statistics: render title

Since we want to get rid of QtCharts, we have to render our own
title. Simply keep around a QGraphicsSimpleTextItem and put in
the center of the chart. Define the borders to the scene as
constants.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

2 files changed, 36 insertions, 2 deletions

diff --git a/stats/statsview.cpp b/stats/statsview.cpp
index 11dbe4f1e..6709407e1 100644
--- a/stats/statsview.cpp
+++ b/stats/statsview.cpp
@@ -18,11 +18,14 @@
 #include <QAbstractSeries>
 #include <QChart>
 #include <QGraphicsSceneHoverEvent>
+#include <QGraphicsSimpleTextItem>
 #include <QLocale>
 
 // Constants that control the graph layouts
 static const QColor quartileMarkerColor(Qt::red);
-static const double quartileMarkerSize = 15;
+static const double quartileMarkerSize = 15.0;
+static const double sceneBorder = 5.0;			// Border between scene edges and statitistics view
+static const double titleBorder = 2.0;			// Border between title and chart
 
 static const QUrl urlStatsView = QUrl(QStringLiteral("qrc:/qml/statsview.qml"));
 
@@ -77,6 +80,9 @@ StatsView::StatsView(QWidget *parent) : QQuickWidget(parent),
 		chart->setAcceptHoverEvents(true);
 		chart->legend()->setVisible(false);
 	}
+
+	QFont font;
+	titleFont = QFont(font.family(), font.pointSize(), QFont::Light);	// Make configurable
 }
 
 StatsView::~StatsView()
@@ -95,6 +101,7 @@ void StatsView::plotAreaChanged(const QRectF &)
 		marker.updatePosition();
 	if (legend)
 		legend->resize();
+	updateTitlePos();
 }
 
 void StatsView::replotIfVisible()
@@ -136,7 +143,21 @@ T *StatsView::createSeries(Args&&... args)
 
 void StatsView::setTitle(const QString &s)
 {
-	chart->setTitle(s);
+	if (s.isEmpty()) {
+		title.reset();
+		return;
+	}
+	title = std::make_unique<QGraphicsSimpleTextItem>(s, chart);
+	title->setFont(titleFont);
+}
+
+void StatsView::updateTitlePos()
+{
+	if (!title)
+		return;
+	QRectF rect = chart->plotArea();
+	title->setPos((rect.width() - title->boundingRect().width()) / 2.0,
+		      sceneBorder);
 }
 
 template <typename T, class... Args>
@@ -166,11 +187,18 @@ void StatsView::reset()
 	lineMarkers.clear();
 	chart->removeAllSeries();
 	axes.clear();
+	title.reset();
 }
 
 void StatsView::plot(const StatsState &stateIn)
 {
 	state = stateIn;
+	plotChart();
+	plotAreaChanged(chart->plotArea());
+}
+
+void StatsView::plotChart()
+{
 	if (!chart || !state.var1)
 		return;
 	reset();
diff --git a/stats/statsview.h b/stats/statsview.h
index 1ef88b96c..fac61a55b 100644
--- a/stats/statsview.h
+++ b/stats/statsview.h
@@ -4,6 +4,7 @@
 
 #include "statsstate.h"
 #include <memory>
+#include <QFont>
 #include <QQuickWidget>
 
 struct dive;
@@ -17,6 +18,7 @@ namespace QtCharts {
 	class QChart;
 }
 class QGraphicsLineItem;
+class QGraphicsSimpleTextItem;
 class StatsSeries;
 class CategoryAxis;
 class CountAxis;
@@ -74,6 +76,8 @@ private:
 				   const StatsVariable *categoryVariable, const StatsBinner *categoryBinner, const StatsVariable *valueVariable);
 	void plotScatter(const std::vector<dive *> &dives, const StatsVariable *categoryVariable, const StatsVariable *valueVariable);
 	void setTitle(const QString &);
+	void updateTitlePos(); // After resizing, set title to correct position
+	void plotChart();
 
 	template <typename T, class... Args>
 	T *createSeries(Args&&... args);
@@ -115,11 +119,13 @@ private:
 
 	StatsState state;
 	QtCharts::QChart *chart;
+	QFont titleFont;
 	std::vector<std::unique_ptr<StatsAxis>> axes;
 	std::vector<std::unique_ptr<StatsSeries>> series;
 	std::unique_ptr<Legend> legend;
 	std::vector<QuartileMarker> quartileMarkers;
 	std::vector<LineMarker> lineMarkers;
+	std::unique_ptr<QGraphicsSimpleTextItem> title;
 	StatsSeries *highlightedSeries;
 
 	// This is unfortunate: we can't derive from QChart, because the chart is allocated by QML.