-- devient ans-

apps/calculation/expression_field.cpp

@@ -1,6 +1,9 @@
 #include "expression_field.h"
 #include <poincare/symbol.h>
+#include <poincare/horizontal_layout.h>
+#include <poincare/code_point_layout.h>
 
+using namespace Poincare;
 namespace Calculation {
 
 bool ExpressionField::handleEvent(Ion::Events::Event event) {
@@ -21,7 +24,30 @@ bool ExpressionField::handleEvent(Ion::Events::Event event) {
        event == Ion::Events::EE)) {
     handleEventWithText(Poincare::Symbol::k_ans);
   }
-  return(::ExpressionField::handleEvent(event));
+  if (event == Ion::Events::Minus
+      && isEditing()
+      && fieldHasOnlyAMinus()) {
+    setText(Poincare::Symbol::k_ans);
+  }
+  return (::ExpressionField::handleEvent(event));
+}
+
+bool ExpressionField::fieldHasOnlyAMinus() const {
+  if (editionIsInTextField()) {
+        const char *inputBuffer = m_textField.draftTextBuffer();
+        return (inputBuffer[0] == '-' && inputBuffer[1] == '\0');
+    } 
+    Layout layout = m_layoutField.layout();
+    if (layout.type() == LayoutNode::Type::HorizontalLayout && layout.numberOfChildren() == 1) {
+        Layout child = layout.childAtIndex(0);
+        if (child.type() == LayoutNode::Type::CodePointLayout) {
+            CodePointLayout &codePointLayout = static_cast<CodePointLayout &>(child);
+            if (codePointLayout.codePoint() == '-'){
+            return true;
+            }
+        }
+    }
+    return false;
 }
 
 }

apps/calculation/expression_field.h

@@ -13,6 +13,8 @@ class ExpressionField : public ::ExpressionField {
   }
 protected:
   bool handleEvent(Ion::Events::Event event) override;
+private:
+  bool fieldHasOnlyAMinus() const;
 };
 
 }

escher/include/escher/expression_field.h

@@ -40,6 +40,10 @@ class ExpressionField : public Responder, public View {
   bool handleEvent(Ion::Events::Event event) override;
   void didBecomeFirstResponder() override;
 
+protected:
+  TextField m_textField;
+  LayoutField m_layoutField;
+
 private:
   static constexpr int k_textFieldBufferSize = TextField::maxBufferSize();
   static constexpr KDCoordinate k_minimalHeight = 37;
@@ -49,8 +53,6 @@ class ExpressionField : public Responder, public View {
   constexpr static KDCoordinate k_separatorThickness = Metric::CellSeparatorThickness;
   KDCoordinate inputViewHeight() const;
   KDCoordinate m_inputViewMemoizedHeight;
-  TextField m_textField;
-  LayoutField m_layoutField;
 };
 
 #endif