[apps/graph] Fix function renaming

Scenario: Funciton renamed f123456 would be saved as f12345 due to
buffer size problem

apps/graph/list/text_field_function_title_cell.cpp

@@ -30,6 +30,7 @@ void TextFieldFunctionTitleCell::setEditing(bool editing) {
   m_textField.setExtensionLength(extensionLength);
   m_textField.setEditing(true);
   m_textField.setText(previousText);
+  m_textField.setDraftTextBufferSize(Poincare::SymbolAbstract::k_maxNameSize+extensionLength);
 }
 
 bool TextFieldFunctionTitleCell::isEditing() const {

apps/graph/list/text_field_function_title_cell.h

@@ -3,7 +3,7 @@
 
 #include <apps/shared/function_title_cell.h>
 #include <apps/shared/function.h>
-#include <apps/shared/text_field_with_extension.h>
+#include "text_field_with_max_length_and_extension.h"
 
 namespace Graph {
 
@@ -42,7 +42,7 @@ private:
   constexpr static KDCoordinate k_textFieldRightMargin = 4;
   constexpr static int k_textFieldBufferSize = Shared::Function::k_maxNameWithArgumentSize;
   float verticalAlignmentGivenExpressionBaselineAndRowHeight(KDCoordinate expressionBaseline, KDCoordinate rowHeight) const override;
-  Shared::TextFieldWithExtension m_textField;
+  TextFieldWithMaxLengthAndExtension m_textField;
   char m_textFieldBuffer[k_textFieldBufferSize];
 };
 

apps/graph/list/text_field_with_max_length_and_extension.h

@@ -0,0 +1,28 @@
+#ifndef GRAPH_TEXT_FIELD_WITH_MAX_LENGTH_AND_EXTENSION_H
+#define GRAPH_TEXT_FIELD_WITH_MAX_LENGTH_AND_EXTENSION_H
+
+#include <apps/shared/text_field_with_extension.h>
+
+namespace Graph {
+
+class TextFieldWithMaxLengthAndExtension : public Shared::TextFieldWithExtension {
+public:
+  TextFieldWithMaxLengthAndExtension(size_t extensionLength,
+      Responder * parentResponder,
+      char * textBuffer,
+      size_t textBufferSize,
+      size_t draftTextBufferSize,
+      ::InputEventHandlerDelegate * inputEventHandlerDelegate,
+      ::TextFieldDelegate * delegate = nullptr,
+      const KDFont * size = KDFont::LargeFont,
+      float horizontalAlignment = 0.0f,
+      float verticalAlignment = 0.5f,
+      KDColor textColor = KDColorBlack,
+      KDColor backgroundColor = KDColorWhite) :
+    TextFieldWithExtension(extensionLength, parentResponder, textBuffer, textBufferSize, draftTextBufferSize, inputEventHandlerDelegate, delegate, size, horizontalAlignment, verticalAlignment, textColor, backgroundColor) {}
+  void setDraftTextBufferSize(size_t size) { m_contentView.setDraftTextBufferSize(size); }
+};
+
+}
+
+#endif

apps/shared/function.h

@@ -25,7 +25,7 @@ public:
   constexpr static int k_parenthesedArgumentCodePointLength = 3;
   constexpr static int k_parenthesedThetaArgumentByteLength = 4;
   constexpr static int k_parenthesedXNTArgumentByteLength = 3;
-  constexpr static int k_maxNameWithArgumentSize = Poincare::SymbolAbstract::k_maxNameSize + k_parenthesedThetaArgumentByteLength; /* Function name and null-terminating char + "(x)" */;
+  constexpr static int k_maxNameWithArgumentSize = Poincare::SymbolAbstract::k_maxNameSize + k_parenthesedThetaArgumentByteLength; /* Function name and null-terminating char + "(θ)" */;
   static bool BaseNameCompliant(const char * baseName, NameNotCompliantError * error = nullptr);
 
   // Constructors

escher/include/escher/text_field.h

@@ -55,6 +55,7 @@ protected:
     void setAlignment(float horizontalAlignment, float verticalAlignment);
     void setEditing(bool isEditing);
     void reinitDraftTextBuffer();
+    void setDraftTextBufferSize(size_t size) { m_draftTextBufferSize = size; }
     /* If the text to be appended is too long to be added without overflowing the
      * buffer, nothing is done (not even adding few letters from the text to reach
      * the maximum buffer capacity) and false is returned. */