Java Assignment Adding Exceptions Link to assignment detail

Java Assignment - Adding Exceptions

Link to assignment details here:

https://docs.google.com/document/d/1oh7_5Mx4BMIV1KDvs0-Temi6mo2m-GIb3NpEZGu6e2M/pub?embedded=true

Solution

public class GridWriter {
  
   private GridItem items[];
   private int size;
   private int rows;
   private int columns;
   private static final int INITIAL_CAPACITY = 4;
  
   /****
   * Create a new GridWriter. It is initially empty. It has the capacity to store four GridItems before it
   * will need to double its array size. The row and column arguments are used in the display method, to
   * determine the size of the grid that is printed to standard output.
   ***/
  
   public GridWriter(int r, int c) {
       items = new GridItem[INITIAL_CAPACITY];
       size = 0;
       rows = r;
       columns = c;
   }
  
  
   /****
   * The GridWriter is a collection style class. It stores GridItems, and prints out a display grid.
   * The add method provides a way to put GridItems into the GridWriter.
   ***/
  
   public void add(GridItem item) {
      
       // If the item array is full, we double its capacity
       if (size == items.length) {
           doubleItemCapacity();
       }
      
       // Store the item GridItem in the items array
       items[size] = item;
      
       // Increment size. Size counts the number of items
       // currently stored in the GridWriter.
       size++;
   }
  
   /****
   * The display method prints a grid into standard output. The size of the grid is determined by the row and
   * column values passed into the constructor
   ***/
  
   public void display() {
       int count;
      
       // Loop through all rows
       for (int r = rows; r >= 0; r--) {
          
           // Loop through all columns
           for (int c = 0; c < columns; c++) {
              
               // Count the number of GridItems that cover this coordinate
               count = 0;
              
               for (int i = 0; i < size; i++) {
                   if (items[i].containsPoint(c, r)) {
                       count++;
                   }
               }
              
               // Print the count in the coordinate location. Or a dot if the count is 0
               if (count == 0) {      
                   System.out.print(\" .\");
               } else {
                   System.out.print(\" \" + count);
               }
           }
          
           // New line at the end of each row
           System.out.println();
       }
   }
  
   /****
   * This is a private helper method that doubles the array capacity of the grid writer
   * This allows it to accomodate a dynamic number of grid item objects
   **/
   private void doubleItemCapacity() {

       // allocate a new array with double capacity
       GridItem temp[] = new GridItem[items.length * 2];
      
       // Copy by hand, so to speak
       for (int i = 0; i < items.length; i++) {
           temp[i] = items[i];
       }
      
       // point the items array at the temp array.
       // The old array will be garbage collected
       items = temp;
   }
  
   public int size(){
       return size;
   }
  
   public GridItem get(int index) throws IndexOutOfBoundsException{
       return items[index];
   }
}