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+/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
+ * full list of contributors). Published under the 2-clause BSD license.
+ * See license.txt in the OpenLayers distribution or repository for the
+ * full text of the license. */
+
+
+/**
+ * @requires OpenLayers/Layer/HTTPRequest.js
+ * @requires OpenLayers/Tile/Image.js
+ */
+
+/**
+ * Class: OpenLayers.Layer.Grid
+ * Base class for layers that use a lattice of tiles. Create a new grid
+ * layer with the <OpenLayers.Layer.Grid> constructor.
+ *
+ * Inherits from:
+ * - <OpenLayers.Layer.HTTPRequest>
+ */
+OpenLayers.Layer.Grid = OpenLayers.Class(OpenLayers.Layer.HTTPRequest, {
+
+ /**
+ * APIProperty: tileSize
+ * {<OpenLayers.Size>}
+ */
+ tileSize: null,
+
+ /**
+ * Property: tileOriginCorner
+ * {String} If the <tileOrigin> property is not provided, the tile origin
+ * will be derived from the layer's <maxExtent>. The corner of the
+ * <maxExtent> used is determined by this property. Acceptable values
+ * are "tl" (top left), "tr" (top right), "bl" (bottom left), and "br"
+ * (bottom right). Default is "bl".
+ */
+ tileOriginCorner: "bl",
+
+ /**
+ * APIProperty: tileOrigin
+ * {<OpenLayers.LonLat>} Optional origin for aligning the grid of tiles.
+ * If provided, requests for tiles at all resolutions will be aligned
+ * with this location (no tiles shall overlap this location). If
+ * not provided, the grid of tiles will be aligned with the layer's
+ * <maxExtent>. Default is ``null``.
+ */
+ tileOrigin: null,
+
+ /** APIProperty: tileOptions
+ * {Object} optional configuration options for <OpenLayers.Tile> instances
+ * created by this Layer, if supported by the tile class.
+ */
+ tileOptions: null,
+
+ /**
+ * APIProperty: tileClass
+ * {<OpenLayers.Tile>} The tile class to use for this layer.
+ * Defaults is OpenLayers.Tile.Image.
+ */
+ tileClass: OpenLayers.Tile.Image,
+
+ /**
+ * Property: grid
+ * {Array(Array(<OpenLayers.Tile>))} This is an array of rows, each row is
+ * an array of tiles.
+ */
+ grid: null,
+
+ /**
+ * APIProperty: singleTile
+ * {Boolean} Moves the layer into single-tile mode, meaning that one tile
+ * will be loaded. The tile's size will be determined by the 'ratio'
+ * property. When the tile is dragged such that it does not cover the
+ * entire viewport, it is reloaded.
+ */
+ singleTile: false,
+
+ /** APIProperty: ratio
+ * {Float} Used only when in single-tile mode, this specifies the
+ * ratio of the size of the single tile to the size of the map.
+ * Default value is 1.5.
+ */
+ ratio: 1.5,
+
+ /**
+ * APIProperty: buffer
+ * {Integer} Used only when in gridded mode, this specifies the number of
+ * extra rows and colums of tiles on each side which will
+ * surround the minimum grid tiles to cover the map.
+ * For very slow loading layers, a larger value may increase
+ * performance somewhat when dragging, but will increase bandwidth
+ * use significantly.
+ */
+ buffer: 0,
+
+ /**
+ * APIProperty: transitionEffect
+ * {String} The transition effect to use when the map is zoomed.
+ * Two posible values:
+ *
+ * "resize" - Existing tiles are resized on zoom to provide a visual
+ * effect of the zoom having taken place immediately. As the
+ * new tiles become available, they are drawn on top of the
+ * resized tiles (this is the default setting).
+ * "map-resize" - Existing tiles are resized on zoom and placed below the
+ * base layer. New tiles for the base layer will cover existing tiles.
+ * This setting is recommended when having an overlay duplicated during
+ * the transition is undesirable (e.g. street labels or big transparent
+ * fills).
+ * null - No transition effect.
+ *
+ * Using "resize" on non-opaque layers can cause undesired visual
+ * effects. Set transitionEffect to null in this case.
+ */
+ transitionEffect: "resize",
+
+ /**
+ * APIProperty: numLoadingTiles
+ * {Integer} How many tiles are still loading?
+ */
+ numLoadingTiles: 0,
+
+ /**
+ * Property: serverResolutions
+ * {Array(Number}} This property is documented in subclasses as
+ * an API property.
+ */
+ serverResolutions: null,
+
+ /**
+ * Property: loading
+ * {Boolean} Indicates if tiles are being loaded.
+ */
+ loading: false,
+
+ /**
+ * Property: backBuffer
+ * {DOMElement} The back buffer.
+ */
+ backBuffer: null,
+
+ /**
+ * Property: gridResolution
+ * {Number} The resolution of the current grid. Used for backbuffer and
+ * client zoom. This property is updated every time the grid is
+ * initialized.
+ */
+ gridResolution: null,
+
+ /**
+ * Property: backBufferResolution
+ * {Number} The resolution of the current back buffer. This property is
+ * updated each time a back buffer is created.
+ */
+ backBufferResolution: null,
+
+ /**
+ * Property: backBufferLonLat
+ * {Object} The top-left corner of the current back buffer. Includes lon
+ * and lat properties. This object is updated each time a back buffer
+ * is created.
+ */
+ backBufferLonLat: null,
+
+ /**
+ * Property: backBufferTimerId
+ * {Number} The id of the back buffer timer. This timer is used to
+ * delay the removal of the back buffer, thereby preventing
+ * flash effects caused by tile animation.
+ */
+ backBufferTimerId: null,
+
+ /**
+ * APIProperty: removeBackBufferDelay
+ * {Number} Delay for removing the backbuffer when all tiles have finished
+ * loading. Can be set to 0 when no css opacity transitions for the
+ * olTileImage class are used. Default is 0 for <singleTile> layers,
+ * 2500 for tiled layers. See <className> for more information on
+ * tile animation.
