gdate.cpp

一个非常有用的开源代码

/*
	Copyright (C) 2006, Mike Gashler

	This library is free software; you can redistribute it and/or
	modify it under the terms of the GNU Lesser General Public
	License as published by the Free Software Foundation; either
	version 2.1 of the License, or (at your option) any later version.

	see http://www.gnu.org/copyleft/lesser.html
*/

#include <string.h>
#include <stdio.h>
#include "GDate.h"
#include "GString.h"
#include "GMacros.h"
#ifndef WIN32
#include <stdlib.h>
#endif // not WIN32

// Constructor
GDate::GDate()
{
   m_nDay = 0;
   m_nMonth = 0;
   m_nYear = 0;
   m_nHours = 0;
   m_nMinutes = 0;
   m_nSeconds = 0;
}

// Destructor
GDate::~GDate()
{

}

// -1 = This date is before pDate
// 0  = This date is the same as pDate
// 1  = This date is after pDate
int GDate::Compare(GDate* pDate)
{
   if(pDate == this)
      return 0;
   if(m_nYear < pDate->m_nYear)
      return -1;
   if(m_nYear > pDate->m_nYear)
      return 1;
   if(m_nMonth < pDate->m_nMonth)
      return -1;
   if(m_nMonth > pDate->m_nMonth)
      return 1;
   if(m_nDay < pDate->m_nDay)
      return -1;
   if(m_nDay > pDate->m_nDay)
      return 1;
      //todo add seconds
   return 0;
}

int GDate::GetYear()
{
   return(m_nYear);
}

// Constant strings used by the month methods
const char* MONTHS = "JanFebMarAprMayJunJulAugSepOctNovDec";

// This Converts a month number like 12 into text like "Dec"
/*static */ void GDate::GetMonthText(int nMonth, char* szBuff, int nMaxSize)
{
   if(nMaxSize < 1)
      return;
   if(nMonth < 1)
   {
      strcpy(szBuff, "");
      return;
   }
   int n;
   for(n = 0; n < 3 && n < nMaxSize - 1; n++)
      szBuff[n] = MONTHS[3 * (nMonth - 1) + n];
   szBuff[n] = '\0';
}

// This converts a string like "July" into a number like 7 [even if it is spelled wrong, like Julyaaaaa
/*static */ int GDate::GetMonthNumber(char* szMonth)
{
   int n;
   int i;
   char c1;
   char c2;
   bool bSame; // loop through each month and check if it is the same
   for(n = 0; n < 12; n++)
   {
      bSame = true;
      for(i = 0; i < 3; i++)
      {
         c1 = szMonth[i];
         c2 = MONTHS[3 * n + i];
         if(c1 >= 'a')
            c1 = c1 - 'a' + 'A';
         if(c2 >= 'a')
            c2 = c2 - 'a' + 'A';
         if(c1 != c2)
            bSame = false;
      }
      if(bSame)
         return(n + 1);
   }
   return(0);
}

// This produces a string like: "4 Jul 1776"
void GDate::GetDateText(char* szBuff, int nMaxSize)
{
   char szDay[20];
   char szMonth[20];
   char szYear[20];
   if(m_nDay > 0)
      sprintf(szDay, "%d", m_nDay);
   else
      strcpy(szDay, "");
   GetMonthText(m_nMonth, szMonth, 20);
   if(m_nYear > 0)
      sprintf(szYear, "%d", m_nYear);
   else
      strcpy(szYear, "");
   char szTot[64];
   sprintf(szTot, "%s %s %s", szDay, szMonth, szYear);
   GString::StrCpy(szBuff, szTot, nMaxSize);
   // todo add the seconds, etc., if they exist
}

int GDate::getAsSecondsPast1970WithAllMonthsAsThirtyDays()
{
	return (m_nYear-1970)*(12*30)*24*60*60+m_nMonth*30*24*60*60+m_nDay*24*60*60+m_nHours*60*60+m_nMinutes*60 + m_nSeconds; // phew!
}

