/* Copyright (c) 2006-2010 by OpenLayers Contributors (see authors.txt for 
 * full list of contributors). Published under the Clear BSD license.  
 * See http://svn.openlayers.org/trunk/openlayers/license.txt for the
 * full text of the license. */
 
/** 
 * @requires OpenLayers/Control.js
 * @requires OpenLayers/BaseTypes.js
 * @requires OpenLayers/Events.js
 */
 
/**
 * Class: OpenLayers.Control.OverviewMap
 * The OverMap control creates a small overview map, useful to display the 
 * extent of a zoomed map and your main map and provide additional 
 * navigation options to the User.  By default the overview map is drawn in
 * the lower right corner of the main map. Create a new overview map with the
 * <OpenLayers.Control.OverviewMap> constructor.
 *
 * Inerits from:
 *  - <OpenLayers.Control>
 */
OpenLayers.Control.OverviewMap = OpenLayers.Class(OpenLayers.Control, {
 
    /**
     * Property: element
     * {DOMElement} The DOM element that contains the overview map
     */
    element: null,
    
    /**
     * APIProperty: ovmap
     * {<OpenLayers.Map>} A reference to the overview map itself.
     */
    ovmap: null,
 
    /**
     * APIProperty: size
     * {<OpenLayers.Size>} The overvew map size in pixels.  Note that this is
     * the size of the map itself - the element that contains the map (default
     * class name olControlOverviewMapElement) may have padding or other style
     * attributes added via CSS.
     */
    size: new OpenLayers.Size(180, 90),
 
    /**
     * APIProperty: layers
     * {Array(<OpenLayers.Layer>)} Ordered list of layers in the overview map.
     * If none are sent at construction, the base layer for the main map is used.
     */
    layers: null,
    
    /**
     * APIProperty: minRectSize
     * {Integer} The minimum width or height (in pixels) of the extent
     *     rectangle on the overview map.  When the extent rectangle reaches
     *     this size, it will be replaced depending on the value of the
     *     <minRectDisplayClass> property.  Default is 15 pixels.
     */
    minRectSize: 15,
    
    /**
     * APIProperty: minRectDisplayClass
     * {String} Replacement style class name for the extent rectangle when
     *     <minRectSize> is reached.  This string will be suffixed on to the
     *     displayClass.  Default is "RectReplacement".
     *
     * Example CSS declaration:
     * (code)
     * .olControlOverviewMapRectReplacement {
     *     overflow: hidden;
     *     cursor: move;
     *     background-image: url("img/overview_replacement.gif");
     *     background-repeat: no-repeat;
     *     background-position: center;
     * }
     * (end)
     */
    minRectDisplayClass: "RectReplacement",
 
    /**
     * APIProperty: minRatio
     * {Float} The ratio of the overview map resolution to the main map
     *     resolution at which to zoom farther out on the overview map.
     */
    minRatio: 8,
 
    /**
     * APIProperty: maxRatio
     * {Float} The ratio of the overview map resolution to the main map
     *     resolution at which to zoom farther in on the overview map.
     */
    maxRatio: 32,
    
    /**
     * APIProperty: mapOptions
     * {Object} An object containing any non-default properties to be sent to
     *     the overview map's map constructor.  These should include any
     *     non-default options that the main map was constructed with.
     */
    mapOptions: null,
 
    /**
     * APIProperty: autoPan
     * {Boolean} Always pan the overview map, so the extent marker remains in
     *     the center.  Default is false.  If true, when you drag the extent
     *     marker, the overview map will update itself so the marker returns
     *     to the center.
     */
    autoPan: false,
    
    /**
     * Property: handlers
     * {Object}
     */
    handlers: null,
 
    /**
     * Property: resolutionFactor
     * {Object}
     */
    resolutionFactor: 1,
 
    /**
     * APIProperty: maximized
     * {Boolean} Start as maximized (visible). Defaults to false.
     */
    maximized: false,
 
    /**
     * Constructor: OpenLayers.Control.OverviewMap
     * Create a new overview map
     *
     * Parameters:
     * object - {Object} Properties of this object will be set on the overview
     * map object.  Note, to set options on the map object contained in this
     * control, set <mapOptions> as one of the options properties.
     */
    initialize: function(options) {
        this.layers = [];
        this.handlers = {};
        OpenLayers.Control.prototype.initialize.apply(this, [options]);
    },
    
    /**
     * APIMethod: destroy
     * Deconstruct the control
     */
    destroy: function() {
        if (!this.mapDiv) { // we've already been destroyed
            return;
        }
        if (this.handlers.click) {
            this.handlers.click.destroy();
        }
        if (this.handlers.drag) {
            this.handlers.drag.destroy();
        }
 
        this.mapDiv.removeChild(this.extentRectangle);
        this.extentRectangle = null;
 
        if (this.rectEvents) {
            this.rectEvents.destroy();
            this.rectEvents = null;
        }
 
        if (this.ovmap) {
            this.ovmap.destroy();
            this.ovmap = null;
        }
        
        this.element.removeChild(this.mapDiv);
        this.mapDiv = null;
 
        this.div.removeChild(this.element);
        this.element = null;
 
        if (this.maximizeDiv) {
            OpenLayers.Event.stopObservingElement(this.maximizeDiv);
            this.div.removeChild(this.maximizeDiv);
            this.maximizeDiv = null;
        }
        
        if (this.minimizeDiv) {
            OpenLayers.Event.stopObservingElement(this.minimizeDiv);
            this.div.removeChild(this.minimizeDiv);
            this.minimizeDiv = null;
        }
 
        this.map.events.un({
            "moveend": this.update,
            "changebaselayer": this.baseLayerDraw,
            scope: this
        });
 
        OpenLayers.Control.prototype.destroy.apply(this, arguments);    
    },
 
    /**
     * Method: draw
     * Render the control in the browser.
     */    
    draw: function() {
        OpenLayers.Control.prototype.draw.apply(this, arguments);
        if(!(this.layers.length > 0)) {
            if (this.map.baseLayer) {
                var layer = this.map.baseLayer.clone();
                this.layers = [layer];
            } else {
                this.map.events.register("changebaselayer", this, this.baseLayerDraw);
                return this.div;
            }
        }
 
        // create overview map DOM elements
        this.element = document.createElement('div');
        this.element.className = this.displayClass + 'Element';
        this.element.style.display = 'none';
 
        this.mapDiv = document.createElement('div');
        this.mapDiv.style.width = this.size.w + 'px';
        this.mapDiv.style.height = this.size.h + 'px';
        this.mapDiv.style.position = 'relative';
        this.mapDiv.style.overflow = 'hidden';
        this.mapDiv.id = OpenLayers.Util.createUniqueID('overviewMap');
        
        this.extentRectangle = document.createElement('div');
        this.extentRectangle.style.position = 'absolute';
        this.extentRectangle.style.zIndex = 1000;  //HACK
        this.extentRectangle.className = this.displayClass+'ExtentRectangle';
        this.mapDiv.appendChild(this.extentRectangle);
 
        this.element.appendChild(this.mapDiv);  
 
        this.div.appendChild(this.element);
 
        // Optionally add min/max buttons if the control will go in the
        // map viewport.
        if(!this.outsideViewport) {
            this.div.className += " " + this.displayClass + 'Container';
            var imgLocation = OpenLayers.Util.getImagesLocation();
            // maximize button div
            var img = imgLocation + 'layer-switcher-maximize.png';
            this.maximizeDiv = OpenLayers.Util.createAlphaImageDiv(
                                        this.displayClass + 'MaximizeButton', 
                                        null, 
                                        new OpenLayers.Size(18,18), 
                                        img, 
                                        'absolute');
            this.maximizeDiv.style.display = 'none';
            this.maximizeDiv.className = this.displayClass + 'MaximizeButton';
            OpenLayers.Event.observe(this.maximizeDiv, 'click', 
                OpenLayers.Function.bindAsEventListener(this.maximizeControl,
                                                        this)
            );
            this.div.appendChild(this.maximizeDiv);
    
            // minimize button div
            var img = imgLocation + 'layer-switcher-minimize.png';
            this.minimizeDiv = OpenLayers.Util.createAlphaImageDiv(
                                        'OpenLayers_Control_minimizeDiv', 
                                        null, 
                                        new OpenLayers.Size(18,18), 
                                        img, 
                                        'absolute');
            this.minimizeDiv.style.display = 'none';
            this.minimizeDiv.className = this.displayClass + 'MinimizeButton';
            OpenLayers.Event.observe(this.minimizeDiv, 'click', 
                OpenLayers.Function.bindAsEventListener(this.minimizeControl,
                                                        this)
            );
            this.div.appendChild(this.minimizeDiv);
            
            var eventsToStop = ['dblclick','mousedown'];
            
            for (var i=0, len=eventsToStop.length; i<len; i++) {
 
                OpenLayers.Event.observe(this.maximizeDiv, 
                                         eventsToStop[i], 
                                         OpenLayers.Event.stop);
 
                OpenLayers.Event.observe(this.minimizeDiv,
                                         eventsToStop[i], 
                                         OpenLayers.Event.stop);
            }
            
            this.minimizeControl();
        } else {
            // show the overview map
            this.element.style.display = '';
        }
        if(this.map.getExtent()) {
            this.update();
        }
        
        this.map.events.register('moveend', this, this.update);
        
        if (this.maximized) {
            this.maximizeControl();
        }
        return this.div;
    },
    
    /**
     * Method: baseLayerDraw
     * Draw the base layer - called if unable to complete in the initial draw
     */
    baseLayerDraw: function() {
        this.draw();
        this.map.events.unregister("changebaselayer", this, this.baseLayerDraw);
    },
 
    /**
     * Method: rectDrag
     * Handle extent rectangle drag
     *
     * Parameters:
     * px - {<OpenLayers.Pixel>} The pixel location of the drag.
     */
    rectDrag: function(px) {
        var deltaX = this.handlers.drag.last.x - px.x;
        var deltaY = this.handlers.drag.last.y - px.y;
        if(deltaX != 0 || deltaY != 0) {
            var rectTop = this.rectPxBounds.top;
            var rectLeft = this.rectPxBounds.left;
            var rectHeight = Math.abs(this.rectPxBounds.getHeight());
            var rectWidth = this.rectPxBounds.getWidth();
            // don't allow dragging off of parent element
            var newTop = Math.max(0, (rectTop - deltaY));
            newTop = Math.min(newTop,
                              this.ovmap.size.h - this.hComp - rectHeight);
            var newLeft = Math.max(0, (rectLeft - deltaX));
            newLeft = Math.min(newLeft,
                               this.ovmap.size.w - this.wComp - rectWidth);
            this.setRectPxBounds(new OpenLayers.Bounds(newLeft,
                                                       newTop + rectHeight,
                                                       newLeft + rectWidth,
                                                       newTop));
        }
    },
    
    /**
     * Method: mapDivClick
     * Handle browser events
     *
     * Parameters:
     * evt - {<OpenLayers.Event>} evt
     */
    mapDivClick: function(evt) {
        var pxCenter = this.rectPxBounds.getCenterPixel();
        var deltaX = evt.xy.x - pxCenter.x;
        var deltaY = evt.xy.y - pxCenter.y;
        var top = this.rectPxBounds.top;
        var left = this.rectPxBounds.left;
        var height = Math.abs(this.rectPxBounds.getHeight());
        var width = this.rectPxBounds.getWidth();
        var newTop = Math.max(0, (top + deltaY));
        newTop = Math.min(newTop, this.ovmap.size.h - height);
        var newLeft = Math.max(0, (left + deltaX));
        newLeft = Math.min(newLeft, this.ovmap.size.w - width);
        this.setRectPxBounds(new OpenLayers.Bounds(newLeft,
                                                   newTop + height,
                                                   newLeft + width,
                                                   newTop));
        this.updateMapToRect();
    },
 
    /**
     * Method: maximizeControl
     * Unhide the control.  Called when the control is in the map viewport.
     *
     * Parameters:
     * e - {<OpenLayers.Event>}
     */
    maximizeControl: function(e) {
        this.element.style.display = '';
        this.showToggle(false);
        if (e != null) {
            OpenLayers.Event.stop(e);                                            
        }
    },
 
    /**
     * Method: minimizeControl
     * Hide all the contents of the control