// Create an overlay on the map from a projected image...
// Author. John D. Coryat 01/2008
// USNaviguide LLC - http://www.usnaviguide.com
// Thanks go to Mile Williams EInsert: http://econym.googlepages.com/einsert.js, Google's GOverlay Example and Bratliff's suggestion...
// Opacity code from TPhoto: http://gmaps.tommangan.us/addtphoto.html
// This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
//
// Parameters: 
//    imageUrl: URL of the image
//    bounds: Bounds object of image destination
//    addZoom: Added Zoom factor as a parameter to the imageUrl (include complete parameter, including separater like '?zoom='
//
	
//function ProjectedOverlay(imageUrl, bounds, addZoom, id) {
function ProjectedOverlay() {
	this.url_ = arguments[0].imageUrl;
	this.bounds_ = arguments[0].bounds;
	this.addZ_ = arguments[0].addZoom;				// Add the zoom to the image as a parameter
	this.id = arguments[0].id;
	//this.initialize(map);
	// Is this IE, if so we need to use AlphaImageLoader

	this.ie = false ;
	var agent = navigator.userAgent.toLowerCase();
	if ((agent.indexOf("msie") > -1) && (agent.indexOf("opera") < 1)) this.ie = true ;
}

ProjectedOverlay.prototype = new GOverlay();

ProjectedOverlay.prototype.initialize = function(map) {
	var div = document.createElement("div");
	div.style.position = "absolute";
	div.setAttribute('id',this.id);
	map.getPane(G_MAP_MAP_PANE).appendChild(div);
	this.map_ = map;
	this.div_ = div;
	if(this.percentOpacity) this.setOpacity(this.percentOpacity);
}

// Remove the main DIV from the map pane

ProjectedOverlay.prototype.remove = function() {
	this.div_.parentNode.removeChild(this.div_);
	delete(this.map);
	delete(this.div);
}

// Copy our data to a new ProjectedOverlay...

ProjectedOverlay.prototype.copy = function() {
	return new ProjectedOverlay(this.url_, this.bounds_, this.addZ_);
}

// Redraw based on the current projection and zoom level...

ProjectedOverlay.prototype.redraw = function(force) {
	// We only need to redraw if the coordinate system has changed
	if (!force) return;
	
	var c1 = this.map_.fromLatLngToDivPixel(this.bounds_.getSouthWest());
	var c2 = this.map_.fromLatLngToDivPixel(this.bounds_.getNorthEast());
	
	// Now position our DIV based on the DIV coordinates of our bounds
	this.div_.style.width = Math.abs(c2.x - c1.x) + "px";
	this.div_.style.height = Math.abs(c2.y - c1.y) + "px";
	this.div_.style.left = Math.min(c2.x, c1.x) + "px";
	this.div_.style.top = Math.min(c2.y, c1.y) + "px";
	
	var url = this.url_ ;
	var extn = url.substring(url.length - 4, 4) ;
	
	if (this.addZ_) url += this.addZ_ + this.map_.getZoom();
	
	if (this.ie && extn.toLowerCase() == '.png') {
		var loader = "filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + url + "', sizingMethod='scale');";
		this.div_.innerHTML = '<div style="height:' + this.div_.style.height + 'px; width:' + this.div_.style.width + 'px; ' + loader + '" ></div>';
	} else {
		this.div_.innerHTML = '<img src="' + url + '"  width=' + this.div_.style.width + ' height=' + this.div_.style.height + ' >';
	}
}

ProjectedOverlay.prototype.setOpacity=function(opacity) {
	if (opacity < 0) opacity = 0;
	if (opacity > 100) opacity = 100;
	var c = opacity/100;
	var d = document.getElementById(this.id);
	if (typeof(d.style.filter)=='string') {
		d.style.filter = 'alpha(opacity:' + opacity + ')';
		//d.style.filter = 'alpha(opacity=' + opacity + ')';
		//d.style.filter = 'progid:DXImageTransform.Microsoft.Alpha(opacity=' + opacity + ')';
	}
	if (typeof(d.style.KHTMLOpacity)=='string') {
		d.style.KHTMLOpacity = c;
	}
	if (typeof(d.style.MozOpacity)=='string') {
		d.style.MozOpacity = c;
	}
	if (typeof(d.style.opacity)=='string') {
		d.style.opacity = c;		
	}
}