Source: src/main/javascript/oracle/oj/ojdatagrid/ArrayCellSet.js

/**
 * Copyright (c) 2014, Oracle and/or its affiliates.
 * All rights reserved.
 */
 
 /**
 * A CellSet represents a collection of cells.  The CellSet is an object returned by the success callback
 * of the fetchCells method on DataGridDataSource.  This implementation of CellSet is used by the
 * array DataGridDataSource.   
 * @param {number} startRow the start row index of the cell set
 * @param {number} endRow the end row index of the cell set
 * @param {number} startColumn the start column index of the cell set
 * @param {number} endColumn the end column index of the cell set
 * @param {Object} callback the callback to invoke on to retrieve data and metadata. 
 * @constructor
 * @export
 */
oj.ArrayCellSet = function(startRow, endRow, startColumn, endColumn, callback)
{
    // assert startRow/startColumn are number
    oj.Assert.assertNumber(startRow, null);
    oj.Assert.assertNumber(endRow, null);
    oj.Assert.assertNumber(startColumn, null);
    oj.Assert.assertNumber(endColumn, null);

    this.m_startRow = startRow;
    this.m_endRow = endRow;
    this.m_startColumn = startColumn;
    this.m_endColumn = endColumn;
    this.m_callback = callback;
};

/**
 * Gets the data of the specified index.  An error is throw when 1) the range is not yet available 
 * 2) the index specified is out of bounds. 
 * @param {Object} indexes the index of each axis in which we want to retrieve the data from.  
 * @param {number} indexes.row the index of the row axis.
 * @param {number} indexes.column the index of the column axis.
 * @return {Object} the data object for the specified index.
 * @export
 */
oj.ArrayCellSet.prototype.getData = function(indexes)
{
    return this.m_callback._getCellData(indexes['row'], indexes['column']);
};

/**
 * Gets the metadata of the specified index.  An error is throw when 1) the range is not yet available 
 * 2) the index specified is out of bounds. 
 * @param {Object} indexes the index of each axis in which we want to retrieve the metadata from.  
 * @param {number} indexes.row the index of the row axis.
 * @param {number} indexes.column the index of the column axis.
 * @return {Object} the metadata object for the specific index.  The metadata that the DataGrid supports are: 
 *         1) keys - the key (of each axis) of the cell.
 * @export
 */
oj.ArrayCellSet.prototype.getMetadata = function(indexes)
{
    return this.m_callback._getCellMetadata(indexes['row'], indexes['column']);
};

/**
 * Gets the start index of the result set for the specified axis.  Valid values are "row" and "column".
 * @param {string} axis the axis in which to inquire the actual count of the result set.
 * @return {number} the start index of the result set for the specified axis.  
 * @export
 */
oj.ArrayCellSet.prototype.getStart = function(axis)
{
    if (axis == "row")
    {
        return this.m_startRow;
    }
    else if (axis == "column")
    {
        return this.m_startColumn;
    }

    return -1;
};

/**
 * Gets the actual count of the result set for the specified axis.  Valid values are "row" and "column".
 * @param {string} axis the axis in which to inquire the actual count of the result set.
 * @return {number} the actual count of the result set for the specified axis.  
 * @export
 */
oj.ArrayCellSet.prototype.getCount = function(axis)
{
    if (axis === "row")
    {
        return Math.max(0, this.m_endRow - this.m_startRow);
    }
    
    if (axis === "column")
    {
        return Math.max(0, this.m_endColumn - this.m_startColumn);
    }

    return 0;
};

////// testing methods to get properties //////
/**
 * Gets the start row property for testing
 * @return {number} the start row
 * @export
 * @ignore
 */
oj.ArrayCellSet.prototype.getStartRow = function()
{
    return this.m_startRow;
};

/**
 * Gets the start column property for testing
 * @return {number} the start column
 * @export
 * @ignore
 */
oj.ArrayCellSet.prototype.getStartColumn = function()
{
    return this.m_startColumn;
};