[poincare] Check equivalent positions when moving Up and Down

Change-Id: I5043d0a43c981592b0b72fd1221769497520b342
2026-03-24 08:10:50 +01:00 · 2018-04-20 11:34:02 +02:00
parent 0487be1ab0
commit 8d32930eae
20 changed files with 84 additions and 66 deletions
--- a/poincare/include/poincare/expression_layout.h
+++ b/poincare/include/poincare/expression_layout.h
@@ -82,8 +82,8 @@ public:
  /* Tree navigation */
  virtual bool moveLeft(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) = 0;
  virtual bool moveRight(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) = 0;
-  virtual bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout);
-  virtual bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout);
+  virtual bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false);
+  virtual bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false);
  virtual bool moveUpInside(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout);
  virtual bool moveDownInside(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout);

@@ -147,6 +147,7 @@ protected:
  bool m_positioned;
 private:
  void detachChildAtIndex(int i);
+  bool moveVertically(VerticalDirection direction, ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited);
  bool moveInside(VerticalDirection direction, ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout);
  ExpressionLayout * replaceWithJuxtapositionOf(ExpressionLayout * leftChild, ExpressionLayout * rightChild, bool deleteAfterReplace);
  KDRect m_frame;
--- a/poincare/src/layout/binomial_coefficient_layout.cpp
+++ b/poincare/src/layout/binomial_coefficient_layout.cpp
@@ -76,22 +76,22 @@ bool BinomialCoefficientLayout::moveRight(ExpressionLayoutCursor * cursor, bool
  return false;
 }

-bool BinomialCoefficientLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool BinomialCoefficientLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // Case: kLayout.
  // Move to nLayout.
  if (cursor->pointedExpressionLayout()->hasAncestor(kLayout(), true)) {
    return nLayout()->moveUpInside(cursor, shouldRecomputeLayout);
  }
-  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

-bool BinomialCoefficientLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool BinomialCoefficientLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // Case: nLayout.
  // Move to kLayout.
  if (cursor->pointedExpressionLayout()->hasAncestor(nLayout(), true)) {
    return kLayout()->moveDownInside(cursor, shouldRecomputeLayout);
  }
-  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

 void BinomialCoefficientLayout::render(KDContext * ctx, KDPoint p, KDColor expressionColor, KDColor backgroundColor) {
--- a/poincare/src/layout/binomial_coefficient_layout.h
+++ b/poincare/src/layout/binomial_coefficient_layout.h
@@ -13,8 +13,8 @@ public:
  ExpressionLayout * clone() const override;
  bool moveLeft(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
  bool moveRight(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
+  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
+  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
  int writeTextInBuffer(char * buffer, int bufferSize, int numberOfSignificantDigits = PrintFloat::k_numberOfStoredSignificantDigits) const override {
    return LayoutEngine::writePrefixExpressionLayoutTextInBuffer(this, buffer, bufferSize, numberOfSignificantDigits, "binomial");
  }
--- a/poincare/src/layout/condensed_sum_layout.cpp
+++ b/poincare/src/layout/condensed_sum_layout.cpp
@@ -90,7 +90,7 @@ bool CondensedSumLayout::moveRight(ExpressionLayoutCursor * cursor, bool * shoul
  return false;
 }

-bool CondensedSumLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool CondensedSumLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // If the cursor is inside the subscript layout, move it to the superscript.
  if (subscriptLayout() && cursor->pointedExpressionLayout()->hasAncestor(subscriptLayout(), true)) {
    assert(superscriptLayout() != nullptr);
@@ -104,10 +104,10 @@ bool CondensedSumLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRe
    assert(superscriptLayout() != nullptr);
    return superscriptLayout()->moveUpInside(cursor, shouldRecomputeLayout);
  }
-  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