+ */
+ removeBackBufferDelay: null,
+
+ /**
+ * APIProperty: className
+ * {String} Name of the class added to the layer div. If not set in the
+ * options passed to the constructor then className defaults to
+ * "olLayerGridSingleTile" for single tile layers (see <singleTile>),
+ * and "olLayerGrid" for non single tile layers.
+ *
+ * Note:
+ *
+ * The displaying of tiles is not animated by default for single tile
+ * layers - OpenLayers' default theme (style.css) includes this:
+ * (code)
+ * .olLayerGrid .olTileImage {
+ * -webkit-transition: opacity 0.2s linear;
+ * -moz-transition: opacity 0.2s linear;
+ * -o-transition: opacity 0.2s linear;
+ * transition: opacity 0.2s linear;
+ * }
+ * (end)
+ * To animate tile displaying for any grid layer the following
+ * CSS rule can be used:
+ * (code)
+ * .olTileImage {
+ * -webkit-transition: opacity 0.2s linear;
+ * -moz-transition: opacity 0.2s linear;
+ * -o-transition: opacity 0.2s linear;
+ * transition: opacity 0.2s linear;
+ * }
+ * (end)
+ * In that case, to avoid flash effects, <removeBackBufferDelay>
+ * should not be zero.
+ */
+ className: null,
+
+ /**
+ * Register a listener for a particular event with the following syntax:
+ * (code)
+ * layer.events.register(type, obj, listener);
+ * (end)
+ *
+ * Listeners will be called with a reference to an event object. The
+ * properties of this event depends on exactly what happened.
+ *
+ * All event objects have at least the following properties:
+ * object - {Object} A reference to layer.events.object.
+ * element - {DOMElement} A reference to layer.events.element.
+ *
+ * Supported event types:
+ * addtile - Triggered when a tile is added to this layer. Listeners receive
+ * an object as first argument, which has a tile property that
+ * references the tile that has been added.
+ * tileloadstart - Triggered when a tile starts loading. Listeners receive
+ * an object as first argument, which has a tile property that
+ * references the tile that starts loading.
+ * tileloaded - Triggered when each new tile is
+ * loaded, as a means of progress update to listeners.
+ * listeners can access 'numLoadingTiles' if they wish to keep
+ * track of the loading progress. Listeners are called with an object
+ * with a 'tile' property as first argument, making the loaded tile
+ * available to the listener, and an 'aborted' property, which will be
+ * true when loading was aborted and no tile data is available.
+ * tileerror - Triggered before the tileloaded event (i.e. when the tile is
+ * still hidden) if a tile failed to load. Listeners receive an object
+ * as first argument, which has a tile property that references the
+ * tile that could not be loaded.
+ * retile - Triggered when the layer recreates its tile grid.
+ */
+
+ /**
+ * Property: gridLayout
+ * {Object} Object containing properties tilelon, tilelat, startcol,
+ * startrow
+ */
+ gridLayout: null,
+
+ /**
+ * Property: rowSign
+ * {Number} 1 for grids starting at the top, -1 for grids starting at the
+ * bottom. This is used for several grid index and offset calculations.
+ */
+ rowSign: null,
+
+ /**
+ * Property: transitionendEvents
+ * {Array} Event names for transitionend
+ */
+ transitionendEvents: [
+ 'transitionend', 'webkitTransitionEnd', 'otransitionend',
+ 'oTransitionEnd'
+ ],
+
+ /**
+ * Constructor: OpenLayers.Layer.Grid
+ * Create a new grid layer
+ *
+ * Parameters:
+ * name - {String}
+ * url - {String}
+ * params - {Object}
+ * options - {Object} Hashtable of extra options to tag onto the layer
+ */
+ initialize: function(name, url, params, options) {
+ OpenLayers.Layer.HTTPRequest.prototype.initialize.apply(this,
+ arguments);
+ this.grid = [];
+ this._removeBackBuffer = OpenLayers.Function.bind(this.removeBackBuffer, this);
+
+ this.initProperties();
+
+ this.rowSign = this.tileOriginCorner.substr(0, 1) === "t" ? 1 : -1;
+ },
+
+ /**
+ * Method: initProperties
+ * Set any properties that depend on the value of singleTile.
+ * Currently sets removeBackBufferDelay and className
+ */
+ initProperties: function() {
+ if (this.options.removeBackBufferDelay === undefined) {
+ this.removeBackBufferDelay = this.singleTile ? 0 : 2500;
+ }
+
+ if (this.options.className === undefined) {
+ this.className = this.singleTile ? 'olLayerGridSingleTile' :
+ 'olLayerGrid';
+ }
+ },
+
+ /**
+ * Method: setMap
+ *
+ * Parameters:
+ * map - {<OpenLayers.Map>} The map.
+ */
+ setMap: function(map) {
+ OpenLayers.Layer.HTTPRequest.prototype.setMap.call(this, map);
+ OpenLayers.Element.addClass(this.div, this.className);
+ },
+
+ /**
+ * Method: removeMap
+ * Called when the layer is removed from the map.
+ *
+ * Parameters:
+ * map - {<OpenLayers.Map>} The map.
+ */
+ removeMap: function(map) {
+ this.removeBackBuffer();
+ },
+
+ /**
+ * APIMethod: destroy
+ * Deconstruct the layer and clear the grid.
+ */
+ destroy: function() {
+ this.removeBackBuffer();
+ this.clearGrid();
+
+ this.grid = null;
+ this.tileSize = null;
+ OpenLayers.Layer.HTTPRequest.prototype.destroy.apply(this, arguments);
+ },
+
+ /**
+ * APIMethod: mergeNewParams
+ * Refetches tiles with new params merged, keeping a backbuffer. Each
+ * loading new tile will have a css class of '.olTileReplacing'. If a
+ * stylesheet applies a 'display: none' style to that class, any fade-in
+ * transition will not apply, and backbuffers for each tile will be removed
+ * as soon as the tile is loaded.
