[shared] Make a parent class to Function: ExpressionModel (factorize

code for furtur model Equation)

apps/shared/expression_model.cpp

@@ -0,0 +1,87 @@
+#include "function.h"
+#include <string.h>
+#include <cmath>
+#include <assert.h>
+
+using namespace Poincare;
+
+namespace Shared {
+
+ExpressionModel::ExpressionModel() :
+  m_text{0},
+  m_expression(nullptr),
+  m_layout(nullptr)
+{
+}
+
+ExpressionModel::~ExpressionModel() {
+  if (m_layout != nullptr) {
+    delete m_layout;
+    m_layout = nullptr;
+  }
+  if (m_expression != nullptr) {
+    delete m_expression;
+    m_expression = nullptr;
+  }
+}
+
+ExpressionModel& ExpressionModel::operator=(const ExpressionModel& other) {
+  // Self-assignment is benign
+  setContent(other.m_text);
+  return *this;
+}
+
+const char * ExpressionModel::text() const {
+  return m_text;
+}
+
+Poincare::Expression * ExpressionModel::expression(Poincare::Context * context) const {
+  if (m_expression == nullptr) {
+    m_expression = Expression::ParseAndSimplify(m_text, *context);
+  }
+  return m_expression;
+}
+
+Poincare::ExpressionLayout * ExpressionModel::layout() {
+  if (m_layout == nullptr) {
+    Expression * nonSimplifiedExpression = Expression::parse(m_text);
+    if (nonSimplifiedExpression != nullptr) {
+      m_layout = nonSimplifiedExpression->createLayout(PrintFloat::Mode::Decimal);
+      delete nonSimplifiedExpression;
+    }
+  }
+  return m_layout;
+}
+
+bool ExpressionModel::isDefined() {
+  return m_text[0] != 0;
+}
+
+bool ExpressionModel::isEmpty() {
+  return m_text[0] == 0;
+}
+
+void ExpressionModel::setContent(const char * c) {
+  strlcpy(m_text, c, sizeof(m_text));
+  if (m_layout != nullptr) {
+    delete m_layout;
+    m_layout = nullptr;
+  }
+  if (m_expression != nullptr) {
+    delete m_expression;
+    m_expression = nullptr;
+  }
+}
+
+void ExpressionModel::tidy() {
+  if (m_layout != nullptr) {
+    delete m_layout;
+    m_layout = nullptr;
+  }
+  if (m_expression != nullptr) {
+    delete m_expression;
+    m_expression = nullptr;
+  }
+}
+
+}