statistics: implement shift-selection of ranges

For all the series but the scatter series (which supports
lasso selection), implement a range-selection using shift.

The code is fairly similar for all series and one might
think about factoring it out. But why bother?

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

6 files changed, 80 insertions, 6 deletions

diff --git a/stats/barseries.cpp b/stats/barseries.cpp
index 95b02111e..698a87738 100644
--- a/stats/barseries.cpp
+++ b/stats/barseries.cpp
@@ -31,6 +31,21 @@ bool BarSeries::Index::operator==(const Index &i2) const
 	return std::tie(bar, subitem) == std::tie(i2.bar, i2.subitem);
 }
 
+// Note: only defined for valid indices.
+bool BarSeries::Index::operator<=(const Index &i2) const
+{
+	return std::tie(bar, subitem) <= std::tie(i2.bar, i2.subitem);
+}
+
+// Note: only defined for valid indices.
+void BarSeries::inc(Index &index)
+{
+	if (++index.subitem < binCount())
+		return;
+	++index.bar;
+	index.subitem = 0;
+}
+
 BarSeries::BarSeries(StatsView &view, StatsAxis *xAxis, StatsAxis *yAxis,
 		     bool horizontal, bool stacked, const QString &categoryName,
 		     const StatsVariable *valueVariable, std::vector<QString> valueBinNames) :
@@ -415,9 +430,25 @@ bool BarSeries::selectItemsUnderMouse(const QPointF &pos, SelectionModifier modi
 {
 	Index index = getItemUnderMouse(pos);
 
+	if (modifier.shift && index.bar < 0)
+		return false;
+
+	if (!modifier.shift || lastClicked.bar < 0)
+		lastClicked = index;
+
 	std::vector<dive *> divesUnderMouse;
-	if (index.bar >= 0)
+	if (modifier.shift && lastClicked.bar >= 0 && index.bar >= 0) {
+		Index first = lastClicked;
+		Index last = index;
+		if (last <= first)
+			std::swap(first, last);
+		for (Index idx = first; idx <= last; inc(idx)) {
+			const std::vector<dive *> &dives = items[idx.bar].subitems[idx.subitem].dives;
+			divesUnderMouse.insert(divesUnderMouse.end(), dives.begin(), dives.end());
+		}
+	} else if (index.bar >= 0) {
 		divesUnderMouse = items[index.bar].subitems[index.subitem].dives;
+	}
 	processSelection(std::move(divesUnderMouse), modifier);
 
 	return index.bar >= 0;
diff --git a/stats/barseries.h b/stats/barseries.h
index 6779e5b6c..c14ce9ee2 100644
--- a/stats/barseries.h
+++ b/stats/barseries.h
@@ -82,7 +82,9 @@ private:
 		Index();
 		Index(int bar, int subitem);
 		bool operator==(const Index &i2) const;
+		bool operator<=(const Index &i2) const;
 	};
+	void inc(Index &index);
 
 	// Get item under mouse pointer, or -1 if none
 	Index getItemUnderMouse(const QPointF &f) const;
@@ -135,6 +137,7 @@ private:
 	const StatsVariable *valueVariable; // null: this is count based
 	std::vector<QString> valueBinNames;
 	Index highlighted;
+	Index lastClicked;
 	struct SubItemDesc {
 		double v;
 		std::vector<dive *> dives;
diff --git a/stats/boxseries.cpp b/stats/boxseries.cpp
index 1bbfa2cfc..c1e5537c4 100644
--- a/stats/boxseries.cpp
+++ b/stats/boxseries.cpp
@@ -18,7 +18,7 @@ static const int boxBorderWidth = 2.0;
 BoxSeries::BoxSeries(StatsView &view, StatsAxis *xAxis, StatsAxis *yAxis,
 		     const QString &variable, const QString &unit, int decimals) :
 	StatsSeries(view, xAxis, yAxis),
-	variable(variable), unit(unit), decimals(decimals), highlighted(-1)
+	variable(variable), unit(unit), decimals(decimals), highlighted(-1), lastClicked(-1)
 {
 }
 
