[76] | 1 | /* Copyright (c) 2006-2010 by OpenLayers Contributors (see authors.txt for |
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| 2 | * full list of contributors). Published under the Clear BSD license. |
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| 3 | * See http://svn.openlayers.org/trunk/openlayers/license.txt for the |
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| 4 | * full text of the license. */ |
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| 5 | |
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| 6 | |
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| 7 | /** |
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| 8 | * @requires OpenLayers/Layer/HTTPRequest.js |
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| 9 | * @requires OpenLayers/Console.js |
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| 10 | */ |
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| 11 | |
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| 12 | /** |
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| 13 | * Class: OpenLayers.Layer.Grid |
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| 14 | * Base class for layers that use a lattice of tiles. Create a new grid |
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| 15 | * layer with the <OpenLayers.Layer.Grid> constructor. |
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| 16 | * |
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| 17 | * Inherits from: |
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| 18 | * - <OpenLayers.Layer.HTTPRequest> |
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| 19 | */ |
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| 20 | OpenLayers.Layer.Grid = OpenLayers.Class(OpenLayers.Layer.HTTPRequest, { |
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| 21 | |
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| 22 | /** |
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| 23 | * APIProperty: tileSize |
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| 24 | * {<OpenLayers.Size>} |
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| 25 | */ |
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| 26 | tileSize: null, |
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| 27 | |
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| 28 | /** |
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| 29 | * Property: grid |
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| 30 | * {Array(Array(<OpenLayers.Tile>))} This is an array of rows, each row is |
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| 31 | * an array of tiles. |
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| 32 | */ |
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| 33 | grid: null, |
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| 34 | |
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| 35 | /** |
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| 36 | * APIProperty: singleTile |
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| 37 | * {Boolean} Moves the layer into single-tile mode, meaning that one tile |
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| 38 | * will be loaded. The tile's size will be determined by the 'ratio' |
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| 39 | * property. When the tile is dragged such that it does not cover the |
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| 40 | * entire viewport, it is reloaded. |
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| 41 | */ |
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| 42 | singleTile: false, |
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| 43 | |
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| 44 | /** APIProperty: ratio |
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| 45 | * {Float} Used only when in single-tile mode, this specifies the |
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| 46 | * ratio of the size of the single tile to the size of the map. |
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| 47 | */ |
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| 48 | ratio: 1.5, |
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| 49 | |
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| 50 | /** |
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| 51 | * APIProperty: buffer |
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| 52 | * {Integer} Used only when in gridded mode, this specifies the number of |
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| 53 | * extra rows and colums of tiles on each side which will |
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| 54 | * surround the minimum grid tiles to cover the map. |
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| 55 | */ |
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| 56 | buffer: 2, |
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| 57 | |
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| 58 | /** |
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| 59 | * APIProperty: numLoadingTiles |
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| 60 | * {Integer} How many tiles are still loading? |
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| 61 | */ |
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| 62 | numLoadingTiles: 0, |
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| 63 | |
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| 64 | /** |
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| 65 | * Constructor: OpenLayers.Layer.Grid |
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| 66 | * Create a new grid layer |
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| 67 | * |
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| 68 | * Parameters: |
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| 69 | * name - {String} |
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| 70 | * url - {String} |
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| 71 | * params - {Object} |
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| 72 | * options - {Object} Hashtable of extra options to tag onto the layer |
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| 73 | */ |
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| 74 | initialize: function(name, url, params, options) { |
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| 75 | OpenLayers.Layer.HTTPRequest.prototype.initialize.apply(this, |
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| 76 | arguments); |
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| 77 | |
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| 78 | //grid layers will trigger 'tileloaded' when each new tile is |
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| 79 | // loaded, as a means of progress update to listeners. |
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| 80 | // listeners can access 'numLoadingTiles' if they wish to keep track |
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| 81 | // of the loading progress |
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| 82 | // |
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| 83 | this.events.addEventType("tileloaded"); |
