style: linting fixes

docs/index.html

@@ -83,6 +83,7 @@ redirect_to: "https://frappe.io/charts"
         <button type="button" class="btn btn-sm btn-secondary active" data-type='axis-mixed'>Mixed</button>
         <button type="button" class="btn btn-sm btn-secondary" data-type='pie'>Pie Chart</button>
         <button type="button" class="btn btn-sm btn-secondary" data-type='donut'>Donut Chart</button>
+        <button type="button" class="btn btn-sm btn-secondary" data-type='funnel'>Funnel Chart</button>
         <button type="button" class="btn btn-sm btn-secondary" data-type='percentage'>Percentage Chart</button>
       </div>
       <div class="btn-group export-buttons margin-top mx-auto" role="group">

src/js/chart.js

@@ -6,6 +6,7 @@ import PieChart from './charts/PieChart';
 import Heatmap from './charts/Heatmap';
 import AxisChart from './charts/AxisChart';
 import DonutChart from './charts/DonutChart';
+import FunnelChart from './charts/FunnelChart';
 
 const chartTypes = {
 	bar: AxisChart,
@@ -15,6 +16,7 @@ const chartTypes = {
 	heatmap: Heatmap,
 	pie: PieChart,
 	donut: DonutChart,
+	funnel: FunnelChart,
 };
 
 function getChartByType(chartType = 'line', parent, options) {

src/js/charts/FunnelChart.js

@@ -0,0 +1,85 @@
+import AggregationChart from './AggregationChart';
+import { getOffset } from '../utils/dom';
+import { getComponent } from '../objects/ChartComponents';
+import { getEndpointsForTrapezoid } from '../utils/draw-utils';
+
+export default class FunnelChart extends AggregationChart {
+	constructor(parent, args) {
+		super(parent, args);
+		this.type = 'funnel';
+		this.setup();
+	}
+
+	calc() {
+		super.calc();
+		let s = this.state;
+		
+		// calculate width and height options
+		const totalheight = this.height * 0.9;
+		const baseWidth = (2 * totalheight) / Math.sqrt(3);
+		
+
+		const reducer = (accumulator, currentValue) => accumulator + currentValue;
+		const weightage = s.sliceTotals.reduce(reducer, 0.0);
+
+		const center_x_offset = this.center.x - baseWidth / 2;
+		const center_y_offset = this.center.y - totalheight / 2;
+
+		let slicePoints = [];
+		let startPoint = [[center_x_offset, center_y_offset], [center_x_offset + baseWidth, center_y_offset]];
+		s.sliceTotals.forEach(d => {
+			let height = totalheight * d / weightage;
+			let endPoint = getEndpointsForTrapezoid(startPoint, height);
+			slicePoints.push([startPoint, endPoint]);
+			startPoint = endPoint;
+		});
+		s.slicePoints = slicePoints;
+	}
+
+	setupComponents() {
+		let s = this.state;
+
+		let componentConfigs = [
+			[
+				'funnelSlices',
+				{ },
+				function() {
+					return {
+						slicePoints: s.slicePoints,
+						colors: this.colors
+					};
+				}.bind(this)
+			]
+		];
+
+		this.components = new Map(componentConfigs
+			.map(args => {
+				let component = getComponent(...args);
+				return [args[0], component];
+			}));
+	}
+
+	bindTooltip() {
+		function getPolygonWidth(slice)  {
+			const points = slice.points;
+			return points[1].x - points[0].x;
+		}
+
+		this.container.addEventListener('mousemove', (e) => {
+			let slices = this.components.get('funnelSlices').store;
+			let slice = e.target;
+			if(slices.includes(slice)) {
+				let i = slices.indexOf(slice);
+
+				let gOff = getOffset(this.container), pOff = getOffset(slice);
+				let x = pOff.left - gOff.left + getPolygonWidth(slice)/2;
+				let y = pOff.top - gOff.top;
+				let title = (this.formatted_labels && this.formatted_labels.length > 0
+					? this.formatted_labels[i] : this.state.labels[i]) + ': ';
+				let percent = (this.state.sliceTotals[i] * 100 / this.state.grandTotal).toFixed(1);
+				this.tip.setValues(x, y, {name: title, value: percent + "%"});
+				this.tip.showTip();
+			}
+		});
+	}
+}

