OpenLayers.Control.OverviewMap

The OverMap control creates a small overview map, useful to display the extent of a zoomed map and your main map and provide additional navigation options to the User. By default the overview map is drawn in the lower right corner of the main map. Create a new overview map with the OpenLayers.Control.OverviewMap constructor.

Inherits from

OpenLayers.Control

Summary

OpenLayers.Control.OverviewMap	The OverMap control creates a small overview map, useful to display the extent of a zoomed map and your main map and provide additional navigation options to the User.
Properties
element	{DOMElement} The DOM element that contains the overview map
ovmap	{OpenLayers.Map} A reference to the overview map itself.
size	{OpenLayers.Size} The overvew map size in pixels.
layers	{Array(OpenLayers.Layer)} Ordered list of layers in the overview map.
minRectSize	{Integer} The minimum width or height (in pixels) of the extent rectangle on the overview map.
minRectDisplayClass	{String} Replacement style class name for the extent rectangle when minRectSize is reached.
minRatio	{Float} The ratio of the overview map resolution to the main map resolution at which to zoom farther out on the overview map.
maxRatio	{Float} The ratio of the overview map resolution to the main map resolution at which to zoom farther in on the overview map.
mapOptions	{Object} An object containing any non-default properties to be sent to the overview map’s map constructor.
autoPan	{Boolean} Always pan the overview map, so the extent marker remains in the center.
handlers	{Object}
resolutionFactor	{Object}
maximized	{Boolean} Start as maximized (visible).
Constructor
OpenLayers.Control.OverviewMap	Create a new overview map
Functions
destroy	Deconstruct the control
draw	Render the control in the browser.
baseLayerDraw
rectDrag	Handle extent rectangle drag
mapDivClick	Handle browser events
onButtonClick
maximizeControl	Unhide the control.
minimizeControl	Hide all the contents of the control, shrink the size, add the maximize icon
showToggle	Hide/Show the toggle depending on whether the control is minimized
update	Update the overview map after layers move.
isSuitableOverview	Determines if the overview map is suitable given the extent and resolution of the main map.
createMap	Construct the map that this control contains
updateRectToMap	Updates the extent rectangle position and size to match the map extent
updateMapToRect	Updates the map extent to match the extent rectangle position and size
setRectPxBounds	Set extent rectangle pixel bounds.
getRectBoundsFromMapBounds	Get the rect bounds from the map bounds.
getMapBoundsFromRectBounds	Get the map bounds from the rect bounds.
getLonLatFromOverviewPx	Get a map location from a pixel location
getOverviewPxFromLonLat	Get a pixel location from a map location

Properties

element

{DOMElement} The DOM element that contains the overview map

ovmap

{OpenLayers.Map} A reference to the overview map itself.

size

{OpenLayers.Size} The overvew map size in pixels. Note that this is the size of the map itself - the element that contains the map (default class name olControlOverviewMapElement) may have padding or other style attributes added via CSS.

layers

{Array(OpenLayers.Layer)} Ordered list of layers in the overview map. If none are sent at construction, the base layer for the main map is used.

minRectSize

{Integer} The minimum width or height (in pixels) of the extent rectangle on the overview map. When the extent rectangle reaches this size, it will be replaced depending on the value of the minRectDisplayClass property. Default is 15 pixels.

minRectDisplayClass

{String} Replacement style class name for the extent rectangle when minRectSize is reached. This string will be suffixed on to the displayClass. Default is “RectReplacement”.

Example CSS declaration

.olControlOverviewMapRectReplacement {
    overflow: hidden;
    cursor: move;
    background-image: url("img/overview_replacement.gif");
    background-repeat: no-repeat;
    background-position: center;
}

minRatio

{Float} The ratio of the overview map resolution to the main map resolution at which to zoom farther out on the overview map.

maxRatio

{Float} The ratio of the overview map resolution to the main map resolution at which to zoom farther in on the overview map.

mapOptions

{Object} An object containing any non-default properties to be sent to the overview map’s map constructor. These should include any non-default options that the main map was constructed with.

autoPan

{Boolean} Always pan the overview map, so the extent marker remains in the center. Default is false. If true, when you drag the extent marker, the overview map will update itself so the marker returns to the center.

handlers

{Object}

resolutionFactor

{Object}

maximized

{Boolean} Start as maximized (visible). Defaults to false.

Constructor

OpenLayers.Control.OverviewMap

Create a new overview map

Parameters

options

{Object} Properties of this object will be set on the overview map object. Note, to set options on the map object contained in this control, set mapOptions as one of the options properties.

Functions

destroy

destroy: function()

Deconstruct the control

draw

draw: function()

Render the control in the browser.

baseLayerDraw

baseLayerDraw: function()

Draw the base layer

called if unable to complete in the initial draw

rectDrag

rectDrag: function( px )

Handle extent rectangle drag

Parameters

px	{OpenLayers.Pixel} The pixel location of the drag.

mapDivClick

mapDivClick: function( evt )

Handle browser events

Parameters

evt	{OpenLayers.Event} evt

onButtonClick

onButtonClick: function( evt )

Parameters

evt

{Event}

maximizeControl

maximizeControl: function( e )

Unhide the control. Called when the control is in the map viewport.

Parameters

e	{OpenLayers.Event}

minimizeControl

minimizeControl: function( e )

Hide all the contents of the control, shrink the size, add the maximize icon

Parameters

e	{OpenLayers.Event}

showToggle

showToggle: function( minimize )

Hide/Show the toggle depending on whether the control is minimized

Parameters

minimize

{Boolean}

update

update: function()

Update the overview map after layers move.

isSuitableOverview

isSuitableOverview: function()

Determines if the overview map is suitable given the extent and resolution of the main map.

createMap

createMap: function()

Construct the map that this control contains

updateRectToMap

updateRectToMap: function()

Updates the extent rectangle position and size to match the map extent

updateMapToRect

updateMapToRect: function()

Updates the map extent to match the extent rectangle position and size

setRectPxBounds

setRectPxBounds: function( pxBounds )

Set extent rectangle pixel bounds.

Parameters

pxBounds

{OpenLayers.Bounds}

getRectBoundsFromMapBounds

getRectBoundsFromMapBounds: function( lonLatBounds )

Get the rect bounds from the map bounds.

Parameters

lonLatBounds

{OpenLayers.Bounds}

Returns

{OpenLayers.Bounds}A bounds which is the passed-in map lon/lat extent translated into pixel bounds for the overview map

getMapBoundsFromRectBounds

getMapBoundsFromRectBounds: function( pxBounds )

Get the map bounds from the rect bounds.

Parameters

pxBounds

{OpenLayers.Bounds}

Returns

{OpenLayers.Bounds} Bounds which is the passed-in overview rect bounds translated into lon/lat bounds for the overview map

getLonLatFromOverviewPx

getLonLatFromOverviewPx: function( overviewMapPx )

Get a map location from a pixel location

Parameters

overviewMapPx

{<OpenLayers.Pixel>|Object} OpenLayers.Pixel or an object with a ‘x’ and ‘y’ properties.

Returns

{Object} Location which is the passed-in overview map OpenLayers.Pixel, translated into lon/lat by the overview map. An object with a ‘lon’ and ‘lat’ properties.

getOverviewPxFromLonLat

getOverviewPxFromLonLat: function( lonlat )

Get a pixel location from a map location

Parameters

lonlat

{<OpenLayers.LonLat>|Object} OpenLayers.LonLat or an object with a ‘lon’ and ‘lat’ properties.

Returns

{Object} Location which is the passed-in OpenLayers.LonLat, translated into overview map pixels