OpenLayers.Map

Instances 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
OpenLayers.MapInstances of OpenLayers.Map are interactive maps embedded in a web page.
Constants
Z_INDEX_BASE{Object} Base z-indexes for different classes of thing
EVENT_TYPES{Array(String)} Supported application event types.
Properties
id{String} Unique identifier for the map
fractionalZoom{Boolean} For a base layer that supports it, allow the map resolution to be set to a value between one of the values in the resolutions array.
events{OpenLayers.Events} An events object that handles all events on the map
allOverlays{Boolean} Allow the map to function with “overlays” only.
div{DOMElement|String} The element that contains the map (or an id for that element).
dragging{Boolean} The map is currently being dragged.
size{OpenLayers.Size} Size of the main div (this.div)
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.
layers{Array(OpenLayers.Layer)} Ordered list of layers in the map
controls{Array(OpenLayers.Control)} List of controls associated with the map.
popups{Array(OpenLayers.Popup)} List of popups associated with the map
baseLayer{OpenLayers.Layer} The currently selected base layer.
center{OpenLayers.LonLat} The current center of the map
resolution{Float} The resolution of the map.
zoom{Integer} The current zoom level of the map
panRatio{Float} The ratio of the current extent within which panning will tween.
viewRequestID{String} Used to store a unique identifier that changes when the map view changes.
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.
resolutions{Array(Float)} A list of map resolutions (map units per pixel) in descending order.
maxResolution{Float} Default max is 360 deg / 256 px, which corresponds to zoom level 0 on gmaps.
minResolution{Float}
maxScale{Float}
minScale{Float}
maxExtent{OpenLayers.Bounds} The maximum extent for the map.
minExtent{OpenLayers.Bounds}
restrictedExtent{OpenLayers.Bounds} Limit map navigation to this extent where possible.
numZoomLevels{Integer} Number of zoom levels for the map.
theme{String} Relative path to a CSS file from which to load theme styles.
displayProjection{OpenLayers.Projection} Requires proj4js support.Projection used by several controls to display data to user.
fallThrough{Boolean} Should OpenLayers allow events on the map to fall through to other elements on the page, or should it swallow them? 
panTween{OpenLayers.Tween} Animated panning tween object, see panTo()
eventListeners{Object} If set as an option at construction, the eventListeners object will be registered with OpenLayers.Events.on.
panMethod{Function} The Easing function to be used for tweening.
panDuration{Integer} The number of steps to be passed to the OpenLayers.Tween.start() method when the map is panned.
paddingForPopups{OpenLayers.Bounds} Outside margin of the popup.
Constructor
OpenLayers.MapConstructor for a new OpenLayers.Map instance.
Functions
renderRender the map to a specified container.
unloadDestroyFunction that is called to destroy the map on page unload.
updateSizeDestroyWhen the map is destroyed, we need to stop listening to updateSize events: this method stores the function we need to unregister in non-IE browsers.
destroyDestroy this map
setOptionsChange the map options
getTileSizeGet the tile size for the map
getByGet a list of objects given a property and a match item.
getLayersByGet a list of layers with properties matching the given criteria.
getLayersByNameGet a list of layers with names matching the given name.
getLayersByClassGet a list of layers of a given class (CLASS_NAME).
getControlsByGet a list of controls with properties matching the given criteria.
getControlsByClassGet a list of controls of a given class (CLASS_NAME).
getLayerGet a layer based on its id
setLayerZIndex
resetLayersZIndexReset each layer’s z-index based on layer’s array index
addLayer
addLayers
removeLayerRemoves 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.
getNumLayers{Int} The number of layers attached to the map.
getLayerIndex
setLayerIndexMove the given layer to the specified (zero-based) index in the layer list, changing its z-index in the map display.
raiseLayerChange the index of the given layer by delta.
setBaseLayerAllows user to specify one of the currently-loaded layers as the Map’s new base layer.
addControl
addControlToMap
getControl
removeControlRemove a control from the map.
addPopup
removePopup
getSize{OpenLayers.Size} An OpenLayers.Size object that represents the size, in pixels, of the div into which OpenLayers has been loaded.
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)
getCurrentSize{OpenLayers.Size} A new OpenLayers.Size object with the dimensions of the map div
calculateBounds
getCenter{OpenLayers.LonLat}
getZoom{Integer}
panAllows user to pan by a value of screen pixels
panToAllows user to pan to a new lonlat If the new lonlat is in the current extent the map will slide smoothly
setCenterSet the map center (and optionally, the zoom level).
moveTo
centerLayerContainerThis function takes care to recenter the layerContainerDiv.
isValidZoomLevel
isValidLonLat
getProjectionThis method returns a string representing the projection.
getProjectionObjectReturns the projection obect from the baselayer.
getMaxResolution{String} The Map’s Maximum Resolution
getMaxExtent
getNumZoomLevels{Integer} The total number of zoom levels that can be displayed by the current baseLayer.
getExtent{OpenLayers.Bounds} A Bounds object which represents the lon/lat bounds of the current viewPort.
getResolution{Float} The current resolution of the map.
getUnits{Float} The current units of the map.
getScale{Float} The current scale denominator of the map.
getZoomForExtent
getResolutionForZoom
getZoomForResolution
zoomToZoom to a specific zoom level
zoomIn
zoomOut
zoomToExtentZoom to the passed in bounds, recenter
zoomToMaxExtentZoom to the full extent and recenter.
zoomToScaleZoom to a specified scale
getLonLatFromViewPortPx
getViewPortPxFromLonLat
getLonLatFromPixel
getPixelFromLonLatReturns a pixel location given a map location.
getViewPortPxFromLayerPx
getLayerPxFromViewPortPx
getLonLatFromLayerPx
getLayerPxFromLonLat
Constants
TILE_WIDTH{Integer} 256 Default tile width (unless otherwise specified)
TILE_HEIGHT{Integer} 256 Default tile height (unless otherwise specified)

