qt_demoe/third/qwtdemo/examples/dials/attitude_indicator.cpp

128 lines
3.3 KiB
C++

#include "attitude_indicator.h"
#include <qwt_point_polar.h>
#include <qwt_round_scale_draw.h>
#include <qevent.h>
#include <qpainter.h>
#include <qpolygon.h>
AttitudeIndicatorNeedle::AttitudeIndicatorNeedle( const QColor &color )
{
QPalette palette;
palette.setColor( QPalette::Text, color );
setPalette( palette );
}
void AttitudeIndicatorNeedle::drawNeedle( QPainter *painter,
double length, QPalette::ColorGroup colorGroup ) const
{
double triangleSize = length * 0.1;
double pos = length - 2.0;
QPainterPath path;
path.moveTo( pos, 0 );
path.lineTo( pos - 2 * triangleSize, triangleSize );
path.lineTo( pos - 2 * triangleSize, -triangleSize );
path.closeSubpath();
painter->setBrush( palette().brush( colorGroup, QPalette::Text ) );
painter->drawPath( path );
double l = length - 2;
painter->setPen( QPen( palette().color( colorGroup, QPalette::Text ), 3 ) );
painter->drawLine( QPointF( 0.0, -l ), QPointF( 0.0, l ) );
}
AttitudeIndicator::AttitudeIndicator(
QWidget *parent ):
QwtDial( parent ),
d_gradient( 0.0 )
{
QwtRoundScaleDraw *scaleDraw = new QwtRoundScaleDraw();
scaleDraw->enableComponent( QwtAbstractScaleDraw::Backbone, false );
scaleDraw->enableComponent( QwtAbstractScaleDraw::Labels, false );
setScaleDraw( scaleDraw );
setMode( RotateScale );
setWrapping( true );
setOrigin( 270.0 );
setScaleMaxMinor( 0 );
setScaleStepSize( 30.0 );
setScale( 0.0, 360.0 );
const QColor color = palette().color( QPalette::Text );
setNeedle( new AttitudeIndicatorNeedle( color ) );
}
void AttitudeIndicator::setGradient( double gradient )
{
if ( gradient < -1.0 )
gradient = -1.0;
else if ( gradient > 1.0 )
gradient = 1.0;
if ( d_gradient != gradient )
{
d_gradient = gradient;
update();
}
}
void AttitudeIndicator::drawScale( QPainter *painter,
const QPointF &center, double radius ) const
{
const double offset = 4.0;
const QPointF p0 = qwtPolar2Pos( center, offset, 1.5 * M_PI );
const double w = innerRect().width();
QPainterPath path;
path.moveTo( qwtPolar2Pos( p0, w, 0.0 ) );
path.lineTo( qwtPolar2Pos( path.currentPosition(), 2 * w, M_PI ) );
path.lineTo( qwtPolar2Pos( path.currentPosition(), w, 0.5 * M_PI ) );
path.lineTo( qwtPolar2Pos( path.currentPosition(), w, 0.0 ) );
painter->save();
painter->setClipPath( path ); // swallow 180 - 360 degrees
QwtDial::drawScale( painter, center, radius );
painter->restore();
}
void AttitudeIndicator::drawScaleContents( QPainter *painter,
const QPointF &, double ) const
{
int dir = 360 - qRound( origin() - value() ); // counter clockwise
int arc = 90 + qRound( gradient() * 90 );
const QColor skyColor( 38, 151, 221 );
painter->save();
painter->setBrush( skyColor );
painter->drawChord( scaleInnerRect(),
( dir - arc ) * 16, 2 * arc * 16 );
painter->restore();
}
void AttitudeIndicator::keyPressEvent( QKeyEvent *event )
{
switch( event->key() )
{
case Qt::Key_Plus:
{
setGradient( gradient() + 0.05 );
break;
}
case Qt::Key_Minus:
{
setGradient( gradient() - 0.05 );
break;
}
default:
QwtDial::keyPressEvent( event );
}
}