From aaca93e9149a6b428022b4e769581bc4dbb8c4ea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9a=20Saviot?= <lea.saviot@numworks.com>
Date: Tue, 9 Jan 2018 11:01:35 +0100
Subject: [PATCH] [poincare] Helper function to create log layouts.

Change-Id: I4f43d11a48e1b8bdddb6660da11e3127778a0bae
---
 poincare/include/poincare/layout_engine.h |  4 ++++
 poincare/src/layout_engine.cpp            | 23 +++++++++++++++++------
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/poincare/include/poincare/layout_engine.h b/poincare/include/poincare/layout_engine.h
index f5838d0f9..2b8c9984d 100644
--- a/poincare/include/poincare/layout_engine.h
+++ b/poincare/include/poincare/layout_engine.h
@@ -11,8 +11,12 @@ public:
   /* Expression to ExpressionLayout */
   static ExpressionLayout * createInfixLayout(const Expression * expression, Expression::FloatDisplayMode floatDisplayMode, Expression::ComplexFormat complexFormat, const char * operatorName);
   static ExpressionLayout * createPrefixLayout(const Expression * expression, Expression::FloatDisplayMode floatDisplayMode, Expression::ComplexFormat complexFormat, const char * operatorName);
+
+  /* Create special layouts */
   static ExpressionLayout * createParenthesedLayout(ExpressionLayout * layout, bool cloneLayout);
   static ExpressionLayout * createStringLayout(const char * buffer, int bufferSize, KDText::FontSize fontSize = KDText::FontSize::Large);
+  static ExpressionLayout * createLogLayout(ExpressionLayout * argument, ExpressionLayout * index);
+
 
   /* Expression to Text */
   typedef bool (*OperandNeedsParenthesis)(const Expression * e);
diff --git a/poincare/src/layout_engine.cpp b/poincare/src/layout_engine.cpp
index 14a1f14f7..f54bbba22 100644
--- a/poincare/src/layout_engine.cpp
+++ b/poincare/src/layout_engine.cpp
@@ -3,6 +3,7 @@
 #include "layout/horizontal_layout.h"
 #include "layout/parenthesis_left_layout.h"
 #include "layout/parenthesis_right_layout.h"
+#include "layout/vertical_offset_layout.h"
 extern "C" {
 #include<assert.h>
 }
@@ -49,6 +50,16 @@ ExpressionLayout * LayoutEngine::createPrefixLayout(const Expression * expressio
   return result;
 }
 
+ExpressionLayout * LayoutEngine::createParenthesedLayout(ExpressionLayout * layout, bool cloneLayout) {
+  HorizontalLayout * result = new HorizontalLayout();
+  result->addChildAtIndex(new ParenthesisLeftLayout(), 0);
+  if (layout != nullptr) {
+    result->addOrMergeChildAtIndex(cloneLayout ? layout->clone() : layout, 1);
+  }
+  result->addChildAtIndex(new ParenthesisRightLayout(), result->numberOfChildren());
+  return result;
+}
+
 ExpressionLayout * LayoutEngine::createStringLayout(const char * buffer, int bufferSize, KDText::FontSize fontSize) {
   assert(bufferSize > 0);
   HorizontalLayout * resultLayout = new HorizontalLayout();
@@ -58,12 +69,12 @@ ExpressionLayout * LayoutEngine::createStringLayout(const char * buffer, int buf
   return resultLayout;
 }
 
-ExpressionLayout * LayoutEngine::createParenthesedLayout(ExpressionLayout * layout, bool cloneLayout) {
-  HorizontalLayout * result = new HorizontalLayout();
-  result->addChildAtIndex(new ParenthesisLeftLayout(), 0);
-  result->addOrMergeChildAtIndex(cloneLayout ? layout->clone() : layout, 1);
-  result->addChildAtIndex(new ParenthesisRightLayout(), result->numberOfChildren());
-  return result;
+ExpressionLayout * LayoutEngine::createLogLayout(ExpressionLayout * argument, ExpressionLayout * index) {
+  HorizontalLayout * resultLayout = static_cast<HorizontalLayout *>(createStringLayout("log", 3));
+  VerticalOffsetLayout * offsetLayout = new VerticalOffsetLayout(index, VerticalOffsetLayout::Type::Subscript, false);
+  resultLayout->addChildAtIndex(offsetLayout, resultLayout->numberOfChildren());
+  resultLayout->addOrMergeChildAtIndex(createParenthesedLayout(argument, false), resultLayout->numberOfChildren());
+  return resultLayout;
 }
 
 int LayoutEngine::writeInfixExpressionTextInBuffer(const Expression * expression, char * buffer, int bufferSize, const char * operatorName, OperandNeedsParenthesis operandNeedsParenthesis) {