qt_demoe/qwtdemo/qwt/qwt_plot_scaleitem.cpp

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2019-11-07 02:55:57 +00:00
/* -*- 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
*****************************************************************************/
#include "qwt_plot_scaleitem.h"
#include "qwt_plot.h"
#include "qwt_scale_map.h"
#include "qwt_interval.h"
#include <qpalette.h>
#include <qpainter.h>
class QwtPlotScaleItem::PrivateData
{
public:
PrivateData():
position( 0.0 ),
borderDistance( -1 ),
scaleDivFromAxis( true ),
scaleDraw( new QwtScaleDraw() )
{
}
~PrivateData()
{
delete scaleDraw;
}
QwtInterval scaleInterval( const QRectF &,
const QwtScaleMap &, const QwtScaleMap & ) const;
QPalette palette;
QFont font;
double position;
int borderDistance;
bool scaleDivFromAxis;
QwtScaleDraw *scaleDraw;
};
QwtInterval QwtPlotScaleItem::PrivateData::scaleInterval( const QRectF &canvasRect,
const QwtScaleMap &xMap, const QwtScaleMap &yMap ) const
{
QwtInterval interval;
if ( scaleDraw->orientation() == Qt::Horizontal )
{
interval.setMinValue( xMap.invTransform( canvasRect.left() ) );
interval.setMaxValue( xMap.invTransform( canvasRect.right() - 1 ) );
}
else
{
interval.setMinValue( yMap.invTransform( canvasRect.bottom() - 1 ) );
interval.setMaxValue( yMap.invTransform( canvasRect.top() ) );
}
return interval;
}
/*!
\brief Constructor for scale item at the position pos.
\param alignment In case of QwtScaleDraw::BottomScale or QwtScaleDraw::TopScale
the scale item is corresponding to the xAxis(),
otherwise it corresponds to the yAxis().
\param pos x or y position, depending on the corresponding axis.
\sa setPosition(), setAlignment()
*/
QwtPlotScaleItem::QwtPlotScaleItem(
QwtScaleDraw::Alignment alignment, const double pos ):
QwtPlotItem( QwtText( "Scale" ) )
{
d_data = new PrivateData;
d_data->position = pos;
d_data->scaleDraw->setAlignment( alignment );
setItemInterest( QwtPlotItem::ScaleInterest, true );
setZ( 11.0 );
}
//! Destructor
QwtPlotScaleItem::~QwtPlotScaleItem()
{
delete d_data;
}
//! \return QwtPlotItem::Rtti_PlotScale
int QwtPlotScaleItem::rtti() const
{
return QwtPlotItem::Rtti_PlotScale;
}
/*!
\brief Assign a scale division
When assigning a scaleDiv the scale division won't be synchronized
with the corresponding axis anymore.
\param scaleDiv Scale division
\sa scaleDiv(), setScaleDivFromAxis(), isScaleDivFromAxis()
*/
void QwtPlotScaleItem::setScaleDiv( const QwtScaleDiv& scaleDiv )
{
d_data->scaleDivFromAxis = false;
d_data->scaleDraw->setScaleDiv( scaleDiv );
}
//! \return Scale division
const QwtScaleDiv& QwtPlotScaleItem::scaleDiv() const
{
return d_data->scaleDraw->scaleDiv();
}
/*!
Enable/Disable the synchronization of the scale division with
the corresponding axis.
\param on true/false
\sa isScaleDivFromAxis()
*/
void QwtPlotScaleItem::setScaleDivFromAxis( bool on )
{
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();
}
}
}
}
/*!
\return True, if the synchronization of the scale division with
the corresponding axis is enabled.
\sa setScaleDiv(), setScaleDivFromAxis()
*/
bool QwtPlotScaleItem::isScaleDivFromAxis() const
{
return d_data->scaleDivFromAxis;
}
/*!
Set the palette
\sa QwtAbstractScaleDraw::draw(), palette()
*/
void QwtPlotScaleItem::setPalette( const QPalette &palette )
{
if ( palette != d_data->palette )
{
d_data->palette = palette;
legendChanged();
itemChanged();
}
}
/*!
\return palette
\sa setPalette()
*/
QPalette QwtPlotScaleItem::palette() const
{
return d_data->palette;
}
/*!
Change the tick label font
\sa font()
*/
void QwtPlotScaleItem::setFont( const QFont &font )
{
if ( font != d_data->font )
{
d_data->font = font;
itemChanged();
}
}
/*!
\return tick label font
\sa setFont()
*/
QFont QwtPlotScaleItem::font() const
{
return d_data->font;
}
/*!
\brief Set a scale draw
\param 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.
\sa scaleDraw()
*/
void QwtPlotScaleItem::setScaleDraw( QwtScaleDraw *scaleDraw )
{
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();
}
/*!
\return Scale draw
\sa setScaleDraw()
*/
const QwtScaleDraw *QwtPlotScaleItem::scaleDraw() const
{
return d_data->scaleDraw;
}
/*!
