plotitem.cpp

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/**********************************************************************
 * LeechCraft - modular cross-platform feature rich internet client.
 * Copyright (C) 2006-2014  Georg Rudoy
 *
 * Distributed under the Boost Software License, Version 1.0.
 * (See accompanying file LICENSE or copy at https://www.boost.org/LICENSE_1_0.txt)
 **********************************************************************/
 
#include "plotitem.h"
#include <vector>
#include <memory>
#include <QStyleOption>
#include <QColor>
#include <QPen>
#include <util/sll/prelude.h>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <qwt_plot_renderer.h>
#include <qwt_plot_grid.h>
#include <qwt_scale_draw.h>
#include <qwt_text_label.h>
#include <qwt_plot_canvas.h>
 
namespace LC::Util
{
    PlotItem::PlotItem (QQuickItem *parent)
    : QQuickPaintedItem { parent }
    , Color_ { 0xFF, 0x4B, 0x10 }
    {
        setFlag (ItemHasContents, true);
    }
 
    QList<QPointF> PlotItem::GetPoints () const
    {
        return Points_;
    }
 
    void PlotItem::SetPoints (const QList<QPointF>& pts)
    {
        if (pts == Points_)
            return;
 
        Points_ = pts;
        emit pointsChanged ();
        update ();
    }
 
    QVariant PlotItem::GetMultipoints () const
    {
        QVariantList result;
        for (const auto& set : Multipoints_)
        {
            QVariantMap map
            {
                { "color", QVariant::fromValue (set.Color_) },
                { "points", QVariant::fromValue (set.Points_) }
            };
 
            if (set.BrushColor_)
                map [QStringLiteral ("brushColor")] = *set.BrushColor_;
 
            result << map;
        }
        return result;
    }
 
    namespace
    {
        struct UnsupportedType
        {
            const char * const Field_;
            const QVariant Value_;
        };
    }
 
    void PlotItem::SetMultipoints (const QVariant& variant)
    {
        Multipoints_.clear ();
 
        try
        {
            for (const auto& set : variant.toList ())
            {
                const auto& map = set.toMap ();
 
                const auto& colorVar = map [QStringLiteral ("color")];
                const auto& color = colorVar.toString ();
                if (color.isEmpty ())
                    throw UnsupportedType { "`color` expected to be a QString", colorVar };
 
                const auto& pointsVar = map [QStringLiteral ("points")];
                QList<QPointF> points;
                if (pointsVar.canConvert<QList<QPointF>> ())
                    points = pointsVar.value<QList<QPointF>> ();
                else if (pointsVar.canConvert<QVariantList> ())
                    points = Util::Map (pointsVar.toList (),
                            [] (const QVariant& var)
                            {
                                if (var.canConvert<QPointF> ())
                                    return var.toPointF ();
                                else
                                    throw UnsupportedType { "point element expected to be a QPointF", var };
                            });
 
                std::optional<QColor> brushColor;
                if (const auto& brushVar = map [QStringLiteral ("brushColor")];
                    !brushVar.isNull ())
                {
                    if (!brushVar.canConvert<QString> ())
                        throw UnsupportedType { "`brush` expected to be a QString", brushVar };
                    brushColor = QColor { brushVar.toString () };
                }
 
                Multipoints_.append ({ color, brushColor, points });
            }
        }
        catch (const UnsupportedType& ty)
        {
            qCritical () << Q_FUNC_INFO
                    << "invalid multipoints map: "
                    << ty.Field_
                    << " but got instead"
                    << ty.Value_;
            return;
        }
 
        update ();
    }
 
    double PlotItem::GetMinXValue () const
    {
        return MinXValue_;
    }
 
    void PlotItem::SetMinXValue (double val)
    {
        SetNewValue (val, MinXValue_, [this] { emit minXValueChanged (); });
    }
 
    double PlotItem::GetMaxXValue () const
    {
        return MaxXValue_;
    }
 
    void PlotItem::SetMaxXValue (double val)
    {
        SetNewValue (val, MaxXValue_, [this] { emit maxXValueChanged (); });
    }
 
    double PlotItem::GetMinYValue () const
    {
        return MinYValue_;
    }
 
    void PlotItem::SetMinYValue (double val)
    {
        SetNewValue (val, MinYValue_, [this] { emit minYValueChanged (); });
    }
 