+ *
+ * Parameters:
+ * newParams - {Object}
+ *
+ * Returns:
+ * redrawn: {Boolean} whether the layer was actually redrawn.
+ */
+
+ /**
+ * Method: clearGrid
+ * Go through and remove all tiles from the grid, calling
+ * destroy() on each of them to kill circular references
+ */
+ clearGrid:function() {
+ if (this.grid) {
+ for(var iRow=0, len=this.grid.length; iRow<len; iRow++) {
+ var row = this.grid[iRow];
+ for(var iCol=0, clen=row.length; iCol<clen; iCol++) {
+ var tile = row[iCol];
+ this.destroyTile(tile);
+ }
+ }
+ this.grid = [];
+ this.gridResolution = null;
+ this.gridLayout = null;
+ }
+ },
+
+ /**
+ * APIMethod: addOptions
+ *
+ * Parameters:
+ * newOptions - {Object}
+ * reinitialize - {Boolean} If set to true, and if resolution options of the
+ * current baseLayer were changed, the map will be recentered to make
+ * sure that it is displayed with a valid resolution, and a
+ * changebaselayer event will be triggered.
+ */
+ addOptions: function (newOptions, reinitialize) {
+ var singleTileChanged = newOptions.singleTile !== undefined &&
+ newOptions.singleTile !== this.singleTile;
+ OpenLayers.Layer.HTTPRequest.prototype.addOptions.apply(this, arguments);
+ if (this.map && singleTileChanged) {
+ this.initProperties();
+ this.clearGrid();
+ this.tileSize = this.options.tileSize;
+ this.setTileSize();
+ this.moveTo(null, true);
+ }
+ },
+
+ /**
+ * APIMethod: clone
+ * Create a clone of this layer
+ *
+ * Parameters:
+ * obj - {Object} Is this ever used?
+ *
+ * Returns:
+ * {<OpenLayers.Layer.Grid>} An exact clone of this OpenLayers.Layer.Grid
+ */
+ clone: function (obj) {
+
+ if (obj == null) {
+ obj = new OpenLayers.Layer.Grid(this.name,
+ this.url,
+ this.params,
+ this.getOptions());
+ }
+
+ //get all additions from superclasses
+ obj = OpenLayers.Layer.HTTPRequest.prototype.clone.apply(this, [obj]);
+
+ // copy/set any non-init, non-simple values here
+ if (this.tileSize != null) {
+ obj.tileSize = this.tileSize.clone();
+ }
+
+ // we do not want to copy reference to grid, so we make a new array
+ obj.grid = [];
+ obj.gridResolution = null;
+ // same for backbuffer
+ obj.backBuffer = null;
+ obj.backBufferTimerId = null;
+ obj.loading = false;
+ obj.numLoadingTiles = 0;
+
+ return obj;
+ },
+
+ /**
+ * Method: moveTo
+ * This function is called whenever the map is moved. All the moving
+ * of actual 'tiles' is done by the map, but moveTo's role is to accept
+ * a bounds and make sure the data that that bounds requires is pre-loaded.
+ *
+ * Parameters:
+ * bounds - {<OpenLayers.Bounds>}
+ * zoomChanged - {Boolean}
+ * dragging - {Boolean}
+ */
+ moveTo:function(bounds, zoomChanged, dragging) {
+
+ OpenLayers.Layer.HTTPRequest.prototype.moveTo.apply(this, arguments);
+
+ bounds = bounds || this.map.getExtent();
+
+ if (bounds != null) {
+
+ // if grid is empty or zoom has changed, we *must* re-tile
+ var forceReTile = !this.grid.length || zoomChanged;
+
+ // total bounds of the tiles
+ var tilesBounds = this.getTilesBounds();
+
+ // the new map resolution
+ var resolution = this.map.getResolution();
+
+ // the server-supported resolution for the new map resolution
+ var serverResolution = this.getServerResolution(resolution);
+
+ if (this.singleTile) {
+
+ // We want to redraw whenever even the slightest part of the
+ // current bounds is not contained by our tile.
+ // (thus, we do not specify partial -- its default is false)
+
+ if ( forceReTile ||
+ (!dragging && !tilesBounds.containsBounds(bounds))) {
+
+ // In single tile mode with no transition effect, we insert
+ // a non-scaled backbuffer when the layer is moved. But if
+ // a zoom occurs right after a move, i.e. before the new
+ // image is received, we need to remove the backbuffer, or
+ // an ill-positioned image will be visible during the zoom
+ // transition.
+
+ if(zoomChanged && this.transitionEffect !== 'resize') {
+ this.removeBackBuffer();
+ }
+
+ if(!zoomChanged || this.transitionEffect === 'resize') {
+ this.applyBackBuffer(resolution);
+ }
+
+ this.initSingleTile(bounds);
+ }
+ } else {
+
+ // if the bounds have changed such that they are not even
+ // *partially* contained by our tiles (e.g. when user has
+ // programmatically panned to the other side of the earth on
+ // zoom level 18), then moveGriddedTiles could potentially have
+ // to run through thousands of cycles, so we want to reTile
+ // instead (thus, partial true).
+ forceReTile = forceReTile ||
+ !tilesBounds.intersectsBounds(bounds, {
+ worldBounds: this.map.baseLayer.wrapDateLine &&
+ this.map.getMaxExtent()
+ });
+
+ if(forceReTile) {
+ if(zoomChanged && (this.transitionEffect === 'resize' ||
+ this.gridResolution === resolution)) {
+ this.applyBackBuffer(resolution);
+ }
+ this.initGriddedTiles(bounds);
+ } else {
+ this.moveGriddedTiles();
+ }
+ }
+ }
+ },
+
+ /**
+ * Method: getTileData
+ * Given a map location, retrieve a tile and the pixel offset within that
+ * tile corresponding to the location. If there is not an existing
+ * tile in the grid that covers the given location, null will be
+ * returned.