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| 84 | |
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| 85 | this.grid = []; |
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| 86 | }, |
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| 87 | |
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| 88 | /** |
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| 89 | * APIMethod: destroy |
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| 90 | * Deconstruct the layer and clear the grid. |
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| 91 | */ |
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| 92 | destroy: function() { |
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| 93 | this.clearGrid(); |
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| 94 | this.grid = null; |
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| 95 | this.tileSize = null; |
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| 96 | OpenLayers.Layer.HTTPRequest.prototype.destroy.apply(this, arguments); |
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| 97 | }, |
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| 98 | |
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| 99 | /** |
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| 100 | * Method: clearGrid |
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| 101 | * Go through and remove all tiles from the grid, calling |
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| 102 | * destroy() on each of them to kill circular references |
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| 103 | */ |
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| 104 | clearGrid:function() { |
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| 105 | if (this.grid) { |
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| 106 | for(var iRow=0, len=this.grid.length; iRow<len; iRow++) { |
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| 107 | var row = this.grid[iRow]; |
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| 108 | for(var iCol=0, clen=row.length; iCol<clen; iCol++) { |
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| 109 | var tile = row[iCol]; |
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| 110 | this.removeTileMonitoringHooks(tile); |
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| 111 | tile.destroy(); |
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| 112 | } |
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| 113 | } |
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| 114 | this.grid = []; |
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| 115 | } |
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| 116 | }, |
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| 117 | |
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| 118 | /** |
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| 119 | * APIMethod: clone |
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| 120 | * Create a clone of this layer |
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| 121 | * |
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| 122 | * Parameters: |
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| 123 | * obj - {Object} Is this ever used? |
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| 124 | * |
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| 125 | * Returns: |
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| 126 | * {<OpenLayers.Layer.Grid>} An exact clone of this OpenLayers.Layer.Grid |
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| 127 | */ |
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| 128 | clone: function (obj) { |
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| 129 | |
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| 130 | if (obj == null) { |
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| 131 | obj = new OpenLayers.Layer.Grid(this.name, |
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| 132 | this.url, |
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| 133 | this.params, |
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| 134 | this.getOptions()); |
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| 135 | } |
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| 136 | |
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| 137 | //get all additions from superclasses |
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| 138 | obj = OpenLayers.Layer.HTTPRequest.prototype.clone.apply(this, [obj]); |
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| 139 | |
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| 140 | // copy/set any non-init, non-simple values here |
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| 141 | if (this.tileSize != null) { |
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| 142 | obj.tileSize = this.tileSize.clone(); |
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| 143 | } |
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| 144 | |
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| 145 | // we do not want to copy reference to grid, so we make a new array |
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| 146 | obj.grid = []; |
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| 147 | |
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| 148 | return obj; |
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| 149 | }, |
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| 150 | |
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| 151 | /** |
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| 152 | * Method: moveTo |
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| 153 | * This function is called whenever the map is moved. All the moving |
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| 154 | * of actual 'tiles' is done by the map, but moveTo's role is to accept |
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| 155 | * a bounds and make sure the data that that bounds requires is pre-loaded. |
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| 156 | * |
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| 157 | * Parameters: |
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| 158 | * bounds - {<OpenLayers.Bounds>} |
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| 159 | * zoomChanged - {Boolean} |
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| 160 | * dragging - {Boolean} |
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| 161 | */ |
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| 162 | moveTo:function(bounds, zoomChanged, dragging) { |
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| 163 | OpenLayers.Layer.HTTPRequest.prototype.moveTo.apply(this, arguments); |
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| 164 | |
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| 165 | bounds = bounds || this.map.getExtent(); |
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| 166 | |
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| 167 | if (bounds != null) { |
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| 168 | |
