Interval/setTimeout起點

Question

我有幾個循環動畫（上/下），它們是由以下函數定義的。

循環間隔

function Cycler(f) { 
    if (!(this instanceof Cycler)) { 
     // Force new 
     return new Cycler(arguments); 
    } 
    // Unbox args 
    if (f instanceof Function) { 
     this.fns = Array.prototype.slice.call(arguments); 
    } else if (f && f.length) { 
     this.fns = Array.prototype.slice.call(f); 
    } else { 
     throw new Error('Invalid arguments supplied to Cycler constructor.'); 
    } 
    this.pos = 0; 
} 

Cycler.prototype.start = function (interval) { 
    var that = this; 
    interval = interval || 1000; 
    this.intervalId = setInterval(function() { 
     that.fns[that.pos++](); 
     that.pos %= that.fns.length; 
    }, interval); 
} 

功能1（向上）

function unpeekTile() { 

    var peekAnimation = WinJS.UI.Animation.createPeekAnimation([tile1, tile2]); 
    tile1.style.top = "0px"; 
    tile2.style.top = "0px"; 

    peekAnimation.execute(); 
} 

功能2（向下）

function peekTile() { 

    var peekAnimation = WinJS.UI.Animation.createPeekAnimation([tile1, tile2]); 
    tile1.style.top = "-120px"; 
    tile2.style.top = "-120px"; 

    peekAnimation.execute(); 

} 

開始

 function c() { Cycler(peekTile, unpeekTile).start(); } 
     setTimeout(c, 0); 

     function c2() { Cycler(peekTile2, unpeekTile2).start(); } 
     setTimeout(c2, 500); 

     function c3() { Cycler(peekTile3, unpeekTile3).start(); } 
     setTimeout(c3, 2000); 

動畫現在開始於1000（間隔時間）+ 0/500/2000（setTimeout），但我希望它們以0,500和2000毫秒開始。任何人都可以幫忙嗎？

Answer 1

如果我理解正確，你有效地說你希望間隔回調不僅限於間隔，而且在超時結束和間隔設置之間執行一次。

這意味着修改Cycler.prototype.start：

Cycler.prototype.start = function (interval) { 
    var that = this, int_callback; //<-- added var 
    interval = interval || 1000; 
    this.intervalId = setInterval(int_callback = function() { 
     that.fns[that.pos++](); 
     that.pos %= that.fns.length; 
    }, interval); 
    int_callback(); //<-- added line - call the func immediately, once 
} 

Answer 2

一個解決辦法是：

Cycler.prototype.start = function (interval,executeImmediately) { 
    var that = this; 
    interval = interval || 1000; 
    var driverFunction = function() { 
     that.fns[that.pos++](); 
     that.pos %= that.fns.length; 
    } 
    this.intervalId = setInterval(driverFunction , interval); 
    if(executeImmediately) { 
     driverFunction(); 
    } 
} 

這使定義一旦你的功能，你只需把它交給setInterval，還可以直接調用它。