Creating Calendars using C Language

Creating Calendars using C Language

This is a project about Creating Calendars using C programming language. which is a console application without graphics. Many properties of Windows have been used in this project to make the calendar colorful. Apart from the color used for the background, the days of the month are white and public holidays (Sundays) are represented by a red foreground color.

In this Calendar project, you can find the day corresponding to a certain date and see the day and date corresponding to a particular month + year. The source code is not that long, more than 400 lines. It is compiled with the GCC compiler in the Code::Blocks IDE. To help you better understand the Calendar Project, there are several comments in the source code. Bank Management System using C Programming Language

About Calendar in C language

Basically, you can do three operations in this calendar app. To find the day corresponding to a certain date, the date, month and year are requested. You can easily list the days and dates of any month of any year.

You can navigate through the months using the arrow keys, or press the ‘N’ and ‘P’ keys to view the next and previous month, respectively. The third feature of this project uses file management in the calendar app. With this feature, you can add important notes with relevant dates.

The functions used in this Calendar Project are simple and easy to understand. The ones listed below have been used to create the color effect background. They are described with comments in the source code.

  • void setColor(int ForgC)
  • void ClearConsoleToColors(int ForgC, int BackC)
  • void setColor&Background(int forgC, int backC)

void gotoxy(int x, int y): You should understand this function because it is important and used in this C language calendar. You can use this function in many C projects. This function allows you to print text anywhere on the screen. Using this function in Code::Blocks requires coding, but can be used directly in Turbo C. Here is some code for this function in Code::Blocks.

Creating Calendars using C Language (Source Code)

#include<stdio.h>
#include<conio.h>
#include<windows.h>
struct Date{
    int dd;
    int mm;
    int yy;
};
struct Date date;

struct Remainder{
    int dd;
    int mm;
    char note[50];
};
struct Remainder R;


COORD xy = {0, 0};

void gotoxy (int x, int y)
{
        xy.X = x; xy.Y = y; // X and Y coordinates
        SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), xy);
}

//This will set the forground color for printing in a console window.
void SetColor(int ForgC)
{
     WORD wColor;
     //We will need this handle to get the current background attribute
     HANDLE hStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
     CONSOLE_SCREEN_BUFFER_INFO csbi;

     //We use csbi for the wAttributes word.
     if(GetConsoleScreenBufferInfo(hStdOut, &csbi))
     {
        //Mask out all but the background attribute, and add in the forgournd color
          wColor = (csbi.wAttributes & 0xF0) + (ForgC & 0x0F);
          SetConsoleTextAttribute(hStdOut, wColor);
     }
     return;
}

void ClearColor(){
    SetColor(15);
}

void ClearConsoleToColors(int ForgC, int BackC)
{
     WORD wColor = ((BackC & 0x0F) << 4) + (ForgC & 0x0F);
     //Get the handle to the current output buffer...
     HANDLE hStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
     //This is used to reset the carat/cursor to the top left.
     COORD coord = {0, 0};
     //A return value... indicating how many chars were written
     //   not used but we need to capture this since it will be
     //   written anyway (passing NULL causes an access violation).
     DWORD count;

     //This is a structure containing all of the console info
     // it is used here to find the size of the console.
     CONSOLE_SCREEN_BUFFER_INFO csbi;
     //Here we will set the current color
     SetConsoleTextAttribute(hStdOut, wColor);
     if(GetConsoleScreenBufferInfo(hStdOut, &csbi))
     {
          //This fills the buffer with a given character (in this case 32=space).
          FillConsoleOutputCharacter(hStdOut, (TCHAR) 32, csbi.dwSize.X * csbi.dwSize.Y, coord, &count);

          FillConsoleOutputAttribute(hStdOut, csbi.wAttributes, csbi.dwSize.X * csbi.dwSize.Y, coord, &count );
          //This will set our cursor position for the next print statement.
          SetConsoleCursorPosition(hStdOut, coord);
     }
     return;
}

void SetColorAndBackground(int ForgC, int BackC)
{
     WORD wColor = ((BackC & 0x0F) << 4) + (ForgC & 0x0F);;
     SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), wColor);
     return;
}

int check_leapYear(int year){ //checks whether the year passed is leap year or not
    if(year % 400 == 0 || (year % 100!=0 && year % 4 ==0))
       return 1;
    return 0;
}