    double PlotItem::GetMaxYValue () const
    {
        return MaxYValue_;
    }
 
    void PlotItem::SetMaxYValue (double val)
    {
        SetNewValue (val, MaxYValue_, [this] { emit maxYValueChanged (); });
    }
 
    bool PlotItem::GetYGridEnabled () const
    {
        return YGridEnabled_;
    }
 
    void PlotItem::SetYGridEnabled (bool val)
    {
        SetNewValue (val, YGridEnabled_, [this] { emit yGridChanged (); });
    }
 
    bool PlotItem::GetYMinorGridEnabled () const
    {
        return YMinorGridEnabled_;
    }
 
    void PlotItem::SetYMinorGridEnabled (bool val)
    {
        SetNewValue (val, YMinorGridEnabled_, [this] { emit yMinorGridChanged (); });
    }
 
    double PlotItem::GetAlpha () const
    {
        return Alpha_;
    }
 
    void PlotItem::SetAlpha (double a)
    {
        Alpha_ = a;
        emit alphaChanged ();
    }
 
    QColor PlotItem::GetColor () const
    {
        return Color_;
    }
 
    void PlotItem::SetColor (const QColor& color)
    {
        SetNewValue (color, Color_, [this] { emit colorChanged (); });
    }
 
    bool PlotItem::GetLeftAxisEnabled () const
    {
        return LeftAxisEnabled_;
    }
 
    void PlotItem::SetLeftAxisEnabled (bool enabled)
    {
        SetNewValue (enabled, LeftAxisEnabled_, [this] { emit leftAxisEnabledChanged (); });
    }
 
    bool PlotItem::GetBottomAxisEnabled () const
    {
        return BottomAxisEnabled_;
    }
 
    void PlotItem::SetBottomAxisEnabled (bool enabled)
    {
        SetNewValue (enabled, BottomAxisEnabled_, [this] { emit bottomAxisEnabledChanged (); });
    }
 
    QString PlotItem::GetLeftAxisTitle () const
    {
        return LeftAxisTitle_;
    }
 
    void PlotItem::SetLeftAxisTitle (const QString& title)
    {
        SetNewValue (title, LeftAxisTitle_, [this] { emit leftAxisTitleChanged (); });
    }
 
    QString PlotItem::GetBottomAxisTitle () const
    {
        return BottomAxisTitle_;
    }
 
    void PlotItem::SetBottomAxisTitle (const QString& title)
    {
        SetNewValue (title, BottomAxisTitle_, [this] { emit bottomAxisTitleChanged (); });
    }
 
    QString PlotItem::GetPlotTitle () const
    {
        return PlotTitle_;
    }
 
    void PlotItem::SetPlotTitle (const QString& title)
    {
        SetNewValue (title, PlotTitle_, [this] { emit plotTitleChanged (); });
    }
 
    QColor PlotItem::GetBackground () const
    {
        return BackgroundColor_;
    }
 
    void PlotItem::SetBackground (const QColor& bg)
    {
        SetNewValue (bg, BackgroundColor_, [this] { emit backgroundChanged (); });
    }
 
    QColor PlotItem::GetTextColor () const
    {
        return TextColor_;
    }
 
    void PlotItem::SetTextColor (const QColor& color)
    {
        SetNewValue (color, TextColor_, [this] { emit textColorChanged (); });
    }
 
    QColor PlotItem::GetGridLinesColor () const
    {
        return GridLinesColor_;
    }
 
    void PlotItem::SetGridLinesColor (const QColor& color)
    {
        SetNewValue (color, GridLinesColor_, [this] { emit gridLinesColorChanged (); });
    }
 
    int PlotItem::GetXExtent () const
    {
        return XExtent_;
    }
 
    int PlotItem::GetYExtent () const
    {
        return YExtent_;
    }
 
    void PlotItem::paint (QPainter *painter)
    {
        const auto& rect = contentsBoundingRect ().toRect ();
 
        if (!Plot_)
        {
            Plot_ = std::make_shared<QwtPlot> ();
            Plot_->setFrameShape (QFrame::NoFrame);
            Plot_->setFrameShadow (QFrame::Plain);
            Plot_->setLineWidth (0);
            Plot_->setMidLineWidth (0);
 
            if (const auto canvas = qobject_cast<QwtPlotCanvas*> (Plot_->canvas ()))
                canvas->setBorderRadius (0);
        }
 
