echarts
Version:
A powerful charting and visualization library for browser
256 lines (228 loc) • 9.15 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 = {};
/**
* Get axis scale extent before niced.
* Item of returned array can only be number (including Infinity and NaN).
*/
axisHelper.getScaleExtent = function (scale, model) {
var scaleType = scale.type;
var min = model.getMin();
var max = model.getMax();
var fixMin = min != null;
var fixMax = max != null;
var originalExtent = scale.getExtent();
var axisDataLen;
var boundaryGap;
var span;
if (scaleType === 'ordinal') {
axisDataLen = (model.get('data') || []).length;
}
else {
boundaryGap = model.get('boundaryGap');
if (!zrUtil.isArray(boundaryGap)) {
boundaryGap = [boundaryGap || 0, boundaryGap || 0];
}
if (typeof boundaryGap[0] === 'boolean') {
if (__DEV__) {
console.warn('Boolean type for boundaryGap is only '
+ 'allowed for ordinal axis. Please use string in '
+ 'percentage instead, e.g., "20%". Currently, '
+ 'boundaryGap is set to be 0.');
}
boundaryGap = [0, 0];
}
boundaryGap[0] = numberUtil.parsePercent(boundaryGap[0], 1);
boundaryGap[1] = numberUtil.parsePercent(boundaryGap[1], 1);
span = (originalExtent[1] - originalExtent[0])
|| Math.abs(originalExtent[0]);
}
// Notice: When min/max is not set (that is, when there are null/undefined,
// which is the most common case), these cases should be ensured:
// (1) For 'ordinal', show all axis.data.
// (2) For others:
// + `boundaryGap` is applied (if min/max set, boundaryGap is
// disabled).
// + If `needCrossZero`, min/max should be zero, otherwise, min/max should
// be the result that originalExtent enlarged by boundaryGap.
// (3) If no data, it should be ensured that `scale.setBlank` is set.
// FIXME
// (1) When min/max is 'dataMin' or 'dataMax', should boundaryGap be able to used?
// (2) When `needCrossZero` and all data is positive/negative, should it be ensured
// that the results processed by boundaryGap are positive/negative?
if (min == null) {
min = scaleType === 'ordinal'
? (axisDataLen ? 0 : NaN)
: originalExtent[0] - boundaryGap[0] * span;
}
if (max == null) {
max = scaleType === 'ordinal'
? (axisDataLen ? axisDataLen - 1 : NaN)
: originalExtent[1] + boundaryGap[1] * span;
}
if (min === 'dataMin') {
min = originalExtent[0];
}
if (max === 'dataMax') {
max = originalExtent[1];
}
(min == null || !isFinite(min)) && (min = NaN);
(max == null || !isFinite(max)) && (max = NaN);
scale.setBlank(zrUtil.eqNaN(min) || zrUtil.eqNaN(max));
// Evaluate if axis needs cross zero
if (model.getNeedCrossZero()) {
// 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;
}
}
return [min, max];
};
axisHelper.niceScaleExtent = function (scale, model) {
var extent = axisHelper.getScaleExtent(scale, model);
var fixMin = model.getMin() != null;
var fixMax = model.getMax() != null;
var splitNumber = model.get('splitNumber');
if (scale.type === 'log') {
scale.base = model.get('logBase');
}
scale.setExtent(extent[0], extent[1]);
scale.niceExtent({
splitNumber: splitNumber,
fixMin: fixMin,
fixMax: fixMax,
minInterval: scale.type === 'interval' ? model.get('minInterval') : null
});
// 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.floor(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;
// FIXME Magic number 1.5
rect[isAxisHorizontal ? 'width' : 'height'] *= 1.3;
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 + 1) * step - 1;
};
/**
* @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 != null ? val : '');
};
})(labelFormatter);
// Consider empty array
return zrUtil.map(labels, labelFormatter);
}
else if (typeof labelFormatter === 'function') {
return zrUtil.map(ticks, function (tick, idx) {
return labelFormatter(
axisHelper.getAxisRawValue(axis, tick),
idx
);
}, this);
}
else {
return labels;
}
};
axisHelper.getAxisRawValue = function (axis, value) {
// In category axis with data zoom, tick is not the original
// index of axis.data. So tick should not be exposed to user
// in category axis.
return axis.type === 'category' ? axis.scale.getLabel(value) : value;
};
module.exports = axisHelper;