新增qwt源码版本

qwtdemo/examples/dials/speedo_meter.cpp

@@ -0,0 +1,52 @@
+#include <qpainter.h>
+#include <qwt_dial_needle.h>
+#include <qwt_round_scale_draw.h>
+#include "speedo_meter.h"
+
+SpeedoMeter::SpeedoMeter( QWidget *parent ):
+    QwtDial( parent ),
+    d_label( "km/h" )
+{
+    QwtRoundScaleDraw *scaleDraw = new QwtRoundScaleDraw();
+    scaleDraw->setSpacing( 8 );
+    scaleDraw->enableComponent( QwtAbstractScaleDraw::Backbone, false );
+    scaleDraw->setTickLength( QwtScaleDiv::MinorTick, 0 );
+    scaleDraw->setTickLength( QwtScaleDiv::MediumTick, 4 );
+    scaleDraw->setTickLength( QwtScaleDiv::MajorTick, 8 );
+    setScaleDraw( scaleDraw );
+
+    setWrapping( false );
+    setReadOnly( true );
+
+    setOrigin( 135.0 );
+    setScaleArc( 0.0, 270.0 );
+
+    QwtDialSimpleNeedle *needle = new QwtDialSimpleNeedle(
+        QwtDialSimpleNeedle::Arrow, true, Qt::red,
+        QColor( Qt::gray ).light( 130 ) );
+    setNeedle( needle );
+}
+
+void SpeedoMeter::setLabel( const QString &label )
+{
+    d_label = label;
+    update();
+}
+
+QString SpeedoMeter::label() const
+{
+    return d_label;
+}
+
+void SpeedoMeter::drawScaleContents( QPainter *painter,
+    const QPointF &center, double radius ) const
+{
+    QRectF rect( 0.0, 0.0, 2.0 * radius, 2.0 * radius - 10.0 );
+    rect.moveCenter( center );
+
+    const QColor color = palette().color( QPalette::Text );
+    painter->setPen( color );
+
+    const int flags = Qt::AlignBottom | Qt::AlignHCenter;
+    painter->drawText( rect, flags, d_label );
+}