QwtPlotPanner Class Reference

QwtPlotPanner provides panning of a plot canvas. More...

#include <qwt_plot_panner.h>

Inheritance diagram for QwtPlotPanner:

Collaboration diagram for QwtPlotPanner:

List of all members.

Classes
class	PrivateData
Public Member Functions
	QwtPlotPanner (QwtPlotCanvas *)
	Create a plot panner.
virtual	~QwtPlotPanner ()
	Destructor.
QwtPlotCanvas *	canvas ()
	Return observed plot canvas.
const QwtPlotCanvas *	canvas () const
	Return Observed plot canvas.
QwtPlot *	plot ()
	Return plot widget, containing the observed plot canvas.
const QwtPlot *	plot () const
	Return plot widget, containing the observed plot canvas.
void	setAxisEnabled (int axis, bool on)
	En/Disable an axis.
bool	isAxisEnabled (int axis) const
Protected Slots
virtual void	moveCanvas (int dx, int dy)

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Detailed Description

QwtPlotPanner provides panning of a plot canvas.

QwtPlotPanner is a panner for a QwtPlotCanvas, that adjusts the scales of the axes after dropping the canvas on its new position.

Together with QwtPlotZoomer and QwtPlotMagnifier powerful ways of navigating on a QwtPlot widget can be implemented easily.

Note:

The axes are not updated, while dragging the canvas

See also:

QwtPlotZoomer, QwtPlotMagnifier

Definition at line 32 of file qwt_plot_panner.h.

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Constructor & Destructor Documentation

QwtPlotPanner::QwtPlotPanner

(

QwtPlotCanvas *

canvas )

[explicit]

Create a plot panner.

The panner is enabled for all axes

Parameters:

canvas

Plot canvas to pan, also the parent object

See also:

setAxisEnabled()

Definition at line 38 of file qwt_plot_panner.cpp.

References moveCanvas(), and QwtPanner::panned().

                                                 :
    QwtPanner(canvas)
{
    d_data = new PrivateData();

    connect(this, SIGNAL(panned(int, int)),
        SLOT(moveCanvas(int, int)));
}

QwtPlotPanner::~QwtPlotPanner

(

)

[virtual]

Destructor.

Definition at line 48 of file qwt_plot_panner.cpp.

{
    delete d_data;
}

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Member Function Documentation

QwtPlotCanvas * QwtPlotPanner::canvas

(

)

Return observed plot canvas.

Definition at line 87 of file qwt_plot_panner.cpp.

Referenced by plot().

{
    QWidget *w = parentWidget();
    if ( w && w->inherits("QwtPlotCanvas") )
        return (QwtPlotCanvas *)w;

    return NULL;
}

const QwtPlotCanvas * QwtPlotPanner::canvas

(

)

const

Return Observed plot canvas.

Definition at line 97 of file qwt_plot_panner.cpp.

{
    return ((QwtPlotPanner *)this)->canvas();
}

bool QwtPlotPanner::isAxisEnabled

(

int

axis )

const

Test if an axis is enabled

Parameters:

axis	Axis, see QwtPlot::Axis

Returns:

True, if the axis is enabled

See also:

setAxisEnabled(), moveCanvas()

Definition at line 78 of file qwt_plot_panner.cpp.

References QwtPlot::axisCnt, and QwtPlotPanner::PrivateData::isAxisEnabled.

{
    if ( axis >= 0 && axis < QwtPlot::axisCnt )
        return d_data->isAxisEnabled[axis];

    return true;
}

void QwtPlotPanner::moveCanvas	(	int	dx,
		int	dy
	)		[protected, virtual, slot]

Adjust the enabled axes according to dx/dy

Parameters:

dx	Pixel offset in x direction
dy	Pixel offset in y direction

See also:

QwtPanner::panned()

Definition at line 130 of file qwt_plot_panner.cpp.

References QwtPlot::autoReplot(), QwtPlot::axisCnt, QwtPlot::axisScaleDiv(), QwtPlot::canvasMap(), QwtScaleMap::invTransform(), QwtPlotPanner::PrivateData::isAxisEnabled, QwtScaleDiv::lowerBound(), plot(), QwtPlot::replot(), QwtPlot::setAutoReplot(), QwtPlot::setAxisScale(), QwtScaleMap::transform(), QwtScaleDiv::upperBound(), QwtPlot::xBottom, and QwtPlot::xTop.

Referenced by QwtPlotPanner().

{
    if ( dx == 0 && dy == 0 )
        return;

    QwtPlot *plot = QwtPlotPanner::plot();
    if ( plot == NULL )
        return;
    
    const bool doAutoReplot = plot->autoReplot();
    plot->setAutoReplot(false);

    for ( int axis = 0; axis < QwtPlot::axisCnt; axis++ )
    {
        if ( !d_data->isAxisEnabled[axis] )
            continue;

        const QwtScaleMap map = plot->canvasMap(axis);

        const int i1 = map.transform(plot->axisScaleDiv(axis)->lowerBound());
        const int i2 = map.transform(plot->axisScaleDiv(axis)->upperBound());

        double d1, d2;
        if ( axis == QwtPlot::xBottom || axis == QwtPlot::xTop )
        {
            d1 = map.invTransform(i1 - dx);
            d2 = map.invTransform(i2 - dx);
        }
        else
        {
            d1 = map.invTransform(i1 - dy);
            d2 = map.invTransform(i2 - dy);
        }

        plot->setAxisScale(axis, d1, d2);
    }

    plot->setAutoReplot(doAutoReplot);
    plot->replot();
}

const QwtPlot * QwtPlotPanner::plot

(

)

const

Return plot widget, containing the observed plot canvas.

Definition at line 117 of file qwt_plot_panner.cpp.

{
    return ((QwtPlotPanner *)this)->plot();
}

QwtPlot * QwtPlotPanner::plot

(

)

Return plot widget, containing the observed plot canvas.

Definition at line 103 of file qwt_plot_panner.cpp.

References canvas().

Referenced by moveCanvas().

{
    QObject *w = canvas();
    if ( w )
    {
        w = w->parent();
        if ( w && w->inherits("QwtPlot") )
            return (QwtPlot *)w;
    }

    return NULL;
}

void QwtPlotPanner::setAxisEnabled	(	int	axis,
		bool	on
	)

En/Disable an axis.

Axes that are enabled will be synchronized to the result of panning. All other axes will remain unchanged.

Parameters:

axis	Axis, see QwtPlot::Axis
on	On/Off

See also:

isAxisEnabled(), moveCanvas()

Definition at line 64 of file qwt_plot_panner.cpp.

References QwtPlot::axisCnt, and QwtPlotPanner::PrivateData::isAxisEnabled.

{
    if ( axis >= 0 && axis < QwtPlot::axisCnt )
        d_data->isAxisEnabled[axis] = on;
}

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

• qwt_plot_panner.h
• qwt_plot_panner.cpp