src/js/objects/ChartComponents.js

@@ -1,5 +1,5 @@
 import { makeSVGGroup } from '../utils/draw';
-import { makeText, makePath, xLine, yLine, yMarker, yRegion, datasetBar, datasetDot, percentageBar, getPaths, heatSquare } from '../utils/draw';
+import { makeText, makePath, xLine, yLine, yMarker, yRegion, datasetBar, datasetDot, percentageBar, getPaths, heatSquare, funnelSlice } from '../utils/draw';
 import { equilizeNoOfElements } from '../utils/draw-utils';
 import { translateHoriLine, translateVertLine, animateRegion, animateBar,
 	animateDot, animatePath, animatePathStr } from '../utils/animate';
@@ -114,6 +114,18 @@ let componentConfigs = {
 			if(newData) return [];
 		}
 	},
+	funnelSlices: {
+		layerClass: 'funnel-slices',
+		makeElements(data) {
+			return data.slicePoints.map((p, i) => {
+				return funnelSlice('funnel-slice', p[0], p[1], data.colors[i]);
+			});
+		},
+
+		animateElements(newData) {
+			if(newData) return [];
+		}
+	},
 	yAxis: {
 		layerClass: 'y axis',
 		makeElements(data) {

src/js/utils/constants.js

@@ -99,7 +99,8 @@ export const DEFAULT_COLORS = {
 	pie: DEFAULT_CHART_COLORS,
 	percentage: DEFAULT_CHART_COLORS,
 	heatmap: HEATMAP_COLORS_GREEN,
-	donut: DEFAULT_CHART_COLORS
+	donut: DEFAULT_CHART_COLORS,
+	funnel: DEFAULT_CHART_COLORS,
 };
 
 // Universal constants

src/js/utils/draw-utils.js

@@ -25,6 +25,34 @@ export function equilizeNoOfElements(array1, array2,
 	return [array1, array2];
 }
 
+export function getEndpointsForTrapezoid(startPositions, height) {
+	const endPosition = [];
+	let [point_a, point_b] = startPositions;
+
+	// For an equilateral triangle, the angles are always 60 deg.
+	// The end points on the polygons can be created using the following formula
+	//
+	// end_point_x = start_x +/- height * 1/√3
+	// end_point_y = start_y + height
+	//
+	//      b
+	//    _______________________________
+	//    \  |_|                        /
+	//     \   |                       /
+	//      \  | h                    /
+	//       \ |                     /
+	//        \|____________________/
+	//
+	//     b = h * tan(30 deg)
+	//
+
+	let multiplicationFactor = 1.0/Math.sqrt(3);
+	endPosition[0] = [point_a[0] + height * multiplicationFactor, point_a[1] + height];
+	endPosition[1] = [point_b[0] - height * multiplicationFactor, point_b[1] + height];
+
+	return endPosition;
+}
+
 export function truncateString(txt, len) {
 	if (!txt) {
 		return;

src/js/utils/draw.js

@@ -190,6 +190,16 @@ export function percentageBar(x, y, width, height,
 	return createSVG("rect", args);
 }
 
+export function funnelSlice(className, start, end, fill='none') {
+	const points = `${start[0].join()} ${start[1].join()} ${end[1].join()} ${end[0].join()}`;
+	let args = {
+		className: 'funnel-slice',
+		points: points,
+		fill: fill
+	};
+	return createSVG("polygon", args);
+}
+
 export function heatSquare(className, x, y, size, fill='none', data={}) {
 	let args = {
 		className: className,