void increase_month(int *mm,  int *yy){ //increase the month by one
    ++*mm;
    if(*mm > 12){
        ++*yy;
        *mm = *mm - 12;
    }
}

void decrease_month(int *mm,  int *yy){ //decrease the month by one
    --*mm;
    if(*mm < 1){
        --*yy;
        if(*yy<1600){
            printf("No record available");
            return;
        }
        *mm = *mm + 12;
    }
}


int getNumberOfDays(int month,int year){ //returns the number of days in given month
   switch(month){                          //and year
      case 1 : return(31);
      case 2 : if(check_leapYear(year)==1)
		 return(29);
	       else
		 return(28);
      case 3 : return(31);
      case 4 : return(30);
      case 5 : return(31);
      case 6 : return(30);
      case 7 : return(31);
      case 8 : return(31);
      case 9 : return(30);
      case 10: return(31);
      case 11: return(30);
      case 12: return(31);
      default: return(-1);
   }
}

char *getName(int day){ //returns the name of the day
   switch(day){
      case 0 :return("Sunday");
      case 1 :return("Monday");
      case 2 :return("Tuesday");
      case 3 :return("Wednesday");
      case 4 :return("Thursday");
      case 5 :return("Friday");
      case 6 :return("Saturday");
      default:return("Error in getName() module.Invalid argument passed");
   }
}

void print_date(int mm, int yy){ //prints the name of month and year
    printf("---------------------------\n");
    gotoxy(25,6);
    switch(mm){
        case 1: printf("January"); break;
        case 2: printf("February"); break;
        case 3: printf("March"); break;
        case 4: printf("April"); break;
        case 5: printf("May"); break;
        case 6: printf("June"); break;
        case 7: printf("July"); break;
        case 8: printf("August"); break;
        case 9: printf("September"); break;
        case 10: printf("October"); break;
        case 11: printf("November"); break;
        case 12: printf("December"); break;
    }
    printf(" , %d", yy);
    gotoxy(20,7);
    printf("---------------------------");
}
int getDayNumber(int day,int mon,int year){ //retuns the day number
    int res = 0, t1, t2, y = year;
    year = year - 1600;
    while(year >= 100){
        res = res + 5;
        year = year - 100;
    }
    res = (res % 7);
    t1 = ((year - 1) / 4);
    t2 = (year-1)-t1;
    t1 = (t1*2)+t2;
    t1 = (t1%7);
    res = res + t1;
    res = res%7;
    t2 = 0;
    for(t1 = 1;t1 < mon; t1++){
        t2 += getNumberOfDays(t1,y);
    }
    t2 = t2 + day;
    t2 = t2 % 7;
    res = res + t2;
    res = res % 7;
    if(y > 2000)
        res = res + 1;
    res = res % 7;
    return res;
}

char *getDay(int dd,int mm,int yy){
    int day;
    if(!(mm>=1 && mm<=12)){
        return("Invalid month value");
    }
    if(!(dd>=1 && dd<=getNumberOfDays(mm,yy))){
        return("Invalid date");
    }
    if(yy>=1600){
        day = getDayNumber(dd,mm,yy);
        day = day%7;
        return(getName(day));
    }else{
        return("Please give year more than 1600");
    }
}

int checkNote(int dd, int mm){
    FILE *fp;
    fp = fopen("note.dat","rb");
    if(fp == NULL){
        printf("Error in Opening the file");
    }
    while(fread(&R,sizeof(R),1,fp) == 1){
        if(R.dd == dd && R.mm == mm){
            fclose(fp);
            return 1;
        }
    }
    fclose(fp);
    return 0;
}

