brushXFilter

Overview

brushXFilter interaction is a horizontal-constrained version of brushFilter, specifically designed for data filtering based on X-axis dimensions. This interaction restricts users to horizontal brush selection operations (along the X-axis direction only) to filter chart elements by range, particularly suitable for time series analysis, horizontal comparison, and other scenarios.

Key characteristics:

Unidirectional operation: Only allows horizontal direction brush selection, Y-axis range is automatically fully selected

Dimensional focus: Precise control of X-axis data range (such as time ranges, numerical intervals)

Responsive updates: Dynamically triggers view updates after filtering

import { Chart } from '@antv/g2';

const chart = new Chart({ container: 'container' });

chart.options({
  type: 'line',
  autoFit: true,
  data: {
    type: 'fetch',
    value:
      'https://gw.alipayobjects.com/os/antvdemo/assets/data/blockchain.json',
  },
  encode: {
    x: (d) => new Date(d.date), // X-axis bound to time data
    y: 'total',
  },
  interaction: {
    brushXFilter: true, // Enable horizontal filtering
  },
});

chart.render();

Usage

There are two ways to configure brushXFilter interaction:

Quick Enable Mode

Enable interaction with a boolean value using default configuration:

({
  type: 'interval',
  interaction: { brushXFilter: true }, // Enable X-axis brush filter with default configuration
});

Custom Configuration Mode

Fine-tune interaction behavior through configuration options:

({
  type: 'interval',
  interaction: {
    brushXFilter: {
      reverse: false, // Disable reverse selection
      maskFill: '#rgba(0,0,0,0.3)', // Custom mask color
    },
  },
});

Configuration Level

Interaction can be configured at the Mark level:

({
  type: 'interval',
  interaction: { brushXFilter: true },
});

It can also be configured at the View level. Interactions declared on the view will be passed to marks declared in children. If the mark has declared the corresponding interaction, they will be merged; otherwise, it won’t be affected.

({
  type: 'view',
  interaction: { brushXFilter: true },
});

Configuration Options

mask

Configure the style of the brush area mask.

When configuring the mask style of the brush area, it’s not configured as an object, but using the mask prefix with property names.

Style configuration example:

({
  interaction: {
    brushXFilter: {
      maskFill: '#000',
      maskFillOpacity: 0.2,
      maskStroke: 'red',
      maskStrokeOpacity: 0.9,
      maskLineWidth: 2,
      maskLineDash: [4, 8],
      maskOpacity: 0.2,
      maskShadowColor: '#d3d3d3',
      maskShadowBlur: 10,
      maskShadowOffsetX: 10,
      maskShadowOffsetY: 10,
      maskCursor: 'pointer',
    },
  },
});

Events

Listening to Events

Listen to brush filter actions:

chart.on('brush:filter', (event) => {
  const {
    data, // Filtered data collection
    nativeEvent, // Original DOM event
  } = event;
  const [xStart, xEnd] = data.selection[0];
  console.log(`Filter range: ${xStart} ~ ${xEnd}`);
});

Triggering Interaction

Trigger filtering programmatically:

// Set X-axis filter range (timestamp example)
chart.emit('brush:filter', {
  data: {
    selection: [
      [new Date('2023-01-01').getTime(), new Date('2023-06-30').getTime()],
    ],
  },
});

Examples

import { Chart } from '@antv/g2';

const data = [
  { letter: 'A', frequency: 0.08167 },
  { letter: 'B', frequency: 0.01492 },
  { letter: 'C', frequency: 0.02782 },
  { letter: 'D', frequency: 0.04253 },
  { letter: 'E', frequency: 0.12702 },
  { letter: 'F', frequency: 0.02288 },
  { letter: 'G', frequency: 0.02015 },
  { letter: 'H', frequency: 0.06094 },
  { letter: 'I', frequency: 0.06966 },
  { letter: 'J', frequency: 0.00153 },
  { letter: 'K', frequency: 0.00772 },
  { letter: 'L', frequency: 0.04025 },
  { letter: 'M', frequency: 0.02406 },
  { letter: 'N', frequency: 0.06749 },
  { letter: 'O', frequency: 0.07507 },
  { letter: 'P', frequency: 0.01929 },
  { letter: 'Q', frequency: 0.00095 },
  { letter: 'R', frequency: 0.05987 },
  { letter: 'S', frequency: 0.06327 },
  { letter: 'T', frequency: 0.09056 },
  { letter: 'U', frequency: 0.02758 },
  { letter: 'V', frequency: 0.00978 },
  { letter: 'W', frequency: 0.0236 },
  { letter: 'X', frequency: 0.0015 },
  { letter: 'Y', frequency: 0.01974 },
  { letter: 'Z', frequency: 0.00074 },
];

const chart = new Chart({
  container: 'container',
});
chart.options({
  type: 'interval',
  autoFit: true,
  data,
  encode: { x: 'letter', y: 'frequency' },
  interaction: {
    brushXFilter: {
      maskFill: '#000',
      maskFillOpacity: 0.2,
      maskStroke: 'red',
      maskStrokeOpacity: 0.9,
      maskLineWidth: 2,
      maskLineDash: [4, 8],
      maskOpacity: 0.2,
      maskShadowColor: '#d3d3d3',
      maskShadowBlur: 10,
      maskShadowOffsetX: 10,
      maskShadowOffsetY: 10,
      maskCursor: 'pointer',
    },
  },
});

chart.render();