// ==========================================================================
// Project:   SproutCore - JavaScript Application Framework
// Copyright: ©2006-2011 Strobe Inc. and contributors.
//            Portions ©2008-2011 Apple Inc. All rights reserved.
// License:   Licensed under MIT license (see license.js)
// ==========================================================================


/** 
  @namespace
  
  CollectionRowDelegates are consulted by SC.ListView and SC.TableView to
  control the height of rows, including specifying custom heights for
  specific rows.
  
  You can implement a custom row height in one of two ways.
*/
SC.CollectionRowDelegate = {

  /**
    Walk like a duck.
  
    @type Boolean
    @default YES
  */
  isCollectionRowDelegate: YES,
  
  /**
    Size of an item without spacing or padding.
    Unless you implement some custom row height
    support, this row height will be used for all items.
    
    @type Number
    @default 18
  */
  itemHeight: 18,
  
  /**
    This inserts empty space between rows that you can use for borders.
    
    @type Number
    @default 0
  */
  rowSpacing: 0,
  
  /**
    This is useful if you are using a custom item view that needs to be padded.
    This value is added to the top and bottom of the itemHeight.
    
    @type Number
    @default 0
  */
  rowPadding: 0,
  
  /**
    Total row height used for calculation. Equal to itemHeight + twice rowPadding.
    
    @type Number
  */
  rowHeight: function(key, value) {
    var rowPadding = this.get('rowPadding');
    var itemHeight = this.get('itemHeight');

    if (value !== undefined) {
      this.set('itemHeight', value-rowPadding*2);
      return value;
    }

    return itemHeight + rowPadding * 2;
  }.property('itemHeight', 'rowPadding'),

  /**
    Index set of rows that should have a custom row height. If you need
    certains rows to have a custom row height, then set this property to a
    non-null value.  Otherwise leave it blank to disable custom row heights.
    
    @type SC.IndexSet
  */
  customRowHeightIndexes: null,
  
  /**
    Called for each index in the customRowHeightIndexes set to get the 
    actual row height for the index.  This method should return the default
    rowHeight if you don't want the row to have a custom height.
    
    The default implementation just returns the default rowHeight.
    
    @param {SC.CollectionView} view the calling view
    @param {Object} content the content array
    @param {Number} contentIndex the index 
    @returns {Number} row height
  */
  contentIndexRowHeight: function(view, content, contentIndex) {
    return this.get('rowHeight');
  }

};