statistics: turn infobox into a QSGNode

A small step in converting from QGraphicsScene to QQuickItem.
This is the second item to be converted (after the legend)
and for now items are drawn in order of creation, which means
that the infobox is on top of the legend. This will have
to be made deterministic in follow-up commits.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

stats/barseries.cpp

@@ -4,6 +4,7 @@
 #include "statscolors.h"
 #include "statshelper.h"
 #include "statstranslations.h"
+#include "statsview.h"
 #include "zvalues.h"
 
 #include <math.h> // for lrint()
@@ -403,7 +404,7 @@ bool BarSeries::hover(QPointF pos)
 		Item &item = items[highlighted.bar];
 		item.highlight(index.subitem, true, binCount());
 		if (!information)
-			information = createItemPtr<InformationBox>(scene);
+			information = view.createChartItem<InformationBox>();
 		information->setText(makeInfo(item, highlighted.subitem), pos);
 	} else {
 		information.reset();

stats/boxseries.cpp

@@ -4,6 +4,7 @@
 #include "statscolors.h"
 #include "statshelper.h"
 #include "statstranslations.h"
+#include "statsview.h"
 #include "zvalues.h"
 
 #include <QLocale>
@@ -149,7 +150,7 @@ bool BoxSeries::hover(QPointF pos)
 		Item &item = *items[highlighted];
 		item.highlight(true);
 		if (!information)
-			information = createItemPtr<InformationBox>(scene);
+			information = view.createChartItem<InformationBox>();
 		information->setText(formatInformation(item), pos);
 	} else {
 		information.reset();

stats/informationbox.cpp

@@ -1,9 +1,9 @@
 #include "informationbox.h"
 #include "statscolors.h"
+#include "statsview.h"
 #include "zvalues.h"
 
 #include <QFontMetrics>
-#include <QGraphicsScene>
 
 static const QColor informationBorderColor(Qt::black);
 static const QColor informationColor(0xff, 0xff, 0x00, 192); // Note: fourth argument is opacity
@@ -11,74 +11,65 @@ static const int informationBorder = 2;
 static const double informationBorderRadius = 4.0; // Radius of rounded corners
 static const int distanceFromPointer = 10; // Distance to place box from mouse pointer or scatter item
 
-InformationBox::InformationBox() : RoundRectItem(informationBorderRadius, nullptr)
+InformationBox::InformationBox(StatsView &v) :
+	ChartRectItem(v, QPen(informationBorderColor, informationBorder),
+		      QBrush(informationColor), informationBorderRadius)
 {
-	setPen(QPen(informationBorderColor, informationBorder));
-	setBrush(informationColor);
-	setZValue(ZValues::informationBox);
 }
 
 void InformationBox::setText(const std::vector<QString> &text, QPointF pos)
 {
-	width = height = 0.0;
-	textItems.clear();
+	QFontMetrics fm(font);
+	double fontHeight = fm.height();
 
+	std::vector<double> widths;
+	widths.reserve(text.size());
+	width = 0.0;
 	for (const QString &s: text) {
-		if (!s.isEmpty())
-			addLine(s);
+		widths.push_back(static_cast<double>(fm.size(Qt::TextSingleLine, s).width()));
+		width = std::max(width, widths.back());
 	}
 
 	width += 4.0 * informationBorder;
-	height += 4.0 * informationBorder;
+	height = widths.size() * fontHeight + 4.0 * informationBorder;
 
-	// Setting the position will also set the proper size
-	setPos(pos);
+	ChartRectItem::resize(QSizeF(width, height));
+
+	painter->setPen(QPen(darkLabelColor)); // QPainter uses QPen to set text color!
+	double y = 2.0 * informationBorder;
+	for (size_t i = 0; i < widths.size(); ++i) {
+		QRectF rect(2.0 * informationBorder, y, widths[i], fontHeight);
+		painter->drawText(rect, text[i]);
+		y += fontHeight;
+	}
 }
 
 void InformationBox::setPos(QPointF pos)
 {
-	QRectF plotArea = scene()->sceneRect();
+	QSizeF size = sceneSize();
 
 	double x = pos.x() + distanceFromPointer;
-	if (x + width >= plotArea.right()) {
-		if (pos.x() - width >= plotArea.x())
+	if (x + width >= size.width()) {
+		if (pos.x() - width >= 0.0)
 			x = pos.x() - width;
 		else
 			x = pos.x() - width / 2.0;
 	}
 	double y = pos.y() + distanceFromPointer;
-	if (y + height >= plotArea.bottom()) {
-		if (pos.y() - height >= plotArea.y())
+	if (y + height >= size.height()) {
+		if (pos.y() - height >= 0.0)
 			y = pos.y() - height;
 		else
 			y = pos.y() - height / 2.0;
 	}
 
