CODEWITHSUNDEEP
javaandroiddatecalendar
input
input

Reputation: 7519

Set first day of the week using array

I have a string array which holds the names of the weekdays:

private final String[] weekdays = new String[]{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};

I have set Monday as the first day of the week by default.

Now I have given the user the option to select if s/he wants to set either Sunday or Monday as the first day of the week:

if (firstDay == 0) {
    holder.txtWeekdays.setText(weekdays[position]);
 }

Using the same String array how do I set Sunday as the first day of the Week? 

else {
     holder.txtWeekdays.setText(weekdays[position]-1);  //this returns an error 
}

UPDATED CODE:

public class CalendarWeekAdapter extends BaseAdapter{

private final String[] weekdays = new String[]{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};
Context mContext;

   private LayoutInflater mInflater;
   public CalendarWeekAdapter(Context c)
   {
          mContext=c;
          mInflater = LayoutInflater.from(c);
   }
   public int getCount()
   {
          return weekdays.length;
   }
   public Object getItem(int position)
   {
          return position;
   }
   public long getItemId(int position)
   {
          return position;
   }
   public View getView(int position, View convertView, ViewGroup parent)
   {
          ViewHolder holder=null;
          if(convertView==null)
          {
                 convertView = mInflater.inflate(R.layout.calendar_week_gridcell, parent,false);
                 holder = new ViewHolder();
                 holder.txtWeekdays=(TextView)convertView.findViewById(R.id.weekdays);
                 if(position==0)
                 {                             
                       convertView.setTag(holder);
                 }
          }
          else
          {
                 holder = (ViewHolder) convertView.getTag();
          }

          if (firstDay == 0) {
              holder.txtWeekdays.setText(weekdays[position]);
          }
          else {
              holder.txtWeekdays.setText(weekdays[position]); 
          }

          return convertView;
   }

}
static class ViewHolder
{        
      TextView txtWeekdays;                 
}

Upvotes: 0

Views: 3235

Answers (8)

Bharat Sinha
Bharat Sinha

Reputation: 14363

What i would do in this case is

private final String[] weekdays = new String[]{"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};

and

if (user selected monday) {
    days_start_index = 1;
    days_end_index = 7;
} else {
    days_start_index = 0;
    days_end_index = 6;
}

You can use it in the following manner...

for (int i=days_start_index; i<=days_end_index;i++)
    // Do whatever you want

EDIT To access nth day you should use...

weekdays[n-1+days_start_index]

OR

Else could be tweaked in this manner:

if(position==0){
    position = 7;
}
holder.txtWeekdays.setText(weekdays[position-1]);

Upvotes: 2

Dave
Dave

Reputation: 106

While it doesn't answer your question directly, this would be best implemented as an enum, something like this:

/*
 * Easily Localize these by setting the short and long day
 * names using standard Java localization techniques
 * 
 * */
enum DayOfWeek {
    MONDAY("Mon", "Monday"), 
    TUESDAY("Tue", "Tuesday"),
    WEDNESAY("Wed", "Wednesday"),
    THURSDAY("Thurs", "Thursday"),
    FRIDAY("Fri", "Friday"),
    SATURDAY("Sat", "Saturday"),
    SUNDAY("Sun", "Sunday");


    DayOfWeek(final String shortDayName, final String longDayName) {
         this.shortName = shortDayName;
         this.longName = longDayName;
    }

    public String shortName() {
        return shortName;
    }

    public String longName() {
        return longName;
    }

    private final String shortName;
    private final String longName;
}

The values are then much more easily manipulated and even localized. You can write a method that takes a DayOfWeek and returns the next day and previous day when passed a day etc.

Upvotes: 2

Jason Carter
Jason Carter

Reputation: 49

I'm not really sure where your position variable comes from, but in your line of thinking, the following would work:

holder.txtWeekdays.setText(weekdays[position-1])

I would suggest using an Enum to hold the days of the week instead. This would be a bit more readable.

Upvotes: 0

Rrr
Rrr

Reputation: 1777

First of all I'll suggest to use enum for week days, since it's finite and predefined, plus you won't have ArrayIndexOutOfBoundsException. Secondly, I would create week abstraction, since it depends from context (e.g. usually working week is only 5 days, but in Israel it starts from Sunday), so this abstraction will have starting day, and collection of week days.

Upvotes: 0

Eng.Fouad
Eng.Fouad

Reputation: 117617

You can do it like this:

holder.txtWeekdays.setText(weekdays[position == 0? weekdays.length - 1 : position - 1]);

Upvotes: 0

Cat
Cat

Reputation: 67522

You are trying to subtract 1 from a string. That's not really going to work.

What you need to do is create a method that returns the day of the week. Something like this:

public String getDayOfWeek(int day, int firstDay) {
   String[] weekdays;
   if (firstDay == 0)
      weekdays = new String[]{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};
   else
      weekdays = new String[]{"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
   return weekdays[day];
}

Now, you COULD do this by position (using weekdays[position - 1]), but the above will help you avoid errors in your code (indexing -1 for example), and give you more clarity as to what is being returned.

Upvotes: 2

Evandro Silva
Evandro Silva

Reputation: 1402

Maybe I'm wrong but is it something like this you want?

else {
     holder.txtWeekdays.setText(weekdays[weekdays.length - 1]); 
}

If you want the las index:

else {
     holder.txtWeekdays.setText(weekdays[position - 1]); 
}

Upvotes: 0

Avichal Badaya
Avichal Badaya

Reputation: 3639

it should be [position -1] instead of weekdays[position]-1 . and check for the position ==0 ( index error)

Upvotes: 0

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