Chart Elements and Hit-Testing

The FlexChart is composed of elements that can be customized using its object model. The elements are:

  • PlotArea: The area within the axes.
  • ChartArea: The area within the control but outside the axes.
  • Legend: The chart legend, usually on the right of the plot area.
  • Header: The chart header, above the plot area.
  • Footer: The chart footer, below the plot area.
  • AxisX: The X-axis, usually horizontal.
  • AxisY: The Y-axis, usually vertical.
  • Series: A chart series.
  • SeriesSymbol: A symbol in a chart series.
  • DataLabel: A label attached to a data point.

You can use the hitTest method to determine what chart area is under the mouse.

import 'bootstrap.css'; import '@grapecity/wijmo.styles/wijmo.css'; import './styles.css'; import * as wjChart from '@grapecity/wijmo.chart'; import * as wjCore from '@grapecity/wijmo'; import { getData } from './data'; // document.readyState === 'complete' ? init() : window.onload = init; // function init() { // create a chart let theChart = new wjChart.FlexChart('#theChart', { itemsSource: getData(), bindingX: 'country', chartType: 'LineSymbols', header: 'Header', footer: 'Footer', dataLabel: { content: '{value:n0}', position: 'Top', offset: 5 }, tooltip: { content: '' }, series: [ { binding: 'sales', name: 'Sales' }, { binding: 'expenses', name: 'Expenses' } ] }); theChart.palette = getRandomPalette(); // // use tooltip to show hit-test information let tt = new wjCore.Tooltip(), tip = ''; // theChart.hostElement.addEventListener('mousemove', e => { // build tooltip text let ht = theChart.hitTest(e), elem = ht.chartElement, series = (ht.series && [1, 2, 3].indexOf(elem) < 0) ? ht.series : null, index = (ht.pointIndex != null && series) ? ht.pointIndex : null, newTip = wjCore.format('chartElement: <b>{elem}</b><br/>series: <b>{series}</b><br/>pointIndex: <b>{index}</b>', { elem: wjChart.ChartElement[elem], series: series ? series.name : 'none', index: index != null ? index : 'none' }); // // update tooltip if (newTip != tip) { tip = newTip; tt.show(e.target, tip, new wjCore.Rect(e.clientX, e.clientY, 0, 0)); } }); // theChart.hostElement.addEventListener('mouseleave', e => { tt.hide(); tip = ''; }); } // function getRandomPalette() { let palettes = Object.getOwnPropertyNames(wjChart.Palettes) .filter(prop => typeof wjChart.Palettes[prop] === "object" && prop !== 'prototype'); let rand = Math.floor(Math.random() * palettes.length); // return wjChart.Palettes[palettes[rand]]; }
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <title>GrapeCity Wijmo FlexChart Chart Elements and Hit-Testing</title> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <!-- SystemJS --> <script src="node_modules/systemjs/dist/system.src.js"></script> <script src="systemjs.config.js"></script> <script> System.import('./src/app'); </script> </head> <body> <div class="container-fluid"> <div id="theChart"></div> </div> </body> </html>
// create some random data export function getData() { let countries = 'US,Germany,UK,Japan,Italy,Greece'.split(','), data = []; // for (let i = 0; i < countries.length; i++) { data.push({ country: countries[i], sales: Math.random() * 10000, expenses: Math.random() * 5000, downloads: Math.round(Math.random() * 20000) }); } // return data; }
.wj-flexchart { height: 300px; } .wj-data-label { font-size: 75%; opacity: .9; } label { width: 150px; text-align: right; } .wj-control { margin-bottom: 3px; } body { margin-bottom: 24pt; }