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| 169 | // if grid is empty or zoom has changed, we *must* re-tile |
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| 170 | var forceReTile = !this.grid.length || zoomChanged; |
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| 171 | |
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| 172 | // total bounds of the tiles |
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| 173 | var tilesBounds = this.getTilesBounds(); |
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| 174 | |
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| 175 | if (this.singleTile) { |
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| 176 | |
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| 177 | // We want to redraw whenever even the slightest part of the |
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| 178 | // current bounds is not contained by our tile. |
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| 179 | // (thus, we do not specify partial -- its default is false) |
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| 180 | if ( forceReTile || |
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| 181 | (!dragging && !tilesBounds.containsBounds(bounds))) { |
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| 182 | this.initSingleTile(bounds); |
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| 183 | } |
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| 184 | } else { |
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| 185 | |
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| 186 | // if the bounds have changed such that they are not even |
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| 187 | // *partially* contained by our tiles (IE user has |
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| 188 | // programmatically panned to the other side of the earth) |
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| 189 | // then we want to reTile (thus, partial true). |
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| 190 | // |
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| 191 | if (forceReTile || !tilesBounds.containsBounds(bounds, true)) { |
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| 192 | this.initGriddedTiles(bounds); |
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| 193 | } else { |
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| 194 | //we might have to shift our buffer tiles |
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| 195 | this.moveGriddedTiles(bounds); |
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| 196 | } |
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| 197 | } |
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| 198 | } |
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| 199 | }, |
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| 200 | |
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| 201 | /** |
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| 202 | * APIMethod: setTileSize |
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| 203 | * Check if we are in singleTile mode and if so, set the size as a ratio |
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| 204 | * of the map size (as specified by the layer's 'ratio' property). |
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| 205 | * |
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| 206 | * Parameters: |
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| 207 | * size - {<OpenLayers.Size>} |
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| 208 | */ |
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| 209 | setTileSize: function(size) { |
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| 210 | if (this.singleTile) { |
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| 211 | size = this.map.getSize(); |
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| 212 | size.h = parseInt(size.h * this.ratio); |
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| 213 | size.w = parseInt(size.w * this.ratio); |
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| 214 | } |
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| 215 | OpenLayers.Layer.HTTPRequest.prototype.setTileSize.apply(this, [size]); |
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| 216 | }, |
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| 217 | |
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| 218 | /** |
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| 219 | * Method: getGridBounds |
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| 220 | * Deprecated. This function will be removed in 3.0. Please use |
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| 221 | * getTilesBounds() instead. |
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| 222 | * |
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| 223 | * Returns: |
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| 224 | * {<OpenLayers.Bounds>} A Bounds object representing the bounds of all the |
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| 225 | * currently loaded tiles (including those partially or not at all seen |
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| 226 | * onscreen) |
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| 227 | */ |
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| 228 | getGridBounds: function() { |
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| 229 | var msg = "The getGridBounds() function is deprecated. It will be " + |
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| 230 | "removed in 3.0. Please use getTilesBounds() instead."; |
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| 231 | OpenLayers.Console.warn(msg); |
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| 232 | return this.getTilesBounds(); |
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| 233 | }, |
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| 234 | |
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| 235 | /** |
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| 236 | * APIMethod: getTilesBounds |
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| 237 | * Return the bounds of the tile grid. |
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| 238 | * |
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| 239 | * Returns: |
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| 240 | * {<OpenLayers.Bounds>} A Bounds object representing the bounds of all the |
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| 241 | * currently loaded tiles (including those partially or not at all seen |
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| 242 | * onscreen). |
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| 243 | */ |
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| 244 | getTilesBounds: function() { |
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| 245 | var bounds = null; |
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| 246 | |
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| 247 | if (this.grid.length) { |
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| 248 | var bottom = this.grid.length - 1; |
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| 249 | var bottomLeftTile = this.grid[bottom][0]; |
