clay-core/src/Tools/animation.js

Provide a more friendly web-side drawing interface!

var _clock = {
    //当前正在运动的动画的tick函数堆栈
    timers: [],
    //唯一定时器的定时间隔
    interval: 13,
    //指定了动画时长duration默认值
    speeds: 400,
    //定时器ID
    timerId: null
};

// 提供间隔执行方法
clay.animation = function (doback, duration, callback) {
    _clock.timer(function (deep) {
        //其中deep为0-1，表示改变的程度
        doback(deep);
    }, duration, callback);
};

//把tick函数推入堆栈
_clock.timer = function (tick, duration, callback) {
    if (!_is_function(tick)) {
        throw new Error('tick is required!');
    }
    duration = typeof _is_number(duration) ? duration : _clock.speeds;
    if (duration < 0) duration = -duration;
    _clock.timers.push({
        "createTime": new Date(),
        "tick": tick,
        "duration": duration,
        "callback": callback
    });
    _clock.start();
};

//开启唯一的定时器timerId
_clock.start = function () {
    if (!_clock.timerId) {
        _clock.timerId = setInterval(_clock.tick, _clock.interval);
    }
};

//被定时器调用，遍历timers堆栈
_clock.tick = function () {
    var createTime, flag, tick, callback, timer, duration, passTime, needStop, deep,
        timers = _clock.timers;
    _clock.timers = [];
    _clock.timers.length = 0;
    for (flag = 0; flag < timers.length; flag++) {
        //初始化数据
        timer = timers[flag];
        createTime = timer.createTime;
        tick = timer.tick;
        duration = timer.duration;
        callback = timer.callback;
        needStop = false;

        //执行
        passTime = (+new Date() - createTime) / duration;
        if (passTime >= 1) {
            needStop = true;
        }
        passTime = passTime > 1 ? 1 : passTime;
        deep = passTime;
        tick(deep);
        if (passTime < 1) {
            //动画没有结束再添加
            _clock.timers.push(timer);
        } else if (callback) {
            callback();
        }
    }
    if (_clock.timers.length <= 0) {
        _clock.stop();
    }
};

//停止定时器，重置timerId=null
_clock.stop = function () {
    if (_clock.timerId) {
        clearInterval(_clock.timerId);
        _clock.timerId = null;
    }
};