/**

* @file 控制值域的类

* @author nikai (@胖嘟嘟的骨头, nikai@baidu.com)

*/

function DataRange(layer) {

Class.call(this);

this.initOptions({

min: 0,

max: 0,

});

this.set('layer', layer);

this.bindTo('data', layer)

this.bindTo('drawOptions', layer)

this.bindTo('drawType', layer)

var me = this;

}

util.inherits(DataRange, Class);

util.extend(DataRange.prototype, {

defaultGradient: {

'0.4': 'blue',

'0.6': 'cyan',

'0.7': 'lime',

'0.8': 'yellow',

'1.0': 'red'

},

colors: [

'rgba(17, 102, 252, 0.8)',

'rgba(52, 139, 251, 0.8)',

'rgba(110, 176, 253, 0.8)',

'rgba(255, 241, 193, 0.8)',

'rgba(255, 146, 149, 0.8)',

'rgba(253, 98, 104, 0.8)',

'rgba(255, 0, 0, 0.8)',

'rgba(255, 51, 61, 0.8)'

],

// 根据count值获取对应的大小，在bubble绘制中用到

getSize: function (count) {

var size = 1;

var splitList = this.splitList;

for (var i = 0; i < splitList.length; i++) {

if ((splitList[i].start === undefined

|| splitList[i].start !== undefined

&& count >= splitList[i].start)

&& (splitList[i].end === undefined

|| splitList[i].end !== undefined && count < splitList[i].end)) {

size = splitList[i].size;

break;

}

}

return size;

},

// 根据count值获取对应的颜色，在choropleth中使用

getColorByRange: function (count) {

var color = 'rgba(50, 50, 255, 1)';

var splitList = this.splitList;

for (var i = 0; i < splitList.length; i++) {

if ((splitList[i].start === undefined

|| splitList[i].start !== undefined

&& count >= splitList[i].start)

&& (splitList[i].end === undefined

|| splitList[i].end !== undefined && count < splitList[i].end)) {

color = splitList[i].color;

break;

}

}

return color;

},

data_changed: function () {

var data = this.get('data');

if (data && data.length > 0) {

this._min = data[0].count;

this._max = data[0].count;

for (var i = 0; i < data.length; i++) {

this._max = Math.max(this._max, data[i].count);

this._min = Math.min(this._min, data[i].count);

}

}

},

drawType_changed: function () {

this.update();

},

drawOptions_changed: function () {

this.update();

},

update: function () {

var drawOptions = this.get("drawOptions");

if (drawOptions && drawOptions.splitList) {

this.splitList = drawOptions.splitList;

} else {

this.generalSplitList();

}

if (this.get("layer").getDrawType() === 'category') {

if (drawOptions && drawOptions.splitList) {

this.categorySplitList = drawOptions.splitList;

} else {

this.generalCategorySplitList();

}

}

if (this.get("layer").getDrawType() === 'heatmap' || this.get("layer").getDrawType() === 'density' || this.get("layer").getDrawType() === 'intensity') {

this.generalGradient(drawOptions.gradient || this.defaultGradient);

}

this.draw();

},

draw: function () {

if (this.get("layer").getDataRangeControl()) {

this.get("layer").dataRangeControl.show();

}

if (this.get("layer").getDrawType() === 'bubble') {

this.get("layer").dataRangeControl.drawSizeSplit(this.splitList, this.get('drawOptions'));

} else if (this.get("layer").getDrawType() === 'category') {

this.get("layer").dataRangeControl.drawCategorySplit(this.categorySplitList, this.get('drawOptions'));

} else if (this.get("layer").getDrawType() === 'choropleth') {

this.get("layer").dataRangeControl.drawChoroplethSplit(this.splitList, this.get('drawOptions'));

} else {

this.get("layer").dataRangeControl.hide();

}

},

generalSplitList: function () {

var splitNum = Math.ceil((this._max - this._min) / 7);

var index = this._min;

this.splitList = [];

var radius = 1;

while (index < this._max) {

this.splitList.push({

start: index,

end: index + splitNum,

size: radius,

color: this.colors[radius - 1]

});

index += splitNum;

radius++;

}

},

generalCategorySplitList: function () {

var colors = ['rgba(255, 255, 0, 0.8)',

'rgba(253, 98, 104, 0.8)',

'rgba(255, 146, 149, 0.8)',

'rgba(255, 241, 193, 0.8)',

'rgba(110, 176, 253, 0.8)',

'rgba(52, 139, 251, 0.8)',

'rgba(17, 102, 252, 0.8)'];

var data = this.get("data");

this.categorySplitList = {};

var count = 0;

for (var i = 0; i < data.length; i++) {

if (this.categorySplitList[data[i].count] === undefined) {

this.categorySplitList[data[i].count] = colors[count];

count++;

}

if (count >= colors.length - 1) {

break;

}

}

this.categorySplitList['other'] = colors[colors.length - 1];

},

getCategoryColor: function (count) {

var splitList = this.categorySplitList;

var color = splitList['other'];

for (var i in splitList) {

if (count == i) {

color = splitList[i];

break;

}

}

return color;

},

generalGradient: function (grad) {

// create a 256x1 gradient that we'll use to turn a grayscale heatmap into a colored one

var canvas = document.createElement('canvas');

var ctx = canvas.getContext('2d');

var gradient = ctx.createLinearGradient(0, 0, 0, 256);

canvas.width = 1;

canvas.height = 256;

for (var i in grad) {

gradient.addColorStop(i, grad[i]);

}

ctx.fillStyle = gradient;

ctx.fillRect(0, 0, 1, 256);

this._grad = ctx.getImageData(0, 0, 1, 256).data;

},

getGradient: function () {

return this._grad;

},

getColorByGradient: function (count) {

var max = this.get("max") || 10;

var index = count / max;

if (index > 1) {

index = 1;

}

index *= 255;

index = parseInt(index, 10);

index *= 4;

var color = 'rgba(' + this._grad[index] + ', ' + this._grad[index + 1] + ', ' + this._grad[index + 2] + ',0.8)';

return color;

}

}); // end extend