profile: add height() member function to DiveTextItem

To layout the profile we need to determine the height
of texts. Add versions for a DiveTextItem and a static
function, which is passed the scale and dpr. The latter
is used to setup items, where we do not necessarily
have a text at creation time (e.g. the tankbar).

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

profile-widget/divetextitem.cpp

@@ -75,6 +75,18 @@ QFont DiveTextItem::getFont(double dpr, double scale)
 	return fnt;
 }
 
+double DiveTextItem::fontHeight(double dpr, double scale)
+{
+	QFont fnt = getFont(dpr, scale);
+	QFontMetrics fm(fnt);
+	return (double)fm.height();
+}
+
+double DiveTextItem::height() const
+{
+	return fontHeight(dpr, scale);
+}
+
 void DiveTextItem::updateText()
 {
 	if (internalText.isEmpty())

profile-widget/divetextitem.h

@@ -22,6 +22,8 @@ public:
 	const QString &text();
 	void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
 	static QFont getFont(double dpr, double scale);
+	static double fontHeight(double dpr, double scale);
+	double height() const;
 
 private:
 	void updateText();