Constants

Z_INDEX_BASE

{Object} Base z-indexes for different classes of thing

EVENT_TYPES

{Array(String)} Supported application event types.  Register a listener for a particular event with the following syntax:

map.events.register(type, obj, listener);

Listeners will be called with a reference to an event object.  The properties of this event depends on exactly what happened.

All event objects have at least the following properties

  • object {Object} A reference to map.events.object.
  • element {DOMElement} A reference to map.events.element.

Browser events have the following additional properties

  • xy {OpenLayers.Pixel} The pixel location of the event (relative to the the map viewport).
  • other properties that come with browser events

Supported map event types

  • preaddlayer triggered before a layer has been added.  The event object will include a layer property that references the layer to be added.
  • addlayer triggered after a layer has been added.  The event object will include a layer property that references the added layer.
  • removelayer triggered after a layer has been removed.  The event object will include a layer property that references the removed layer.
  • changelayer triggered after a layer name change, order change, or visibility change (due to resolution thresholds).  Listeners will receive an event object with layer and property properties.  The layer property will be a reference to the changed layer.  The property property will be a key to the changed property (name, visibility, or order).
  • movestart triggered after the start of a drag, pan, or zoom
  • move triggered after each drag, pan, or zoom
  • moveend triggered after a drag, pan, or zoom completes
  • zoomend triggered after a zoom completes
  • addmarker triggered after a marker has been added
  • removemarker triggered after a marker has been removed
  • clearmarkers triggered after markers have been cleared
  • mouseover triggered after mouseover the map
  • mouseout triggered after mouseout the map
  • mousemove triggered after mousemove the map
  • dragstart Does not work.  Register for movestart instead.
  • drag Does not work.  Register for move instead.
  • dragend Does not work.  Register for moveend instead.
  • changebaselayer triggered after the base layer changes

Properties

id

{String} Unique identifier for the map

fractionalZoom

{Boolean} For a base layer that supports it, allow the map resolution to be set to a value between one of the values in the resolutions array.  Default is false.

When fractionalZoom is set to true, it is possible to zoom to an arbitrary extent.  This requires a base layer from a source that supports requests for arbitrary extents (i.e. not cached tiles on a regular lattice).  This means that fractionalZoom will not work with commercial layers (Google, Yahoo, VE), layers using TileCache, or any other pre-cached data sources.

If you are using fractionalZoom, then you should also use getResolutionForZoom instead of layer.resolutions[zoom] as the former works for non-integer zoom levels.

events

{OpenLayers.Events} An events object that handles all events on the map

allOverlays

{Boolean} Allow the map to function with “overlays” only.  Defaults to false.  If true, the lowest layer in the draw order will act as the base layer.  In addition, if set to true, all layers will have isBaseLayer set to false when they are added to the map.

Note

If you set map.allOverlays to true, then you cannot use map.setBaseLayer or layer.setIsBaseLayer.  With allOverlays true, the lowest layer in the draw layer is the base layer.  So, to change the base layer, use setLayerIndex or raiseLayer to set the layer index to 0.

div

{DOMElement|String} The element that contains the map (or an id for that element).  If the OpenLayers.Map constructor is called with two arguments, this should be provided as the first argument.  Alternatively, the map constructor can be called with the options object as the only argument.  In this case (one argument), a div property may or may not be provided.  If the div property is not provided, the map can be rendered to a container later using the render method.

Note: If you calling render after map construction, do not use maxResolution auto.  Instead, divide your maxExtent by your maximum expected dimension.

dragging

{Boolean} The map is currently being dragged.

size

{OpenLayers.Size} Size of the main div (this.div)

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.

layers

{Array(OpenLayers.Layer)} Ordered list of layers in the map

controls

{Array(OpenLayers.Control)} List of controls associated with the map.

If not provided in the map options at construction, the map will be given the following controls by default:

popups

{Array(OpenLayers.Popup)} List of popups associated with the map

baseLayer

{OpenLayers.Layer} The currently selected base layer.  This determines min/max zoom level, projection, etc.

center

{OpenLayers.LonLat} The current center of the map

resolution

{Float} The resolution of the map.

zoom

{Integer} The current zoom level of the map

panRatio

{Float} The ratio of the current extent within which panning will tween.

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.  Default is “EPSG:4326”.

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.

minResolution

{Float}

maxScale

{Float}

minScale

{Float}

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.

displayProjection

{OpenLayers.Projection} Requires proj4js support.Projection used by several controls to display data to user.  If this property is set, it will be set on any control which has a null displayProjection property at the time the control is added to the map.

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 fall through.

panTween

{OpenLayers.Tween} Animated panning tween object, see panTo()

eventListeners

{Object} If set as an option at construction, the eventListeners object will be registered with OpenLayers.Events.on.  Object structure must be a listeners object as shown in the example for the events.on method.

panMethod

{Function} The Easing function to be used for tweening.  Default is OpenLayers.Easing.Expo.easeOut.  Setting this to ‘null’ turns off animated panning.

panDuration

{Integer} The number of steps to be passed to the OpenLayers.Tween.start() method when the map is panned.  Default is 50.

paddingForPopups

{OpenLayers.Bounds} Outside margin of the popup.  Used to prevent the popup from getting too close to the map border.

Constructor

OpenLayers.Map

Constructor for a new OpenLayers.Map instance.  There are two possible ways to call the map constructor.  See the examples below.

Parameters

div{String} Id of an element in your page that will contain the map.  May be omitted if the div option is provided or if you intend to use render later.
options{Object} Optional object with properties to tag onto the map.

Examples (method one)

// 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: 'm',
    projection: "EPSG:41001"
};
var map = new OpenLayers.Map("map2", options);
Examples (method twosingle argument):
// create a map with non-default options
var map = new OpenLayers.Map({
    div: "map_id",
    maxExtent: new OpenLayers.Bounds(-200000, -200000, 200000, 200000),
    maxResolution: 156543,
    units: 'm',
    projection: "EPSG:41001"
});

// create a map without a reference to a container - call render later
var map = new OpenLayers.Map({
    maxExtent: new OpenLayers.Bounds(-200000, -200000, 200000, 200000),
    maxResolution: 156543,
    units: 'm',
    projection: "EPSG:41001"
});

Functions

render

render: function(div)

Render the map to a specified container.

Parameters

div{String|DOMElement} The container that the map should be rendered to.  If different than the current container, the map viewport will be moved from the current to the new container.

unloadDestroy

Function that is called to destroy the map on page unload. stored here so that if map is manually destroyed, we can unregister this.

updateSizeDestroy

When the map is destroyed, we need to stop listening to updateSize events: this method stores the function we need to unregister in non-IE browsers.

destroy

destroy:function()

Destroy this map

setOptions

setOptions: function(options)

Change the map options

Parameters

options{Object} Hashtable of options to tag to the map

getTileSize

getTileSize: function()

Get the tile size for the map

Returns

{OpenLayers.Size}

getBy

getBy: function(array,
property,
match)

Get a list of objects given a property and a match item.

Parameters

array{String} A property on the map whose value is an array.
property{String} A property on each item of the given array.
match{String | Object} A string to match.  Can also be a regular expression literal or object.  In addition, it can be any object with a method named test.  For reqular expressions or other, if match.test(map[array][i][property]) evaluates to true, the item will be included in the array returned.  If no items are found, an empty array is returned.

Returns

{Array} An array of items where the given property matches the given criteria.

getLayersBy

getLayersBy: function(property,
match)

Get a list of layers with properties matching the given criteria.

Parameter

property{String} A layer property to be matched.
match{String | Object} A string to match.  Can also be a regular expression literal or object.  In addition, it can be any object with a method named test.  For reqular expressions or other, if match.test(layer[property]) evaluates to true, the layer will be included in the array returned.  If no layers are found, an empty array is returned.

Returns

{Array(OpenLayers.Layer)} A list of layers matching the given criteria.  An empty array is returned if no matches are found.

getLayersByName

getLayersByName: function(match)

Get a list of layers with names matching the given name.

Parameter

match{String | Object} A layer name.  The name can also be a regular expression literal or object.  In addition, it can be any object with a method named test.  For reqular expressions or other, if name.test(layer.name) evaluates to true, the layer will be included in the list of layers returned.  If no layers are found, an empty array is returned.

Returns

{Array(OpenLayers.Layer)} A list of layers matching the given name.  An empty array is returned if no matches are found.

getLayersByClass

getLayersByClass: function(match)

Get a list of layers of a given class (CLASS_NAME).

Parameter

match{String | Object} A layer class name.  The match can also be a regular expression literal or object.  In addition, it can be any object with a method named test.  For reqular expressions or other, if type.test(layer.CLASS_NAME) evaluates to true, the layer will be included in the list of layers returned.  If no layers are found, an empty array is returned.

Returns

{Array(OpenLayers.Layer)} A list of layers matching the given class.  An empty array is returned if no matches are found.

getControlsBy

getControlsBy: function(property,
match)

Get a list of controls with properties matching the given criteria.

Parameter

property{String} A control property to be matched.
match{String | Object} A string to match.  Can also be a regular expression literal or object.  In addition, it can be any object with a method named test.  For reqular expressions or other, if match.test(layer[property]) evaluates to true, the layer will be included in the array returned.  If no layers are found, an empty array is returned.

Returns

{Array(OpenLayers.Control)} A list of controls matching the given criteria.  An empty array is returned if no matches are found.

getControlsByClass

getControlsByClass: function(match)

Get a list of controls of a given class (CLASS_NAME).

Parameter

match{String | Object} A control class name.  The match can also be a regular expression literal or object.  In addition, it can be any object with a method named test.  For reqular expressions or other, if type.test(control.CLASS_NAME) evaluates to true, the control will be included in the list of controls returned.  If no controls are found, an empty array is returned.

Returns

{Array(OpenLayers.Control)} A list of controls matching the given class.  An empty array is returned if no matches are found.

getLayer

getLayer: function(id)

Get a layer based on its id

Parameter

id{String} A layer id

Returns

{OpenLayers.Layer} The Layer with the corresponding id from the map’s layer collection, or null if not found.

setLayerZIndex

setLayerZIndex: function (layer,
zIdx)

Parameters

layer{OpenLayers.Layer}
zIdx{int}

resetLayersZIndex

resetLayersZIndex: function()

Reset each layer’s z-index based on layer’s array index

addLayer

addLayer: function (layer)

Parameters

layer{OpenLayers.Layer}

addLayers

addLayers: function (layers)

Parameters

layers{Array(OpenLayers.Layer)}

removeLayer

removeLayer: function(layer,
setNewBaseLayer)

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

layer{OpenLayers.Layer}
setNewBaseLayer{Boolean} Default is true

getNumLayers

getNumLayers: function ()

Returns

{Int} The number of layers attached to the map.

getLayerIndex

getLayerIndex: function (layer)

Parameters

layer{OpenLayers.Layer}

Returns

{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.

setLayerIndex

setLayerIndex: function (layer,
idx)

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

layer{OpenLayers.Layer}
idx{int}

raiseLayer

raiseLayer: function (layer,
delta)

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

layer{OpenLayers.Layer}
delta{int}

setBaseLayer

setBaseLayer: function(newBaseLayer)

Allows user to specify one of the currently-loaded layers as the Map’s new base layer.

Parameters

newBaseLayer{OpenLayers.Layer}

addControl

addControl: function (control,
px)

Parameters

control{OpenLayers.Control}
px{OpenLayers.Pixel}

addControlToMap

addControlToMap: function (control,
px)

Parameters

control{OpenLayers.Control}
px{OpenLayers.Pixel}

getControl

getControl: function (id)

Parameters

id{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.

removeControl

removeControl: function (control)

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

control{OpenLayers.Control} The control to remove.

addPopup

addPopup: function(popup,
exclusive)

Parameters

popup{OpenLayers.Popup}
exclusive{Boolean} If true, closes all other popups first

removePopup

removePopup: function(popup)

Parameters

popup{OpenLayers.Popup}

getSize

getSize: function ()

Returns

{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.

updateSize

updateSize: function()

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)

getCurrentSize

getCurrentSize: function()

Returns

{OpenLayers.Size} A new OpenLayers.Size object with the dimensions of the map div

calculateBounds

calculateBounds: function(center,
resolution)

Parameters

center{OpenLayers.LonLat} Default is this.getCenter()
resolution{float} Default is this.getResolution()

Returns

{OpenLayers.Bounds} A bounds based on resolution, center, and current mapsize.

getCenter

getCenter: function ()

Returns

{OpenLayers.LonLat}

getZoom

getZoom: function ()

Returns

{Integer}

pan

pan: function(dx,
dy,
options)

Allows user to pan by a value of screen pixels

Parameters

dx{Integer}
dy{Integer}
options{Object} Options to configure panning:
  • animate {Boolean} Use panTo instead of setCenter.  Default is true.
  • dragging {Boolean} Call setCenter with dragging true.  Default is false.

panTo

panTo: function(lonlat)

Allows user to pan to a new lonlat If the new lonlat is in the current extent the map will slide smoothly

Parameters

lonlat{<OpenLayers.Lonlat>}

setCenter

setCenter: function(lonlat,
zoom,
dragging,
forceZoomChange)

Set the map center (and optionally, the zoom level).

Parameters

lonlat{OpenLayers.LonLat} The new center location.
zoom{Integer} Optional zoom level.
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

moveTo

moveTo: function(lonlat,
zoom,
options)

Parameters

lonlat{OpenLayers.LonLat}
zoom{Integer}
options{Object}

centerLayerContainer

centerLayerContainer: function (lonlat)

This function takes care to recenter the layerContainerDiv.

Parameters

lonlat{OpenLayers.LonLat}

isValidZoomLevel

isValidZoomLevel: function(zoomLevel)

Parameters

zoomLevel{Integer}

Returns

{Boolean} Whether or not the zoom level passed in is non-null and within the min/max range of zoom levels.

isValidLonLat

isValidLonLat: function(lonlat)

Parameters

lonlat{OpenLayers.LonLat}

Returns

{Boolean} Whether or not the lonlat passed in is non-null and within the maxExtent bounds

getProjection

getProjection: function()

This method returns a string representing the projection.  In the case of projection support, this will be the srsCode which is loaded -- otherwise it will simply be the string value that was passed to the projection at startup.

FIXME: In 3.0, we will remove getProjectionObject, and instead return a Projection object from this function.

Returns

{String} The Projection string from the base layer or null.

getProjectionObject

getProjectionObject: function()

Returns the projection obect from the baselayer.

Returns

{OpenLayers.Projection} The Projection of the base layer.

getMaxResolution

getMaxResolution: function()

Returns

{String} The Map’s Maximum Resolution

getMaxExtent

getMaxExtent: function (options)

Parameters

options{Object}

Allowed Options

restricted{Boolean} If true, returns restricted extent (if it is available.)

Returns

{OpenLayers.Bounds} The maxExtent property as set on the current baselayer, unless the ‘restricted’ option is set, in which case the ‘restrictedExtent’ option from the map is returned (if it is set).

getNumZoomLevels

getNumZoomLevels: function()

Returns

{Integer} The total number of zoom levels that can be displayed by the current baseLayer.

getExtent

getExtent: function ()

Returns

{OpenLayers.Bounds} A Bounds object which represents the lon/lat bounds of the current viewPort.  If no baselayer is set, returns null.

getResolution

getResolution: function ()

Returns

{Float} The current resolution of the map.  If no baselayer is set, returns null.

getUnits

getUnits: function ()

Returns

{Float} The current units of the map.  If no baselayer is set, returns null.

getScale

getScale: function ()

Returns

{Float} The current scale denominator of the map.  If no baselayer is set, returns null.

getZoomForExtent

getZoomForExtent: function (bounds,
closest)

Parameters

bounds{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.

getResolutionForZoom

getResolutionForZoom: function(zoom)

Parameter

zoom{Float}

Returns

{Float} A suitable resolution for the specified zoom.  If no baselayer is set, returns null.

getZoomForResolution

getZoomForResolution: function(resolution,
closest)

Parameter

resolution{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.

zoomTo

zoomTo: function(zoom)

Zoom to a specific zoom level

Parameters

zoom{Integer}

zoomIn

zoomIn: function()

Parameters

zoom{int}

zoomOut

zoomOut: function()

Parameters

zoom{int}

zoomToExtent

zoomToExtent: function(bounds,
closest)

Zoom to the passed in bounds, recenter

Parameters

bounds{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.

zoomToMaxExtent

zoomToMaxExtent: function(options)

Zoom to the full extent and recenter.

