[apps/graph] FunctionTitleCell reload

Changed TextFieldFunctionTitleCell::reloadCell to solve an issue with
the alignment of a function's name and definition when changing the
expression :
  - typing u_n = (1/3)/2 then changing to u_n = 1/(2/3) without erasing
    the formula first. u_n would no longer be aligned with the = sign.

Change-Id: Ib58e4220dc67c77639272c7ea784418bddffb432

apps/graph/list/text_field_function_title_cell.cpp

@@ -62,6 +62,11 @@ void TextFieldFunctionTitleCell::layoutSubviews(bool force) {
   m_textField.setAlignment(horizontalAlignment, verticalAlignment());
 }
 
+void TextFieldFunctionTitleCell::reloadCell() {
+  layoutSubviews();
+  FunctionTitleCell::reloadCell();
+}
+
 void TextFieldFunctionTitleCell::didBecomeFirstResponder() {
   if (isEditing()) {
     Container::activeApp()->setFirstResponder(&m_textField);

apps/graph/list/text_field_function_title_cell.h

@@ -35,6 +35,7 @@ public:
     return &m_textField;
   }
   void layoutSubviews(bool force = false) override;
+  void reloadCell() override;
 
   // Responder
   void didBecomeFirstResponder() override;