Upsilon/apps/tree/layout_node.h

#ifndef LAYOUT_NODE_H
#define LAYOUT_NODE_H

#include "tree_node.h"

class LayoutCursor;

class LayoutNode : public TreeNode {
public:
  static TreeNode * FailedAllocationStaticNode();
  TreeNode * failedAllocationStaticNode() override { return FailedAllocationStaticNode(); }
  static int AllocationFailureNodeIdentifier() {
    return FailedAllocationStaticNode()->identifier();
  }
  int allocationFailureNodeIdentifier() override {
    return AllocationFailureNodeIdentifier();
  }

  /* Hierarchy */
  LayoutNode * parent() const { return static_cast<LayoutNode *>(parentTree()); }

  /* Rendering */
  void draw();
  int origin();
  int absoluteOrigin();

  /* Tree navigation */
  virtual void moveCursorLeft(LayoutCursor * cursor, bool * shouldRecomputeLayout) {}
  virtual void moveCursorRight(LayoutCursor * cursor, bool * shouldRecomputeLayout) {}
  virtual void moveCursorUp(LayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) {}
  virtual void moveCursorDown(LayoutCursor * cursor, bool * shouldRecomputeLayout, bool equivalentPositionVisited = false) {}


  LayoutNode * childAtIndex(int i) { return static_cast<LayoutNode *>(childTreeAtIndex(i)); }

protected:
  class Iterator {
    public:
    Iterator(LayoutNode * node) : m_node(node) {}
    LayoutNode * operator*() { return m_node; }
    bool operator!=(const Iterator& it) const { return (m_node != it.m_node); }
  protected:
    LayoutNode * m_node;
  };
  class DirectChildren {
  public:
    DirectChildren(LayoutNode * node) : m_node(node) {}
    class Iterator : public LayoutNode::Iterator {
    public:
      using LayoutNode::Iterator::Iterator;
      Iterator & operator++() {
        m_node = static_cast<LayoutNode *>(m_node->nextSibling());
        return *this;
      }
    };
    Iterator begin() const { return Iterator(static_cast<LayoutNode *>(m_node->next())); }
    Iterator end() const { return Iterator(static_cast<LayoutNode *>(m_node->nextSibling())); }
  private:
    LayoutNode * m_node;
  };
  DirectChildren children() { return DirectChildren(this); }

private:
  virtual void render() {};
};

#endif