cfilter.h

一个小的非常好用的电子书阅读器源码

#ifndef __CFILTER_H
#define __CFILTER_H

#include "CExpander.h"

class CFilter : public CCharacterSource
{
  friend class CFilterChain;
 protected:
  CCharacterSource* parent;
public:
  CFilter() : parent(NULL) {}
  void setparent(CCharacterSource* p) { parent = p; }
  virtual ~CFilter() {};
};

class vanilla : public CFilter
{
public:
  vanilla() {}
  virtual ~vanilla() {}
  virtual int getch()
  {
    return parent->getch();
  }
};

class CFilterChain
{
  CFilter* first;
  CFilter* front;
 public:
  CFilterChain() : first(NULL), front(NULL) {};
  ~CFilterChain()
    {
      CFilter* p = front;
      while (p != first)
	{
	  CFilter* pnext = p;
	  p = (CFilter*)(p->parent);
	  delete pnext;
	}
      delete first;
    }
  int getch() { return front->getch(); }
  void addfilter(CFilter* p)
    {
      if (first == NULL)
	{
	  first = front = p;
	}
      else
	{
	  p->setparent(front);
	  front = p;
	}
    }
  void setsource(CCharacterSource* p)
    {
      if (first == NULL) first = front = new vanilla;
      first->setparent(p);
    }
};

class stripcr : public CFilter
{
public:
  stripcr() {}
  virtual ~stripcr() {}
  virtual int getch()
  {
    int ch;
    do
      {
	ch = parent->getch();
      }
    while (ch == 13);
    return ch;
  }
};

class unindent : public CFilter
{
  char lc;
public:
  unindent() : lc(0) {}
  virtual ~unindent() {}
  virtual int getch()
  {
    int ch;
    if (lc == 10)
      {
	while ((ch = parent->getch()) == ' ');
      }
    else ch = parent->getch();
    lc = ch;
    return ch;
  }
};

class repara : public CFilter
{
  int tch;
public:
  repara() : tch(0) {}
  virtual ~repara() {}
  virtual int getch()
  {
    int ch = parent->getch();
    if (ch == 10)
      {
	if (tch == 10)
	  {
	    return ch;
	  }
	else
	  {
	    tch = ch;
	    return ' ';
	  }
      }
    tch = ch;
    return ch;
  }
};

class indenter : public CFilter
{
  int amnt;
  int indent;
public:
  indenter(int _a=5) : amnt(_a), indent(0) {}
  virtual ~indenter() {}
  virtual int getch()
    {
      if (indent > 0)
	{
	  indent--;
	  return ' ';
	}
      int ch = parent->getch();
      if (ch == 10)
	{
	  indent = amnt;
	}
      return ch;
    }
};

class dblspce : public CFilter
{
  bool lastlf;
public:
  dblspce() : lastlf(false) {}
  virtual ~dblspce() {}
  virtual int getch()
    {
      if (lastlf)
	{
	  lastlf = false;
	  return 10;
	}
      int ch = parent->getch();
      lastlf = (ch == 10);
      return ch;
    }
};

#endif