RoamController.js

/*
* 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 Eventful from 'zrender/src/mixin/Eventful';
import * as eventTool from 'zrender/src/core/event';
import * as interactionMutex from './interactionMutex';

/**
 * @alias module:echarts/component/helper/RoamController
 * @constructor
 * @mixin {module:zrender/mixin/Eventful}
 *
 * @param {module:zrender/zrender~ZRender} zr
 */
function RoamController(zr) {

    /**
     * @type {Function}
     */
    this.pointerChecker;

    /**
     * @type {module:zrender}
     */
    this._zr = zr;

    /**
     * @type {Object}
     */
    this._opt = {};

    // Avoid two roamController bind the same handler
    var bind = zrUtil.bind;
    var mousedownHandler = bind(mousedown, this);
    var mousemoveHandler = bind(mousemove, this);
    var mouseupHandler = bind(mouseup, this);
    var mousewheelHandler = bind(mousewheel, this);
    var pinchHandler = bind(pinch, this);

    Eventful.call(this);

    /**
     * @param {Function} pointerChecker
     *                   input: x, y
     *                   output: boolean
     */
    this.setPointerChecker = function (pointerChecker) {
        this.pointerChecker = pointerChecker;
    };

    /**
     * Notice: only enable needed types. For example, if 'zoom'
     * is not needed, 'zoom' should not be enabled, otherwise
     * default mousewheel behaviour (scroll page) will be disabled.
     *
     * @param  {boolean|string} [controlType=true] Specify the control type,
     *                          which can be null/undefined or true/false
     *                          or 'pan/move' or 'zoom'/'scale'
     * @param {Object} [opt]
     * @param {Object} [opt.zoomOnMouseWheel=true] The value can be: true / false / 'shift' / 'ctrl' / 'alt'.
     * @param {Object} [opt.moveOnMouseMove=true] The value can be: true / false / 'shift' / 'ctrl' / 'alt'.
     * @param {Object} [opt.moveOnMouseWheel=false] The value can be: true / false / 'shift' / 'ctrl' / 'alt'.
     * @param {Object} [opt.preventDefaultMouseMove=true] When pan.
     */
    this.enable = function (controlType, opt) {

        // Disable previous first
        this.disable();

        this._opt = zrUtil.defaults(zrUtil.clone(opt) || {}, {
            zoomOnMouseWheel: true,
            moveOnMouseMove: true,
            // By default, wheel do not trigger move.
            moveOnMouseWheel: false,
            preventDefaultMouseMove: true
        });

        if (controlType == null) {
            controlType = true;
        }

        if (controlType === true || (controlType === 'move' || controlType === 'pan')) {
            zr.on('mousedown', mousedownHandler);
            zr.on('mousemove', mousemoveHandler);
            zr.on('mouseup', mouseupHandler);
        }
        if (controlType === true || (controlType === 'scale' || controlType === 'zoom')) {
            zr.on('mousewheel', mousewheelHandler);
            zr.on('pinch', pinchHandler);
        }
    };

    this.disable = function () {
        zr.off('mousedown', mousedownHandler);
        zr.off('mousemove', mousemoveHandler);
        zr.off('mouseup', mouseupHandler);
        zr.off('mousewheel', mousewheelHandler);
        zr.off('pinch', pinchHandler);
    };

    this.dispose = this.disable;

    this.isDragging = function () {
        return this._dragging;
    };

    this.isPinching = function () {
        return this._pinching;
    };
}

zrUtil.mixin(RoamController, Eventful);


function mousedown(e) {
    if (eventTool.isMiddleOrRightButtonOnMouseUpDown(e)
        || (e.target && e.target.draggable)
    ) {
        return;
    }

    var x = e.offsetX;
    var y = e.offsetY;