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| 250 | |
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| 251 | var right = this.grid[0].length - 1; |
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| 252 | var topRightTile = this.grid[0][right]; |
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| 253 | |
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| 254 | bounds = new OpenLayers.Bounds(bottomLeftTile.bounds.left, |
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| 255 | bottomLeftTile.bounds.bottom, |
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| 256 | topRightTile.bounds.right, |
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| 257 | topRightTile.bounds.top); |
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| 258 | |
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| 259 | } |
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| 260 | return bounds; |
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| 261 | }, |
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| 262 | |
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| 263 | /** |
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| 264 | * Method: initSingleTile |
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| 265 | * |
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| 266 | * Parameters: |
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| 267 | * bounds - {<OpenLayers.Bounds>} |
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| 268 | */ |
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| 269 | initSingleTile: function(bounds) { |
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| 270 | |
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| 271 | //determine new tile bounds |
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| 272 | var center = bounds.getCenterLonLat(); |
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| 273 | var tileWidth = bounds.getWidth() * this.ratio; |
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| 274 | var tileHeight = bounds.getHeight() * this.ratio; |
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| 275 | |
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| 276 | var tileBounds = |
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| 277 | new OpenLayers.Bounds(center.lon - (tileWidth/2), |
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| 278 | center.lat - (tileHeight/2), |
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| 279 | center.lon + (tileWidth/2), |
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| 280 | center.lat + (tileHeight/2)); |
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| 281 | |
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| 282 | var ul = new OpenLayers.LonLat(tileBounds.left, tileBounds.top); |
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| 283 | var px = this.map.getLayerPxFromLonLat(ul); |
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| 284 | |
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| 285 | if (!this.grid.length) { |
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| 286 | this.grid[0] = []; |
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| 287 | } |
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| 288 | |
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| 289 | var tile = this.grid[0][0]; |
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| 290 | if (!tile) { |
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| 291 | tile = this.addTile(tileBounds, px); |
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| 292 | |
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| 293 | this.addTileMonitoringHooks(tile); |
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| 294 | tile.draw(); |
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| 295 | this.grid[0][0] = tile; |
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| 296 | } else { |
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| 297 | tile.moveTo(tileBounds, px); |
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| 298 | } |
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| 299 | |
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| 300 | //remove all but our single tile |
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| 301 | this.removeExcessTiles(1,1); |
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| 302 | }, |
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| 303 | |
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| 304 | /** |
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| 305 | * Method: calculateGridLayout |
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| 306 | * Generate parameters for the grid layout. This |
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| 307 | * |
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| 308 | * Parameters: |
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| 309 | * bounds - {<OpenLayers.Bound>} |
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| 310 | * extent - {<OpenLayers.Bounds>} |
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| 311 | * resolution - {Number} |
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| 312 | * |
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| 313 | * Returns: |
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| 314 | * Object containing properties tilelon, tilelat, tileoffsetlat, |
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| 315 | * tileoffsetlat, tileoffsetx, tileoffsety |
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| 316 | */ |
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| 317 | calculateGridLayout: function(bounds, extent, resolution) { |
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| 318 | var tilelon = resolution * this.tileSize.w; |
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| 319 | var tilelat = resolution * this.tileSize.h; |
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| 320 | |
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| 321 | var offsetlon = bounds.left - extent.left; |
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| 322 | var tilecol = Math.floor(offsetlon/tilelon) - this.buffer; |
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| 323 | var tilecolremain = offsetlon/tilelon - tilecol; |
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| 324 | var tileoffsetx = -tilecolremain * this.tileSize.w; |
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| 325 | var tileoffsetlon = extent.left + tilecol * tilelon; |
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| 326 | |
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| 327 | var offsetlat = bounds.top - (extent.bottom + tilelat); |
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| 328 | var tilerow = Math.ceil(offsetlat/tilelat) + this.buffer; |
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| 329 | var tilerowremain = tilerow - offsetlat/tilelat; |
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| 330 | var tileoffsety = -tilerowremain * this.tileSize.h; |
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| 331 | var tileoffsetlat = extent.bottom + tilerow * tilelat; |
