[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 | * @requires OpenLayers/Strategy.js |
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| 8 | */ |
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| 9 | |
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| 10 | /** |
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| 11 | * Class: OpenLayers.Strategy.Fixed |
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| 12 | * A simple strategy that requests features once and never requests new data. |
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| 13 | * |
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| 14 | * Inherits from: |
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| 15 | * - <OpenLayers.Strategy> |
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| 16 | */ |
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| 17 | OpenLayers.Strategy.Fixed = OpenLayers.Class(OpenLayers.Strategy, { |
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| 18 | |
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| 19 | /** |
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| 20 | * APIProperty: preload |
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| 21 | * {Boolean} Load data before layer made visible. Enabling this may result |
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| 22 | * in considerable overhead if your application loads many data layers |
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| 23 | * that are not visible by default. Default is false. |
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| 24 | */ |
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| 25 | preload: false, |
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| 26 | |
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| 27 | /** |
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| 28 | * Constructor: OpenLayers.Strategy.Fixed |
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| 29 | * Create a new Fixed strategy. |
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| 30 | * |
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| 31 | * Parameters: |
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| 32 | * options - {Object} Optional object whose properties will be set on the |
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| 33 | * instance. |
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| 34 | */ |
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| 35 | initialize: function(options) { |
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| 36 | OpenLayers.Strategy.prototype.initialize.apply(this, [options]); |
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| 37 | }, |
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| 38 | |
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| 39 | /** |
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| 40 | * APIMethod: destroy |
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| 41 | * Clean up the strategy. |
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| 42 | */ |
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| 43 | destroy: function() { |
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| 44 | OpenLayers.Strategy.prototype.destroy.apply(this, arguments); |
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| 45 | }, |
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| 46 | |
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| 47 | /** |
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| 48 | * Method: activate |
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| 49 | * Activate the strategy: load data or add listener to load when visible |
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| 50 | * |
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| 51 | * Returns: |
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| 52 | * {Boolean} True if the strategy was successfully activated or false if |
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| 53 | * the strategy was already active. |
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| 54 | */ |
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| 55 | activate: function() { |
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| 56 | if(OpenLayers.Strategy.prototype.activate.apply(this, arguments)) { |
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| 57 | this.layer.events.on({ |
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| 58 | "refresh": this.load, |
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| 59 | scope: this |
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| 60 | }); |
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| 61 | if(this.layer.visibility == true || this.preload) { |
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| 62 | this.load(); |
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| 63 | } else { |
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| 64 | this.layer.events.on({ |
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| 65 | "visibilitychanged": this.load, |
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| 66 | scope: this |
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| 67 | }); |
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| 68 | } |
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| 69 | return true; |
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| 70 | } |
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| 71 | return false; |
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| 72 | }, |
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| 73 | |
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| 74 | /** |
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| 75 | * Method: deactivate |
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| 76 | * Deactivate the strategy. Undo what is done in <activate>. |
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| 77 | * |
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| 78 | * Returns: |
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| 79 | * {Boolean} The strategy was successfully deactivated. |
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| 80 | */ |
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| 81 | deactivate: function() { |
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| 82 | var deactivated = OpenLayers.Strategy.prototype.deactivate.call(this); |
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| 83 | if(deactivated) { |
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| 84 | this.layer.events.un({ |
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| 85 | "refresh": this.load, |
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| 86 | "visibilitychanged": this.load, |
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| 87 | scope: this |
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| 88 | }); |
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| 89 | } |
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| 90 | return deactivated; |
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| 91 | }, |
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| 92 | |
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| 93 | /** |
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| 94 | * Method: load |
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| 95 | * Tells protocol to load data and unhooks the visibilitychanged event |
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| 96 | * |
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| 97 | * Parameters: |
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| 98 | * options - {Object} options to pass to protocol read. |
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| 99 | */ |
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| 100 | load: function(options) { |
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| 101 | this.layer.events.triggerEvent("loadstart"); |
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| 102 | this.layer.protocol.read(OpenLayers.Util.applyDefaults({ |
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| 103 | callback: this.merge, |
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| 104 | filter: this.layer.filter, |
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| 105 | scope: this |
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| 106 | }, options)); |
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| 107 | this.layer.events.un({ |
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| 108 | "visibilitychanged": this.load, |
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| 109 | scope: this |
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| 110 | }); |
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| 111 | }, |
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| 112 | |
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| 113 | /** |
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| 114 | * Method: merge |
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| 115 | * Add all features to the layer. |
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| 116 | */ |
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| 117 | merge: function(resp) { |
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| 118 | this.layer.destroyFeatures(); |
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| 119 | var features = resp.features; |
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| 120 | if (features && features.length > 0) { |
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| 121 | var remote = this.layer.projection; |
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| 122 | var local = this.layer.map.getProjectionObject(); |
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| 123 | if(!local.equals(remote)) { |
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| 124 | var geom; |
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| 125 | for(var i=0, len=features.length; i<len; ++i) { |
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| 126 | geom = features[i].geometry; |
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| 127 | if(geom) { |
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| 128 | geom.transform(remote, local); |
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| 129 | } |
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| 130 | } |
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| 131 | } |
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| 132 | this.layer.addFeatures(features); |
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| 133 | } |
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| 134 | this.layer.events.triggerEvent("loadend"); |
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| 135 | }, |
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| 136 | |
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| 137 | CLASS_NAME: "OpenLayers.Strategy.Fixed" |
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| 138 | }); |
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