    // Only check on mosedown, but not mousemove.
    // Mouse can be out of target when mouse moving.
    if (this.pointerChecker && this.pointerChecker(e, x, y)) {
        this._x = x;
        this._y = y;
        this._dragging = true;
    }
}

function mousemove(e) {
    if (!this._dragging
        || !isAvailableBehavior('moveOnMouseMove', e, this._opt)
        || e.gestureEvent === 'pinch'
        || interactionMutex.isTaken(this._zr, 'globalPan')
    ) {
        return;
    }

    var x = e.offsetX;
    var y = e.offsetY;

    var oldX = this._x;
    var oldY = this._y;

    var dx = x - oldX;
    var dy = y - oldY;

    this._x = x;
    this._y = y;

    this._opt.preventDefaultMouseMove && eventTool.stop(e.event);

    trigger(this, 'pan', 'moveOnMouseMove', e, {
        dx: dx, dy: dy, oldX: oldX, oldY: oldY, newX: x, newY: y
    });
}

function mouseup(e) {
    if (!eventTool.isMiddleOrRightButtonOnMouseUpDown(e)) {
        this._dragging = false;
    }
}

function mousewheel(e) {
    var shouldZoom = isAvailableBehavior('zoomOnMouseWheel', e, this._opt);
    var shouldMove = isAvailableBehavior('moveOnMouseWheel', e, this._opt);
    var wheelDelta = e.wheelDelta;
    var absWheelDeltaDelta = Math.abs(wheelDelta);
    var originX = e.offsetX;
    var originY = e.offsetY;

    // wheelDelta maybe -0 in chrome mac.
    if (wheelDelta === 0 || (!shouldZoom && !shouldMove)) {
        return;
    }

    // If both `shouldZoom` and `shouldMove` is true, trigger
    // their event both, and the final behavior is determined
    // by event listener themselves.

    if (shouldZoom) {
        // Convenience:
        // Mac and VM Windows on Mac: scroll up: zoom out.
        // Windows: scroll up: zoom in.

        // FIXME: Should do more test in different environment.
        // wheelDelta is too complicated in difference nvironment
        // (https://developer.mozilla.org/en-US/docs/Web/Events/mousewheel),
        // although it has been normallized by zrender.
        // wheelDelta of mouse wheel is bigger than touch pad.
        var factor = absWheelDeltaDelta > 3 ? 1.4 : absWheelDeltaDelta > 1 ? 1.2 : 1.1;
        var scale = wheelDelta > 0 ? factor : 1 / factor;
        checkPointerAndTrigger(this, 'zoom', 'zoomOnMouseWheel', e, {
            scale: scale, originX: originX, originY: originY
        });
    }

    if (shouldMove) {
        // FIXME: Should do more test in different environment.
        var absDelta = Math.abs(wheelDelta);
        // wheelDelta of mouse wheel is bigger than touch pad.
        var scrollDelta = (wheelDelta > 0 ? 1 : -1) * (absDelta > 3 ? 0.4 : absDelta > 1 ? 0.15 : 0.05);
        checkPointerAndTrigger(this, 'scrollMove', 'moveOnMouseWheel', e, {
            scrollDelta: scrollDelta, originX: originX, originY: originY
        });
    }
}

function pinch(e) {
    if (interactionMutex.isTaken(this._zr, 'globalPan')) {
        return;
    }
    var scale = e.pinchScale > 1 ? 1.1 : 1 / 1.1;
    checkPointerAndTrigger(this, 'zoom', null, e, {
        scale: scale, originX: e.pinchX, originY: e.pinchY
    });
}

function checkPointerAndTrigger(controller, eventName, behaviorToCheck, e, contollerEvent) {
    if (controller.pointerChecker
        && controller.pointerChecker(e, contollerEvent.originX, contollerEvent.originY)
    ) {
        // When mouse is out of roamController rect,
        // default befavoius should not be be disabled, otherwise
        // page sliding is disabled, contrary to expectation.
        eventTool.stop(e.event);

        trigger(controller, eventName, behaviorToCheck, e, contollerEvent);
    }
}

function trigger(controller, eventName, behaviorToCheck, e, contollerEvent) {
    // Also provide behavior checker for event listener, for some case that
    // multiple components share one listener.
    contollerEvent.isAvailableBehavior = zrUtil.bind(isAvailableBehavior, null, behaviorToCheck, e);
    controller.trigger(eventName, contollerEvent);
}

// settings: {
//     zoomOnMouseWheel
//     moveOnMouseMove
//     moveOnMouseWheel
// }
// The value can be: true / false / 'shift' / 'ctrl' / 'alt'.
function isAvailableBehavior(behaviorToCheck, e, settings) {
    var setting = settings[behaviorToCheck];
    return !behaviorToCheck || (
        setting && (!zrUtil.isString(setting) || e.event[setting + 'Key'])
    );
}

export default RoamController;