Parameters

options -

Allowed Options

restricted{Boolean} True to zoom to restricted extent if it is set.  Defaults to true.

zoomToScale

zoomToScale: function(scale,
closest)

Zoom to a specified scale

Parameters

scale{float}
closest{Boolean} Find the zoom level that most closely fits the specified scale.  Note that this may result in a zoom that does not exactly contain the entire extent.  Default is false.

getLonLatFromViewPortPx

getLonLatFromViewPortPx: function (viewPortPx)

Parameters

viewPortPx{OpenLayers.Pixel}

Returns

{OpenLayers.LonLat} An OpenLayers.LonLat which is the passed-in view port OpenLayers.Pixel, translated into lon/lat by the current base layer.

getViewPortPxFromLonLat

getViewPortPxFromLonLat: function (lonlat)

Parameters

lonlat{OpenLayers.LonLat}

Returns

{OpenLayers.Pixel} An OpenLayers.Pixel which is the passed-in OpenLayers.LonLat, translated into view port pixels by the current base layer.

getLonLatFromPixel

getLonLatFromPixel: function (px)

Parameters

px{OpenLayers.Pixel}

Returns

{OpenLayers.LonLat} An OpenLayers.LonLat corresponding to the given OpenLayers.Pixel, translated into lon/lat by the current base layer

getPixelFromLonLat

getPixelFromLonLat: function (lonlat)

Returns a pixel location given a map location.  The map location is translated to an integer pixel location (in viewport pixel coordinates) by the current base layer.

Parameters

lonlat{OpenLayers.LonLat} A map location.

Returns

{OpenLayers.Pixel} An OpenLayers.Pixel corresponding to the OpenLayers.LonLat translated into view port pixels by the current base layer.

getViewPortPxFromLayerPx

getViewPortPxFromLayerPx:function(layerPx)

Parameters

layerPx{OpenLayers.Pixel}

Returns

{OpenLayers.Pixel} Layer Pixel translated into ViewPort Pixel coordinates

getLayerPxFromViewPortPx

getLayerPxFromViewPortPx:function(viewPortPx)

Parameters

viewPortPx{OpenLayers.Pixel}

Returns

{OpenLayers.Pixel} ViewPort Pixel translated into Layer Pixel coordinates

getLonLatFromLayerPx

getLonLatFromLayerPx: function (px)

Parameters

px{OpenLayers.Pixel}

Returns

{OpenLayers.LonLat}

getLayerPxFromLonLat

getLayerPxFromLonLat: function (lonlat)

Parameters

lonlat{OpenLayers.LonLat} lonlat

Returns

{OpenLayers.Pixel} An OpenLayers.Pixel which is the passed-in OpenLayers.LonLat, translated into layer pixels by the current base layer

Constants

TILE_WIDTH

{Integer} 256 Default tile width (unless otherwise specified)

TILE_HEIGHT

{Integer} 256 Default tile height (unless otherwise specified)

