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core.js
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core.js
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import {each, callback as call, sign, valueOrDefault} from 'chart.js/helpers';
import {panFunctions, updateRange, zoomFunctions, zoomRectFunctions} from './scale.types';
import {getState} from './state';
import {directionEnabled, getEnabledScalesByPoint} from './utils';
function shouldUpdateScaleLimits(scale, originalScaleLimits, updatedScaleLimits) {
const {id, options: {min, max}} = scale;
if (!originalScaleLimits[id] || !updatedScaleLimits[id]) {
return true;
}
const previous = updatedScaleLimits[id];
return previous.min !== min || previous.max !== max;
}
function removeMissingScales(limits, scales) {
each(limits, (opt, key) => {
if (!scales[key]) {
delete limits[key];
}
});
}
function storeOriginalScaleLimits(chart, state) {
const {scales} = chart;
const {originalScaleLimits, updatedScaleLimits} = state;
each(scales, function(scale) {
if (shouldUpdateScaleLimits(scale, originalScaleLimits, updatedScaleLimits)) {
originalScaleLimits[scale.id] = {
min: {scale: scale.min, options: scale.options.min},
max: {scale: scale.max, options: scale.options.max},
};
}
});
removeMissingScales(originalScaleLimits, scales);
removeMissingScales(updatedScaleLimits, scales);
return originalScaleLimits;
}
function doZoom(scale, amount, center, limits) {
const fn = zoomFunctions[scale.type] || zoomFunctions.default;
call(fn, [scale, amount, center, limits]);
}
function doZoomRect(scale, amount, from, to, limits) {
const fn = zoomRectFunctions[scale.type] || zoomRectFunctions.default;
call(fn, [scale, amount, from, to, limits]);
}
function getCenter(chart) {
const ca = chart.chartArea;
return {
x: (ca.left + ca.right) / 2,
y: (ca.top + ca.bottom) / 2,
};
}
/**
* @param chart The chart instance
* @param {number | {x?: number, y?: number, focalPoint?: {x: number, y: number}}} amount The zoom percentage or percentages and focal point
* @param {string} [transition] Which transition mode to use. Defaults to 'none'
*/
export function zoom(chart, amount, transition = 'none') {
const {x = 1, y = 1, focalPoint = getCenter(chart)} = typeof amount === 'number' ? {x: amount, y: amount} : amount;
const state = getState(chart);
const {options: {limits, zoom: zoomOptions}} = state;
storeOriginalScaleLimits(chart, state);
const xEnabled = x !== 1;
const yEnabled = y !== 1;
const enabledScales = getEnabledScalesByPoint(zoomOptions, focalPoint, chart);
each(enabledScales || chart.scales, function(scale) {
if (scale.isHorizontal() && xEnabled) {
doZoom(scale, x, focalPoint, limits);
} else if (!scale.isHorizontal() && yEnabled) {
doZoom(scale, y, focalPoint, limits);
}
});
chart.update(transition);
call(zoomOptions.onZoom, [{chart}]);
}
export function zoomRect(chart, p0, p1, transition = 'none') {
const state = getState(chart);
const {options: {limits, zoom: zoomOptions}} = state;
const {mode = 'xy'} = zoomOptions;
storeOriginalScaleLimits(chart, state);
const xEnabled = directionEnabled(mode, 'x', chart);
const yEnabled = directionEnabled(mode, 'y', chart);
each(chart.scales, function(scale) {
if (scale.isHorizontal() && xEnabled) {
doZoomRect(scale, p0.x, p1.x, limits);
} else if (!scale.isHorizontal() && yEnabled) {
doZoomRect(scale, p0.y, p1.y, limits);
}
});
chart.update(transition);
call(zoomOptions.onZoom, [{chart}]);
}
export function zoomScale(chart, scaleId, range, transition = 'none') {
storeOriginalScaleLimits(chart, getState(chart));
const scale = chart.scales[scaleId];
updateRange(scale, range, undefined, true);
chart.update(transition);
}
export function resetZoom(chart, transition = 'default') {
const state = getState(chart);
const originalScaleLimits = storeOriginalScaleLimits(chart, state);
each(chart.scales, function(scale) {
const scaleOptions = scale.options;
if (originalScaleLimits[scale.id]) {
scaleOptions.min = originalScaleLimits[scale.id].min.options;
scaleOptions.max = originalScaleLimits[scale.id].max.options;
} else {
delete scaleOptions.min;
delete scaleOptions.max;
}
});
chart.update(transition);
call(state.options.zoom.onZoomComplete, [{chart}]);
}
function getOriginalRange(state, scaleId) {
const original = state.originalScaleLimits[scaleId];
if (!original) {
return;
}
const {min, max} = original;
return valueOrDefault(max.options, max.scale) - valueOrDefault(min.options, min.scale);
}
export function getZoomLevel(chart) {
const state = getState(chart);
let min = 1;
let max = 1;
each(chart.scales, function(scale) {
const origRange = getOriginalRange(state, scale.id);
if (origRange) {
const level = Math.round(origRange / (scale.max - scale.min) * 100) / 100;
min = Math.min(min, level);
max = Math.max(max, level);
}
});
return min < 1 ? min : max;
}
function panScale(scale, delta, limits, state) {
const {panDelta} = state;
// Add possible cumulative delta from previous pan attempts where scale did not change
const storedDelta = panDelta[scale.id] || 0;
if (sign(storedDelta) === sign(delta)) {
delta += storedDelta;
}
const fn = panFunctions[scale.type] || panFunctions.default;
if (call(fn, [scale, delta, limits])) {
// The scale changed, reset cumulative delta
panDelta[scale.id] = 0;
} else {
// The scale did not change, store cumulative delta
panDelta[scale.id] = delta;
}
}
export function pan(chart, delta, enabledScales, transition = 'none') {
const {x = 0, y = 0} = typeof delta === 'number' ? {x: delta, y: delta} : delta;
const state = getState(chart);
const {options: {pan: panOptions, limits}} = state;
const {onPan} = panOptions || {};
storeOriginalScaleLimits(chart, state);
const xEnabled = x !== 0;
const yEnabled = y !== 0;
each(enabledScales || chart.scales, function(scale) {
if (scale.isHorizontal() && xEnabled) {
panScale(scale, x, limits, state);
} else if (!scale.isHorizontal() && yEnabled) {
panScale(scale, y, limits, state);
}
});
chart.update(transition);
call(onPan, [{chart}]);
}
export function getInitialScaleBounds(chart) {
const state = getState(chart);
storeOriginalScaleLimits(chart, state);
const scaleBounds = {};
for (const scaleId of Object.keys(chart.scales)) {
const {min, max} = state.originalScaleLimits[scaleId] || {min: {}, max: {}};
scaleBounds[scaleId] = {min: min.scale, max: max.scale};
}
return scaleBounds;
}
export function isZoomedOrPanned(chart) {
const scaleBounds = getInitialScaleBounds(chart);
for (const scaleId of Object.keys(chart.scales)) {
const {min: originalMin, max: originalMax} = scaleBounds[scaleId];
if (originalMin !== undefined && chart.scales[scaleId].min !== originalMin) {
return true;
}
if (originalMax !== undefined && chart.scales[scaleId].max !== originalMax) {
return true;
}
}
return false;
}