// Parses a string into the date object like 12 May 2005 12:34:35 [last are for times!]
void GDate::SetDate(char* szDate)
{
// searches for either a recognizable month, or numbers, takes the larger of the two numbers as the day... [takes the first two numbers or three...or something...with just numbers I don't know what it does]
   m_nDay = 0;
   m_nMonth = 0;
   m_nYear = 0;
   int nData[3];
   bool bMonth[3];
   int nPieces = 0;
   int n = 0;
   int i;
   char c;

   while(true)
   {
      if(nPieces >= 3)
         break;

      // Search for the start of the next piece of info
      while(true)
      {
         if(szDate[n] == '\0')
            break;
         if(szDate[n] >= '0' && szDate[n] <= '9')
            break;
         if(szDate[n] >= 'A' && szDate[n] <= 'Z')
            break;
         if(szDate[n] >= 'a' && szDate[n] <= 'z')
            break;
         n++;
      }
      if(szDate[n] == '\0')
         break; // reached the end.

      if(szDate[n] >= '0' && szDate[n] <= '9')
      {
         // We found a number
         for(i = n + 1; true; i++)
         {
            if(szDate[i] < '0' || szDate[i] > '9')
               break;
         }
         c = szDate[i];
         szDate[i] = '\0';
         nData[nPieces] = atoi(szDate + n);
         bMonth[nPieces] = false;
         nPieces++;
         szDate[i] = c;
         n = i;
      }
      else if ( (szDate[n] <= 'z' && szDate[n] >= 'a') || (szDate[n] <= 'Z' && szDate[n] >= 'A') )
      {
         // We found some letters -- continue parsing until we are past them
         for(i = n + 1; true; i++)
         {
	 	bool isLetter = false;
            if(szDate[i] >= 'A' && szDate[i] <= 'Z')
               isLetter = true;
            else if(szDate[i] <= 'z' && szDate[i] >= 'a')
               isLetter = true;
	    if(!isLetter)
	    	break;
         }
         c = szDate[i];
         szDate[i] = '\0'; // temporarily add a zero in there, so that GetMonthNumber will be able to parse it 'quickly' when called
	 int monthNumberGot = GetMonthNumber(szDate + n);
	 if(monthNumberGot != 0)
	 {
		nData[nPieces] = monthNumberGot; 
         	bMonth[nPieces] = true;
         	nPieces++;
	 }
         szDate[i] = c;
         n = i;
      }else
      {
        //weird char!
      	n++;
      }
   }

   // Put the data we found into the right field
   for(int j = 0; j < nPieces; j++)

   {
      if(bMonth[j])
         m_nMonth = nData[j];
      else
      {
         if(nData[j] <= 31)
            m_nDay = nData[j];
         else
            m_nYear = nData[j];
      }
   }

   // now look for 00:00:00 -- or rather three more numbers...
   int numberWeHaveSoFar = 0;
   int allNumbersToHere[3];
    while(numberWeHaveSoFar < 3 && szDate[n] != '\0')
      {
      
      while(true)
      {
         if(szDate[n] == '\0')
            break;
         if(szDate[n] >= '0' && szDate[n] <= '9')
            break;
         n++;
      }
      
         if(szDate[n] == '\0')
            break;
	else if((szDate[n] >= '0' && szDate[n] <= '9'))
	{      
         for(i = n + 1; true; i++)
         {
            if(szDate[i] < '0' || szDate[i] > '9')
               break;
         }
	 // go and get it with atoi
         c = szDate[i];
         szDate[i] = '\0';
         allNumbersToHere[numberWeHaveSoFar] = atoi(szDate + n);
         numberWeHaveSoFar++;
         szDate[i] = c;
         n = i;}
	 else
	 {
	 //garbage
	 	n++;
	 }
      }
      
      if(numberWeHaveSoFar > 0)
      {
      	m_nHours = allNumbersToHere[0];
       }
      
      if(numberWeHaveSoFar > 1)
      {
      	m_nMinutes = allNumbersToHere[1];
       }
       if(numberWeHaveSoFar > 2)
      {
      	m_nMinutes = allNumbersToHere[2];
       }
   
}