\return Scale draw
\sa setScaleDraw()
*/
QwtScaleDraw *QwtPlotScaleItem::scaleDraw()
{
return d_data->scaleDraw;
}
/*!
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.
\param pos New position
\sa position(), setAlignment()
*/
void QwtPlotScaleItem::setPosition( double pos )
{
if ( d_data->position != pos )
{
d_data->position = pos;
d_data->borderDistance = -1;
itemChanged();
}
}
/*!
\return Position of the scale
\sa setPosition(), setAlignment()
*/
double QwtPlotScaleItem::position() const
{
return d_data->position;
}
/*!
\brief Align the scale to the canvas
If distance is >= 0 the scale will be aligned to a
border of the contents rectangle 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().
\param distance Number of pixels between the canvas border and the
backbone of the scale.
\sa setPosition(), borderDistance()
*/
void QwtPlotScaleItem::setBorderDistance( int distance )
{
if ( distance < 0 )
distance = -1;
if ( distance != d_data->borderDistance )
{
d_data->borderDistance = distance;
itemChanged();
}
}
/*!
\return Distance from a canvas border
\sa setBorderDistance(), setPosition()
*/
int QwtPlotScaleItem::borderDistance() const
{
return d_data->borderDistance;
}
/*!
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().
\sa scaleDraw(), QwtScaleDraw::alignment(), setPosition()
*/
void QwtPlotScaleItem::setAlignment( QwtScaleDraw::Alignment alignment )
{
QwtScaleDraw *sd = d_data->scaleDraw;
if ( sd->alignment() != alignment )
{
sd->setAlignment( alignment );
itemChanged();
}
}
/*!
\brief Draw the scale
*/
void QwtPlotScaleItem::draw( QPainter *painter,
const QwtScaleMap &xMap, const QwtScaleMap &yMap,
const QRectF &canvasRect ) const
{
QwtScaleDraw *sd = d_data->scaleDraw;
if ( d_data->scaleDivFromAxis )
{
const QwtInterval interval =
d_data->scaleInterval( canvasRect, xMap, yMap );
if ( interval != sd->scaleDiv().interval() )
{
QwtScaleDiv scaleDiv = sd->scaleDiv();
scaleDiv.setInterval( interval );
sd->setScaleDiv( scaleDiv );
}
}
QPen pen = painter->pen();
pen.setStyle( Qt::SolidLine );
painter->setPen( pen );
if ( sd->orientation() == Qt::Horizontal )
{
double y;
if ( d_data->borderDistance >= 0 )
{
if ( sd->alignment() == QwtScaleDraw::BottomScale )
y = canvasRect.top() + d_data->borderDistance;
else
{
y = canvasRect.bottom() - d_data->borderDistance;
}
}
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 );
QwtTransform *transform = NULL;
if ( xMap.transformation() )
transform = xMap.transformation()->copy();
sd->setTransformation( transform );
}
else // == Qt::Vertical
{
double x;
if ( d_data->borderDistance >= 0 )
{
if ( sd->alignment() == QwtScaleDraw::RightScale )
x = canvasRect.left() + d_data->borderDistance;
else
{
x = canvasRect.right() - d_data->borderDistance;
}
}
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 );
QwtTransform *transform = NULL;
if ( yMap.transformation() )
transform = yMap.transformation()->copy();
sd->setTransformation( transform );
}
painter->setFont( d_data->font );
sd->draw( painter, d_data->palette );
}
/*!
\brief Update the item to changes of the axes scale division
In case of isScaleDivFromAxis(), the scale draw is synchronized
to the correspond axis.
\param xScaleDiv Scale division of the x-axis
\param yScaleDiv Scale division of the y-axis
\sa QwtPlot::updateAxes()
*/
void QwtPlotScaleItem::updateScaleDiv( const QwtScaleDiv& xScaleDiv,
const QwtScaleDiv& yScaleDiv )
{
QwtScaleDraw *scaleDraw = d_data->scaleDraw;
if ( d_data->scaleDivFromAxis && scaleDraw )
{
const QwtScaleDiv &scaleDiv =
scaleDraw->orientation() == Qt::Horizontal ? xScaleDiv : yScaleDiv;
const QwtPlot *plt = plot();
if ( plt != NULL )
{
const QRectF canvasRect = plt->canvas()->contentsRect();
const QwtInterval interval = d_data->scaleInterval(
canvasRect, plt->canvasMap( xAxis() ), plt->canvasMap( yAxis() ) );
QwtScaleDiv sd = scaleDiv;
sd.setInterval( interval );
if ( sd != scaleDraw->scaleDiv() )
{
// the internal label cache of QwtScaleDraw
// is cleared here, so better avoid pointless
// assignments.
scaleDraw->setScaleDiv( sd );
}
}
else
{
scaleDraw->setScaleDiv( scaleDiv );
}
}
}