-	setRect(x, y, width, height);
-	double actY = y + 2.0 * informationBorder;
-	for (auto &item: textItems) {
-		item->setPos(QPointF(x + 2.0 * informationBorder, actY));
-		actY += item->boundingRect().height();
-	}
-}
-
-void InformationBox::addLine(const QString &s)
-{
-	textItems.emplace_back(new QGraphicsSimpleTextItem(s, this));
-	QGraphicsSimpleTextItem &item = *textItems.back();
-	item.setBrush(QBrush(darkLabelColor));
-	item.setPos(QPointF(0.0, height));
-	item.setFont(font);
-	item.setZValue(ZValues::informationBox);
-	QRectF rect = item.boundingRect();
-	width = std::max(width, rect.width());
-	height += rect.height();
+	ChartRectItem::setPos(QPointF(x, y));
 }
 
 // Try to stay within three-thirds of the chart height
 int InformationBox::recommendedMaxLines() const
 {
 	QFontMetrics fm(font);
-	int maxHeight = static_cast<int>(scene()->sceneRect().height());
+	int maxHeight = static_cast<int>(sceneSize().height());
 	return maxHeight * 2 / fm.height() / 3;
 }

stats/informationbox.h

@@ -4,26 +4,24 @@
 #ifndef INFORMATION_BOX_H
 #define INFORMATION_BOX_H
 
-#include "backend-shared/roundrectitem.h"
+#include "chartitem.h"
 
 #include <vector>
 #include <memory>
 #include <QFont>
 
 struct dive;
-class QGraphicsScene;
+class StatsView;
 
 // Information window showing data of highlighted dive
-struct InformationBox : RoundRectItem {
-	InformationBox();
+struct InformationBox : ChartRectItem {
+	InformationBox(StatsView &);
 	void setText(const std::vector<QString> &text, QPointF pos);
 	void setPos(QPointF pos);
 	int recommendedMaxLines() const;
 private:
 	QFont font; // For future specialization.
 	double width, height;
-	void addLine(const QString &s);
-	std::vector<std::unique_ptr<QGraphicsSimpleTextItem>> textItems;
 };
 
 #endif

stats/pieseries.cpp

@@ -4,6 +4,7 @@
 #include "statscolors.h"
 #include "statshelper.h"
 #include "statstranslations.h"
+#include "statsview.h"
 #include "zvalues.h"
 
 #include <numeric>
@@ -246,7 +247,7 @@ bool PieSeries::hover(QPointF pos)
 	if (highlighted >= 0 && highlighted < (int)items.size()) {
 		items[highlighted].highlight(highlighted, true, (int)items.size());
 		if (!information)
-			information = createItemPtr<InformationBox>(scene);
+			information = view.createChartItem<InformationBox>();
 		information->setText(makeInfo(highlighted), pos);
 	} else {
 		information.reset();

stats/scatterseries.cpp

@@ -5,6 +5,7 @@
 #include "statshelper.h"
 #include "statstranslations.h"
 #include "statsvariables.h"
+#include "statsview.h"
 #include "zvalues.h"
 #include "core/dive.h"
 #include "core/divelist.h"
@@ -173,7 +174,7 @@ bool ScatterSeries::hover(QPointF pos)
 		return false;
 	} else {
 		if (!information)
-			information = createItemPtr<InformationBox>(scene);
+			information = view.createChartItem<InformationBox>();
 
 		std::vector<QString> text;
 		text.reserve(highlighted.size() * 5);

stats/statsview.cpp

@@ -279,14 +279,6 @@ T *StatsView::createAxis(const QString &title, Args&&... args)
 	return res;
 }
 
-template <typename T, class... Args>
-std::unique_ptr<T> StatsView::createChartItem(Args&&... args)
-{
-	std::unique_ptr<T> res(new T(*this, std::forward<Args>(args)...));
-	items.push_back(res.get());
-	return res;
-}
-
 void StatsView::setAxes(StatsAxis *x, StatsAxis *y)
 {
 	xAxis = x;

stats/statsview.h

@@ -52,6 +52,9 @@ public:
 	QSizeF size() const;
 	void addQSGNode(QSGNode *node, int z);	// Must only be called in render thread!
 	void unregisterChartItem(const ChartItem *item);
+	template <typename T, class... Args>
+	std::unique_ptr<T> createChartItem(Args&&... args);
+
 private slots:
 	void replotIfVisible();
 private:
@@ -109,9 +112,6 @@ private:
 	template <typename T, class... Args>
 	T *createAxis(const QString &title, Args&&... args);
 
-	template <typename T, class... Args>
-	std::unique_ptr<T> createChartItem(Args&&... args);
-
 	template<typename T>
 	CategoryAxis *createCategoryAxis(const QString &title, const StatsBinner &binner,
 					 const std::vector<T> &bins, bool isHorizontal);
@@ -179,4 +179,14 @@ private:
 	QSGImageNode *rootNode;
 };
 
+// This implementation detail must be known to users of the class.
+// Perhaps move it into a statsview_impl.h file.
+template <typename T, class... Args>
+std::unique_ptr<T> StatsView::createChartItem(Args&&... args)
+{
+	std::unique_ptr<T> res(new T(*this, std::forward<Args>(args)...));
+	items.push_back(res.get());
+	return res;
+}
+
 #endif