Tooltip

F2 has modular structure provides best tree-shaking results and package size optimization.

If you just import F2 from '@antv/f2', then it has included tooltip by default. But if you want a better package size optimization, you can register manually:

const F2 = require('@antv/f2/lib/core');
const Tooltip = require('@antv/f2/lib/plugin/tooltip');
// Method 1: Global Registeration
F2.Chart.plugins.register(Tooltip); 

// Or Method2: Registeration for a Chart instance
const chart = new Chart({
  id: 'canvas',
  plugins: Tooltip
});

Tooltip Configuration

If you call chart.tooltip(false), tooltip will not be rendered.

Below is the method for configuring tooltip, the detail properties can be found in table.

chart.tooltip({
  // see detail properties in table
});

Name

Type

Default

Description

alwaysShow

Boolean

false

Whether the tooltip is still show when the touch area is not in the chart.It can be set to be true to preserve displaying.

offsetX

Number

Tooltip offset in x direction.

offsetY

Number

Tooltip offset in y direction.

triggerOn

String / Array

[ 'touchstart', 'touchmove' ]

The event that will trigger tooltip.

triggerOff

String / Array

'touchend'

The event that will hide tooltip.

showTitle

Boolean

false

Wether to show the title.

showCrosshairs

Boolean

Wether to show the tooltip crosshairs. The default value of different charts is different, point, line, area and path will show by default.

crosshairsStyle

Object

Style of the crosshairs line, default setting is:

{

stroke: 'rgba(0, 0, 0, 0.25)',

lineWidth: 2

}

showTooltipMarker

Boolean

true

Wether to display tooltipMarker.

tooltipMarkerStyle

Object

Style of the tooltipMarker.

background

Object

The background style of tooltip content box.

titleStyle

Object

Style for tooltip's title, invalid if showTitle is false.

nameStyle

Object

Style for each tooltip item's name part.

valueStyle

Object

Style for each tooltip item's value part.

showItemMarker

Boolean

true

Wether to show the each tooltip item's marker.

itemMarkerStyle

Object

Style for each tooltip item's marker.

custom

Boolean

false

Wether to custom the tooltip. See custom tooltip.

onShow

Function

Callback when the tooltip show. See callback.

onHide

Function

Callback when the tooltip hide. See callback.

onChange

Function

Callback when the tooltip content change. See callback.

The picture below shows the structure of tooltip content, it includes title and a group of items, each item consists of marker, name and value.

The tooltip items passed to the tooltip onShow , onChange, onHide callbacks implement the following interface:

{
  // X position of matching tooltip item
  x: Number,
  
  // Y position of matching tooltip item
  y: Number,
  
  // Color of matching tooltip item
  color: String,
  
  // The data of matching tooltip item
  origin: Object,
  
  // The value of the `name` attribute in tooltip item
  name: String,
  
  // The value of the `value` attribute in tooltip item
  value: String / Number,
  
  // The title of current tooltip
  title: String
  
  // The marker of matching tooltip item
  marker: Object
}

`onShow` callback

We can use onShow callback to change the tooltip's show content. It will trigger when the tooltip is shown.

chart.tooltip({
  onShow(obj) {}
});

// The following is the parameter `Obj` interface
{
  // X position of current event
  x: Number,
  
  // Y position of current event
  y: Number,
  
  // The tootlip instance
  tooltip: Object
  
  // Tooltip content items
  items: Array,
  
  // The style of tooltipMarker
  tooltipMarkerCfg: Object
}

As following example, we will change the value of name to the value of title, see demo and code here.

chart.tooltip({
  onShow: function onShow(ev) {
    var items = ev.items;
    items[0].name = items[0].title;
  }
});

`onChange` callback

It will trigger when the tooltip's content changed. Usually combined with the custom attribute for custom tooltip.

chart.tooltip({
  onChange(obj) {}
});

// The following is the parameter `Obj` interface
{
  // X position of current event
  x: Number,
  
  // Y position of current event
  y: Number,
  
  // The tootlip instance
  tooltip: Object
  
  // Tooltip content items
  items: Array,
  
  // The style of tooltipMarker
  tooltipMarkerCfg: Object
}

`onHide` callback

It will trigger when the tooltip is disappeared.

chart.tooltip({
  onHide(obj) {}
});

// The following is the parameter `Obj` interface
{
  // The tootlip instance
  tooltip: Object
}

Custom tooltips allow you to hook into the tooltip rendering process so that you can render the tooltip in your own custom way. Generally this is used to create an HTML tooltip instead of an canvas one or combined with legend.

