From 99af9b869240120f520376a33af5911cb134e79a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89milie=20Feral?= <emilie.feral@numworks.com>
Date: Thu, 3 Nov 2016 17:18:54 +0100
Subject: [PATCH] [apps/calculation] create a class evaluate context

Change-Id: Ic2aa40a00dec0ff67aeeb63edcb1776c3825cfbe
---
 apps/calculation/Makefile             |  1 +
 apps/calculation/evaluate_context.cpp | 27 +++++++++++++++++++++++++++
 apps/calculation/evaluate_context.h   | 22 ++++++++++++++++++++++
 3 files changed, 50 insertions(+)
 create mode 100644 apps/calculation/evaluate_context.cpp
 create mode 100644 apps/calculation/evaluate_context.h

diff --git a/apps/calculation/Makefile b/apps/calculation/Makefile
index 91c0e452e..638d36b49 100644
--- a/apps/calculation/Makefile
+++ b/apps/calculation/Makefile
@@ -2,6 +2,7 @@ app_objs += $(addprefix apps/calculation/,\
   app.o\
   calculation.o\
   calculation_store.o\
+  evaluate_context.o\
   selectable_table_view.o\
   history_view_cell.o\
   history_controller.o\
diff --git a/apps/calculation/evaluate_context.cpp b/apps/calculation/evaluate_context.cpp
new file mode 100644
index 000000000..08808a30e
--- /dev/null
+++ b/apps/calculation/evaluate_context.cpp
@@ -0,0 +1,27 @@
+#include "evaluate_context.h"
+#include <string.h>
+
+namespace Calculation {
+
+EvaluateContext::EvaluateContext(::Context * parentContext, CalculationStore * calculationStore) :
+  m_ansValue(Float(0.0f)),
+  m_calculationStore(calculationStore),
+  m_context(parentContext)
+{
+}
+
+Float * EvaluateContext::ansValue() {
+  Calculation * lastCalculation = m_calculationStore->calculationAtIndex(m_calculationStore->numberOfCalculations()-1);
+  m_ansValue = Float(lastCalculation->evaluation());
+  return &m_ansValue;
+}
+
+const Expression * EvaluateContext::expressionForSymbol(const Symbol * symbol) {
+  if (symbol->name() == Symbol::SpecialSymbols::Ans) {
+    return ansValue();
+  } else {
+    return m_context->expressionForSymbol(symbol);
+  }
+}
+
+}
diff --git a/apps/calculation/evaluate_context.h b/apps/calculation/evaluate_context.h
new file mode 100644
index 000000000..c79f1c9ba
--- /dev/null
+++ b/apps/calculation/evaluate_context.h
@@ -0,0 +1,22 @@
+#ifndef CALCULATION_EVALUATECONTEXT_H
+#define CALCULATION_EVALUATECONTEXT_H
+
+#include <poincare.h>
+#include "calculation_store.h"
+
+namespace Calculation {
+
+class EvaluateContext : public ::Context {
+  public:
+    EvaluateContext(Context * parentContext, CalculationStore * calculationStore);
+    Float * ansValue();
+    const Expression * expressionForSymbol(const Symbol * symbol) override;
+  private:
+    Float m_ansValue;
+    CalculationStore * m_calculationStore;
+    ::Context * m_context;
+};
+
+}
+
+#endif
\ No newline at end of file