[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.Refresh |
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| 12 | * A strategy that refreshes the layer. By default the strategy waits for a |
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| 13 | * call to <refresh> before refreshing. By configuring the strategy with |
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| 14 | * the <interval> option, refreshing can take place automatically. |
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| 15 | * |
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| 16 | * Inherits from: |
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| 17 | * - <OpenLayers.Strategy> |
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| 18 | */ |
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| 19 | OpenLayers.Strategy.Refresh = OpenLayers.Class(OpenLayers.Strategy, { |
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| 20 | |
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| 21 | /** |
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| 22 | * Property: force |
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| 23 | * {Boolean} Force a refresh on the layer. Default is false. |
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| 24 | */ |
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| 25 | force: false, |
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| 26 | |
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| 27 | /** |
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| 28 | * Property: interval |
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| 29 | * {Number} Auto-refresh. Default is 0. If > 0, layer will be refreshed |
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| 30 | * every N milliseconds. |
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| 31 | */ |
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| 32 | interval: 0, |
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| 33 | |
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| 34 | /** |
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| 35 | * Property: timer |
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| 36 | * {Number} The id of the timer. |
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| 37 | */ |
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| 38 | timer: null, |
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| 39 | |
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| 40 | /** |
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| 41 | * Constructor: OpenLayers.Strategy.Refresh |
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| 42 | * Create a new Refresh strategy. |
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| 43 | * |
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| 44 | * Parameters: |
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| 45 | * options - {Object} Optional object whose properties will be set on the |
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| 46 | * instance. |
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| 47 | */ |
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| 48 | initialize: function(options) { |
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| 49 | OpenLayers.Strategy.prototype.initialize.apply(this, [options]); |
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| 50 | }, |
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| 51 | |
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| 52 | /** |
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| 53 | * APIMethod: activate |
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| 54 | * Activate the strategy. Register any listeners, do appropriate setup. |
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| 55 | * |
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| 56 | * Returns: |
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| 57 | * {Boolean} True if the strategy was successfully activated. |
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| 58 | */ |
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| 59 | activate: function() { |
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| 60 | var activated = OpenLayers.Strategy.prototype.activate.call(this); |
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| 61 | if(activated) { |
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| 62 | if(this.layer.visibility === true) { |
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| 63 | this.start(); |
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| 64 | } |
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| 65 | this.layer.events.on({ |
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| 66 | "visibilitychanged": this.reset, |
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| 67 | scope: this |
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| 68 | }); |
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| 69 | } |
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| 70 | return activated; |
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| 71 | }, |
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| 72 | |
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| 73 | /** |
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| 74 | * APIMethod: deactivate |
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| 75 | * Deactivate the strategy. Unregister any listeners, do appropriate |
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| 76 | * tear-down. |
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| 77 | * |
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| 78 | * Returns: |
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| 79 | * {Boolean} True if 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.stop(); |
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| 85 | } |
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| 86 | return deactivated; |
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| 87 | }, |
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| 88 | |
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| 89 | /** |
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| 90 | * Method: reset |
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| 91 | * Start or cancel the refresh interval depending on the visibility of |
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| 92 | * the layer. |
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| 93 | */ |
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| 94 | reset: function() { |
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| 95 | if(this.layer.visibility === true) { |
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| 96 | this.start(); |
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| 97 | } else { |
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| 98 | this.stop(); |
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| 99 | } |
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| 100 | }, |
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| 101 | |
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| 102 | /** |
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| 103 | * Method: start |
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| 104 | * Start the refresh interval. |
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| 105 | */ |
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| 106 | start: function() { |
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| 107 | if(this.interval && typeof this.interval === "number" && |
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| 108 | this.interval > 0) { |
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| 109 | |
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| 110 | this.timer = window.setInterval( |
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| 111 | OpenLayers.Function.bind(this.refresh, this), |
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| 112 | this.interval); |
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| 113 | } |
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| 114 | }, |
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| 115 | |
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| 116 | /** |
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| 117 | * APIMethod: refresh |
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| 118 | * Tell the strategy to refresh which will refresh the layer. |
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| 119 | */ |
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| 120 | refresh: function() { |
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| 121 | if (this.layer && this.layer.refresh && |
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| 122 | typeof this.layer.refresh == "function") { |
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| 123 | |
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| 124 | this.layer.refresh({force: this.force}); |
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| 125 | } |
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| 126 | }, |
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| 127 | |
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| 128 | /** |
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| 129 | * Method: stop |
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| 130 | * Cancels the refresh interval. |
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| 131 | */ |
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| 132 | stop: function() { |
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| 133 | if(this.timer !== null) { |
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| 134 | window.clearInterval(this.timer); |
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| 135 | this.timer = null; |
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| 136 | } |
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| 137 | }, |
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| 138 | |
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| 139 | CLASS_NAME: "OpenLayers.Strategy.Refresh" |
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| 140 | }); |
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