From 7e6694990075448df8aa30ccff6db6c8d6ef7a39 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89milie=20Feral?= <emilie.feral@numworks.com>
Date: Tue, 3 Jan 2017 14:56:51 +0100
Subject: [PATCH] [apps/regression] Add methods in data model to set the cursor
 position at a specific abscissa/ordinate

Change-Id: I95cde32b36405f57e3e6ccfa37e6e0cda70da59a
---
 apps/regression/data.cpp | 18 ++++++++++++++++++
 apps/regression/data.h   |  3 +++
 2 files changed, 21 insertions(+)

diff --git a/apps/regression/data.cpp b/apps/regression/data.cpp
index e12a6b41d..7110f805e 100644
--- a/apps/regression/data.cpp
+++ b/apps/regression/data.cpp
@@ -107,6 +107,20 @@ int Data::selectedDotIndex() {
   return m_selectedDotIndex;
 }
 
+void Data::setCursorPositionAtAbscissa(float abscissa) {
+  m_xCursorPosition = abscissa;
+  centerAxisAround(CurveViewWindow::Axis::X, m_xCursorPosition);
+  m_yCursorPosition = yValueForXValue(m_xCursorPosition);
+  centerAxisAround(CurveViewWindow::Axis::Y, m_yCursorPosition);
+}
+
+void Data::setCursorPositionAtOrdinate(float ordinate) {
+  m_yCursorPosition = ordinate;
+  centerAxisAround(CurveViewWindow::Axis::Y, m_yCursorPosition);
+  m_xCursorPosition = xValueForYValue(m_yCursorPosition);
+  centerAxisAround(CurveViewWindow::Axis::X, m_xCursorPosition);
+}
+
 /* Window */
 
 void Data::setDefault() {
@@ -197,6 +211,10 @@ float Data::yValueForXValue(float x) {
   return slope()*x+yIntercept();
 }
 
+float Data::xValueForYValue(float y) {
+  return (y - yIntercept())/slope();
+}
+
 float Data::correlationCoefficient() {
   return covariance()/(xStandardDeviation()*yStandardDeviation());
 }
diff --git a/apps/regression/data.h b/apps/regression/data.h
index f8b4731d4..abf4546cd 100644
--- a/apps/regression/data.h
+++ b/apps/regression/data.h
@@ -27,6 +27,8 @@ public:
   /* The selectedDotIndex is -1 when no dot is selected, m_numberOfPairs when
    * the mean dot is selected and the dot index otherwise */
   int selectedDotIndex();
+  void setCursorPositionAtAbscissa(float abscissa);
+  void setCursorPositionAtOrdinate(float ordinate);
 
   // Window
   void setDefault();
@@ -47,6 +49,7 @@ public:
   float slope();
   float yIntercept();
   float yValueForXValue(float x);
+  float xValueForYValue(float y);
   float correlationCoefficient();
   float squaredCorrelationCoefficient();