Benutzer:CF/Schnee.js

var letItSnow =
{
  snowPer100x100Pixels : 0.35,
  snowing : true,
  snow : [],
  interval : null,
  loopindex : 0,

  letItSnow : function(p)
  {
    if (!letItSnow.snowing) return;
    if (letItSnow.interval) letItSnow.stopIt(true);
    letItSnow.newSnow(true);
    letItSnow.interval = window.setInterval(letItSnow.loop, 50);
  },
  loop : function()
  {
    for (var i=0; i<letItSnow.snow.length; ++i)
      if (letItSnow.snow[i].fall() && letItSnow.snow[i].remove())
        letItSnow.snow.splice(i--, 1);

    if (! (letItSnow.loopindex = ((++(letItSnow.loopindex)) % 10)))
      letItSnow.newSnow(false);
  },
  newSnow : function(inWindow)
  {
    var snowCount = Math.floor(window.innerHeight * window.innerWidth * letItSnow.snowPer100x100Pixels / 10000) - letItSnow.snow.length;
    for (var i=0; i<snowCount; ++i)
      letItSnow.snow.push(new letItSnow.Snow(inWindow));
  },
  Snow : function(inWindow)
  {
    this.vx = 0 + Math.random()* 0.051;
    this.vy = 2 + Math.random()* 5;
    this.dx = 5 + Math.random()*10;
    this.x  = 0 + Math.random()*(window.innerWidth-30);
    this.y  = 0 + Math.random()*window.innerHeight - (inWindow ? 0 : window.innerHeight);
    this.e  = document.createElement("img");
    this.e.src = "https://stargatewiki.de/images/3/36/SGW-Schnee.png";
    this.e.alt = "*";
    this.e.style.width = "30px";
    this.e.style.height = "30px";
    this.e.style.position = "fixed";
    this.e.style.left = Math.floor(this.x + Math.sin(this.y*this.vx)*this.dx)+"px";
    this.e.style.top = Math.floor(this.y)+"px";
    this.e.style.zIndex = "100";
    document.body.appendChild(this.e);

    this.fall = function()
    {
      this.y += this.vy;
      if (this.y >= window.innerHeight) return true;

      this.e.style.left = Math.floor(this.x + Math.sin(this.y*this.vx)*this.dx)+"px";
      this.e.style.top = Math.floor(this.y)+"px";
      return false;
    };
    this.remove = function()
    {
      document.body.removeChild(this.e);
      return true;
    };
  },
  stopIt : function(restart)
  {
    window.clearInterval(letItSnow.interval);
    if (!restart)
      letItSnow.snowing = false;
    for (var i=0; i<letItSnow.snow.length; ++i)
      letItSnow.snow[i].remove();
    letItSnow.snow = [];
  },
  addButton : function()
  {
    var w = document.getElementById("ca-watch");
    if (!w) w = document.getElementById("ca-unwatch");
    var node = mw.util.addPortletLink((skin=="vector" ? "p-views" : "p-cactions"), "#", "Schnee", "ca-snow", "Schneeanimation an- und ausschalten", "s", w);
    if (node)
    {
      node.onclick = function() {
        if (this.className == "selected")
        {
          this.className = "";
          letItSnow.stopIt();
        }
        else
        {
          this.className = "selected";
          letItSnow.snowing = true;
          letItSnow.letItSnow(letItSnow);
        }
      };
      if (skin == "vector")
      {
        var img = document.createElement("img");
        img.alt = "Schneeanimation an- oder ausschalten";
        img.src = "https://stargatewiki.de/images/3/36/SGW-Schnee.png";
        img.style.width = "24px";
        img.style.height = "24px";
        img.style.position = "relative";
        img.style.top = "-5px";
        node.firstChild.firstChild.replaceChild(img, node.firstChild.firstChild.firstChild);
      }
    }
  }
};

// addOnloadHook( letItSnow.letItSnow("letItSnow") );
// solange noch nicht richtig eingebunden:
//letItSnow.letItSnow("letItSnow");

// oder nur den Schalter
letItSnow.addButton();