piechartview.cpp

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#include <QFont>
#include <QScrollBar>
#include <QPen>
#include <QPainter>
#include <QPaintEvent>

#include "piechartview.h"
#include "../Data/dataproject.h"
#include "../Models/exercisemodel.h"

#ifndef M_PI
    #define M_PI 3.1415927
#endif

PieChartView::PieChartView(QWidget *parent) : QAbstractItemView(parent)
{
    horizontalScrollBar()->setRange(0, 0);
    verticalScrollBar()->setRange(0, 0);

    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

    margin = 8;
    totalSize = 500;
    pieSize = totalSize - 2 * margin;
    totalValue = 0.0;
}

PieChartView::~PieChartView()
{

}

bool PieChartView::edit(const QModelIndex &index, EditTrigger trigger, QEvent *event)
{
    Q_UNUSED(event);
    Q_UNUSED(trigger);
    Q_UNUSED(index);
    return false;
}

QModelIndex PieChartView::indexAt(const QPoint &point) const
{
    return QModelIndex();
}

bool PieChartView::isIndexHidden(const QModelIndex &index) const
{
    Q_UNUSED(index);
    return false;
}

int PieChartView::horizontalOffset() const
{
    return horizontalScrollBar()->value();
}

QModelIndex PieChartView::moveCursor(QAbstractItemView::CursorAction cursorAction, Qt::KeyboardModifiers /*modifiers*/)
{
    return QModelIndex();
}

QList<int> PieChartView::aggregateItemList()
{
    QList<int> values;

    int correct = 0;
    int wrong = 0;
    int incomplete = 0;

    ExerciseModel *exerciseModel = (ExerciseModel*)model();
    if(exerciseModel)
    {
        ExerciseItem *root = exerciseModel->getRootItem();
        for(int i = 0; i < root->childCount(); i++)
        {
            ExerciseItem *chapter = root->child(i);
            for(int j = 0; j < chapter->childCount(); j++)
            {
                ExerciseItem *exercise = chapter->child(j);

                QVariantList list = exercise->itemInfo();
                QString name = list.value(0).toString();
                QMap<QString, QVariant> data = list.value(1).toMap();
                int state = data.value("state").toInt();
                if(state == Correct)
                {
                    correct++;
                }
                else if(state == NotCompleted)
                {
                    incomplete++;
                }
                else if(state == Wrong)
                {
                    wrong++;
                }
            }
        }
    }

    values << correct;
    values << wrong;
    values << incomplete;

    totalValue = correct + wrong + incomplete;
    emit exerciseStatesChanged(values);
    return values;
}

void PieChartView::paintEvent(QPaintEvent *event)
{
    /* Sum up the totalsum */
    QList<int> items = aggregateItemList();

    if(totalValue > 0)
    {
        QStyleOptionViewItem option = viewOptions();
        QStyle::State state = option.state;

        QBrush background = option.palette.base();
        QPen foreground(Qt::white);
        QPen textPen(option.palette.color(QPalette::Text));

        QPainter painter(viewport());
        painter.setRenderHint(QPainter::Antialiasing);

        painter.fillRect(event->rect(), background);
        painter.setPen(foreground);

        // Viewport rectangles
        QRect pieRect = QRect(margin, margin, pieSize, pieSize);
        QPoint keyPoint = QPoint(totalSize - horizontalScrollBar()->value(), margin - verticalScrollBar()->value());

        painter.save();
        painter.translate(pieRect.x() - horizontalScrollBar()->value(), pieRect.y() - verticalScrollBar()->value());
        painter.drawEllipse(0, 0, pieSize, pieSize);
        double startAngle = 0.0;
        uint totalPieces = 0;

        int value = -1;
        int count = 0;
        foreach(value, items)
        {
            if(value > 0)
            {
                double angle = 360 * value / totalValue;

                QColor color;
                switch(count)
                {
                    case 0:
                        color = QColor(Qt::green);
                        break;
                    case 1:
                        color = QColor(Qt::red);
                        break;
                    case 2:
                        color.setRgb(229, 229, 229);
                        break;
                }

                painter.setBrush(QBrush(color));
                painter.drawPie(0, 0, pieSize, pieSize, int(startAngle*16), int(angle*16));

                startAngle += angle;
                totalPieces++;
            }
            count++;
        }
        painter.restore();
    }
}

void PieChartView::resizeEvent(QResizeEvent *event)
{
    Q_UNUSED(event);
    if(viewport()->width() >= size().height())
    {
        // can't display the pieChart in fullsize (the height overlaps -- need to resize it to fit)
        totalSize = size().height();
    }
    else
    {
        // normal resizing procedure
        totalSize = size().width() - margin/2;
    }
    pieSize = totalSize - 2 * margin;
    updateGeometries();
}

int PieChartView::rows(const QModelIndex &index) const
{
    return model()->rowCount(QModelIndex());
}

void PieChartView::scrollContentsBy(int dx, int dy)
{
    viewport()->scroll(dx, dy);
}

void PieChartView::scrollTo(const QModelIndex &index, ScrollHint)
{
    QRect area = viewport()->rect();
    QRect rect = visualRect(index);

    if(rect.left() < area.left())
    {
        horizontalScrollBar()->setValue(horizontalScrollBar()->value() + rect.left() - area.left());
    }
    else if(rect.right() > area.right())
    {
        horizontalScrollBar()->setValue(horizontalScrollBar()->value() + qMin(rect.right() - area.right(), rect.left() - area.left()));
    }

    if(rect.top() < area.top())
    {
        verticalScrollBar()->setValue(verticalScrollBar()->value() + rect.top() - area.top());
    }
    else if(rect.bottom() > area.bottom())
    {
        verticalScrollBar()->setValue(verticalScrollBar()->value() + qMin(rect.bottom() - area.bottom(), rect.top() - area.top()));
    }

    update();
}

void PieChartView::setSelection(const QRect &rect, QItemSelectionModel::SelectionFlags command)
{
}

void PieChartView::updateGeometries()
{
    horizontalScrollBar()->setPageStep(viewport()->width());
    horizontalScrollBar()->setRange(0, qMax(0, totalSize - viewport()->width()));
    verticalScrollBar()->setPageStep(viewport()->height());
    verticalScrollBar()->setRange(0, qMax(0, totalSize - viewport()->height()));
}

int PieChartView::verticalOffset() const
{
    return verticalScrollBar()->value();
}

QRect PieChartView::visualRect(const QModelIndex &index) const
{
    return QRect();
}

QRegion PieChartView::visualRegionForSelection(const QItemSelection &selection) const
{
    return QRect();
}

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