如何检测用户用JavaScript在网页上向某个方向滑动手指?

我想知道是否有一种解决方案可以同时适用于iPhone和Android手机上的网站。


当前回答

我也合并了一些答案,主要是第一个和第二个与类,下面是我的版本:

export default class Swipe {
    constructor(options) {
        this.xDown = null;
        this.yDown = null;

        this.options = options;

        this.handleTouchStart = this.handleTouchStart.bind(this);
        this.handleTouchMove = this.handleTouchMove.bind(this);

        document.addEventListener('touchstart', this.handleTouchStart, false);
        document.addEventListener('touchmove', this.handleTouchMove, false);

    }

    onLeft() {
        this.options.onLeft();
    }

    onRight() {
        this.options.onRight();
    }

    onUp() {
        this.options.onUp();
    }

    onDown() {
        this.options.onDown();
    }

    static getTouches(evt) {
        return evt.touches      // browser API

    }

    handleTouchStart(evt) {
        const firstTouch = Swipe.getTouches(evt)[0];
        this.xDown = firstTouch.clientX;
        this.yDown = firstTouch.clientY;
    }

    handleTouchMove(evt) {
        if ( ! this.xDown || ! this.yDown ) {
            return;
        }

        let xUp = evt.touches[0].clientX;
        let yUp = evt.touches[0].clientY;

        let xDiff = this.xDown - xUp;
        let yDiff = this.yDown - yUp;


        if ( Math.abs( xDiff ) > Math.abs( yDiff ) ) {/*most significant*/
            if ( xDiff > 0 && this.options.onLeft) {
                /* left swipe */
                this.onLeft();
            } else if (this.options.onRight) {
                /* right swipe */
                this.onRight();
            }
        } else {
            if ( yDiff > 0 && this.options.onUp) {
                /* up swipe */
                this.onUp();
            } else if (this.options.onDown){
                /* down swipe */
                this.onDown();
            }
        }

        /* reset values */
        this.xDown = null;
        this.yDown = null;
    }
}

之后可以这样使用:

let swiper = new Swipe({
                    onLeft() {
                        console.log('You swiped left.');
                    }
});

当你只想调用“onLeft”方法时,它有助于避免控制台错误。

其他回答

我之前使用的方法是,您必须检测mousedown事件,记录其x,y位置(任何相关的位置),然后检测mouseup事件,并减去两个值。

再加上这个答案。这个增加了对鼠标事件的支持,用于桌面测试:

<!--scripts-->
class SwipeEventDispatcher {
    constructor(element, options = {}) {
        this.evtMap = {
            SWIPE_LEFT: [],
            SWIPE_UP: [],
            SWIPE_DOWN: [],
            SWIPE_RIGHT: []
        };

        this.xDown = null;
        this.yDown = null;
        this.element = element;
        this.isMouseDown = false;
        this.listenForMouseEvents = true;
        this.options = Object.assign({ triggerPercent: 0.3 }, options);

        element.addEventListener('touchstart', evt => this.handleTouchStart(evt), false);
        element.addEventListener('touchend', evt => this.handleTouchEnd(evt), false);
        element.addEventListener('mousedown', evt => this.handleMouseDown(evt), false);
        element.addEventListener('mouseup', evt => this.handleMouseUp(evt), false);
    }

    on(evt, cb) {
        this.evtMap[evt].push(cb);
    }

    off(evt, lcb) {
        this.evtMap[evt] = this.evtMap[evt].filter(cb => cb !== lcb);
    }

    trigger(evt, data) {
        this.evtMap[evt].map(handler => handler(data));
    }

    handleTouchStart(evt) {
        this.xDown = evt.touches[0].clientX;
        this.yDown = evt.touches[0].clientY;
    }

    handleMouseDown(evt) {
        if (this.listenForMouseEvents==false) return;
        this.xDown = evt.clientX;
        this.yDown = evt.clientY;
        this.isMouseDown = true;
    }

    handleMouseUp(evt) {
        if (this.isMouseDown == false) return;
        const deltaX = evt.clientX - this.xDown;
        const deltaY = evt.clientY - this.yDown;
        const distMoved = Math.abs(Math.abs(deltaX) > Math.abs(deltaY) ? deltaX : deltaY);
        const activePct = distMoved / this.element.offsetWidth;

        if (activePct > this.options.triggerPercent) {
            if (Math.abs(deltaX) > Math.abs(deltaY)) {
                deltaX < 0 ? this.trigger('SWIPE_LEFT') : this.trigger('SWIPE_RIGHT');
            } else {
                deltaY > 0 ? this.trigger('SWIPE_UP') : this.trigger('SWIPE_DOWN');
            }
        }
    }

    handleTouchEnd(evt) {
        const deltaX = evt.changedTouches[0].clientX - this.xDown;
        const deltaY = evt.changedTouches[0].clientY - this.yDown;
        const distMoved = Math.abs(Math.abs(deltaX) > Math.abs(deltaY) ? deltaX : deltaY);
        const activePct = distMoved / this.element.offsetWidth;

        if (activePct > this.options.triggerPercent) {
            if (Math.abs(deltaX) > Math.abs(deltaY)) {
                deltaX < 0 ? this.trigger('SWIPE_LEFT') : this.trigger('SWIPE_RIGHT');
            } else {
                deltaY > 0 ? this.trigger('SWIPE_UP') : this.trigger('SWIPE_DOWN');
            }
        }
    }
}