-bool CondensedSumLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool CondensedSumLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // If the cursor is inside the superscript layout, move it to the subscript.
  if (superscriptLayout() && cursor->pointedExpressionLayout()->hasAncestor(superscriptLayout(), true)) {
    assert(subscriptLayout() != nullptr);
@@ -121,7 +121,7 @@ bool CondensedSumLayout::moveDown(ExpressionLayoutCursor * cursor, bool * should
    assert(subscriptLayout() != nullptr);
    return subscriptLayout()->moveUpInside(cursor, shouldRecomputeLayout);
  }
-  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

 ExpressionLayout * CondensedSumLayout::layoutToPointWhenInserting() {
--- a/poincare/src/layout/condensed_sum_layout.h
+++ b/poincare/src/layout/condensed_sum_layout.h
@@ -12,8 +12,8 @@ public:
  ExpressionLayout * clone() const override;
  bool moveLeft(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
  bool moveRight(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
+  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
+  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
  int writeTextInBuffer(char * buffer, int bufferSize, int numberOfSignificantDigits = PrintFloat::k_numberOfStoredSignificantDigits) const override {
    return LayoutEngine::writePrefixExpressionLayoutTextInBuffer(this, buffer, bufferSize, numberOfSignificantDigits, "sum");
  }
--- a/poincare/src/layout/expression_layout.cpp
+++ b/poincare/src/layout/expression_layout.cpp
@@ -237,22 +237,16 @@ char ExpressionLayout::XNTChar() const {
  return m_parent->XNTChar();
 }

-bool ExpressionLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
-  if (m_parent) {
-    return m_parent->moveUp(cursor, shouldRecomputeLayout);
-  }
-  return false;
+bool ExpressionLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
+  return moveVertically(VerticalDirection::Up, cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

 bool ExpressionLayout::moveUpInside(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
  return moveInside(VerticalDirection::Up, cursor, shouldRecomputeLayout);
 }

-bool ExpressionLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
-  if (m_parent) {
-    return m_parent->moveDown(cursor, shouldRecomputeLayout);
-  }
-  return false;
+bool ExpressionLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
+  return moveVertically(VerticalDirection::Down, cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

 bool ExpressionLayout::moveDownInside(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
@@ -343,6 +337,29 @@ bool ExpressionLayout::moveInside(VerticalDirection direction, ExpressionLayoutC
  return true;
 }

+bool ExpressionLayout::moveVertically(VerticalDirection direction, ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
+  if (!equivalentPositionVisited) {
+    ExpressionLayoutCursor cursorEquivalent = equivalentCursor(cursor);
+    if (cursorEquivalent.isDefined()) {
+      cursor->setPointedExpressionLayout(cursorEquivalent.pointedExpressionLayout());
+      cursor->setPosition(cursorEquivalent.position());
+      if (direction == VerticalDirection::Up) {
+        return cursor->pointedExpressionLayout()->moveUp(cursor, shouldRecomputeLayout, true);
+      } else {
+        return cursor->pointedExpressionLayout()->moveDown(cursor, shouldRecomputeLayout, true);
+      }
+    }
+  }
+  if (m_parent) {
+    if (direction == VerticalDirection::Up) {
+        return m_parent->moveUp(cursor, shouldRecomputeLayout, true);
+      } else {
+        return m_parent->moveDown(cursor, shouldRecomputeLayout, true);
+      }
+  }
+  return false;
+}
+
 void ExpressionLayout::moveCursorInsideAtDirection (
    VerticalDirection direction,
    ExpressionLayoutCursor * cursor,
--- a/poincare/src/layout/fraction_layout.cpp
+++ b/poincare/src/layout/fraction_layout.cpp
@@ -143,7 +143,7 @@ bool FractionLayout::moveRight(ExpressionLayoutCursor * cursor, bool * shouldRec
  return false;
 }

-bool FractionLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool FractionLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // If the cursor is inside denominator, move it to the numerator.
  if (denominatorLayout() && cursor->pointedExpressionLayout()->hasAncestor(denominatorLayout(), true)) {
    assert(numeratorLayout() != nullptr);
@@ -154,10 +154,10 @@ bool FractionLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomp
    assert(numeratorLayout() != nullptr);
    return numeratorLayout()->moveUpInside(cursor, shouldRecomputeLayout);
  }
-  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