+ *
+ * Parameters:
+ * loc - {<OpenLayers.LonLat>} map location
+ *
+ * Returns:
+ * {Object} Object with the following properties: tile ({<OpenLayers.Tile>}),
+ * i ({Number} x-pixel offset from top left), and j ({Integer} y-pixel
+ * offset from top left).
+ */
+ getTileData: function(loc) {
+ var data = null,
+ x = loc.lon,
+ y = loc.lat,
+ numRows = this.grid.length;
+
+ if (this.map && numRows) {
+ var res = this.map.getResolution(),
+ tileWidth = this.tileSize.w,
+ tileHeight = this.tileSize.h,
+ bounds = this.grid[0][0].bounds,
+ left = bounds.left,
+ top = bounds.top;
+
+ if (x < left) {
+ // deal with multiple worlds
+ if (this.map.baseLayer.wrapDateLine) {
+ var worldWidth = this.map.getMaxExtent().getWidth();
+ var worldsAway = Math.ceil((left - x) / worldWidth);
+ x += worldWidth * worldsAway;
+ }
+ }
+ // tile distance to location (fractional number of tiles);
+ var dtx = (x - left) / (res * tileWidth);
+ var dty = (top - y) / (res * tileHeight);
+ // index of tile in grid
+ var col = Math.floor(dtx);
+ var row = Math.floor(dty);
+ if (row >= 0 && row < numRows) {
+ var tile = this.grid[row][col];
+ if (tile) {
+ data = {
+ tile: tile,
+ // pixel index within tile
+ i: Math.floor((dtx - col) * tileWidth),
+ j: Math.floor((dty - row) * tileHeight)
+ };
+ }
+ }
+ }
+ return data;
+ },
+
+ /**
+ * Method: destroyTile
+ *
+ * Parameters:
+ * tile - {<OpenLayers.Tile>}
+ */
+ destroyTile: function(tile) {
+ this.removeTileMonitoringHooks(tile);
+ tile.destroy();
+ },
+
+ /**
+ * Method: getServerResolution
+ * Return the closest server-supported resolution.
+ *
+ * Parameters:
+ * resolution - {Number} The base resolution. If undefined the
+ * map resolution is used.
+ *
+ * Returns:
+ * {Number} The closest server resolution value.
+ */
+ getServerResolution: function(resolution) {
+ var distance = Number.POSITIVE_INFINITY;
+ resolution = resolution || this.map.getResolution();
+ if(this.serverResolutions &&
+ OpenLayers.Util.indexOf(this.serverResolutions, resolution) === -1) {
+ var i, newDistance, newResolution, serverResolution;
+ for(i=this.serverResolutions.length-1; i>= 0; i--) {
+ newResolution = this.serverResolutions[i];
+ newDistance = Math.abs(newResolution - resolution);
+ if (newDistance > distance) {
+ break;
+ }
+ distance = newDistance;
+ serverResolution = newResolution;
+ }
+ resolution = serverResolution;
+ }
+ return resolution;
+ },
+
+ /**
+ * Method: getServerZoom
+ * Return the zoom value corresponding to the best matching server
+ * resolution, taking into account <serverResolutions> and <zoomOffset>.
+ *
+ * Returns:
+ * {Number} The closest server supported zoom. This is not the map zoom
+ * level, but an index of the server's resolutions array.
+ */
+ getServerZoom: function() {
+ var resolution = this.getServerResolution();
+ return this.serverResolutions ?
+ OpenLayers.Util.indexOf(this.serverResolutions, resolution) :
+ this.map.getZoomForResolution(resolution) + (this.zoomOffset || 0);
+ },
+
+ /**
+ * Method: applyBackBuffer
+ * Create, insert, scale and position a back buffer for the layer.
+ *
+ * Parameters:
+ * resolution - {Number} The resolution to transition to.
+ */
+ applyBackBuffer: function(resolution) {
+ if(this.backBufferTimerId !== null) {
+ this.removeBackBuffer();
+ }
+ var backBuffer = this.backBuffer;
+ if(!backBuffer) {
+ backBuffer = this.createBackBuffer();
+ if(!backBuffer) {
+ return;
+ }
+ if (resolution === this.gridResolution) {
+ this.div.insertBefore(backBuffer, this.div.firstChild);
+ } else {
+ this.map.baseLayer.div.parentNode.insertBefore(backBuffer, this.map.baseLayer.div);
+ }
+ this.backBuffer = backBuffer;
+
+ // set some information in the instance for subsequent
+ // calls to applyBackBuffer where the same back buffer
+ // is reused
+ var topLeftTileBounds = this.grid[0][0].bounds;
+ this.backBufferLonLat = {
+ lon: topLeftTileBounds.left,
+ lat: topLeftTileBounds.top
+ };
+ this.backBufferResolution = this.gridResolution;
+ }
+
+ var ratio = this.backBufferResolution / resolution;
+
+ // scale the tiles inside the back buffer
+ var tiles = backBuffer.childNodes, tile;
+ for (var i=tiles.length-1; i>=0; --i) {
+ tile = tiles[i];
+ tile.style.top = ((ratio * tile._i * tile._h) | 0) + 'px';
+ tile.style.left = ((ratio * tile._j * tile._w) | 0) + 'px';
+ tile.style.width = Math.round(ratio * tile._w) + 'px';
+ tile.style.height = Math.round(ratio * tile._h) + 'px';
+ }
+
+ // and position it (based on the grid's top-left corner)
+ var position = this.getViewPortPxFromLonLat(
+ this.backBufferLonLat, resolution);
+ var leftOffset = this.map.layerContainerOriginPx.x;
+ var topOffset = this.map.layerContainerOriginPx.y;
+ backBuffer.style.left = Math.round(position.x - leftOffset) + 'px';
+ backBuffer.style.top = Math.round(position.y - topOffset) + 'px';
+ },
+
+ /**
+ * Method: createBackBuffer
+ * Create a back buffer.
