//
//  Drawing classes for Wind Guages and Rotators
//

//
//  this is the base class that rotates an arrow
//
function WindRotate(parrowobj,parrowwidth,pstartangle)
{
	if ( arguments.length > 0 ) 
		this.init(parrowobj,parrowwidth,pstartangle);
}

WindRotate.prototype.init = function(parrowobj, parrowwidth, pstartangle) 
{
	this.curangle=pstartangle;
	this.new_angle=0;
	this.arrowObj=parrowobj;
	this.arrow_width=parrowwidth;
	this.timer=new Timer(this);

	this.switchArrow(this.curangle);
}

WindRotate.prototype.setValue = function (val)
{
	//this.rotateToNewPosition(parseInt(val));
	// AJS - speed up older browsers
	this.switchArrow(parseInt(val));
}

WindRotate.prototype.switchArrow = function(new_angle)
{
	var the_style=this.getStyleObject(this.arrowObj);
	var new_left=parseInt(new_angle*this.arrow_width*-1);

	if (the_style)
	{
    	if (!document.layers) 
    	{
    	  	new_left = new_left + "px";
    	}

    	// now actually move the DIV
    	//
    	the_style.left = new_left;
	}
}

WindRotate.prototype.rotateToNewPositionCallback = function()
{
	if (this.curangle==this.new_angle) return;

	var dir1=(this.new_angle-this.curangle);
	if (dir1<0) dir1+=360;
	var dir2=(this.curangle-this.new_angle);
	if (dir2<0) dir2+=360;
	if (dir1 < dir2)
	{
		this.curangle++;
	}
	else
		this.curangle--;

	if (this.curangle==-1) this.curangle=359;
	if (this.curangle==360) this.curangle=0;

	this.switchArrow(this.curangle);
	this.timer.setTimeout("rotateToNewPositionCallback",5);


};
WindRotate.prototype.rotateToNewPosition = function( pnew_angle)
{
	if (pnew_angle < 0 || pnew_angle > 360) pnew_angle=0;
	this.new_angle=pnew_angle;
	this.rotateToNewPositionCallback();
};

WindRotate.prototype.getStyleObject = function(objectId) {
    // cross-browser function to get an object's style object given its
    if(document.getElementById && document.getElementById(objectId)) {
	// W3C DOM
	return document.getElementById(objectId).style;
    } else if (document.all && document.all(objectId)) {
	// MSIE 4 DOM
	return document.all(objectId).style;
    } else if (document.layers && document.layers[objectId]) {
	// NN 4 DOM.. note: this won't find nested layers
	return document.layers[objectId];
    } else {
	return false;
    }
}; // getStyleObject


//
// WindGuage is a class that rotates and arrow, and moves it around a circle
//

WindGuage.prototype = new WindRotate();
WindGuage.prototype.constructor = WindGuage;
WindGuage.superclass = WindRotate.prototype;

function WindGuage(pwindobj,parrowobj,pradius,pradiusoffset,parrowwidth,pstartangle)
{
//var the_timeout;
	if ( arguments.length > 0 ) 
		this.init(pwindobj,parrowobj,pradius,pradiusoffset,parrowwidth,pstartangle);

}


WindGuage.prototype.init= function (pwindobj,parrowobj,pradius,pradiusoffset,parrowwidth,pstartangle)
{
	WindGuage.superclass.init.call(this,parrowobj, parrowwidth,pstartangle);
	this.radius=pradius;
	this.radiusoffset=pradiusoffset;
	this.windObj=pwindobj;

	if (this.curangle==360) this.curangle=0;
	this.moveElementToAngle(this.curangle);
}
	
WindGuage.prototype.setValue = function (val)
{
	this.animateToNewPosition(parseInt(val));
}



WindGuage.prototype.moveElement = function( new_left, new_top)
{
	var the_style=this.getStyleObject(this.windObj);

    // add the px or don't, depending on the browser
	if (the_style)
	{
    	if (!document.layers) 
    	{
      	new_left = new_left + "px";
      	new_top = new_top + "px";
    	}

    	// now actually move the DIV
    	//
    	the_style.left = new_left;
    	the_style.top = new_top;
	}
}

WindGuage.prototype.moveElementToAngle = function(new_angle)
{
	// calculate new position on the circle
  	var x = this.radius * Math.sin(new_angle * Math.PI / 180);
  	var y = this.radius * Math.cos(new_angle * Math.PI / 180);
	y=this.radius-y+this.radiusoffset;
	x=this.radius+x+this.radiusoffset;
	x = parseInt(x);
	y = parseInt(y);

//	var coords=getXY(objectId);
//	var oldx=coords[0];
//	var oldy=coords[1];

	this.switchArrow(new_angle);

	x-=this.arrow_width/2;
	y-=this.arrow_width/2;
	this.moveElement( x, y);
//	var newcoords=getXY(objectId);
//	var newoldx=newcoords[0];
//	var newoldy=newcoords[1];

//	if (oldx==newoldx && oldy==newoldy) alert('same');

};


WindGuage.prototype.animateToNewPositionCallback = function(objectId)
{
	if (this.curangle==this.new_angle) return;

	var dir1=(this.new_angle-this.curangle);
	if (dir1<0) dir1+=360;
	var dir2=(this.curangle-this.new_angle);
	if (dir2<0) dir2+=360;
	if (dir1 < dir2)
	{
		this.curangle++;
	}
	else
		this.curangle--;

	if (this.curangle==-1) this.curangle=359;
	if (this.curangle==360) this.curangle=0;

	this.moveElementToAngle(this.curangle)
	this.timer.setTimeout("animateToNewPositionCallback",10);

};

WindGuage.prototype.animateToNewPosition = function( pnew_angle)
{
	if (pnew_angle < 0 || pnew_angle > 360) pnew_angle=0;
	this.new_angle=pnew_angle;
	this.animateToNewPositionCallback();

};