+ /**
+ * Gets the text colour.
+ * @remarks This colour is computed by comparing the lightness
+ * of the trace colour against a threshold to determine whether
+ * white or black would be more visible.
+ */
+ QColor get_text_colour() const;
+
+ /**
+ * Paints a zero axis across the viewport.
+ * @param p the QPainter to paint into.
+ * @param y the y-offset of the axis.
+ * @param left the x-coordinate of the left edge of the view.
+ * @param right the x-coordinate of the right edge of the view.
+ */
+ void paint_axis(QPainter &p, int y, int left, int right);
+
+ void add_colour_option(QWidget *parent, QFormLayout *form);
+
+ void create_popup_form();
+
+ virtual void populate_popup_form(QWidget *parent, QFormLayout *form);
+
+private Q_SLOTS:
+ void on_text_changed(const QString &text);
+
+ void on_colour_changed(const QColor &colour);
+
+ void on_popup_closed();
+
+Q_SIGNALS:
+ void visibility_changed();