+ *
+ * Returns:
+ * {DOMElement} The DOM element for the back buffer, undefined if the
+ * grid isn't initialized yet.
+ */
+ createBackBuffer: function() {
+ var backBuffer;
+ if(this.grid.length > 0) {
+ backBuffer = document.createElement('div');
+ backBuffer.id = this.div.id + '_bb';
+ backBuffer.className = 'olBackBuffer';
+ backBuffer.style.position = 'absolute';
+ var map = this.map;
+ backBuffer.style.zIndex = this.transitionEffect === 'resize' ?
+ this.getZIndex() - 1 :
+ // 'map-resize':
+ map.Z_INDEX_BASE.BaseLayer -
+ (map.getNumLayers() - map.getLayerIndex(this));
+ for(var i=0, lenI=this.grid.length; i<lenI; i++) {
+ for(var j=0, lenJ=this.grid[i].length; j<lenJ; j++) {
+ var tile = this.grid[i][j],
+ markup = this.grid[i][j].createBackBuffer();
+ if (markup) {
+ markup._i = i;
+ markup._j = j;
+ markup._w = tile.size.w;
+ markup._h = tile.size.h;
+ markup.id = tile.id + '_bb';
+ backBuffer.appendChild(markup);
+ }
+ }
+ }
+ }
+ return backBuffer;
+ },
+
+ /**
+ * Method: removeBackBuffer
+ * Remove back buffer from DOM.
+ */
+ removeBackBuffer: function() {
+ if (this._transitionElement) {
+ for (var i=this.transitionendEvents.length-1; i>=0; --i) {
+ OpenLayers.Event.stopObserving(this._transitionElement,
+ this.transitionendEvents[i], this._removeBackBuffer);
+ }
+ delete this._transitionElement;
+ }
+ if(this.backBuffer) {
+ if (this.backBuffer.parentNode) {
+ this.backBuffer.parentNode.removeChild(this.backBuffer);
+ }
+ this.backBuffer = null;
+ this.backBufferResolution = null;
+ if(this.backBufferTimerId !== null) {
+ window.clearTimeout(this.backBufferTimerId);
+ this.backBufferTimerId = null;
+ }
+ }
+ },
+
+ /**
+ * Method: moveByPx
+ * Move the layer based on pixel vector.
+ *
+ * Parameters:
+ * dx - {Number}
+ * dy - {Number}
+ */
+ moveByPx: function(dx, dy) {
+ if (!this.singleTile) {
+ this.moveGriddedTiles();
+ }
+ },
+
+ /**
+ * APIMethod: setTileSize
+ * Check if we are in singleTile mode and if so, set the size as a ratio
+ * of the map size (as specified by the layer's 'ratio' property).
+ *
+ * Parameters:
+ * size - {<OpenLayers.Size>}
+ */
+ setTileSize: function(size) {
+ if (this.singleTile) {
+ size = this.map.getSize();
+ size.h = parseInt(size.h * this.ratio, 10);
+ size.w = parseInt(size.w * this.ratio, 10);
+ }
+ OpenLayers.Layer.HTTPRequest.prototype.setTileSize.apply(this, [size]);
+ },
+
+ /**
+ * APIMethod: getTilesBounds
+ * Return the bounds of the tile grid.
+ *
+ * Returns:
+ * {<OpenLayers.Bounds>} A Bounds object representing the bounds of all the
+ * currently loaded tiles (including those partially or not at all seen
+ * onscreen).
+ */
+ getTilesBounds: function() {
+ var bounds = null;
+
+ var length = this.grid.length;
+ if (length) {
+ var bottomLeftTileBounds = this.grid[length - 1][0].bounds,
+ width = this.grid[0].length * bottomLeftTileBounds.getWidth(),
+ height = this.grid.length * bottomLeftTileBounds.getHeight();
+
+ bounds = new OpenLayers.Bounds(bottomLeftTileBounds.left,
+ bottomLeftTileBounds.bottom,
+ bottomLeftTileBounds.left + width,
+ bottomLeftTileBounds.bottom + height);
+ }
+ return bounds;
+ },
+
+ /**
+ * Method: initSingleTile
+ *
+ * Parameters:
+ * bounds - {<OpenLayers.Bounds>}
+ */
+ initSingleTile: function(bounds) {
+ this.events.triggerEvent("retile");
+
+ //determine new tile bounds
+ var center = bounds.getCenterLonLat();
+ var tileWidth = bounds.getWidth() * this.ratio;
+ var tileHeight = bounds.getHeight() * this.ratio;
+
+ var tileBounds =
+ new OpenLayers.Bounds(center.lon - (tileWidth/2),
+ center.lat - (tileHeight/2),
+ center.lon + (tileWidth/2),
+ center.lat + (tileHeight/2));
+
+ var px = this.map.getLayerPxFromLonLat({
+ lon: tileBounds.left,
+ lat: tileBounds.top
+ });
+
+ if (!this.grid.length) {
+ this.grid[0] = [];
+ }
+
+ var tile = this.grid[0][0];
+ if (!tile) {
+ tile = this.addTile(tileBounds, px);
+
+ this.addTileMonitoringHooks(tile);
+ tile.draw();
+ this.grid[0][0] = tile;
+ } else {
+ tile.moveTo(tileBounds, px);
+ }
+
+ //remove all but our single tile
+ this.removeExcessTiles(1,1);
+
+ // store the resolution of the grid
+ this.gridResolution = this.getServerResolution();
+ },
+
+ /**
+ * Method: calculateGridLayout
+ * Generate parameters for the grid layout.