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| 332 | |
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| 333 | return { |
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| 334 | tilelon: tilelon, tilelat: tilelat, |
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| 335 | tileoffsetlon: tileoffsetlon, tileoffsetlat: tileoffsetlat, |
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| 336 | tileoffsetx: tileoffsetx, tileoffsety: tileoffsety |
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| 337 | }; |
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| 338 | |
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| 339 | }, |
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| 340 | |
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| 341 | /** |
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| 342 | * Method: initGriddedTiles |
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| 343 | * |
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| 344 | * Parameters: |
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| 345 | * bounds - {<OpenLayers.Bounds>} |
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| 346 | */ |
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| 347 | initGriddedTiles:function(bounds) { |
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| 348 | |
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| 349 | // work out mininum number of rows and columns; this is the number of |
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| 350 | // tiles required to cover the viewport plus at least one for panning |
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| 351 | |
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| 352 | var viewSize = this.map.getSize(); |
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| 353 | var minRows = Math.ceil(viewSize.h/this.tileSize.h) + |
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| 354 | Math.max(1, 2 * this.buffer); |
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| 355 | var minCols = Math.ceil(viewSize.w/this.tileSize.w) + |
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| 356 | Math.max(1, 2 * this.buffer); |
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| 357 | |
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| 358 | var extent = this.getMaxExtent(); |
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| 359 | var resolution = this.map.getResolution(); |
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| 360 | |
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| 361 | var tileLayout = this.calculateGridLayout(bounds, extent, resolution); |
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| 362 | |
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| 363 | var tileoffsetx = Math.round(tileLayout.tileoffsetx); // heaven help us |
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| 364 | var tileoffsety = Math.round(tileLayout.tileoffsety); |
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| 365 | |
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| 366 | var tileoffsetlon = tileLayout.tileoffsetlon; |
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| 367 | var tileoffsetlat = tileLayout.tileoffsetlat; |
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| 368 | |
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| 369 | var tilelon = tileLayout.tilelon; |
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| 370 | var tilelat = tileLayout.tilelat; |
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| 371 | |
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| 372 | this.origin = new OpenLayers.Pixel(tileoffsetx, tileoffsety); |
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| 373 | |
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| 374 | var startX = tileoffsetx; |
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| 375 | var startLon = tileoffsetlon; |
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| 376 | |
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| 377 | var rowidx = 0; |
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| 378 | |
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| 379 | var layerContainerDivLeft = parseInt(this.map.layerContainerDiv.style.left); |
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| 380 | var layerContainerDivTop = parseInt(this.map.layerContainerDiv.style.top); |
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| 381 | |
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| 382 | |
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| 383 | do { |
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| 384 | var row = this.grid[rowidx++]; |
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| 385 | if (!row) { |
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| 386 | row = []; |
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| 387 | this.grid.push(row); |
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| 388 | } |
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| 389 | |
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| 390 | tileoffsetlon = startLon; |
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| 391 | tileoffsetx = startX; |
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| 392 | var colidx = 0; |
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| 393 | |
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| 394 | do { |
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| 395 | var tileBounds = |
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| 396 | new OpenLayers.Bounds(tileoffsetlon, |
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| 397 | tileoffsetlat, |
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| 398 | tileoffsetlon + tilelon, |
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| 399 | tileoffsetlat + tilelat); |
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| 400 | |
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| 401 | var x = tileoffsetx; |
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| 402 | x -= layerContainerDivLeft; |
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| 403 | |
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| 404 | var y = tileoffsety; |
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| 405 | y -= layerContainerDivTop; |
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| 406 | |
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| 407 | var px = new OpenLayers.Pixel(x, y); |
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| 408 | var tile = row[colidx++]; |
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| 409 | if (!tile) { |
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| 410 | tile = this.addTile(tileBounds, px); |
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| 411 | this.addTileMonitoringHooks(tile); |
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| 412 | row.push(tile); |
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| 413 | } else { |
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| 414 | tile.moveTo(tileBounds, px, false); |
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| 415 | } |
