@antv/f2
Version:
Charts for mobile visualization.
110 lines • 3.48 kB
JavaScript
import { getTickMethod } from '../../deps/f2-scale/src';
import { getRange, isArray } from '@antv/util';
import { toTimeStamp } from '../../util';
// 判断新老values是否相等，这里只要判断前后是否相等即可
function isValuesEqual(values, newValues) {
if (values.length !== newValues.length) {
return false;
}
var lastIndex = values.length - 1;
return values[0] === newValues[0] && values[lastIndex] === newValues[lastIndex];
}
function updateCategoryRange(scale, originScale, range) {
var currentValues = scale.values,
currentTicks = scale.ticks,
tickMethod = scale.tickMethod,
tickCount = scale.tickCount;
var originValues = originScale.values;
var start = range[0],
end = range[1];
var len = originValues.length;
var valueStart = start * len;
var valueEnd = end * len;
// 保持滑动时个数的稳定
var diff = valueEnd - valueStart;
var precision = parseFloat(diff.toFixed(3)); // js 计算精度问题
var count = Math.round(precision);
var sliceSatrt = Math.min(Math.round(valueStart), len - count);
// 从原始数据里截取需要显示的数据
var newValues = originValues.slice(sliceSatrt, sliceSatrt + count);
// 根据当前数据的比例，和定义的tickCount计算应该需要多少个ticks
var newTickCount = Math.round(tickCount * originValues.length / newValues.length);
// 计算新的ticks
var catTicks = getTickMethod(tickMethod);
var newTicks = catTicks({
tickCount: newTickCount,
values: originValues
});
// 如果新数组和当前显示的数组相同，则不更新
if (isValuesEqual(currentValues, newValues) && isValuesEqual(currentTicks, newTicks)) {
return;
}
scale.change({
values: newValues,
ticks: newTicks
});
return scale;
}
function updateLinearRange(scale, originScale, range) {
var min = originScale.min,
max = originScale.max;
var start = range[0],
end = range[1];
var newMin = min + (max - min) * start;
var newMax = min + (max - min) * end;
scale.change({
min: newMin,
max: newMax,
nice: false
});
}
function updateScale(scale, values) {
var isLinear = scale.isLinear;
if (isLinear) {
var _a = getRange(values),
min = _a.min,
max = _a.max;
return scale.change({
min: min,
max: max,
nice: true
});
}
}
function updateRange(scale, originScale, range) {
var isCategory = scale.isCategory,
isLinear = scale.isLinear;
if (isCategory) {
return updateCategoryRange(scale, originScale, range);
}
if (isLinear) {
return updateLinearRange(scale, originScale, range);
}
}
function updateFollow(scales, mainScale, data) {
var mainField = mainScale.field,
mainType = mainScale.type,
mainValues = mainScale.values;
// 转成 map 提高查询性能
var mainValuesMap = {};
mainValues.forEach(function (item) {
mainValuesMap[item] = true;
});
return scales.map(function (scale) {
var followField = scale.field;
var values = [];
data.forEach(function (item) {
var value = mainType === 'timeCat' ? toTimeStamp(item[mainField]) : item[mainField];
if (mainValuesMap[value]) {
var followItemValue = item[followField];
if (isArray(followItemValue)) {
values.push.apply(values, followItemValue);
} else {
values.push(followItemValue);
}
}
});
return updateScale(scale, values);
});
}
export { updateRange, updateFollow };