echarts
Version:
A powerful charting and visualization library for browser
188 lines (175 loc) • 6.48 kB
JavaScript
var OrdinalScale = require('../scale/Ordinal');
var IntervalScale = require('../scale/Interval');
require('../scale/Time');
require('../scale/Log');
var Scale = require('../scale/Scale');
var numberUtil = require('../util/number');
var zrUtil = require('zrender/lib/core/util');
var textContain = require('zrender/lib/contain/text');
var axisHelper = {};
axisHelper.niceScaleExtent = function (axis, model) {
var scale = axis.scale;
var originalExtent = scale.getExtent();
var span = originalExtent[1] - originalExtent[0];
if (scale.type === 'ordinal') {
// If series has no data, scale extent may be wrong
if (!isFinite(span)) {
scale.setExtent(0, 0);
}
return;
}
var min = model.get('min');
var max = model.get('max');
var crossZero = !model.get('scale');
var boundaryGap = model.get('boundaryGap');
if (!zrUtil.isArray(boundaryGap)) {
boundaryGap = [boundaryGap || 0, boundaryGap || 0];
}
boundaryGap[0] = numberUtil.parsePercent(boundaryGap[0], 1);
boundaryGap[1] = numberUtil.parsePercent(boundaryGap[1], 1);
var fixMin = true;
var fixMax = true;
// Add boundary gap
if (min == null) {
min = originalExtent[0] - boundaryGap[0] * span;
fixMin = false;
}
if (max == null) {
max = originalExtent[1] + boundaryGap[1] * span;
fixMax = false;
}
// TODO Only one data
if (min === 'dataMin') {
min = originalExtent[0];
}
if (max === 'dataMax') {
max = originalExtent[1];
}
// Evaluate if axis needs cross zero
if (crossZero) {
// Axis is over zero and min is not set
if (min > 0 && max > 0 && !fixMin) {
min = 0;
}
// Axis is under zero and max is not set
if (min < 0 && max < 0 && !fixMax) {
max = 0;
}
}
scale.setExtent(min, max);
scale.niceExtent(model.get('splitNumber'), fixMin, fixMax);
// If some one specified the min, max. And the default calculated interval
// is not good enough. He can specify the interval. It is often appeared
// in angle axis with angle 0 - 360. Interval calculated in interval scale is hard
// to be 60.
// FIXME
var interval = model.get('interval');
if (interval != null) {
scale.setInterval && scale.setInterval(interval);
}
};
/**
* @param {module:echarts/model/Model} model
* @param {string} [axisType] Default retrieve from model.type
* @return {module:echarts/scale/*}
*/
axisHelper.createScaleByModel = function(model, axisType) {
axisType = axisType || model.get('type');
if (axisType) {
switch (axisType) {
// Buildin scale
case 'category':
return new OrdinalScale(
model.getCategories(), [Infinity, -Infinity]
);
case 'value':
return new IntervalScale();
// Extended scale, like time and log
default:
return (Scale.getClass(axisType) || IntervalScale).create(model);
}
}
};
/**
* Check if the axis corss 0
*/
axisHelper.ifAxisCrossZero = function (axis) {
var dataExtent = axis.scale.getExtent();
var min = dataExtent[0];
var max = dataExtent[1];
return !((min > 0 && max > 0) || (min < 0 && max < 0));
};
/**
* @param {Array.<number>} tickCoords In axis self coordinate.
* @param {Array.<string>} labels
* @param {string} font
* @param {boolean} isAxisHorizontal
* @return {number}
*/
axisHelper.getAxisLabelInterval = function (tickCoords, labels, font, isAxisHorizontal) {
// FIXME
// 不同角的axis和label，不只是horizontal和vertical.
var textSpaceTakenRect;
var autoLabelInterval = 0;
var accumulatedLabelInterval = 0;
var step = 1;
if (labels.length > 40) {
// Simple optimization for large amount of labels
step = Math.round(labels.length / 40);
}
for (var i = 0; i < tickCoords.length; i += step) {
var tickCoord = tickCoords[i];
var rect = textContain.getBoundingRect(
labels[i], font, 'center', 'top'
);
rect[isAxisHorizontal ? 'x' : 'y'] += tickCoord;
rect[isAxisHorizontal ? 'width' : 'height'] *= 1.5;
if (!textSpaceTakenRect) {
textSpaceTakenRect = rect.clone();
}
// There is no space for current label;
else if (textSpaceTakenRect.intersect(rect)) {
accumulatedLabelInterval++;
autoLabelInterval = Math.max(autoLabelInterval, accumulatedLabelInterval);
}
else {
textSpaceTakenRect.union(rect);
// Reset
accumulatedLabelInterval = 0;
}
}
if (autoLabelInterval === 0 && step > 1) {
return step;
}
return autoLabelInterval * step;
};
/**
* @param {Object} axis
* @param {Function} labelFormatter
* @return {Array.<string>}
*/
axisHelper.getFormattedLabels = function (axis, labelFormatter) {
var scale = axis.scale;
var labels = scale.getTicksLabels();
var ticks = scale.getTicks();
if (typeof labelFormatter === 'string') {
labelFormatter = (function (tpl) {
return function (val) {
return tpl.replace('{value}', val);
};
})(labelFormatter);
return zrUtil.map(labels, labelFormatter);
}
else if (typeof labelFormatter === 'function') {
return zrUtil.map(ticks, function (tick, idx) {
return labelFormatter(
axis.type === 'category' ? scale.getLabel(tick) : tick,
idx
);
}, this);
}
else {
return labels;
}
};
module.exports = axisHelper;