Qwt 6.0.1 Support

Upgrade to QWT 6.0.1, but still uses a locally patched copy
since support for 8 axes has not been included, despite it
being a relatively simple patch.

Fixes #634.
Fixes #567.

qwt/examples/navigation/plot.cpp

@@ -0,0 +1,146 @@
+#include "plot.h"
+#include <qglobal.h>
+#include <qpainter.h>
+#include <qwt_plot_grid.h>
+#include <qwt_plot_canvas.h>
+#include <qwt_plot_layout.h>
+#include <qwt_interval.h>
+#include <qwt_painter.h>
+#include <qwt_plot_item.h>
+
+class RectItem: public QwtPlotItem
+{
+public:
+    enum Type
+    {
+        Rect,
+        Ellipse
+    };
+
+    RectItem(Type type):
+        d_type(type)
+    {
+    }
+
+    void setPen(const QPen &pen)
+    {
+        if ( pen != d_pen )
+        {
+            d_pen = pen;
+            itemChanged();
+        }
+    }
+
+    void setBrush(const QBrush &brush)
+    {
+        if ( brush != d_brush )
+        {
+            d_brush = brush;
+            itemChanged();
+        }
+    }
+    void setRect(const QRectF &rect)
+    {
+        if ( d_rect != rect )
+        {
+            d_rect = rect;
+            itemChanged();
+        }
+    }
+
+    virtual QRectF boundingRect() const
+    {
+        return d_rect;
+    }
+
+    virtual void draw(QPainter *painter,
+        const QwtScaleMap &xMap, const QwtScaleMap &yMap,
+        const QRectF &) const
+    {
+        if ( d_rect.isValid() )
+        {
+            const QRectF rect = QwtScaleMap::transform(
+                xMap, yMap, d_rect);
+            painter->setPen(d_pen);
+            painter->setBrush(d_brush);
+            if ( d_type == Ellipse )
+                QwtPainter::drawEllipse(painter, rect);
+            else
+                QwtPainter::drawRect(painter, rect);
+        }
+    }
+private:
+    QPen d_pen;
+    QBrush d_brush;
+    QRectF d_rect;
+    Type d_type;
+};
+
+Plot::Plot(QWidget *parent, const QwtInterval &interval):
+    QwtPlot(parent)
+{
+    for ( int axis = 0; axis < QwtPlot::axisCnt; axis ++ )
+        setAxisScale(axis, interval.minValue(), interval.maxValue());
+
+    setCanvasBackground(QColor(Qt::darkBlue));
+    plotLayout()->setAlignCanvasToScales(true);
+
+    // grid
+    QwtPlotGrid *grid = new QwtPlotGrid;
+    //grid->enableXMin(true);
+    grid->setMajPen(QPen(Qt::white, 0, Qt::DotLine));
+    grid->setMinPen(QPen(Qt::gray, 0 , Qt::DotLine));
+    grid->attach(this);
+
+    const int numEllipses = 10;
+
+    for ( int i = 0; i < numEllipses; i++ )
+    {
+        const double x = interval.minValue() +
+            qrand() % qRound(interval.width());
+        const double y = interval.minValue() +
+            qrand() % qRound(interval.width());
+        const double r = interval.minValue() +
+            qrand() % qRound(interval.width() / 6);
+
+        const QRectF area(x - r, y - r , 2 * r, 2 * r);
+
+        RectItem *item = new RectItem(RectItem::Ellipse);
+        item->setRenderHint(QwtPlotItem::RenderAntialiased, true);
+        item->setRect(area);
+        item->setPen(QPen(Qt::yellow));
+        item->attach(this);
+    }
+
+
+    d_rectOfInterest = new RectItem(RectItem::Rect);
+    d_rectOfInterest->setPen(Qt::NoPen);
+    QColor c = Qt::gray;
+    c.setAlpha(100);
+    d_rectOfInterest->setBrush(QBrush(c));
+    d_rectOfInterest->attach(this);
+}
+
+void Plot::updateLayout()
+{
+    QwtPlot::updateLayout();
+
+    const QwtScaleMap xMap = canvasMap(QwtPlot::xBottom);
+    const QwtScaleMap yMap = canvasMap(QwtPlot::yLeft);
+
+    const QRect cr = canvas()->contentsRect();
+    const double x1 = xMap.invTransform(cr.left());
+    const double x2 = xMap.invTransform(cr.right());
+    const double y1 = yMap.invTransform(cr.bottom());
+    const double y2 = yMap.invTransform(cr.top());
+
+    const double xRatio = (x2 - x1) / cr.width();
+    const double yRatio = (y2 - y1) / cr.height();
+
+    Q_EMIT resized(xRatio, yRatio);
+}
+
+void Plot::setRectOfInterest(const QRectF &rect)
+{
+    d_rectOfInterest->setRect(rect);
+}