-bool FractionLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool FractionLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // If the cursor is inside numerator, move it to the denominator.
  if (numeratorLayout() && cursor->pointedExpressionLayout()->hasAncestor(numeratorLayout(), true)) {
    assert(denominatorLayout() != nullptr);
@@ -168,7 +168,7 @@ bool FractionLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldReco
    assert(denominatorLayout() != nullptr);
    return denominatorLayout()->moveDownInside(cursor, shouldRecomputeLayout);
  }
-  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

 int FractionLayout::writeTextInBuffer(char * buffer, int bufferSize, int numberOfSignificantDigits) const {
--- a/poincare/src/layout/fraction_layout.h
+++ b/poincare/src/layout/fraction_layout.h
@@ -14,8 +14,8 @@ public:
  void deleteBeforeCursor(ExpressionLayoutCursor * cursor) override;
  bool moveLeft(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
  bool moveRight(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
+  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
+  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
  int writeTextInBuffer(char * buffer, int bufferSize, int numberOfSignificantDigits = PrintFloat::k_numberOfStoredSignificantDigits) const override;
  ExpressionLayout * layoutToPointWhenInserting() override;
  bool canBeOmittedMultiplicationRightFactor() const override { return false; }
--- a/poincare/src/layout/grid_layout.cpp
+++ b/poincare/src/layout/grid_layout.cpp
@@ -94,7 +94,7 @@ bool GridLayout::moveRight(ExpressionLayoutCursor * cursor, bool * shouldRecompu
  return false;
 }

-bool GridLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool GridLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // If the cursor is child that is not on the top row, move it inside the upper
  // neighbourg.
  int childIndex = m_numberOfColumns;
@@ -104,10 +104,10 @@ bool GridLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeL
    }
    childIndex++;
  }
-  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

-bool GridLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool GridLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  int childIndex = 0;
  while (childIndex < numberOfChildren() - m_numberOfColumns) {
    if (cursor->pointedExpressionLayout()->hasAncestor(child(childIndex), true)) {
@@ -115,7 +115,7 @@ bool GridLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomput
    }
    childIndex++;
  }
-  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

 void GridLayout::removeChildAtIndex(int index, bool deleteAfterRemoval) {
--- a/poincare/src/layout/grid_layout.h
+++ b/poincare/src/layout/grid_layout.h
@@ -15,8 +15,8 @@ public:
  /* Navigation */
  bool moveLeft(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
  bool moveRight(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
+  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
+  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;

  /* Dynamic layout */
  void removeChildAtIndex(int index, bool deleteAfterRemoval) override;
--- a/poincare/src/layout/integral_layout.cpp
+++ b/poincare/src/layout/integral_layout.cpp
@@ -117,7 +117,7 @@ bool IntegralLayout::moveRight(ExpressionLayoutCursor * cursor, bool * shouldRec
  return false;
 }

-bool IntegralLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool IntegralLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // If the cursor is inside the lower bound, move it to the upper bound.
  if (lowerBoundLayout() && cursor->pointedExpressionLayout()->hasAncestor(lowerBoundLayout(), true)) {
    assert(upperBoundLayout() != nullptr);
@@ -131,10 +131,10 @@ bool IntegralLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomp
    assert(upperBoundLayout() != nullptr);
    return upperBoundLayout()->moveUpInside(cursor, shouldRecomputeLayout);
  }
-  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

-bool IntegralLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool IntegralLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // If the cursor is inside the upper bound, move it to the lower bound.
  if (upperBoundLayout() && cursor->pointedExpressionLayout()->hasAncestor(upperBoundLayout(), true)) {
    assert(lowerBoundLayout() != nullptr);
@@ -148,7 +148,7 @@ bool IntegralLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldReco
    assert(lowerBoundLayout() != nullptr);
    return lowerBoundLayout()->moveDownInside(cursor, shouldRecomputeLayout);
  }
-  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

 int IntegralLayout::writeTextInBuffer(char * buffer, int bufferSize, int numberOfSignificantDigits) const {
--- a/poincare/src/layout/integral_layout.h
+++ b/poincare/src/layout/integral_layout.h
@@ -19,8 +19,8 @@ public:
  /* Tree navigation */
  bool moveLeft(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
  bool moveRight(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
+  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
+  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;

