From 8b758027469920e554ce0f17fb5648cc5efe8252 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9a=20Saviot?= <lea.saviot@numworks.com>
Date: Thu, 20 Sep 2018 17:21:34 +0200
Subject: [PATCH] [calculation] Don't recompute HistoryViewCell layout if same
 calculation

---
 apps/calculation/calculation.cpp       | 5 +++++
 apps/calculation/calculation.h         | 1 +
 apps/calculation/history_view_cell.cpp | 5 +++++
 apps/calculation/history_view_cell.h   | 1 +
 4 files changed, 12 insertions(+)

diff --git a/apps/calculation/calculation.cpp b/apps/calculation/calculation.cpp
index f056918b1..a1fe11bb1 100644
--- a/apps/calculation/calculation.cpp
+++ b/apps/calculation/calculation.cpp
@@ -21,6 +21,11 @@ Calculation::Calculation() :
 {
 }
 
+bool Calculation::operator==(const Calculation& c) {
+  return strcmp(m_inputText, c.m_inputText) == 0
+      && strcmp(m_approximateOutputText, c.m_approximateOutputText) == 0;
+}
+
 void Calculation::reset() {
   m_inputText[0] = 0;
   m_exactOutputText[0] = 0;
diff --git a/apps/calculation/calculation.h b/apps/calculation/calculation.h
index 1f9b112ea..95b10336c 100644
--- a/apps/calculation/calculation.h
+++ b/apps/calculation/calculation.h
@@ -16,6 +16,7 @@ public:
     Equal
   };
   Calculation();
+  bool operator==(const Calculation& c);
   /* c.reset() is the equivalent of c = Calculation() without copy assingment. */
   void reset();
   void setContent(const char * c, Poincare::Context * context, Poincare::Expression ansExpression);
diff --git a/apps/calculation/history_view_cell.cpp b/apps/calculation/history_view_cell.cpp
index 2162786b5..3db472b29 100644
--- a/apps/calculation/history_view_cell.cpp
+++ b/apps/calculation/history_view_cell.cpp
@@ -9,6 +9,7 @@ namespace Calculation {
 
 HistoryViewCell::HistoryViewCell(Responder * parentResponder) :
   Responder(parentResponder),
+  m_calculation(nullptr),
   m_inputLayout(),
   m_exactOutputLayout(),
   m_approximateOutputLayout(),
@@ -94,6 +95,10 @@ void HistoryViewCell::layoutSubviews() {
 }
 
 void HistoryViewCell::setCalculation(Calculation * calculation) {
+  if (m_calculation != nullptr && *calculation == *m_calculation) {
+    return;
+  }
+  m_calculation = calculation;
   m_inputLayout = calculation->createInputLayout();
   m_inputView.setLayout(m_inputLayout);
   App * calculationApp = (App *)app();
diff --git a/apps/calculation/history_view_cell.h b/apps/calculation/history_view_cell.h
index 401c3ebf4..0892cba9b 100644
--- a/apps/calculation/history_view_cell.h
+++ b/apps/calculation/history_view_cell.h
@@ -36,6 +36,7 @@ public:
   Shared::ScrollableExactApproximateExpressionsView * outputView();
 private:
   constexpr static KDCoordinate k_resultWidth = 80;
+  Calculation * m_calculation;
   Poincare::Layout m_inputLayout;
   Poincare::Layout m_exactOutputLayout;
   Poincare::Layout m_approximateOutputLayout;