/**
* @class Ext.chart.Label
*
* Labels is a mixin whose methods are appended onto the Series class. Labels is an interface with methods implemented
* in each of the Series (Pie, Bar, etc) for label creation and label placement.
*
* The methods implemented by the Series are:
*
* - **`onCreateLabel(storeItem, item, i, display)`** Called each time a new label is created.
* The arguments of the method are:
* - *`storeItem`* The element of the store that is related to the label sprite.
* - *`item`* The item related to the label sprite. An item is an object containing the position of the shape
* used to describe the visualization and also pointing to the actual shape (circle, rectangle, path, etc).
* - *`i`* The index of the element created (i.e the first created label, second created label, etc)
* - *`display`* The display type. May be <b>false</b> if the label is hidden
*
* - **`onPlaceLabel(label, storeItem, item, i, display, animate)`** Called for updating the position of the label.
* The arguments of the method are:
* - *`label`* The sprite label.</li>
* - *`storeItem`* The element of the store that is related to the label sprite</li>
* - *`item`* The item related to the label sprite. An item is an object containing the position of the shape
* used to describe the visualization and also pointing to the actual shape (circle, rectangle, path, etc).
* - *`i`* The index of the element to be updated (i.e. whether it is the first, second, third from the labelGroup)
* - *`display`* The display type. May be <b>false</b> if the label is hidden.
* - *`animate`* A boolean value to set or unset animations for the labels.
*/
Ext.define('Ext.chart.Label', {
/* Begin Definitions */
requires: ['Ext.draw.Color'],
/* End Definitions */
/**
* @cfg {String} display
* Specifies the presence and position of labels for each pie slice. Either "rotate", "middle", "insideStart",
* "insideEnd", "outside", "over", "under", or "none" to prevent label rendering.
* Default value: 'none'.
*/
/**
* @cfg {String} color
* The color of the label text.
* Default value: '#000' (black).
*/
/**
* @cfg {String} field
* The name of the field to be displayed in the label.
* Default value: 'name'.
*/
/**
* @cfg {Number} minMargin
* Specifies the minimum distance from a label to the origin of the visualization.
* This parameter is useful when using PieSeries width variable pie slice lengths.
* Default value: 50.
*/
/**
* @cfg {String} font
* The font used for the labels.
* Defautl value: "11px Helvetica, sans-serif".
*/
/**
* @cfg {String} orientation
* Either "horizontal" or "vertical".
* Dafault value: "horizontal".
*/
/**
* @cfg {Function} renderer
* Optional function for formatting the label into a displayable value.
* Default value: function(v) { return v; }
* @param v
*/
//@private a regex to parse url type colors.
colorStringRe: /url\s*\(\s*#([^\/)]+)\s*\)/,
//@private the mixin constructor. Used internally by Series.
constructor: function(config) {
var me = this;
me.label = Ext.applyIf(me.label || {},
{
display: "none",
color: "#000",
field: "name",
minMargin: 50,
font: "11px Helvetica, sans-serif",
orientation: "horizontal",
renderer: function(v) {
return v;
}
});
if (me.label.display !== 'none') {
me.labelsGroup = me.chart.surface.getGroup(me.seriesId + '-labels');
}
},
//@private a method to render all labels in the labelGroup
renderLabels: function() {
var me = this,
chart = me.chart,
gradients = chart.gradients,
gradient,
items = me.items,
animate = chart.animate,
config = me.label,
display = config.display,
color = config.color,
field = [].concat(config.field),
group = me.labelsGroup,
store = me.chart.store,
len = store.getCount(),
ratio = items.length / len,
i, count, j,
k, gradientsCount = (gradients || 0) && gradients.length,
colorStopTotal, colorStopIndex, colorStop,
item, label, storeItem,
sprite, spriteColor, spriteBrightness, labelColor,
Color = Ext.draw.Color,
colorString;
if (display == 'none') {
return;
}
for (i = 0, count = 0; i < len; i++) {
for (j = 0; j < ratio; j++) {
item = items[count];
label = group.getAt(count);
storeItem = store.getAt(i);
if (!item && label) {
label.hide(true);
}
if (item && field[j]) {
if (!label) {
label = me.onCreateLabel(storeItem, item, i, display, j, count);
}
me.onPlaceLabel(label, storeItem, item, i, display, animate, j, count);
//set contrast
if (config.contrast && item.sprite) {
sprite = item.sprite;
colorString = sprite._to && sprite._to.fill || sprite.attr.fill;
spriteColor = Color.fromString(colorString);
//color wasn't parsed property maybe because it's a gradient id
if (colorString && !spriteColor) {
colorString = colorString.match(me.colorStringRe)[1];
for (k = 0; k < gradientsCount; k++) {
gradient = gradients[k];
if (gradient.id == colorString) {
//avg color stops
colorStop = 0; colorStopTotal = 0;
for (colorStopIndex in gradient.stops) {
colorStop++;
colorStopTotal += Color.fromString(gradient.stops[colorStopIndex].color).getGrayscale();
}
spriteBrightness = (colorStopTotal / colorStop) / 255;
break;
}
}
}
else {
spriteBrightness = spriteColor.getGrayscale() / 255;
}
labelColor = Color.fromString(label.attr.color || label.attr.fill).getHSL();
labelColor[2] = spriteBrightness > 0.5? 0.2 : 0.8;
label.setAttributes({
fill: String(Color.fromHSL.apply({}, labelColor))
}, true);
}
}
count++;
}
}
me.hideLabels(count);
},
//@private a method to hide labels.
hideLabels: function(index) {
var labelsGroup = this.labelsGroup, len;
if (labelsGroup) {
len = labelsGroup.getCount();
while (len-->index) {
labelsGroup.getAt(len).hide(true);
}
}
}
});