+ *
+ * Parameters:
+ * bounds - {<OpenLayers.Bound>|Object} OpenLayers.Bounds or an
+ * object with a 'left' and 'top' properties.
+ * origin - {<OpenLayers.LonLat>|Object} OpenLayers.LonLat or an
+ * object with a 'lon' and 'lat' properties.
+ * resolution - {Number}
+ *
+ * Returns:
+ * {Object} Object containing properties tilelon, tilelat, startcol,
+ * startrow
+ */
+ calculateGridLayout: function(bounds, origin, resolution) {
+ var tilelon = resolution * this.tileSize.w;
+ var tilelat = resolution * this.tileSize.h;
+
+ var offsetlon = bounds.left - origin.lon;
+ var tilecol = Math.floor(offsetlon/tilelon) - this.buffer;
+
+ var rowSign = this.rowSign;
+
+ var offsetlat = rowSign * (origin.lat - bounds.top + tilelat);
+ var tilerow = Math[~rowSign ? 'floor' : 'ceil'](offsetlat/tilelat) - this.buffer * rowSign;
+
+ return {
+ tilelon: tilelon, tilelat: tilelat,
+ startcol: tilecol, startrow: tilerow
+ };
+
+ },
+
+ /**
+ * Method: getTileOrigin
+ * Determine the origin for aligning the grid of tiles. If a <tileOrigin>
+ * property is supplied, that will be returned. Otherwise, the origin
+ * will be derived from the layer's <maxExtent> property. In this case,
+ * the tile origin will be the corner of the <maxExtent> given by the
+ * <tileOriginCorner> property.
+ *
+ * Returns:
+ * {<OpenLayers.LonLat>} The tile origin.
+ */
+ getTileOrigin: function() {
+ var origin = this.tileOrigin;
+ if (!origin) {
+ var extent = this.getMaxExtent();
+ var edges = ({
+ "tl": ["left", "top"],
+ "tr": ["right", "top"],
+ "bl": ["left", "bottom"],
+ "br": ["right", "bottom"]
+ })[this.tileOriginCorner];
+ origin = new OpenLayers.LonLat(extent[edges[0]], extent[edges[1]]);
+ }
+ return origin;
+ },
+
+ /**
+ * Method: getTileBoundsForGridIndex
+ *
+ * Parameters:
+ * row - {Number} The row of the grid
+ * col - {Number} The column of the grid
+ *
+ * Returns:
+ * {<OpenLayers.Bounds>} The bounds for the tile at (row, col)
+ */
+ getTileBoundsForGridIndex: function(row, col) {
+ var origin = this.getTileOrigin();
+ var tileLayout = this.gridLayout;
+ var tilelon = tileLayout.tilelon;
+ var tilelat = tileLayout.tilelat;
+ var startcol = tileLayout.startcol;
+ var startrow = tileLayout.startrow;
+ var rowSign = this.rowSign;
+ return new OpenLayers.Bounds(
+ origin.lon + (startcol + col) * tilelon,
+ origin.lat - (startrow + row * rowSign) * tilelat * rowSign,
+ origin.lon + (startcol + col + 1) * tilelon,
+ origin.lat - (startrow + (row - 1) * rowSign) * tilelat * rowSign
+ );
+ },
+
+ /**
+ * Method: initGriddedTiles
+ *
+ * Parameters:
+ * bounds - {<OpenLayers.Bounds>}
+ */
+ initGriddedTiles:function(bounds) {
+ this.events.triggerEvent("retile");
+
+ // work out mininum number of rows and columns; this is the number of
+ // tiles required to cover the viewport plus at least one for panning
+
+ var viewSize = this.map.getSize();
+
+ var origin = this.getTileOrigin();
+ var resolution = this.map.getResolution(),
+ serverResolution = this.getServerResolution(),
+ ratio = resolution / serverResolution,
+ tileSize = {
+ w: this.tileSize.w / ratio,
+ h: this.tileSize.h / ratio
+ };
+
+ var minRows = Math.ceil(viewSize.h/tileSize.h) +
+ 2 * this.buffer + 1;
+ var minCols = Math.ceil(viewSize.w/tileSize.w) +
+ 2 * this.buffer + 1;
+
+ var tileLayout = this.calculateGridLayout(bounds, origin, serverResolution);
+ this.gridLayout = tileLayout;
+
+ var tilelon = tileLayout.tilelon;
+ var tilelat = tileLayout.tilelat;
+
+ var layerContainerDivLeft = this.map.layerContainerOriginPx.x;
+ var layerContainerDivTop = this.map.layerContainerOriginPx.y;
+
+ var tileBounds = this.getTileBoundsForGridIndex(0, 0);
+ var startPx = this.map.getViewPortPxFromLonLat(
+ new OpenLayers.LonLat(tileBounds.left, tileBounds.top)
+ );
+ startPx.x = Math.round(startPx.x) - layerContainerDivLeft;
+ startPx.y = Math.round(startPx.y) - layerContainerDivTop;
+
+ var tileData = [], center = this.map.getCenter();
+
+ var rowidx = 0;
+ do {
+ var row = this.grid[rowidx];
+ if (!row) {
+ row = [];
+ this.grid.push(row);
+ }
+
+ var colidx = 0;
+ do {
+ tileBounds = this.getTileBoundsForGridIndex(rowidx, colidx);
+ var px = startPx.clone();
+ px.x = px.x + colidx * Math.round(tileSize.w);
+ px.y = px.y + rowidx * Math.round(tileSize.h);
+ var tile = row[colidx];
+ if (!tile) {
+ tile = this.addTile(tileBounds, px);
+ this.addTileMonitoringHooks(tile);
+ row.push(tile);
+ } else {
+ tile.moveTo(tileBounds, px, false);
+ }
+ var tileCenter = tileBounds.getCenterLonLat();
+ tileData.push({
+ tile: tile,
+ distance: Math.pow(tileCenter.lon - center.lon, 2) +
+ Math.pow(tileCenter.lat - center.lat, 2)
+ });
+
+ colidx += 1;
+ } while ((tileBounds.right <= bounds.right + tilelon * this.buffer)
+ || colidx < minCols);
+
+ rowidx += 1;
+ } while((tileBounds.bottom >= bounds.bottom - tilelat * this.buffer)
+ || rowidx < minRows);
+
+ //shave off exceess rows and colums
+ this.removeExcessTiles(rowidx, colidx);
+
+ var resolution = this.getServerResolution();
+ // store the resolution of the grid
+ this.gridResolution = resolution;
+
+ //now actually draw the tiles
+ tileData.sort(function(a, b) {
+ return a.distance - b.distance;
+ });
+ for (var i=0, ii=tileData.length; i<ii; ++i) {
+ tileData[i].tile.draw();
+ }
+ },
+
+ /**
+ * Method: getMaxExtent
+ * Get this layer's maximum extent. (Implemented as a getter for
+ * potential specific implementations in sub-classes.)
