >= 0 the scale will be aligned to a border of the contents rect of the canvas. If alignment() is QwtScaleDraw::LeftScale, the scale will be aligned to the right border, if it is QwtScaleDraw::TopScale it will be aligned to the bottom (and vice versa),

If distance is < 0 the scale will be at the position().

Parameters:

distance Number of pixels between the canvas border and the backbone of the scale.

See also:: setPosition(), borderDistance()

Definition at line 304 of file qwt_plot_scaleitem.cpp.

References QwtPlotScaleItem::PrivateData::borderDistance, QuadProgPP::distance(), and QwtPlotItem::itemChanged().

{
    if ( distance < 0 )
        distance = -1;

    if ( distance != d_data->borderDistance )
    {
        d_data->borderDistance = distance;
        itemChanged();
    }
}

void QwtPlotScaleItem::setColorGroup ( const QColorGroup & colorGroup )

Set the color group

See also:: QwtAbstractScaleDraw::draw(), colorGroup()

Definition at line 143 of file qwt_plot_scaleitem.cpp.

References colorGroup(), QwtPlotScaleItem::PrivateData::colorGroup, and QwtPlotItem::itemChanged().

{
    if ( colorGroup != d_data->colorGroup )
    {
        d_data->colorGroup = colorGroup;
        itemChanged();
    }
}

void QwtPlotScaleItem::setFont ( const QFont & font )

Change the tick label font

See also:: font()

Definition at line 191 of file qwt_plot_scaleitem.cpp.

References font(), QwtPlotScaleItem::PrivateData::font, and QwtPlotItem::itemChanged().

{
    if ( font != d_data->font )
    {
        d_data->font = font;
        itemChanged();
    }
}

void QwtPlotScaleItem::setPosition ( double pos )

Change the position of the scale

The position is interpreted as y value for horizontal axes and as x value for vertical axes.

The border distance is set to -1.

Parameters:

pos	New position

See also:: position(), setAlignment()

Definition at line 269 of file qwt_plot_scaleitem.cpp.

References QwtPlotScaleItem::PrivateData::borderDistance, QwtPlotItem::itemChanged(), and QwtPlotScaleItem::PrivateData::position.

{
    if ( d_data->position != pos )
    {
        d_data->position = pos;
        d_data->borderDistance = -1;
        itemChanged();
    }
}

void QwtPlotScaleItem::setScaleDiv ( const QwtScaleDiv & scaleDiv )

Assign a scale division.

When assigning a scaleDiv the scale division won't be synchronized with the corresponding axis anymore.

Parameters:

scaleDiv Scale division

See also:: scaleDiv(), setScaleDivFromAxis(), isScaleDivFromAxis()

Definition at line 90 of file qwt_plot_scaleitem.cpp.

References QwtPlotScaleItem::PrivateData::scaleDivFromAxis, QwtPlotScaleItem::PrivateData::scaleDraw, and QwtAbstractScaleDraw::setScaleDiv().

{
    d_data->scaleDivFromAxis = false;
    d_data->scaleDraw->setScaleDiv(scaleDiv);
}

void QwtPlotScaleItem::setScaleDivFromAxis ( bool on )

Enable/Disable the synchronization of the scale division with the corresponding axis.

Parameters:

on	true/false

See also:: isScaleDivFromAxis()

Definition at line 109 of file qwt_plot_scaleitem.cpp.

References QwtPlot::axisScaleDiv(), QwtPlotItem::itemChanged(), QwtPlotItem::plot(), QwtPlotScaleItem::PrivateData::scaleDivFromAxis, updateScaleDiv(), QwtPlotItem::xAxis(), and QwtPlotItem::yAxis().

{
    if ( on != d_data->scaleDivFromAxis )
    {
        d_data->scaleDivFromAxis = on;
        if ( on )
        {
            const QwtPlot *plt = plot();
            if ( plt )
            {
                updateScaleDiv( *plt->axisScaleDiv(xAxis()),
                    *plt->axisScaleDiv(yAxis()) );
                itemChanged();
            }
        }
    }
}

void QwtPlotScaleItem::setScaleDraw ( QwtScaleDraw * scaleDraw )

Set a scale draw.

Parameters:

scaleDraw object responsible for drawing scales.

The main use case for replacing the default QwtScaleDraw is to overload QwtAbstractScaleDraw::label, to replace or swallow tick labels.

See also:: scaleDraw()

Definition at line 220 of file qwt_plot_scaleitem.cpp.

References QwtPlot::axisScaleDiv(), QwtPlotItem::itemChanged(), QwtPlotItem::plot(), scaleDraw(), QwtPlotScaleItem::PrivateData::scaleDraw, updateScaleDiv(), QwtPlotItem::xAxis(), and QwtPlotItem::yAxis().

{
    if ( scaleDraw == NULL )
        return;

    if ( scaleDraw != d_data->scaleDraw )
        delete d_data->scaleDraw;

    d_data->scaleDraw = scaleDraw;

    const QwtPlot *plt = plot();
    if ( plt )
    {
        updateScaleDiv( *plt->axisScaleDiv(xAxis()),
            *plt->axisScaleDiv(yAxis()) );
    }

    itemChanged();
}

void QwtPlotScaleItem::updateScaleDiv	(	const QwtScaleDiv &	xScaleDiv,
		const QwtScaleDiv &	yScaleDiv
	)		`[virtual]`

Update the item to changes of the axes scale division.

In case of isScaleDivFromAxis(), the scale draw is synchronized to the correspond axis.

Parameters:

xScaleDiv	Scale division of the x-axis
yScaleDiv	Scale division of the y-axis

See also:: QwtPlot::updateAxes()

Reimplemented from QwtPlotItem.

Definition at line 444 of file qwt_plot_scaleitem.cpp.

References QwtScaleDraw::orientation(), QwtPlotScaleItem::PrivateData::scaleDivFromAxis, QwtPlotScaleItem::PrivateData::scaleDraw, and QwtAbstractScaleDraw::setScaleDiv().

Referenced by setScaleDivFromAxis(), and setScaleDraw().

{
    QwtScaleDraw *sd = d_data->scaleDraw;
    if ( d_data->scaleDivFromAxis && sd )
    {
        sd->setScaleDiv(
            sd->orientation() == Qt::Horizontal ? xScaleDiv : yScaleDiv);
        updateBorders();
    }
}

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

QwtPlotScaleItem Class Reference

Classes

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation