OpenLayers.MapInstances of OpenLayers.Map are interactive maps embedded in a web page. Create a new map with the OpenLayers.Map constructor. On their own maps do not provide much functionality. To extend a map it’s necessary to add controls (OpenLayers.Control) and layers (OpenLayers.Layer) to the map. Summary | Instances of OpenLayers.Map are interactive maps embedded in a web page. | | | | {Object} Base z-indexes for different classes of thing | | {Array(String)} supported application event types | | | | {String} Unique identifier for the map | | | | {DOMElement} The element that contains the map | | | | {HTMLDivElement} The element that represents the map viewport | | { OpenLayers.LonLat} The lonlat at which the later container was re-initialized (on-zoom) | | {HTMLDivElement} The element that contains the layers. | | | | | | | | | | | | {Integer} The current zoom level of the map | | {String} Used to store a unique identifier that changes when the map view changes. | | { OpenLayers.Size} Set in the map options to override the default tile size for this map. | | {String} Set in the map options to override the default projection string this map - also set maxExtent, maxResolution, and units if appropriate. | | | | {Array(Float)} A list of map resolutions (map units per pixel) in descending order. | | {Float} Default max is 360 deg / 256 px, which corresponds to zoom level 0 on gmaps. | | | | | | | | | | | | | | {Integer} Number of zoom levels for the map. | | {String} Relative path to a CSS file from which to load theme styles. | | {Boolean} Should OpenLayers allow events on the map to fall through to other elements on the page, or should it swallow them? | | | | Constructor for a new OpenLayers.Map instance. | | | | Function that is called to destroy the map on page unload. | | | | | | Get the tile size for the map | | Get a layer based on its id | | | | | | | | Removes a layer from the map by removing its visual element (the layer.div property), then removing it from the map’s internal list of layers, setting the layer’s map property to null. | | {Int} The number of layers attached to the map. | | | | Move the given layer to the specified (zero-based) index in the layer list, changing its z-index in the map display. | | Change the index of the given layer by delta. | | Allows user to specify one of the currently-loaded layers as the Map’s new base layer. | | | | | | | | Remove a control from the map. | | | | | | | | This function should be called by any external code which dynamically changes the size of the map div (because mozilla wont let us catch the “onresize” for an element) | | | | | | | | | | Allows user to pan by a value of screen pixels | | | | This function takes care to recenter the layerContainerDiv. | | | | | | {String} The Projection of the base layer. | | {String} The Map’s Maximum Resolution | | | | {Integer} The total number of zoom levels that can be displayed by the current baseLayer. | | { OpenLayers.Bounds} A Bounds object which represents the lon/lat bounds of the current viewPort. | | {Float} The current resolution of the map. | | {Float} The current scale denominator of the map. | | | | | | Zoom to a specific zoom level | | | | | | Zoom to the passed in bounds, recenter | | Zoom to the full extent and recenter. | | Zoom to a specified scale | | | | | | | | | | | | | | | | | | | | {Integer} 256 Default tile width (unless otherwise specified) | | {Integer} 256 Default tile height (unless otherwise specified) |
Z_INDEX_BASE{Object} Base z-indexes for different classes of thing
EVENT_TYPES{Array(String)} supported application event types
id{String} Unique identifier for the map
div{DOMElement} The element that contains the map
viewPortDiv{HTMLDivElement} The element that represents the map viewport
layerContainerOrigin{OpenLayers.LonLat} The lonlat at which the later container was re-initialized (on-zoom)
layerContainerDiv{HTMLDivElement} The element that contains the layers.
baseLayer{OpenLayers.Layer} The currently selected base layer. This determines min/max zoom level, projection, etc.
zoom{Integer} The current zoom level of the map
viewRequestID{String} Used to store a unique identifier that changes when the map view changes. viewRequestID should be used when adding data asynchronously to the map: viewRequestID is incremented when you initiate your request (right now during changing of baselayers and changing of zooms). It is stored here in the map and also in the data that will be coming back asynchronously. Before displaying this data on request completion, we check that the viewRequestID of the data is still the same as that of the map. Fix for #480
tileSize{OpenLayers.Size} Set in the map options to override the default tile size for this map.
projection{String} Set in the map options to override the default projection string this map - also set maxExtent, maxResolution, and units if appropriate.
units{String} The map units. Defaults to ‘degrees’. Possible values are ‘degrees’ (or ‘dd’), ‘m’, ‘ft’, ‘km’, ‘mi’, ‘inches’.
resolutions{Array(Float)} A list of map resolutions (map units per pixel) in descending order. If this is not set in the layer constructor, it will be set based on other resolution related properties (maxExtent, maxResolution, maxScale, etc.).
maxResolution{Float} Default max is 360 deg / 256 px, which corresponds to zoom level 0 on gmaps. Specify a different value in the map options if you are not using a geographic projection and displaying the whole world.
maxExtent{OpenLayers.Bounds} The maximum extent for the map. Defaults to the whole world in decimal degrees (-180, -90, 180, 90). Specify a different extent in the map options if you are not using a geographic projection and displaying the whole world.
restrictedExtent{OpenLayers.Bounds} Limit map navigation to this extent where possible. If a non-null restrictedExtent is set, panning will be restricted to the given bounds. In addition, zooming to a resolution that displays more than the restricted extent will center the map on the restricted extent. If you wish to limit the zoom level or resolution, use maxResolution.
numZoomLevels{Integer} Number of zoom levels for the map. Defaults to 16. Set a different value in the map options if needed.
theme{String} Relative path to a CSS file from which to load theme styles. Specify null in the map options (e.g. {theme: null}) if you want to get cascading style declarations - by putting links to stylesheets or style declarations directly in your page.
fallThrough{Boolean} Should OpenLayers allow events on the map to fall through to other elements on the page, or should it swallow them? (#457) Default is to swallow them.
OpenLayers.MapConstructor for a new OpenLayers.Map instance. Parametersdiv | {String} Id of an element in your page that will contain the map. | options | {Object} Optional object with properties to tag onto the map. |
Examples// create a map with default options in an element with the id "map1" var map = new OpenLayers.Map("map1");
// create a map with non-default options in an element with id "map2" var options = { maxExtent: new OpenLayers.Bounds(-200000, -200000, 200000, 200000), maxResolution: 156543, units: 'meters', projection: "EPSG:41001" }; var map = new OpenLayers.Map("map2", options);
unloadDestroyFunction that is called to destroy the map on page unload. stored here so that if map is manually destroyed, we can unregister this.
setOptionssetOptions: function( | options | ) |
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Change the map options Parametersoptions | {Object} Hashtable of options to tag to the map |
getLayerGet a layer based on its id ParameterReturns{OpenLayers.Layer} The Layer with the corresponding id from the map’s layer collection, or null if not found.
setLayerZIndexsetLayerZIndex: function ( | layer, | | zIdx | ) |
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Parameters
addLayeraddLayer: function ( | layer | ) |
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Parameters
addLayersaddLayers: function ( | layers | ) |
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Parameters
removeLayerremoveLayer: function( | layer, | | setNewBaseLayer | ) |
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Removes a layer from the map by removing its visual element (the layer.div property), then removing it from the map’s internal list of layers, setting the layer’s map property to null. a “removelayer” event is triggered. very worthy of mention is that simply removing a layer from a map will not cause the removal of any popups which may have been created by the layer. this is due to the fact that it was decided at some point that popups would not belong to layers. thus there is no way for us to know here to which layer the popup belongs. A simple solution to this is simply to call destroy() on the layer. the default OpenLayers.Layer class’s destroy() function automatically takes care to remove itself from whatever map it has been attached to. The correct solution is for the layer itself to register an event-handler on “removelayer” and when it is called, if it recognizes itself as the layer being removed, then it cycles through its own personal list of popups, removing them from the map. Parameters
getNumLayersgetNumLayers: function () |
Returns{Int} The number of layers attached to the map.
getLayerIndexgetLayerIndex: function ( | layer | ) |
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ParametersReturns{Integer} The current (zero-based) index of the given layer in the map’s layer stack. Returns -1 if the layer isn’t on the map.
setLayerIndexsetLayerIndex: function ( | layer, | | idx | ) |
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Move the given layer to the specified (zero-based) index in the layer list, changing its z-index in the map display. Use map.getLayerIndex() to find out the current index of a layer. Note that this cannot (or at least should not) be effectively used to raise base layers above overlays. Parameters
raiseLayerraiseLayer: function ( | layer, | | delta | ) |
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Change the index of the given layer by delta. If delta is positive, the layer is moved up the map’s layer stack; if delta is negative, the layer is moved down. Again, note that this cannot (or at least should not) be effectively used to raise base layers above overlays. Paremeters
setBaseLayersetBaseLayer: function( | newBaseLayer | ) |
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Allows user to specify one of the currently-loaded layers as the Map’s new base layer. Parameters
addControladdControl: function ( | control, | | px | ) |
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Parameters
addControlToMapaddControlToMap: function ( | control, | | px | ) |
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Parameters
getControlgetControl: function ( | id | ) |
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Parametersid | {String} ID of the control to return. |
Returns{OpenLayers.Control} The control from the map’s list of controls which has a matching ‘id’. If none found, returns null.
removeControlremoveControl: function ( | control | ) |
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Remove a control from the map. Removes the control both from the map object’s internal array of controls, as well as from the map’s viewPort (assuming the control was not added outsideViewport) Parameters
addPopupaddPopup: function( | popup, | | exclusive | ) |
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Parameterspopup | {OpenLayers.Popup} | exclusive | {Boolean} If true, closes all other popups first |
removePopupremovePopup: function( | popup | ) |
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Parameters
getSizeReturns{OpenLayers.Size} An OpenLayers.Size object that represents the size, in pixels, of the div into which OpenLayers has been loaded. Note - A clone() of this locally cached variable is returned, so as not to allow users to modify it.
updateSizeThis function should be called by any external code which dynamically changes the size of the map div (because mozilla wont let us catch the “onresize” for an element)
calculateBoundscalculateBounds: function( | center, | | resolution | ) |
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Parameterscenter | {OpenLayers.LonLat} Default is this.getCenter() | resolution | {float} Default is this.getResolution() |
Returns{OpenLayers.Bounds} A bounds based on resolution, center, and current mapsize.
panAllows user to pan by a value of screen pixels Parameters
setCentersetCenter: function ( | lonlat, | | zoom, | | dragging, | | forceZoomChange | ) |
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Parameterslonlat | {OpenLayers.LonLat} | zoom | {Integer} | dragging | {Boolean} Specifies whether or not to trigger movestart/end events | forceZoomChange | {Boolean} Specifies whether or not to trigger zoom change events (needed on baseLayer change) |
TBD: reconsider forceZoomChange in 3.0
centerLayerContainercenterLayerContainer: function ( | lonlat | ) |
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This function takes care to recenter the layerContainerDiv. Parameters
isValidZoomLevelisValidZoomLevel: function( | zoomLevel | ) |
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ParametersReturns{Boolean} Whether or not the zoom level passed in is non-null and within the min/max range of zoom levels.
isValidLonLatisValidLonLat: function( | lonlat | ) |
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ParametersReturns{Boolean} Whether or not the lonlat passed in is non-null and within the maxExtent bounds
getProjectiongetProjection: function() |
Returns{String} The Projection of the base layer.
getMaxResolutiongetMaxResolution: function() |
Returns{String} The Map’s Maximum Resolution
getNumZoomLevelsgetNumZoomLevels: function() |
Returns{Integer} The total number of zoom levels that can be displayed by the current baseLayer.
getExtentReturns{OpenLayers.Bounds} A Bounds object which represents the lon/lat bounds of the current viewPort. If no baselayer is set, returns null.
getResolutiongetResolution: function () |
Returns{Float} The current resolution of the map. If no baselayer is set, returns null.
getScaleReturns{Float} The current scale denominator of the map. If no baselayer is set, returns null.
getZoomForExtentgetZoomForExtent: function ( | bounds, | | closest | ) |
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Parametersbounds | {OpenLayers.Bounds} | closest | {Boolean} Find the zoom level that most closely fits the specified bounds. Note that this may result in a zoom that does not exactly contain the entire extent. Default is false. |
Returns{Integer} A suitable zoom level for the specified bounds. If no baselayer is set, returns null.
getZoomForResolutiongetZoomForResolution: function( | resolution, | | closest | ) |
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Parameterresolution | {Float} | closest | {Boolean} Find the zoom level that corresponds to the absolute closest resolution, which may result in a zoom whose corresponding resolution is actually smaller than we would have desired (if this is being called from a getZoomForExtent() call, then this means that the returned zoom index might not actually contain the entire extent specified... but it’ll be close). Default is false. |
Returns{Integer} A suitable zoom level for the specified resolution. If no baselayer is set, returns null.
zoomToZoom to a specific zoom level Parameters
zoomToExtentzoomToExtent: function( | bounds | ) |
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Zoom to the passed in bounds, recenter Parameters
zoomToMaxExtentzoomToMaxExtent: function() |
Zoom to the full extent and recenter.
zoomToScalezoomToScale: function( | scale | ) |
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Zoom to a specified scale Parameters
getLonLatFromViewPortPxgetLonLatFromViewPortPx: function ( | viewPortPx | ) |
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ParametersReturns{OpenLayers.LonLat} An OpenLayers.LonLat which is the passed-in view port OpenLayers.Pixel, translated into lon/lat by the current base layer.
getViewPortPxFromLonLatgetViewPortPxFromLonLat: function ( | lonlat | ) |
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ParametersReturns{OpenLayers.Pixel} An OpenLayers.Pixel which is the passed-in OpenLayers.LonLat, translated into view port pixels by the current base layer.
getLonLatFromPixelgetLonLatFromPixel: function ( | px | ) |
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ParametersReturns{OpenLayers.LonLat} An OpenLayers.LonLat corresponding to the given OpenLayers.Pixel, translated into lon/lat by the current base layer
getPixelFromLonLatgetPixelFromLonLat: function ( | lonlat | ) |
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ParametersReturns{OpenLayers.Pixel} An OpenLayers.Pixel corresponding to the OpenLayers.LonLat translated into view port pixels by the current base layer.
getViewPortPxFromLayerPxgetViewPortPxFromLayerPx:function( | layerPx | ) |
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ParametersReturns{OpenLayers.Pixel} Layer Pixel translated into ViewPort Pixel coordinates
getLayerPxFromViewPortPxgetLayerPxFromViewPortPx:function( | viewPortPx | ) |
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ParametersReturns{OpenLayers.Pixel} ViewPort Pixel translated into Layer Pixel coordinates
getLonLatFromLayerPxgetLonLatFromLayerPx: function ( | px | ) |
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ParametersReturns{OpenLayers.LonLat}
getLayerPxFromLonLatgetLayerPxFromLonLat: function ( | lonlat | ) |
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ParametersReturns{OpenLayers.Pixel} An OpenLayers.Pixel which is the passed-in OpenLayers.LonLat, translated into layer pixels by the current base layer
TILE_WIDTH{Integer} 256 Default tile width (unless otherwise specified)
TILE_HEIGHT{Integer} 256 Default tile height (unless otherwise specified)
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