+ *
+ * Returns:
+ * {<OpenLayers.Bounds>}
+ */
+ getMaxExtent: function() {
+ return this.maxExtent;
+ },
+
+ /**
+ * APIMethod: addTile
+ * Create a tile, initialize it, and add it to the layer div.
+ *
+ * Parameters
+ * bounds - {<OpenLayers.Bounds>}
+ * position - {<OpenLayers.Pixel>}
+ *
+ * Returns:
+ * {<OpenLayers.Tile>} The added OpenLayers.Tile
+ */
+ addTile: function(bounds, position) {
+ var tile = new this.tileClass(
+ this, position, bounds, null, this.tileSize, this.tileOptions
+ );
+ this.events.triggerEvent("addtile", {tile: tile});
+ return tile;
+ },
+
+ /**
+ * Method: addTileMonitoringHooks
+ * This function takes a tile as input and adds the appropriate hooks to
+ * the tile so that the layer can keep track of the loading tiles.
+ *
+ * Parameters:
+ * tile - {<OpenLayers.Tile>}
+ */
+ addTileMonitoringHooks: function(tile) {
+
+ var replacingCls = 'olTileReplacing';
+
+ tile.onLoadStart = function() {
+ //if that was first tile then trigger a 'loadstart' on the layer
+ if (this.loading === false) {
+ this.loading = true;
+ this.events.triggerEvent("loadstart");
+ }
+ this.events.triggerEvent("tileloadstart", {tile: tile});
+ this.numLoadingTiles++;
+ if (!this.singleTile && this.backBuffer && this.gridResolution === this.backBufferResolution) {
+ OpenLayers.Element.addClass(tile.getTile(), replacingCls);
+ }
+ };
+
+ tile.onLoadEnd = function(evt) {
+ this.numLoadingTiles--;
+ var aborted = evt.type === 'unload';
+ this.events.triggerEvent("tileloaded", {
+ tile: tile,
+ aborted: aborted
+ });
+ if (!this.singleTile && !aborted && this.backBuffer && this.gridResolution === this.backBufferResolution) {
+ var tileDiv = tile.getTile();
+ if (OpenLayers.Element.getStyle(tileDiv, 'display') === 'none') {
+ var bufferTile = document.getElementById(tile.id + '_bb');
+ if (bufferTile) {
+ bufferTile.parentNode.removeChild(bufferTile);
+ }
+ }
+ OpenLayers.Element.removeClass(tileDiv, replacingCls);
+ }
+ //if that was the last tile, then trigger a 'loadend' on the layer
+ if (this.numLoadingTiles === 0) {
+ if (this.backBuffer) {
+ if (this.backBuffer.childNodes.length === 0) {
+ // no tiles transitioning, remove immediately
+ this.removeBackBuffer();
+ } else {
+ // wait until transition has ended or delay has passed
+ this._transitionElement = aborted ?
+ this.div.lastChild : tile.imgDiv;
+ var transitionendEvents = this.transitionendEvents;
+ for (var i=transitionendEvents.length-1; i>=0; --i) {
+ OpenLayers.Event.observe(this._transitionElement,
+ transitionendEvents[i],
+ this._removeBackBuffer);
+ }
+ // the removal of the back buffer is delayed to prevent
+ // flash effects due to the animation of tile displaying
+ this.backBufferTimerId = window.setTimeout(
+ this._removeBackBuffer, this.removeBackBufferDelay
+ );
+ }
+ }
+ this.loading = false;
+ this.events.triggerEvent("loadend");
+ }
+ };
+
+ tile.onLoadError = function() {
+ this.events.triggerEvent("tileerror", {tile: tile});
+ };
+
+ tile.events.on({
+ "loadstart": tile.onLoadStart,
+ "loadend": tile.onLoadEnd,
+ "unload": tile.onLoadEnd,
+ "loaderror": tile.onLoadError,
+ scope: this
+ });
+ },
+
+ /**
+ * Method: removeTileMonitoringHooks
+ * This function takes a tile as input and removes the tile hooks
+ * that were added in addTileMonitoringHooks()
+ *
+ * Parameters:
+ * tile - {<OpenLayers.Tile>}
+ */
+ removeTileMonitoringHooks: function(tile) {
+ tile.unload();
+ tile.events.un({
+ "loadstart": tile.onLoadStart,
+ "loadend": tile.onLoadEnd,
+ "unload": tile.onLoadEnd,
+ "loaderror": tile.onLoadError,
+ scope: this
+ });
+ },
+
+ /**
+ * Method: moveGriddedTiles
+ */
+ moveGriddedTiles: function() {
+ var buffer = this.buffer + 1;
+ while(true) {
+ var tlTile = this.grid[0][0];
+ var tlViewPort = {
+ x: tlTile.position.x +
+ this.map.layerContainerOriginPx.x,
+ y: tlTile.position.y +
+ this.map.layerContainerOriginPx.y
+ };
+ var ratio = this.getServerResolution() / this.map.getResolution();
+ var tileSize = {
+ w: Math.round(this.tileSize.w * ratio),
+ h: Math.round(this.tileSize.h * ratio)
+ };
+ if (tlViewPort.x > -tileSize.w * (buffer - 1)) {
+ this.shiftColumn(true, tileSize);
+ } else if (tlViewPort.x < -tileSize.w * buffer) {
+ this.shiftColumn(false, tileSize);
+ } else if (tlViewPort.y > -tileSize.h * (buffer - 1)) {
+ this.shiftRow(true, tileSize);
+ } else if (tlViewPort.y < -tileSize.h * buffer) {
+ this.shiftRow(false, tileSize);
+ } else {
+ break;
+ }
+ }
+ },
+
+ /**
+ * Method: shiftRow
+ * Shifty grid work
+ *
+ * Parameters:
+ * prepend - {Boolean} if true, prepend to beginning.