  /* Expression Engine */
  int writeTextInBuffer(char * buffer, int bufferSize, int numberOfSignificantDigits = PrintFloat::k_numberOfStoredSignificantDigits) const override;
--- a/poincare/src/layout/matrix_layout.cpp
+++ b/poincare/src/layout/matrix_layout.cpp
@@ -80,7 +80,7 @@ bool MatrixLayout::moveRight(ExpressionLayoutCursor * cursor, bool * shouldRecom
  return GridLayout::moveRight(cursor, shouldRecomputeLayout);
 }

-bool MatrixLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool MatrixLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  bool shouldRemoveGreySquares = false;
  for (int childIndex = 0; childIndex < m_numberOfColumns; childIndex++) {
    if (cursor->pointedExpressionLayout()->hasAncestor(child(childIndex), true)) {
@@ -89,7 +89,7 @@ bool MatrixLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomput
      break;
    }
  }
-  bool returnValue = GridLayout::moveUp(cursor, shouldRecomputeLayout);
+  bool returnValue = GridLayout::moveUp(cursor, shouldRecomputeLayout, equivalentPositionVisited);
  if (returnValue && shouldRemoveGreySquares) {
    assert(hasGreySquares());
    removeGreySquares();
@@ -98,7 +98,7 @@ bool MatrixLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomput
  return returnValue;
 }

-bool MatrixLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool MatrixLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  bool shouldRemoveGreySquares = false;
  for (int childIndex = numberOfChildren() - m_numberOfColumns; childIndex < m_numberOfChildren; childIndex++) {
    if (cursor->pointedExpressionLayout()->hasAncestor(child(childIndex), true)) {
@@ -107,7 +107,7 @@ bool MatrixLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomp
      break;
    }
  }
-  bool returnValue = GridLayout::moveDown(cursor, shouldRecomputeLayout);
+  bool returnValue = GridLayout::moveDown(cursor, shouldRecomputeLayout, equivalentPositionVisited);
  if (returnValue && shouldRemoveGreySquares) {
    assert(hasGreySquares());
    removeGreySquares();
--- a/poincare/src/layout/matrix_layout.h
+++ b/poincare/src/layout/matrix_layout.h
@@ -13,8 +13,8 @@ public:
  /* Navigation */
  bool moveLeft(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
  bool moveRight(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
+  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
+  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
  bool moveUpInside(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
  bool moveDownInside(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;

--- a/poincare/src/layout/nth_root_layout.cpp
+++ b/poincare/src/layout/nth_root_layout.cpp
@@ -133,7 +133,7 @@ bool NthRootLayout::moveRight(ExpressionLayoutCursor * cursor, bool * shouldReco
  return false;
 }

-bool NthRootLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool NthRootLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // If the cursor is Left of the radicand, move it to the index.
  if (indexLayout()
      && radicandLayout()
@@ -153,10 +153,10 @@ bool NthRootLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecompu
    cursor->setPosition(ExpressionLayoutCursor::Position::Left);
    return true;
  }
-  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

-bool NthRootLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool NthRootLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  if (indexLayout() && cursor->pointedExpressionLayout()->hasAncestor(indexLayout(), true)) {
    // If the cursor is Right of the index, move it to the radicand.
    if (cursor->positionIsEquivalentTo(indexLayout(), ExpressionLayoutCursor::Position::Right)) {
@@ -172,7 +172,7 @@ bool NthRootLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecom
      return true;
    }
  }
-  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

 static_assert('\x90' == Ion::Charset::Root, "Unicode error");
--- a/poincare/src/layout/nth_root_layout.h
+++ b/poincare/src/layout/nth_root_layout.h
@@ -20,8 +20,8 @@ public:
  /* Tree navigation */
  bool moveLeft(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
  bool moveRight(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
+  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
+  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;

