CategoryAxis.js revision 8209f3939e32e0e5bde64192267fdaf9db6f4fbc
/**
* CategoryAxis manages category data on an axis.
*
* @param {Object} config (optional) Configuration parameters for the Chart.
* @class CategoryAxis
* @constructor
* @extends AxisType
*/
function CategoryAxis(config)
{
CategoryAxis.superclass.constructor.apply(this, arguments);
}
CategoryAxis.NAME = "categoryAxis";
Y.extend(CategoryAxis, Y.AxisType,
{
/**
* Object storing key data.
*
* @property _indices
* @private
*/
_indices: null,
/**
* Constant used to generate unique id.
*
* @property GUID
* @type String
* @private
*/
GUID: "yuicategoryaxis",
/**
* Type of data used in `Axis`.
*
* @property _dataType
* @readOnly
* @private
*/
_type: "category",
/**
* Calculates the maximum and minimum values for the `Axis`.
*
* @method _updateMinAndMax
* @private
*/
_updateMinAndMax: function()
{
this._dataMaximum = Math.max(this.get("data").length - 1, 0);
this._dataMinimum = 0;
},
/**
* Gets an array of values based on a key.
*
* @method _getKeyArray
* @param {String} key Value key associated with the data array.
* @param {Array} data Array in which the data resides.
* @return Array
* @private
*/
_getKeyArray: function(key, data)
{
var i = 0,
obj,
keyArr = [],
labels = [],
len = data.length;
if(!this._indices)
{
this._indices = {};
}
for(; i < len; ++i)
{
obj = data[i];
keyArr[i] = i;
labels[i] = obj[key];
}
this._indices[key] = keyArr;
return labels;
},
/**
* Sets data by key
*
* @method _setDataByKey
* @param {String} key Key value to use.
* @param {Array} data Array to use.
* @private
*/
_setDataByKey: function(key)
{
var i,
obj,
arr = [],
labels = [],
dv = this._dataClone.concat(),
len = dv.length;
if(!this._indices)
{
this._indices = {};
}
for(i = 0; i < len; ++i)
{
obj = dv[i];
arr[i] = i;
labels[i] = obj[key];
}
this._indices[key] = arr;
this.get("keys")[key] = labels.concat();
this._updateTotalDataFlag = true;
},
/**
* Returns an array of values based on an identifier key.
*
* @method getDataByKey
* @param {String} value value used to identify the array
* @return Array
*/
getDataByKey: function (value)
{
if(!this._indices)
{
this.get("keys");
}
var keys = this._indices;
if(keys[value])
{
return keys[value];
}
return null;
},
/**
* Returns the total number of majorUnits that will appear on an axis.
*
* @method getTotalMajorUnits
* @param {Object} majorUnit Object containing properties related to the majorUnit.
* @param {Number} len Length of the axis.
* @return Number
*/
getTotalMajorUnits: function(majorUnit, len)
{
return this.get("data").length;
},
/**
* Returns the distance between major units on an axis.
*
* @method getMajorUnitDistance
* @param {Number} len Number of ticks
* @param {Number} uiLen Size of the axis.
* @param {Object} majorUnit Hash of properties used to determine the majorUnit
* @return Number
*/
getMajorUnitDistance: function(len, uiLen, majorUnit)
{
var dist;
if(majorUnit.determinant === "count")
{
dist = uiLen/len;
}
else if(majorUnit.determinant === "distance")
{
dist = majorUnit.distance;
}
return dist;
},
/**
* Gets the distance that the first and last ticks are offset from there respective
* edges.
*
* @method getEdgeOffset
* @param {Number} ct Number of ticks on the axis.
* @param {Number} l Length (in pixels) of the axis.
* @return Number
*/
getEdgeOffset: function(ct, l)
{
return l/ct;
},
/**
* Calculates and returns a value based on the number of labels and the index of
* the current label.
*
* @method getLabelByIndex
* @param {Number} i Index of the label.
* @param {Number} l Total number of labels.
* @return String
*/
getLabelByIndex: function(i, l)
{
var label,
data = this.get("data"),
position = this.get("position");
if(position == "bottom" || position == "top")
{
label = data[i];
}
else
{
label = data[l - (i + 1)];
}
return label;
}
});
Y.CategoryAxis = CategoryAxis;