        auto& plot = *Plot_;
        plot.enableAxis (QwtPlot::yLeft, LeftAxisEnabled_);
        plot.enableAxis (QwtPlot::xBottom, BottomAxisEnabled_);
        plot.setAxisTitle (QwtPlot::yLeft, LeftAxisTitle_);
        plot.setAxisTitle (QwtPlot::xBottom, BottomAxisTitle_);
 
        if (plot.size () != rect.size ())
            plot.resize (rect.size ());
 
        auto setPaletteColor = [&plot] (const QColor& color, QPalette::ColorRole role)
        {
            if (!color.isValid ())
                return;
 
            auto pal = plot.palette ();
            pal.setColor (role, { color });
            plot.setPalette (pal);
        };
 
        setPaletteColor (BackgroundColor_, QPalette::Window);
        setPaletteColor (TextColor_, QPalette::WindowText);
        setPaletteColor (TextColor_, QPalette::Text);
 
        if (!PlotTitle_.isEmpty ())
            plot.setTitle (QwtText { PlotTitle_ });
 
        if (MinYValue_ < MaxYValue_)
        {
            plot.setAxisAutoScale (QwtPlot::yLeft, false);
            plot.setAxisScale (QwtPlot::yLeft, MinYValue_, MaxYValue_);
        }
        plot.setAutoFillBackground (false);
        plot.setCanvasBackground (Qt::transparent);
 
        if (YGridEnabled_)
        {
            auto grid = new QwtPlotGrid;
            grid->enableYMin (YMinorGridEnabled_);
            grid->enableX (false);
            grid->setMajorPen (QPen (GridLinesColor_, 1, Qt::SolidLine));
            grid->setMinorPen (QPen (GridLinesColor_, 1, Qt::DashLine));
            grid->attach (&plot);
        }
 
        auto items = Multipoints_;
        if (items.isEmpty ())
            items.push_back ({ Color_, {}, Points_ });
 
        if (MinXValue_ < MaxXValue_)
            plot.setAxisScale (QwtPlot::xBottom, MinXValue_, MaxXValue_);
        else if (const auto ptsCount = items.first ().Points_.size ())
            plot.setAxisScale (QwtPlot::xBottom, 0, ptsCount - 1);
 
        std::vector<std::unique_ptr<QwtPlotCurve>> curves;
        for (const auto& item : items)
        {
            curves.emplace_back (new QwtPlotCurve);
            const auto curve = curves.back ().get ();
 
            curve->setPen (QPen (item.Color_));
 
            if (item.BrushColor_)
                curve->setBrush (*item.BrushColor_);
            else
            {
                auto brushColor = item.Color_;
                brushColor.setAlphaF (Alpha_);
                curve->setBrush (brushColor);
            }
 
            curve->setRenderHint (QwtPlotItem::RenderAntialiased);
            curve->attach (&plot);
 
            curve->setSamples (item.Points_.toVector ());
        }
 
        plot.replot ();
 
        QwtPlotRenderer {}.render (&plot, painter, rect);
 
        const auto xExtent = CalcXExtent (plot);
        const auto yExtent = CalcYExtent (plot);
        if (xExtent != XExtent_ || yExtent != YExtent_)
        {
            XExtent_ = xExtent;
            YExtent_ = yExtent;
            emit extentsChanged ();
        }
    }
 
    template<typename T, typename Notifier>
    void PlotItem::SetNewValue (T val, T& ourVal, Notifier&& notifier)
    {
        if (val == ourVal)
            return;
 
        ourVal = val;
        notifier ();
        update ();
    }
 
    int PlotItem::CalcXExtent (QwtPlot& plot) const
    {
        int result = 0;
        if (LeftAxisEnabled_)
            result += plot.axisScaleDraw (QwtPlot::yLeft)->extent (plot.axisFont (QwtPlot::yLeft));
        return result;
    }
 
    int PlotItem::CalcYExtent (QwtPlot& plot) const
    {
        int result = 0;
        if (BottomAxisEnabled_)
            result += plot.axisScaleDraw (QwtPlot::xBottom)->extent (plot.axisFont (QwtPlot::xBottom));
        if (!PlotTitle_.isEmpty ())
            result += plot.titleLabel ()->sizeHint ().height ();
        return result;
    }
}