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| 416 | |
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| 417 | tileoffsetlon += tilelon; |
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| 418 | tileoffsetx += this.tileSize.w; |
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| 419 | } while ((tileoffsetlon <= bounds.right + tilelon * this.buffer) |
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| 420 | || colidx < minCols); |
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| 421 | |
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| 422 | tileoffsetlat -= tilelat; |
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| 423 | tileoffsety += this.tileSize.h; |
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| 424 | } while((tileoffsetlat >= bounds.bottom - tilelat * this.buffer) |
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| 425 | || rowidx < minRows); |
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| 426 | |
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| 427 | //shave off exceess rows and colums |
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| 428 | this.removeExcessTiles(rowidx, colidx); |
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| 429 | |
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| 430 | //now actually draw the tiles |
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| 431 | this.spiralTileLoad(); |
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| 432 | }, |
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| 433 | |
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| 434 | /** |
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| 435 | * Method: getMaxExtent |
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| 436 | * Get this layer's maximum extent. (Implemented as a getter for |
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| 437 | * potential specific implementations in sub-classes.) |
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| 438 | * |
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| 439 | * Returns: |
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| 440 | * {OpenLayers.Bounds} |
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| 441 | */ |
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| 442 | getMaxExtent: function() { |
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| 443 | return this.maxExtent; |
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| 444 | }, |
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| 445 | |
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| 446 | /** |
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| 447 | * Method: spiralTileLoad |
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| 448 | * Starts at the top right corner of the grid and proceeds in a spiral |
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| 449 | * towards the center, adding tiles one at a time to the beginning of a |
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| 450 | * queue. |
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| 451 | * |
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| 452 | * Once all the grid's tiles have been added to the queue, we go back |
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| 453 | * and iterate through the queue (thus reversing the spiral order from |
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| 454 | * outside-in to inside-out), calling draw() on each tile. |
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| 455 | */ |
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| 456 | spiralTileLoad: function() { |
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| 457 | var tileQueue = []; |
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| 458 | |
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| 459 | var directions = ["right", "down", "left", "up"]; |
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| 460 | |
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| 461 | var iRow = 0; |
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| 462 | var iCell = -1; |
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| 463 | var direction = OpenLayers.Util.indexOf(directions, "right"); |
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| 464 | var directionsTried = 0; |
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| 465 | |
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| 466 | while( directionsTried < directions.length) { |
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| 467 | |
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| 468 | var testRow = iRow; |
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| 469 | var testCell = iCell; |
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| 470 | |
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| 471 | switch (directions[direction]) { |
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| 472 | case "right": |
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| 473 | testCell++; |
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| 474 | break; |
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| 475 | case "down": |
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| 476 | testRow++; |
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| 477 | break; |
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| 478 | case "left": |
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| 479 | testCell--; |
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| 480 | break; |
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| 481 | case "up": |
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| 482 | testRow--; |
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| 483 | break; |
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| 484 | } |
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| 485 | |
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| 486 | // if the test grid coordinates are within the bounds of the |
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| 487 | // grid, get a reference to the tile. |
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| 488 | var tile = null; |
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| 489 | if ((testRow < this.grid.length) && (testRow >= 0) && |
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| 490 | (testCell < this.grid[0].length) && (testCell >= 0)) { |
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| 491 | tile = this.grid[testRow][testCell]; |
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| 492 | } |
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| 493 | |
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| 494 | if ((tile != null) && (!tile.queued)) { |
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| 495 | //add tile to beginning of queue, mark it as queued. |
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| 496 | tileQueue.unshift(tile); |
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| 497 | tile.queued = true; |
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| 498 | |
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| 499 | //restart the directions counter and take on the new coords |