Instances of this class represent a width/height pair
This class represents a longitude and latitude pair
Controls affect the display or behavior of the map.
A popup is a small div that can opened and closed on the map.
Instances of this class represent bounding boxes.
Class for coordinate transforms between coordinate systems.
on: function(object)
Convenience method for registering listeners with a common scope.
render: function(div)
Render the map to a specified container.
destroy:function()
Destroy this map
setOptions: function(options)
Change the map options
getTileSize: function()
Get the tile size for the map
getBy: function(array,
property,
match)
Get a list of objects given a property and a match item.
getLayersBy: function(property,
match)
Get a list of layers with properties matching the given criteria.
getLayersByName: function(match)
Get a list of layers with names matching the given name.
getLayersByClass: function(match)
Get a list of layers of a given class (CLASS_NAME).
getControlsBy: function(property,
match)
Get a list of controls with properties matching the given criteria.
getControlsByClass: function(match)
Get a list of controls of a given class (CLASS_NAME).
getLayer: function(id)
Get a layer based on its id
setLayerZIndex: function (layer,
zIdx)
resetLayersZIndex: function()
Reset each layer’s z-index based on layer’s array index
addLayer: function (layer)
addLayers: function (layers)
removeLayer: function(layer,
setNewBaseLayer)
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.
getNumLayers: function ()
{Int} The number of layers attached to the map.
getLayerIndex: function (layer)
setLayerIndex: function (layer,
idx)
Move the given layer to the specified (zero-based) index in the layer list, changing its z-index in the map display.
raiseLayer: function (layer,
delta)
Change the index of the given layer by delta.
setBaseLayer: function(newBaseLayer)
Allows user to specify one of the currently-loaded layers as the Map’s new base layer.
addControl: function (control,
px)
addControlToMap: function (control,
px)
getControl: function (id)
removeControl: function (control)
Remove a control from the map.
addPopup: function(popup,
exclusive)
removePopup: function(popup)
getSize: function ()
{OpenLayers.Size} An OpenLayers.Size object that represents the size, in pixels, of the div into which OpenLayers has been loaded.
updateSize: function()
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)
getCurrentSize: function()
{OpenLayers.Size} A new OpenLayers.Size object with the dimensions of the map div
calculateBounds: function(center,
resolution)
getCenter: function ()
{OpenLayers.LonLat}
getZoom: function ()
{Integer}
pan: function(dx,
dy,
options)
Allows user to pan by a value of screen pixels
panTo: function(lonlat)
Allows user to pan to a new lonlat If the new lonlat is in the current extent the map will slide smoothly
setCenter: function(lonlat,
zoom,
dragging,
forceZoomChange)
Set the map center (and optionally, the zoom level).
moveTo: function(lonlat,
zoom,
options)
centerLayerContainer: function (lonlat)
This function takes care to recenter the layerContainerDiv.
isValidZoomLevel: function(zoomLevel)
isValidLonLat: function(lonlat)
getProjection: function()
This method returns a string representing the projection.
getProjectionObject: function()
Returns the projection obect from the baselayer.
getMaxResolution: function()
{String} The Map’s Maximum Resolution
getMaxExtent: function (options)
getNumZoomLevels: function()
{Integer} The total number of zoom levels that can be displayed by the current baseLayer.
getExtent: function ()
{OpenLayers.Bounds} A Bounds object which represents the lon/lat bounds of the current viewPort.
getResolution: function ()
{Float} The current resolution of the map.
getUnits: function ()
{Float} The current units of the map.
getScale: function ()
{Float} The current scale denominator of the map.
getZoomForExtent: function (bounds,
closest)
getResolutionForZoom: function(zoom)
getZoomForResolution: function(resolution,
closest)
zoomTo: function(zoom)
Zoom to a specific zoom level
zoomIn: function()
zoomOut: function()
zoomToExtent: function(bounds,
closest)
Zoom to the passed in bounds, recenter
zoomToMaxExtent: function(options)
Zoom to the full extent and recenter.
zoomToScale: function(scale,
closest)
Zoom to a specified scale
getLonLatFromViewPortPx: function (viewPortPx)
getViewPortPxFromLonLat: function (lonlat)
getLonLatFromPixel: function (px)
getPixelFromLonLat: function (lonlat)
Returns a pixel location given a map location.
getViewPortPxFromLayerPx:function(layerPx)
getLayerPxFromViewPortPx:function(viewPortPx)
getLonLatFromLayerPx: function (px)
getLayerPxFromLonLat: function (lonlat)
Constructor for a new OpenLayers.Map instance.
This class represents a screen coordinate, in x and y coordinates
{Float} Default max is 360 deg / 256 px, which corresponds to zoom level 0 on gmaps.
{OpenLayers.Bounds} The maximum extent for the map.
The navigation control handles map browsing with mouse events (dragging, double-clicking, and scrolling the wheel).
The PanZoom is a visible control, composed of a OpenLayers.Control.PanPanel and a OpenLayers.Control.ZoomPanel.
The ArgParser control adds location bar querystring parsing functionality to an OpenLayers Map.
The attribution control adds attribution from layers to the map display.
{DOMElement|String} The element that contains the map (or an id for that element).
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