/**
+ * @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);
+ }
+ }
+ }
+});