/**********************************************************************
 *  kaZoomOnClick.js
 *
 *  Date: 17th May 2006
 *
 *  purpose: A convenient zoom tool that allows the user to zoom in
 *           or out of the map location where it was clicked.
 *  
 *  author: Wei Yang, Ng - Wayne
 *
 *  Acknowledgments: Paul Spencer for his guidance.
 *  Note: Alot of the code was borrowed from kaTool.js
 **********************************************************************
 *  Usage:
 *  1) Add the following to your page:
 *     <script type="text/javascript" src="kaZoomOnClick.js"></script>
 *  
 *  2) create 2 instances of kaZoomOnClick: 
 *     (hint: look for initialization code - eg. myOnLoad() in startUp.js)
 *     myKaZoomInOnClick = new kaZoomOnClick( myKaMap, KAMAP_ZOOMIN );
 *     myKaZoomOutOnClick = new kaZoomOnClick( myKaMap, KAMAP_ZOOMOUT );
 *
 *  3) Include the following img icons in your webpage:
 *    <img id="toolZoomIn" class="clickIcon" onclick="switchMode(this.id)" 
 *     src="./images/a_pixel.gif" border="0" title="Switch to Zoom In Mode" 
 *     alt="Switch to Zoom In Mode" />
 *    <img id="toolZoomOut" class="clickIcon" onclick="switchMode(this.id)"
 *     src="./images/a_pixel.gif" border="0" title="Switch to Zoom Out Mode"
 *     alt="Switch to Zoom Out Mode" />
 *
 *  Note: the switchMode function in startUp.js just went through major changes
 *        ensure you are using the latest startUp.js version
 *
 **********************************************************************/
var KAMAP_ZOOMIN = 0;
var KAMAP_ZOOMOUT = 1;

/**
 *  kaZoomOnClick constructor
 */
function kaZoomOnClick( oKaMap, type ) {
    kaTool.apply( this, [oKaMap] );
    this.name = 'kaZoomOnClick';
    this.cursor = ["url('images/cross.png'),move"];
    this.type = type;

    for (var p in kaTool.prototype) {
        if (!kaZoomOnClick.prototype[p])
            kaZoomOnClick.prototype[p]= kaTool.prototype[p];
    }
}

/**
 *  Move to the point where the cursor was double clicked and zoom in.
 *  This is basically a slight modification of the "kaNavigator.prototype.ondblclick"
 *  function in kaTool.js
 */
kaZoomOnClick.prototype.onmouseup = function(e) {
    e = (e)?e:((event)?event:null);
        
    var posX = 0, posY = 0;
        
    if (e.pageX && e.pageY) {
        posX = e.pageX;
        posY = e.pageY;
    } else {
        var iebody=(document.compatMode && document.compatMode != "BackCompat")? document.documentElement : document.body;
        var scrollX = iebody.scrollLeft?iebody.scrollLeft:(window.pageXOffset?window.pageXOffset:0);
        var scrollY = iebody.scrollTop?iebody.scrollTop:(window.pageYOffset?window.pageYOffset:0);
        
        posX = e.clientX + scrollX;
        posY = e.clientY + scrollY;
    }

    var aPixPos = this.adjustPixPosition( posX, posY);

    var vpX = this.kaMap.viewportWidth/2;
    var vpY = this.kaMap.viewportHeight/2;

    var dx = parseInt(this.kaMap.theInsideLayer.style.left) - this.kaMap.xOrigin - vpX - aPixPos[0];
    var dy = parseInt(this.kaMap.theInsideLayer.style.top) - this.kaMap.yOrigin - vpY - aPixPos[1];

    this.kaMap.moveBy(-dx, -dy);
    if (this.type == KAMAP_ZOOMIN) {
        myZoomIn();
    } else if (this.type == KAMAP_ZOOMOUT) {
        myZoomOut();
    }
    return false;
}