(function (global) { System.config({ transpiler: 'plugin-babel', babelOptions: { es2015: true }, meta: { '*.css': { loader: 'css' } }, paths: { // paths serve as alias 'npm:': 'node_modules/' }, // map tells the System loader where to look for things map: { 'jszip': 'npm:jszip/dist/jszip.js', '@grapecity/wijmo': 'npm:@grapecity/wijmo/index.js', '@grapecity/wijmo.input': 'npm:@grapecity/wijmo.input/index.js', '@grapecity/wijmo.styles': 'npm:@grapecity/wijmo.styles', '@grapecity/wijmo.cultures': 'npm:@grapecity/wijmo.cultures', '@grapecity/wijmo.chart': 'npm:@grapecity/wijmo.chart/index.js', '@grapecity/wijmo.chart.analytics': 'npm:@grapecity/wijmo.chart.analytics/index.js', '@grapecity/wijmo.chart.animation': 'npm:@grapecity/wijmo.chart.animation/index.js', '@grapecity/wijmo.chart.annotation': 'npm:@grapecity/wijmo.chart.annotation/index.js', '@grapecity/wijmo.chart.finance': 'npm:@grapecity/wijmo.chart.finance/index.js', '@grapecity/wijmo.chart.finance.analytics': 'npm:@grapecity/wijmo.chart.finance.analytics/index.js', '@grapecity/wijmo.chart.hierarchical': 'npm:@grapecity/wijmo.chart.hierarchical/index.js', '@grapecity/wijmo.chart.interaction': 'npm:@grapecity/wijmo.chart.interaction/index.js', '@grapecity/wijmo.chart.radar': 'npm:@grapecity/wijmo.chart.radar/index.js', '@grapecity/wijmo.chart.render': 'npm:@grapecity/wijmo.chart.render/index.js', '@grapecity/wijmo.chart.webgl': 'npm:@grapecity/wijmo.chart.webgl/index.js', '@grapecity/wijmo.gauge': 'npm:@grapecity/wijmo.gauge/index.js', '@grapecity/wijmo.grid': 'npm:@grapecity/wijmo.grid/index.js', '@grapecity/wijmo.grid.detail': 'npm:@grapecity/wijmo.grid.detail/index.js', '@grapecity/wijmo.grid.filter': 'npm:@grapecity/wijmo.grid.filter/index.js', '@grapecity/wijmo.grid.search': 'npm:@grapecity/wijmo.grid.search/index.js', '@grapecity/wijmo.grid.grouppanel': 'npm:@grapecity/wijmo.grid.grouppanel/index.js', '@grapecity/wijmo.grid.multirow': 'npm:@grapecity/wijmo.grid.multirow/index.js', '@grapecity/wijmo.grid.transposed': 'npm:@grapecity/wijmo.grid.transposed/index.js', '@grapecity/wijmo.grid.transposedmultirow': 'npm:@grapecity/wijmo.grid.transposedmultirow/index.js', '@grapecity/wijmo.grid.pdf': 'npm:@grapecity/wijmo.grid.pdf/index.js', '@grapecity/wijmo.grid.sheet': 'npm:@grapecity/wijmo.grid.sheet/index.js', '@grapecity/wijmo.grid.xlsx': 'npm:@grapecity/wijmo.grid.xlsx/index.js', '@grapecity/wijmo.grid.selector': 'npm:@grapecity/wijmo.grid.selector/index.js', '@grapecity/wijmo.grid.cellmaker': 'npm:@grapecity/wijmo.grid.cellmaker/index.js', '@grapecity/wijmo.nav': 'npm:@grapecity/wijmo.nav/index.js', '@grapecity/wijmo.odata': 'npm:@grapecity/wijmo.odata/index.js', '@grapecity/wijmo.olap': 'npm:@grapecity/wijmo.olap/index.js', '@grapecity/wijmo.pdf': 'npm:@grapecity/wijmo.pdf/index.js', '@grapecity/wijmo.pdf.security': 'npm:@grapecity/wijmo.pdf.security/index.js', '@grapecity/wijmo.viewer': 'npm:@grapecity/wijmo.viewer/index.js', '@grapecity/wijmo.xlsx': 'npm:@grapecity/wijmo.xlsx/index.js', '@grapecity/wijmo.undo': 'npm:@grapecity/wijmo.undo/index.js', '@grapecity/wijmo.interop.grid': 'npm:@grapecity/wijmo.interop.grid/index.js', '@grapecity/wijmo.touch': 'npm:@grapecity/wijmo.touch/index.js', '@grapecity/wijmo.cloud': 'npm:@grapecity/wijmo.cloud/index.js', '@grapecity/wijmo.barcode': 'npm:@grapecity/wijmo.barcode/index.js', '@grapecity/wijmo.barcode.common': 'npm:@grapecity/wijmo.barcode.common/index.js', '@grapecity/wijmo.barcode.composite': 'npm:@grapecity/wijmo.barcode.composite/index.js', '@grapecity/wijmo.barcode.specialized': 'npm:@grapecity/wijmo.barcode.specialized/index.js', 'jszip': 'npm:jszip/dist/jszip.js', 'bootstrap.css': 'npm:bootstrap/dist/css/bootstrap.min.css', 'css': 'npm:systemjs-plugin-css/css.js', 'plugin-babel': 'npm:systemjs-plugin-babel/plugin-babel.js', 'systemjs-babel-build':'npm:systemjs-plugin-babel/systemjs-babel-browser.js' }, // packages tells the System loader how to load when no filename and/or no extension packages: { src: { defaultExtension: 'js' }, "node_modules": { defaultExtension: 'js' }, } }); })(this);