src/component/axisPointer/globalListener.ts

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/

import * as zrUtil from 'zrender/src/core/util';
import env from 'zrender/src/core/env';
import {makeInner} from '../../util/model';
import ExtensionAPI from '../../core/ExtensionAPI';
import { ZRenderType } from 'zrender/src/zrender';
import { ZRElementEvent } from '../../util/types';
import { Dictionary } from 'zrender/src/core/types';

type DispatchActionMethod = ExtensionAPI['dispatchAction'];

type Handler = (
    currTrigger: 'click' | 'mousemove' | 'leave',
    event: ZRElementEvent,
    dispatchAction: DispatchActionMethod
) => void;

interface Record {
    handler: Handler
}

interface InnerStore {
    initialized: boolean
    records: Dictionary<Record>
}

interface ShowTipPayload {
    type: 'showTip'
    dispatchAction: DispatchActionMethod
}

interface HideTipPayload {
    type: 'hideTip'
    dispatchAction: DispatchActionMethod
}
interface Pendings {
    showTip: ShowTipPayload[]
    hideTip: HideTipPayload[]
}

const inner = makeInner<InnerStore, ZRenderType>();
const each = zrUtil.each;

/**
 * @param {string} key
 * @param {module:echarts/ExtensionAPI} api
 * @param {Function} handler
 *      param: {string} currTrigger
 *      param: {Array.<number>} point
 */
export function register(key: string, api: ExtensionAPI, handler?: Handler) {
    if (env.node) {
        return;
    }

    const zr = api.getZr();
    inner(zr).records || (inner(zr).records = {});

    initGlobalListeners(zr, api);

    const record = inner(zr).records[key] || (inner(zr).records[key] = {} as Record);
    record.handler = handler;
}

function initGlobalListeners(zr: ZRenderType, api?: ExtensionAPI) {
    if (inner(zr).initialized) {
        return;
    }

    inner(zr).initialized = true;

    useHandler('click', zrUtil.curry(doEnter, 'click'));
    useHandler('mousemove', zrUtil.curry(doEnter, 'mousemove'));
    // useHandler('mouseout', onLeave);
    useHandler('globalout', onLeave);

    function useHandler(
        eventType: string,
        cb: (record: Record, e: ZRElementEvent, dispatchAction: DispatchActionMethod) => void
    ) {
        zr.on(eventType, function (e: ZRElementEvent) {
            const dis = makeDispatchAction(api);

            each(inner(zr).records, function (record) {
                record && cb(record, e, dis.dispatchAction);
            });

            dispatchTooltipFinally(dis.pendings, api);
        });
    }
}

function dispatchTooltipFinally(pendings: Pendings, api: ExtensionAPI) {
    const showLen = pendings.showTip.length;
    const hideLen = pendings.hideTip.length;

    let actuallyPayload;
    if (showLen) {
        actuallyPayload = pendings.showTip[showLen - 1];
    }
    else if (hideLen) {
        actuallyPayload = pendings.hideTip[hideLen - 1];
    }
    if (actuallyPayload) {
        actuallyPayload.dispatchAction = null;
        api.dispatchAction(actuallyPayload);
    }
}

function onLeave(
    record: Record,
    e: ZRElementEvent,
    dispatchAction: DispatchActionMethod
) {
    record.handler('leave', null, dispatchAction);
}

function doEnter(
    currTrigger: 'click' | 'mousemove' | 'leave',
    record: Record,
    e: ZRElementEvent,
    dispatchAction: DispatchActionMethod
) {
    record.handler(currTrigger, e, dispatchAction);
}

function makeDispatchAction(api: ExtensionAPI) {
    const pendings: Pendings = {
        showTip: [],
        hideTip: []
    };
    // FIXME
    // better approach?
    // 'showTip' and 'hideTip' can be triggered by axisPointer and tooltip,
    // which may be conflict, (axisPointer call showTip but tooltip call hideTip);
    // So we have to add "final stage" to merge those dispatched actions.
    const dispatchAction = function (payload: ShowTipPayload | HideTipPayload) {
        const pendingList = pendings[payload.type];
        if (pendingList) {
            (pendingList as ShowTipPayload[]).push(payload as ShowTipPayload);
        }
        else {
            payload.dispatchAction = dispatchAction;
            api.dispatchAction(payload);
        }
    };

    return {
        dispatchAction: dispatchAction,
        pendings: pendings
    };
}

export function unregister(key: string, api: ExtensionAPI) {
    if (env.node) {
        return;
    }
    const zr = api.getZr();
    const record = (inner(zr).records || {})[key];
    if (record) {
        inner(zr).records[key] = null;
    }
}