@@ -150,9 +150,25 @@ bool BoxSeries::selectItemsUnderMouse(const QPointF &pos, SelectionModifier modi
 {
 	int index = getItemUnderMouse(pos);
 
+	if (modifier.shift && index < 0)
+		return false;
+
+	if (!modifier.shift || lastClicked < 0)
+		lastClicked = index;
+
 	std::vector<dive *> divesUnderMouse;
-	if (index >= 0)
+	if (modifier.shift && lastClicked >= 0 && index >= 0) {
+		int first = lastClicked;
+		int last = index;
+		if (last < first)
+			std::swap(first, last);
+		for (int idx = first; idx <= last; ++idx) {
+			const std::vector<dive *> &dives = items[idx]->q.dives;
+			divesUnderMouse.insert(divesUnderMouse.end(), dives.begin(), dives.end());
+		}
+	} else if (index >= 0) {
 		divesUnderMouse = items[index]->q.dives;
+	}
 	processSelection(std::move(divesUnderMouse), modifier);
 
 	return index >= 0;
diff --git a/stats/boxseries.h b/stats/boxseries.h
index 75e6cfa49..f7bf21183 100644
--- a/stats/boxseries.h
+++ b/stats/boxseries.h
@@ -53,6 +53,7 @@ private:
 	ChartItemPtr<InformationBox> information;
 	std::vector<std::unique_ptr<Item>> items;
 	int highlighted; // -1: no item highlighted
+	int lastClicked; // -1: no item clicked
 	void divesSelected(const QVector<dive *> &) override;
 };
 
diff --git a/stats/pieseries.cpp b/stats/pieseries.cpp
index 2a518debe..994ca8a57 100644
--- a/stats/pieseries.cpp
+++ b/stats/pieseries.cpp
@@ -81,7 +81,8 @@ PieSeries::PieSeries(StatsView &view, StatsAxis *xAxis, StatsAxis *yAxis, const
 	StatsSeries(view, xAxis, yAxis),
 	item(view.createChartItem<ChartPieItem>(ChartZValue::Series, pieBorderWidth)),
 	categoryName(categoryName),
-	highlighted(-1)
+	highlighted(-1),
+	lastClicked(-1)
 {
 	// Pie charts with many slices are unreadable. Therefore, subsume slices under
 	// a certain percentage as "other". But draw a minimum number of slices
@@ -270,9 +271,30 @@ bool PieSeries::selectItemsUnderMouse(const QPointF &pos, SelectionModifier modi
 {
 	int index = getItemUnderMouse(pos);
 
+	if (modifier.shift && index < 0)
+		return false;
+
+	if (!modifier.shift || lastClicked < 0)
+		lastClicked = index;
+
 	std::vector<dive *> divesUnderMouse;
-	if (index >= 0)
+	if (modifier.shift && lastClicked >= 0 && index >= 0) {
+		// Selecting a range in a pie plot is a bit special due to its cyclic nature.
+		// One way would be to always select the "shorter" path, but that would restrict the user.
+		// Thus, always select in the "positive" direction, i.e. clockwise.
+		int idx = lastClicked;
+		int last = index;
+		for (;;) {
+			const std::vector<dive *> &dives = items[idx].dives;
+			divesUnderMouse.insert(divesUnderMouse.end(), dives.begin(), dives.end());
+			if (idx == last)
+				break;
+			if (++idx >= (int)items.size())
+				idx = 0;
+		}
+	} else if (index >= 0) {
 		divesUnderMouse = items[index].dives;
+	}
 	processSelection(std::move(divesUnderMouse), modifier);
 
 	return index >= 0;
diff --git a/stats/pieseries.h b/stats/pieseries.h
index 1a132ebc3..7545e5176 100644
--- a/stats/pieseries.h
+++ b/stats/pieseries.h
@@ -65,7 +65,8 @@ private:
 	ChartItemPtr<InformationBox> information;
 	QPointF center; // center of drawing area
 	double radius; // radius of pie
-	int highlighted;
+	int highlighted; // -1: no item highlighted
+	int lastClicked; // -1: no item clicked
 	void divesSelected(const QVector<dive *> &) override;
 };