var CanvasPool = require('../../display/canvas/CanvasPool'); 
var MeasureText = function (textStyle){ 
var canvas = CanvasPool.create(this); 
var context = canvas.getContext('2d'); 
textStyle.syncFont(canvas, context); 
var width = Math.ceil(context.measureText(textStyle.testString).width * 1.2); 
var baseline = width; 
var height = 2 * baseline; 
baseline = baseline * 1.4 | 0; 
canvas.width = width; 
canvas.height = height; 
context.fillStyle = '#f00'; 
context.fillRect(0, 0, width, height); 
context.font = textStyle._font; 
context.textBaseline = 'alphabetic'; 
context.fillStyle = '#000'; 
context.fillText(textStyle.testString, 0, baseline); 
var output = { 
ascent: 0,
descent: 0,
fontSize: 0}
; 
if (!context.getImageData(0, 0, width, height)) { 
output.ascent = baseline; 
output.descent = baseline + 6; 
output.fontSize = output.ascent + output.descent; 
CanvasPool.remove(canvas); 
return output; 
} 
var imagedata = context.getImageData(0, 0, width, height).data; 
var pixels = _AN_Read_length('length', imagedata); 
var line = width * 4; 
var i; 
var j; 
var idx = 0; 
var stop = false ; 
for (i = 0; i < baseline; i++ ){ 
for (j = 0; j < line; j += 4){ 
if (imagedata[idx + j] !== 255) { 
stop = true ; 
break ; 
} 
} 
if (!stop) { 
idx += line; 
} 
 else { 
break ; 
} 
} 
output.ascent = baseline - i; 
idx = pixels - line; 
stop = false ; 
for (i = height; i > baseline; i-- ){ 
for (j = 0; j < line; j += 4){ 
if (imagedata[idx + j] !== 255) { 
stop = true ; 
break ; 
} 
} 
if (!stop) { 
idx -= line; 
} 
 else { 
break ; 
} 
} 
output.descent = (i - baseline); 
output.fontSize = output.ascent + output.descent; 
CanvasPool.remove(canvas); 
return output; 
} 
; 
module.exports = MeasureText;