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| 500 | directionsTried = 0; |
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| 501 | iRow = testRow; |
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| 502 | iCell = testCell; |
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| 503 | } else { |
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| 504 | //need to try to load a tile in a different direction |
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| 505 | direction = (direction + 1) % 4; |
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| 506 | directionsTried++; |
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| 507 | } |
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| 508 | } |
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| 509 | |
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| 510 | // now we go through and draw the tiles in forward order |
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| 511 | for(var i=0, len=tileQueue.length; i<len; i++) { |
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| 512 | var tile = tileQueue[i]; |
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| 513 | tile.draw(); |
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| 514 | //mark tile as unqueued for the next time (since tiles are reused) |
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| 515 | tile.queued = false; |
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| 516 | } |
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| 517 | }, |
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| 518 | |
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| 519 | /** |
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| 520 | * APIMethod: addTile |
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| 521 | * Gives subclasses of Grid the opportunity to create an |
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| 522 | * OpenLayer.Tile of their choosing. The implementer should initialize |
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| 523 | * the new tile and take whatever steps necessary to display it. |
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| 524 | * |
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| 525 | * Parameters |
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| 526 | * bounds - {<OpenLayers.Bounds>} |
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| 527 | * position - {<OpenLayers.Pixel>} |
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| 528 | * |
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| 529 | * Returns: |
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| 530 | * {<OpenLayers.Tile>} The added OpenLayers.Tile |
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| 531 | */ |
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| 532 | addTile:function(bounds, position) { |
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| 533 | // Should be implemented by subclasses |
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| 534 | }, |
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| 535 | |
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| 536 | /** |
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| 537 | * Method: addTileMonitoringHooks |
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| 538 | * This function takes a tile as input and adds the appropriate hooks to |
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| 539 | * the tile so that the layer can keep track of the loading tiles. |
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| 540 | * |
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| 541 | * Parameters: |
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| 542 | * tile - {<OpenLayers.Tile>} |
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| 543 | */ |
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| 544 | addTileMonitoringHooks: function(tile) { |
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| 545 | |
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| 546 | tile.onLoadStart = function() { |
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| 547 | //if that was first tile then trigger a 'loadstart' on the layer |
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| 548 | if (this.numLoadingTiles == 0) { |
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| 549 | this.events.triggerEvent("loadstart"); |
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| 550 | } |
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| 551 | this.numLoadingTiles++; |
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| 552 | }; |
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| 553 | tile.events.register("loadstart", this, tile.onLoadStart); |
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| 554 | |
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| 555 | tile.onLoadEnd = function() { |
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| 556 | this.numLoadingTiles--; |
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| 557 | this.events.triggerEvent("tileloaded"); |
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| 558 | //if that was the last tile, then trigger a 'loadend' on the layer |
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| 559 | if (this.numLoadingTiles == 0) { |
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| 560 | this.events.triggerEvent("loadend"); |
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| 561 | } |
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| 562 | }; |
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| 563 | tile.events.register("loadend", this, tile.onLoadEnd); |
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| 564 | tile.events.register("unload", this, tile.onLoadEnd); |
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| 565 | }, |
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| 566 | |
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| 567 | /** |
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| 568 | * Method: removeTileMonitoringHooks |
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| 569 | * This function takes a tile as input and removes the tile hooks |
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| 570 | * that were added in addTileMonitoringHooks() |
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| 571 | * |
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| 572 | * Parameters: |
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| 573 | * tile - {<OpenLayers.Tile>} |
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| 574 | */ |
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| 575 | removeTileMonitoringHooks: function(tile) { |
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| 576 | tile.unload(); |
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| 577 | tile.events.un({ |
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| 578 | "loadstart": tile.onLoadStart, |
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| 579 | "loadend": tile.onLoadEnd, |
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| 580 | "unload": tile.onLoadEnd, |
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| 581 | scope: this |
---|