// add a listener on load
window.addEventListener("load", function(event) {
    const dispatcher = new SwipeEventDispatcher(document.body);
    dispatcher.on('SWIPE_RIGHT', () => { console.log('I swiped right!') })
    dispatcher.on('SWIPE_LEFT', () => { console.log('I swiped left!') })
});

jQuery Mobile还包括滑动支持:http://api.jquerymobile.com/swipe/

例子

$("#divId").on("swipe", function(event) {
    alert("It's a swipe!");
});

我重新包装了TouchWipe作为一个简短的jquery插件:detectSwipe

我遇到了触摸端处理程序连续发射的问题,而用户正在拖着一个手指。我不知道这是不是因为我做错了什么但是我重新连接了这个用touchmove来累积移动touchend实际上触发了回调。

我还需要大量这样的实例,所以我添加了启用/禁用方法。

还有一个阈值,短刷不会触发。每次Touchstart 0的计数器。

您可以动态地更改target_node。创建时启用是可选选项。

/** Usage: */
touchevent = new Modules.TouchEventClass(callback, target_node);
touchevent.enable();
touchevent.disable();

/** 
*
*   Touch event module
*
*   @param method   set_target_mode
*   @param method   __touchstart
*   @param method   __touchmove
*   @param method   __touchend
*   @param method   enable
*   @param method   disable
*   @param function callback
*   @param node     target_node
*/
Modules.TouchEventClass = class {

    constructor(callback, target_node, enable=false) {

        /** callback function */
        this.callback = callback;

        this.xdown = null;
        this.ydown = null;
        this.enabled = false;
        this.target_node = null;

        /** move point counts [left, right, up, down] */
        this.counts = [];

        this.set_target_node(target_node);

        /** Enable on creation */
        if (enable === true) {
            this.enable();
        }

    }

    /** 
    *   Set or reset target node
    *
    *   @param string/node target_node
    *   @param string      enable (optional)
    */
    set_target_node(target_node, enable=false) {

        /** check if we're resetting target_node */
        if (this.target_node !== null) {

            /** remove old listener */
           this.disable();
        }

        /** Support string id of node */
        if (target_node.nodeName === undefined) {
            target_node = document.getElementById(target_node);
        }

        this.target_node = target_node;

        if (enable === true) {
            this.enable();
        }
    }

    /** enable listener */
    enable() {
        this.enabled = true;
        this.target_node.addEventListener("touchstart", this.__touchstart.bind(this));
        this.target_node.addEventListener("touchmove", this.__touchmove.bind(this));
        this.target_node.addEventListener("touchend", this.__touchend.bind(this));
    }

    /** disable listener */
    disable() {
        this.enabled = false;
        this.target_node.removeEventListener("touchstart", this.__touchstart);
        this.target_node.removeEventListener("touchmove", this.__touchmove);
        this.target_node.removeEventListener("touchend", this.__touchend);
    }

    /** Touchstart */
    __touchstart(event) {
        event.stopPropagation();
        this.xdown = event.touches[0].clientX;
        this.ydown = event.touches[0].clientY;

        /** reset count of moves in each direction, [left, right, up, down] */
        this.counts = [0, 0, 0, 0];
    }

    /** Touchend */
    __touchend(event) {
        let max_moves = Math.max(...this.counts);
        if (max_moves > 500) { // set this threshold appropriately
            /** swipe happened */
            let index = this.counts.indexOf(max_moves);
            if (index == 0) {
                this.callback("left");
            } else if (index == 1) {
                this.callback("right");
            } else if (index == 2) {
                this.callback("up");
            } else {
                this.callback("down");
            }
        }
    }

    /** Touchmove */
    __touchmove(event) {

        event.stopPropagation();
        if (! this.xdown || ! this.ydown) {
            return;
        }

        let xup = event.touches[0].clientX;
        let yup = event.touches[0].clientY;

        let xdiff = this.xdown - xup;
        let ydiff = this.ydown - yup;

        /** Check x or y has greater distance */
        if (Math.abs(xdiff) > Math.abs(ydiff)) {
            if (xdiff > 0) {
                this.counts[0] += Math.abs(xdiff);
            } else {
                this.counts[1] += Math.abs(xdiff);
            }
        } else {
            if (ydiff > 0) {
                this.counts[2] += Math.abs(ydiff);
            } else {
                this.counts[3] += Math.abs(ydiff);
            }
        }
    }
}