  /* Expression Engine */
  int writeTextInBuffer(char * buffer, int bufferSize, int numberOfSignificantDigits = PrintFloat::k_numberOfStoredSignificantDigits) const override;
--- a/poincare/src/layout/sequence_layout.cpp
+++ b/poincare/src/layout/sequence_layout.cpp
@@ -98,7 +98,7 @@ bool SequenceLayout::moveRight(ExpressionLayoutCursor * cursor, bool * shouldRec
  return false;
 }

-bool SequenceLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool SequenceLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // If the cursor is inside the lower bound, move it to the upper bound.
  if (lowerBoundLayout() && cursor->pointedExpressionLayout()->hasAncestor(lowerBoundLayout(), true)) {
    assert(upperBoundLayout() != nullptr);
@@ -111,10 +111,10 @@ bool SequenceLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomp
    assert(upperBoundLayout() != nullptr);
    return upperBoundLayout()->moveUpInside(cursor, shouldRecomputeLayout);
  }
-  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

-bool SequenceLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool SequenceLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // If the cursor is inside the upper bound, move it to the lower bound.
  if (upperBoundLayout() && cursor->pointedExpressionLayout()->hasAncestor(upperBoundLayout(), true)) {
    assert(lowerBoundLayout() != nullptr);
@@ -127,7 +127,7 @@ bool SequenceLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldReco
    assert(lowerBoundLayout() != nullptr);
    return lowerBoundLayout()->moveDownInside(cursor, shouldRecomputeLayout);
  }
-  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

 ExpressionLayout * SequenceLayout::layoutToPointWhenInserting() {
--- a/poincare/src/layout/sequence_layout.h
+++ b/poincare/src/layout/sequence_layout.h
@@ -13,8 +13,8 @@ public:
  void deleteBeforeCursor(ExpressionLayoutCursor * cursor) override;
  bool moveLeft(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
  bool moveRight(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
+  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
+  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
  ExpressionLayout * layoutToPointWhenInserting() override;
  char XNTChar() const override;
 protected:
--- a/poincare/src/layout/vertical_offset_layout.cpp
+++ b/poincare/src/layout/vertical_offset_layout.cpp
@@ -120,7 +120,7 @@ bool VerticalOffsetLayout::moveRight(ExpressionLayoutCursor * cursor, bool * sho
  return false;
 }

-bool VerticalOffsetLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool VerticalOffsetLayout::moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // Case: Superscript.
  if (m_type == VerticalOffsetLayout::Type::Superscript) {
    // Case: Right.
@@ -151,10 +151,10 @@ bool VerticalOffsetLayout::moveUp(ExpressionLayoutCursor * cursor, bool * should
    cursor->setPointedExpressionLayout(this);
    return true;
  }
-  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveUp(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

-bool VerticalOffsetLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) {
+bool VerticalOffsetLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited) {
  // Case: Subscript.
  if (m_type == VerticalOffsetLayout::Type::Subscript) {
    // Case: Right.
@@ -184,7 +184,7 @@ bool VerticalOffsetLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shou
    cursor->setPointedExpressionLayout(this);
    return true;
  }
-  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout);
+  return ExpressionLayout::moveDown(cursor, shouldRecomputeLayout, equivalentPositionVisited);
 }

 int VerticalOffsetLayout::writeTextInBuffer(char * buffer, int bufferSize, int numberOfSignificantDigits) const {
--- a/poincare/src/layout/vertical_offset_layout.h
+++ b/poincare/src/layout/vertical_offset_layout.h
@@ -17,8 +17,8 @@ public:
  void deleteBeforeCursor(ExpressionLayoutCursor * cursor) override;
  bool moveLeft(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
  bool moveRight(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
-  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout) override;
+  bool moveUp(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
+  bool moveDown(ExpressionLayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) override;
  int writeTextInBuffer(char * buffer, int bufferSize, int numberOfSignificantDigits = PrintFloat::k_numberOfStoredSignificantDigits) const override;
  bool mustHaveLeftSibling() const override { return true; }
  bool isVerticalOffset() const { return true; }