void printMonth(int mon,int year,int x,int y){ //prints the month with all days
    int nod, day, cnt, d = 1, x1 = x, y1 = y, isNote = 0;
    if(!(mon>=1 && mon<=12)){
        printf("INVALID MONTH");
        getch();
        return;
    }
    if(!(year>=1600)){
        printf("INVALID YEAR");
        getch();
        return;
    }
    gotoxy(20,y);
    print_date(mon,year);
    y += 3;
    gotoxy(x,y);
    printf("S   M   T   W   T   F   S   ");
    y++;
    nod = getNumberOfDays(mon,year);
    day = getDayNumber(d,mon,year);
    switch(day){ //locates the starting day in calender
        case 0 :
            x=x;
            cnt=1;
            break;
        case 1 :
            x=x+4;
            cnt=2;
            break;
        case 2 :
            x=x+8;
            cnt=3;
            break;
        case 3 :
            x=x+12;
            cnt=4;
            break;
        case 4 :
            x=x+16;
            cnt=5;
            break;
        case 5 :
            x=x+20;
            cnt=6;
            break;
        case 6 :
            x=x+24;
            cnt=7;
            break;
        default :
            printf("INVALID DATA FROM THE getOddNumber()MODULE");
            return;
    }
    gotoxy(x,y);
    if(cnt == 1){
        SetColor(12);
    }
    if(checkNote(d,mon)==1){
            SetColorAndBackground(15,12);
    }
    printf("%02d",d);
    SetColorAndBackground(15,1);
    for(d=2;d<=nod;d++){
        if(cnt%7==0){
            y++;
            cnt=0;
            x=x1-4;
        }
        x = x+4;
        cnt++;
        gotoxy(x,y);
        if(cnt==1){
            SetColor(12);
        }else{
            ClearColor();
        }
        if(checkNote(d,mon)==1){
            SetColorAndBackground(15,12);
        }
        printf("%02d",d);
        SetColorAndBackground(15,1);
    }
    gotoxy(8, y+2);
    SetColor(14);
    printf("Press 'n'  to Next, Press 'p' to Previous and 'q' to Quit");
    gotoxy(8,y+3);
    printf("Red Background indicates the NOTE, Press 's' to see note: ");
    ClearColor();
}

void AddNote(){
    FILE *fp;
    fp = fopen("note.dat","ab+");
    system("cls");
    gotoxy(5,7);
    printf("Enter the date(DD/MM): ");
    scanf("%d%d",&R.dd, &R.mm);
    gotoxy(5,8);
    printf("Enter the Note(50 character max): ");
    fflush(stdin);
    scanf("%[^\n]",R.note);
    if(fwrite(&R,sizeof(R),1,fp)){
        gotoxy(5,12);
        puts("Note is saved sucessfully");
        fclose(fp);
    }else{
        gotoxy(5,12);
        SetColor(12);
        puts("\aFail to save!!\a");
        ClearColor();
    }
    gotoxy(5,15);
    printf("Press any key............");
    getch();
    fclose(fp);
}

void showNote(int mm){
    FILE *fp;
    int i = 0, isFound = 0;
    system("cls");
    fp = fopen("note.dat","rb");
    if(fp == NULL){
        printf("Error in opening the file");
    }
    while(fread(&R,sizeof(R),1,fp) == 1){
        if(R.mm == mm){
            gotoxy(10,5+i);
            printf("Note %d Day = %d: %s", i+1, R.dd,  R.note);
            isFound = 1;
            i++;
        }
    }
    if(isFound == 0){
        gotoxy(10,5);
        printf("This Month contains no note");
    }
    gotoxy(10,7+i);
    printf("Press any key to back.......");
    getch();

}

int main(){
    ClearConsoleToColors(15, 1);
    SetConsoleTitle("Calender Project - Programming-technique.blogspot.com");
    int choice;
    char ch = 'a';
    while(1){
        system("cls");
        printf("1. Find Out the Day\n");
        printf("2. Print all the day of month\n");
        printf("3. Add Note\n");
        printf("4. EXIT\n");
        printf("ENTER YOUR CHOICE : ");
        scanf("%d",&choice);
        system("cls");
        switch(choice){
            case 1:
                printf("Enter date (DD MM YYYY) : ");
                scanf("%d %d %d",&date.dd,&date.mm,&date.yy);
                printf("Day is : %s",getDay(date.dd,date.mm,date.yy));
                printf("\nPress any key to continue......");
                getch();
                break;
            case 2 :
                printf("Enter month and year (MM YYYY) : ");
                scanf("%d %d",&date.mm,&date.yy);
                system("cls");
                while(ch!='q'){
                    printMonth(date.mm,date.yy,20,5);
                    ch = getch();
                    if(ch == 'n'){
                        increase_month(&date.mm,&date.yy);
                        system("cls");
                        printMonth(date.mm,date.yy,20,5);
                    }else if(ch == 'p'){
                        decrease_month(&date.mm,&date.yy);
                        system("cls");
                        printMonth(date.mm,date.yy,20,5);
                    }else if(ch == 's'){
                        showNote(date.mm);
                        system("cls");
                    }
                }
                break;
            case 3:
                AddNote();
                break;
            case 4 :
                exit(0);
        }
    }
    return 0;
}