+ * if false, then append to end
+ * tileSize - {Object} rendered tile size; object with w and h properties
+ */
+ shiftRow: function(prepend, tileSize) {
+ var grid = this.grid;
+ var rowIndex = prepend ? 0 : (grid.length - 1);
+ var sign = prepend ? -1 : 1;
+ var rowSign = this.rowSign;
+ var tileLayout = this.gridLayout;
+ tileLayout.startrow += sign * rowSign;
+
+ var modelRow = grid[rowIndex];
+ var row = grid[prepend ? 'pop' : 'shift']();
+ for (var i=0, len=row.length; i<len; i++) {
+ var tile = row[i];
+ var position = modelRow[i].position.clone();
+ position.y += tileSize.h * sign;
+ tile.moveTo(this.getTileBoundsForGridIndex(rowIndex, i), position);
+ }
+ grid[prepend ? 'unshift' : 'push'](row);
+ },
+
+ /**
+ * Method: shiftColumn
+ * Shift grid work in the other dimension
+ *
+ * Parameters:
+ * prepend - {Boolean} if true, prepend to beginning.
+ * if false, then append to end
+ * tileSize - {Object} rendered tile size; object with w and h properties
+ */
+ shiftColumn: function(prepend, tileSize) {
+ var grid = this.grid;
+ var colIndex = prepend ? 0 : (grid[0].length - 1);
+ var sign = prepend ? -1 : 1;
+ var tileLayout = this.gridLayout;
+ tileLayout.startcol += sign;
+
+ for (var i=0, len=grid.length; i<len; i++) {
+ var row = grid[i];
+ var position = row[colIndex].position.clone();
+ var tile = row[prepend ? 'pop' : 'shift']();
+ position.x += tileSize.w * sign;
+ tile.moveTo(this.getTileBoundsForGridIndex(i, colIndex), position);
+ row[prepend ? 'unshift' : 'push'](tile);
+ }
+ },
+
+ /**
+ * Method: removeExcessTiles
+ * When the size of the map or the buffer changes, we may need to
+ * remove some excess rows and columns.
+ *
+ * Parameters:
+ * rows - {Integer} Maximum number of rows we want our grid to have.
+ * columns - {Integer} Maximum number of columns we want our grid to have.
+ */
+ removeExcessTiles: function(rows, columns) {
+ var i, l;
+
+ // remove extra rows
+ while (this.grid.length > rows) {
+ var row = this.grid.pop();
+ for (i=0, l=row.length; i<l; i++) {
+ var tile = row[i];
+ this.destroyTile(tile);
+ }
+ }
+
+ // remove extra columns
+ for (i=0, l=this.grid.length; i<l; i++) {
+ while (this.grid[i].length > columns) {
+ var row = this.grid[i];
+ var tile = row.pop();
+ this.destroyTile(tile);
+ }
+ }
+ },
+
+ /**
+ * Method: onMapResize
+ * For singleTile layers, this will set a new tile size according to the
+ * dimensions of the map pane.
+ */
+ onMapResize: function() {
+ if (this.singleTile) {
+ this.clearGrid();
+ this.setTileSize();
+ }
+ },
+
+ /**
+ * APIMethod: getTileBounds
+ * Returns The tile bounds for a layer given a pixel location.
+ *
+ * Parameters:
+ * viewPortPx - {<OpenLayers.Pixel>} The location in the viewport.
+ *
+ * Returns:
+ * {<OpenLayers.Bounds>} Bounds of the tile at the given pixel location.
+ */
+ getTileBounds: function(viewPortPx) {
+ var maxExtent = this.maxExtent;
+ var resolution = this.getResolution();
+ var tileMapWidth = resolution * this.tileSize.w;
+ var tileMapHeight = resolution * this.tileSize.h;
+ var mapPoint = this.getLonLatFromViewPortPx(viewPortPx);
+ var tileLeft = maxExtent.left + (tileMapWidth *
+ Math.floor((mapPoint.lon -
+ maxExtent.left) /
+ tileMapWidth));
+ var tileBottom = maxExtent.bottom + (tileMapHeight *
+ Math.floor((mapPoint.lat -
+ maxExtent.bottom) /
+ tileMapHeight));
+ return new OpenLayers.Bounds(tileLeft, tileBottom,
+ tileLeft + tileMapWidth,
+ tileBottom + tileMapHeight);
+ },
+
+ CLASS_NAME: "OpenLayers.Layer.Grid"
+});
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-16 22:15:16 +0000