| 582 | }); |
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| 583 | }, |
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| 584 | |
---|
| 585 | /** |
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| 586 | * Method: moveGriddedTiles |
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| 587 | * |
---|
| 588 | * Parameters: |
---|
| 589 | * bounds - {<OpenLayers.Bounds>} |
---|
| 590 | */ |
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| 591 | moveGriddedTiles: function(bounds) { |
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| 592 | var buffer = this.buffer || 1; |
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| 593 | while (true) { |
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| 594 | var tlLayer = this.grid[0][0].position; |
---|
| 595 | var tlViewPort = |
---|
| 596 | this.map.getViewPortPxFromLayerPx(tlLayer); |
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| 597 | if (tlViewPort.x > -this.tileSize.w * (buffer - 1)) { |
---|
| 598 | this.shiftColumn(true); |
---|
| 599 | } else if (tlViewPort.x < -this.tileSize.w * buffer) { |
---|
| 600 | this.shiftColumn(false); |
---|
| 601 | } else if (tlViewPort.y > -this.tileSize.h * (buffer - 1)) { |
---|
| 602 | this.shiftRow(true); |
---|
| 603 | } else if (tlViewPort.y < -this.tileSize.h * buffer) { |
---|
| 604 | this.shiftRow(false); |
---|
| 605 | } else { |
---|
| 606 | break; |
---|
| 607 | } |
---|
| 608 | }; |
---|
| 609 | }, |
---|
| 610 | |
---|
| 611 | /** |
---|
| 612 | * Method: shiftRow |
---|
| 613 | * Shifty grid work |
---|
| 614 | * |
---|
| 615 | * Parameters: |
---|
| 616 | * prepend - {Boolean} if true, prepend to beginning. |
---|
| 617 | * if false, then append to end |
---|
| 618 | */ |
---|
| 619 | shiftRow:function(prepend) { |
---|
| 620 | var modelRowIndex = (prepend) ? 0 : (this.grid.length - 1); |
---|
| 621 | var grid = this.grid; |
---|
| 622 | var modelRow = grid[modelRowIndex]; |
---|
| 623 | |
---|
| 624 | var resolution = this.map.getResolution(); |
---|
| 625 | var deltaY = (prepend) ? -this.tileSize.h : this.tileSize.h; |
---|
| 626 | var deltaLat = resolution * -deltaY; |
---|
| 627 | |
---|
| 628 | var row = (prepend) ? grid.pop() : grid.shift(); |
---|
| 629 | |
---|
| 630 | for (var i=0, len=modelRow.length; i<len; i++) { |
---|
| 631 | var modelTile = modelRow[i]; |
---|
| 632 | var bounds = modelTile.bounds.clone(); |
---|
| 633 | var position = modelTile.position.clone(); |
---|
| 634 | bounds.bottom = bounds.bottom + deltaLat; |
---|
| 635 | bounds.top = bounds.top + deltaLat; |
---|
| 636 | position.y = position.y + deltaY; |
---|
| 637 | row[i].moveTo(bounds, position); |
---|
| 638 | } |
---|
| 639 | |
---|
| 640 | if (prepend) { |
---|
| 641 | grid.unshift(row); |
---|
| 642 | } else { |
---|
| 643 | grid.push(row); |
---|
| 644 | } |
---|
| 645 | }, |
---|
| 646 | |
---|
| 647 | /** |
---|
| 648 | * Method: shiftColumn |
---|
| 649 | * Shift grid work in the other dimension |
---|
| 650 | * |
---|
| 651 | * Parameters: |
---|
| 652 | * prepend - {Boolean} if true, prepend to beginning. |
---|
| 653 | * if false, then append to end |
---|
| 654 | */ |
---|
| 655 | shiftColumn: function(prepend) { |
---|
| 656 | var deltaX = (prepend) ? -this.tileSize.w : this.tileSize.w; |
---|
| 657 | var resolution = this.map.getResolution(); |
---|
| 658 | var deltaLon = resolution * deltaX; |
---|
| 659 | |
---|
| 660 | for (var i=0, len=this.grid.length; i<len; i++) { |
---|
| 661 | var row = this.grid[i]; |
---|
| 662 | var modelTileIndex = (prepend) ? 0 : (row.length - 1); |
---|
| 663 | var modelTile = row[modelTileIndex]; |
---|
| 664 | |
---|
| 665 | var bounds = modelTile.bounds.clone(); |
---|
| 666 | var position = modelTile.position.clone(); |
---|
| 667 | bounds.left = bounds.left + deltaLon; |
---|
| 668 | bounds.right = bounds.right + deltaLon; |
---|
| 669 | position.x = position.x + deltaX; |
---|
| 670 | |
---|
| 671 | var tile = prepend ? this.grid[i].pop() : this.grid[i].shift(); |
---|
| 672 | tile.moveTo(bounds, position); |
---|
| 673 | if (prepend) { |
---|
| 674 | row.unshift(tile); |
---|
| 675 | } else { |
---|
| 676 | row.push(tile); |
---|
| 677 | } |
---|
| 678 | } |
---|
| 679 | }, |
---|
| 680 | |
---|
| 681 | /** |
---|
| 682 | * Method: removeExcessTiles |
---|
| 683 | * When the size of the map or the buffer changes, we may need to |
---|
| 684 | * remove some excess rows and columns. |
---|
| 685 | * |
---|
| 686 | * Parameters: |
---|
| 687 | * rows - {Integer} Maximum number of rows we want our grid to have. |
---|
| 688 | * colums - {Integer} Maximum number of columns we want our grid to have. |
---|
| 689 | */ |
---|
| 690 | removeExcessTiles: function(rows, columns) { |
---|
| 691 | |
---|
| 692 | // remove extra rows |
---|
| 693 | while (this.grid.length > rows) { |
---|
| 694 | var row = this.grid.pop(); |
---|
| 695 | for (var i=0, l=row.length; i<l; i++) { |
---|
| 696 | var tile = row[i]; |
---|
| 697 | this.removeTileMonitoringHooks(tile); |
---|
| 698 | tile.destroy(); |
---|
| 699 | } |
---|
| 700 | } |
---|
| 701 | |
---|
| 702 | // remove extra columns |
---|
| 703 | while (this.grid[0].length > columns) { |
---|
| 704 | for (var i=0, l=this.grid.length; i<l; i++) { |
---|
| 705 | var row = this.grid[i]; |
---|
| 706 | var tile = row.pop(); |
---|
| 707 | this.removeTileMonitoringHooks(tile); |
---|
| 708 | tile.destroy(); |
---|
| 709 | } |
---|
| 710 | } |
---|
| 711 | }, |
---|
| 712 | |
---|
| 713 | /** |
---|
| 714 | * Method: onMapResize |
---|
| 715 | * For singleTile layers, this will set a new tile size according to the |
---|
| 716 | * dimensions of the map pane. |
---|
| 717 | */ |
---|
| 718 | onMapResize: function() { |
---|
| 719 | if (this.singleTile) { |
---|
| 720 | this.clearGrid(); |
---|
| 721 | this.setTileSize(); |
---|
| 722 | } |
---|
| 723 | }, |
---|
| 724 | |
---|
| 725 | /** |
---|
| 726 | * APIMethod: getTileBounds |
---|
| 727 | * Returns The tile bounds for a layer given a pixel location. |
---|
| 728 | * |
---|
| 729 | * Parameters: |
---|
| 730 | * viewPortPx - {<OpenLayers.Pixel>} The location in the viewport. |
---|
| 731 | * |
---|
| 732 | * Returns: |
---|
| 733 | * {<OpenLayers.Bounds>} Bounds of the tile at the given pixel location. |
---|
| 734 | */ |
---|
| 735 | getTileBounds: function(viewPortPx) { |
---|
| 736 | var maxExtent = this.maxExtent; |
---|
| 737 | var resolution = this.getResolution(); |
---|
| 738 | var tileMapWidth = resolution * this.tileSize.w; |
---|
| 739 | var tileMapHeight = resolution * this.tileSize.h; |
---|
| 740 | var mapPoint = this.getLonLatFromViewPortPx(viewPortPx); |
---|
| 741 | var tileLeft = maxExtent.left + (tileMapWidth * |
---|
| 742 | Math.floor((mapPoint.lon - |
---|
| 743 | maxExtent.left) / |
---|
| 744 | tileMapWidth)); |
---|
| 745 | var tileBottom = maxExtent.bottom + (tileMapHeight * |
---|
| 746 | Math.floor((mapPoint.lat - |
---|
| 747 | maxExtent.bottom) / |
---|
| 748 | tileMapHeight)); |
---|
| 749 | return new OpenLayers.Bounds(tileLeft, tileBottom, |
---|
| 750 | tileLeft + tileMapWidth, |
---|
| 751 | tileBottom + tileMapHeight); |
---|
| 752 | }, |
---|
| 753 | |
---|
| 754 | CLASS_NAME: "OpenLayers.Layer.Grid" |
---|
| 755 | }); |
---|