On mobile, in order to make better use of the screen size, the tooltip and legend are often combined in the chart design. Like this:

In F2, we can use a custom tooltip to implement, see demo and code here:

chart.tooltip({
    custom: true, // required
    onChange(obj) {
      var legend = chart.get('legendController').legends.top[0]; // get the top legend instance
      var tooltipItems = obj.items;
      var legendItems = legend.items;
      var map = {};
      legendItems.map(function(item) {
        map[item.name] = _.clone(item);
      });
      tooltipItems.map(function(item) {
        var name = item.name;
        var value = item.value;
        if (map[name]) {
          map[name].value = value;
        }
      });
      legend.setItems(_.values(map)); // update legend items
    },
    onHide: function onHide() {
      var legend = chart.get('legendController').legends.top[0];
      legend.setItems(chart.getLegendItems().country); // revert the original items of the legend
    }
  });

We also can define a html tooltip, like this, see demo and code here:

chart.tooltip({
  custom: true,
  showCrosshairs: false,
  onChange: function onChange(ev) {
    var tooltipEl = $('.f2-tooltip'); // get the tooltip html element 
    var currentData = ev.items[0];
    var text = currentData.value;
    tooltipEl.html(['<span>' + currentData.origin.date + '</span>', '<span>' + 'Web Visits: <b>' + text + '</b></span>'].join(''));

    tooltipEl.css({
      opacity: 1,
      left: canvasOffsetLeft + currentData.x - tooltipEl.outerWidth() / 2 + 'px',
      top: canvasOffsetTop + currentData.y - tooltipEl.outerHeight() - 15 + 'px'
    });
  },
  onHide: function onHide() {
    var tooltipEl = $('.f2-tooltip');
    tooltipEl.css({
      opacity: 0
    });
  }
});

Or Like this, combine with Guide.Html and Tooltip, see demo and code here:

chart.guide().html({
  position: ['min', 'max'],
  html: '<div id="tooltipWrapper" style="height: 45px;background-color:#E9F1FF;line-height: 45px;">' + '<div id="tooltipName" style="float:left;font-size:12px;color:#2E2E2E;"></div>' + '<div id="tooltipValue" style="float:right;font-size:12px;color:#2E2E2E;"></div>' + '</div>',
  offsetY: -22.5
});
chart.tooltip({
  showCrosshairs: true,
  custom: true,
  onChange: function onChange(obj) {
    var items = obj.items;
    var originData = items[0].origin;
    var date = originData.date;
    var value = originData.value;
    var tag = originData.tag;

    $('#tooltipWrapper').width($('#mountNode').width());
    $('#tooltipWrapper').css('left', 0);
    $('#tooltipName').css('margin-left', 15);
    $('#tooltipValue').css('margin-right', 15);

    if (tag === 1) {
      $('#tooltipName').html(date + '<img style="width:27.5px;vertical-align:middle;margin-left:3px;" src="https://gw.alipayobjects.com/zos/rmsportal/RcgYrLNGIUfTytjjijER.png">');
    } else if (tag === 2) {
      $('#tooltipName').html(date + '<img style="width:27.5px;vertical-align:middle;margin-left:3px;" src="https://gw.alipayobjects.com/zos/rmsportal/XzNFpOkuSLlmEWUSZErB.png">');
    } else {
      $('#tooltipName').text(date);
    }
    var color;
    if (value >= 0) {
      color = '#FA541C';
    } else {
      color = '#1CAA3D';
    }

    $('#tooltipValue').html('涨幅：<span style="color:' + color + '">' + items[0].value + '</span>');
    $('#tooltipWrapper').show();
  },
  onHide: function onHide() {
    $('#tooltipWrapper').hide();
  }
});