subsurface/stats/statsaxis.h
Berthold Stoeger ada5e8a49d statistics: turn axes into QSGNode
Render the labels and the title into a pixmap and render
the ticks and the base line using individual QSGNodes.
Attempting to render the ticks likewise into the pixmap
gave horrible results, because (quite obviously) rendering
with QPainter and the QSG shader gives non-matching ticks
and grid lines.

The memory management had to be changed a bit: The ChartItems
were collected in the root QSGNode. However, the axes are added
before the first plotting, so this node might not exist.
Therefore, store the axes in the StatsView object.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2021-01-20 08:47:18 +01:00

123 lines
3.7 KiB
C++

// SPDX-License-Identifier: GPL-2.0
#ifndef STATS_AXIS_H
#define STATS_AXIS_H
#include "chartitem.h"
#include <memory>
#include <vector>
#include <QFont>
class StatsView;
class ChartLineItem;
class QFontMetrics;
// The labels and the title of the axis are rendered into a pixmap.
// The ticks and the baseline are realized as individual ChartLineItems.
class StatsAxis : public ChartPixmapItem {
public:
virtual ~StatsAxis();
// Returns minimum and maximum of shown range, not of data points.
std::pair<double, double> minMax() const;
std::pair<double, double> minMaxScreen() const; // minimum and maximum in screen coordinates
std::pair<double, double> horizontalOverhang() const; // space that labels peak out in horizontal axes
double width() const; // Only supported by vertical axes. Only valid after setSize().
double height() const; // Only supported for horizontal axes. Always valid.
void setSize(double size); // Width for horizontal and height for vertical.
void setPos(QPointF pos); // Must be called after setSize().
void setRange(double, double);
// Map x (horizontal) or y (vertical) coordinate to or from screen coordinate
double toScreen(double) const;
double toValue(double) const;
std::vector<double> ticksPositions() const; // Positions in screen coordinates
protected:
StatsAxis(StatsView &view, const QString &title, bool horizontal, bool labelsBetweenTicks);
std::unique_ptr<ChartLineItem> line;
QString title;
double titleWidth;
struct Label {
QString label;
int width;
double pos;
};
std::vector<Label> labels;
void addLabel(const QFontMetrics &fm, const QString &label, double pos);
virtual void updateLabels() = 0;
virtual std::pair<QString, QString> getFirstLastLabel() const = 0;
struct Tick {
std::unique_ptr<ChartLineItem> item;
double pos;
};
std::vector<Tick> ticks;
void addTick(double pos);
int guessNumTicks(const std::vector<QString> &strings) const;
bool horizontal;
bool labelsBetweenTicks; // When labels are between ticks, they can be moved closer to the axis
QFont labelFont, titleFont;
double size; // width for horizontal, height for vertical
double zeroOnScreen;
QPointF offset; // Offset of the label and title pixmap with respect to the (0,0) position.
double min, max;
double labelWidth; // Maximum width of labels
private:
double titleSpace() const; // Space needed for title
};
class ValueAxis : public StatsAxis {
public:
ValueAxis(StatsView &view, const QString &title, double min, double max, int decimals, bool horizontal);
private:
double min, max;
int decimals;
void updateLabels() override;
std::pair<QString, QString> getFirstLastLabel() const override;
};
class CountAxis : public ValueAxis {
public:
CountAxis(StatsView &view, const QString &title, int count, bool horizontal);
private:
int count;
void updateLabels() override;
std::pair<QString, QString> getFirstLastLabel() const override;
};
class CategoryAxis : public StatsAxis {
public:
CategoryAxis(StatsView &view, const QString &title, const std::vector<QString> &labels, bool horizontal);
private:
std::vector<QString> labelsText;
void updateLabels();
std::pair<QString, QString> getFirstLastLabel() const override;
};
struct HistogramAxisEntry {
QString name;
double value;
bool recommended;
};
class HistogramAxis : public StatsAxis {
public:
HistogramAxis(StatsView &view, const QString &title, std::vector<HistogramAxisEntry> bin_values, bool horizontal);
private:
void updateLabels() override;
std::pair<QString, QString> getFirstLastLabel() const override;
std::vector<HistogramAxisEntry> bin_values;
int preferred_step;
};
class DateAxis : public HistogramAxis {
public:
DateAxis(StatsView &view, const QString &title, double from, double to, bool horizontal);
};
#endif