MarkerClustererPlus for Google Maps V3

The library creates and manages per-zoom-level clusters for large amounts of markers.

This is an enhanced V3 implementation of the V2 MarkerClusterer by Xiaoxi Wu. It is based on the V3 MarkerClusterer port by Luke Mahe. MarkerClustererPlus was created by Gary Little.

v2.0 release: MarkerClustererPlus v2.0 is backward compatible with MarkerClusterer v1.0. It adds support for the ignoreHidden, title, printable, batchSizeIE, and calculator properties as well as support for four more events. It also allows greater control over the styling of the text that appears on the cluster marker. The documentation has been significantly improved and the overall code has been simplified and polished. Very large numbers of markers can now be managed without causing Javascript timeout errors on Internet Explorer. Note that the name of the clusterclick event has been deprecated. The new name is click, so please change your application code now.

For a description and examples of how to use this library, check out the how-to.

class Cluster

Constructor

Constructor	Description
`Cluster(mc:MarkerClusterer)`	Creates a single cluster that manages a group of proximate markers. Used internally, do not call this constructor directly.

Methods

Methods	Return Value	Description
`getCenter()`	`google.maps.LatLng`	Returns the center of the cluster. You can call this from a `click`, `mouseover`, or `mouseout` event handler for the `MarkerClusterer` object.
`getMarkers()`	`Array`	Returns the array of markers managed by the cluster. You can call this from a `click`, `mouseover`, or `mouseout` event handler for the `MarkerClusterer` object.
`getSize()`	`number`	Returns the number of markers managed by the cluster. You can call this from a `click`, `mouseover`, or `mouseout` event handler for the `MarkerClusterer` object.

class ClusterIconInfo

This class is an object containing general information about a cluster icon. This is the object that a calculator function returns.

Properties

Properties	Type	Description
`index`	`number`	The index plus 1 of the element in the `styles` array to be used to style the cluster icon.
`text`	`string`	The text of the label to be shown on the cluster icon.

class ClusterIconStyle

This class represents the object for values in the styles array passed to the MarkerClusterer constructor. The element in this array that is used to style the cluster icon is determined by calling the calculator function.

Properties

Properties	Type	Description
`anchor`	`Array`	The anchor position (in pixels) of the label text to be shown on the cluster icon, relative to the top left corner of the icon. The format is `[yoffset, xoffset]`. The `yoffset` must be positive and less than `height` and the `xoffset` must be positive and less than `width`. The default is to anchor the label text so that it is centered on the icon.
`backgroundPosition`	`string`	The position of the cluster icon image within the image defined by `url`. The format is `"xpos ypos"` (the same format as for the CSS `background-position` property). You must set this property appropriately when the image defined by `url` represents a sprite containing multiple images. The default value is `"0 0"`.
`fontFamily`	`number`	The value of the CSS `font-family` property for the label text shown on the cluster icon. The default value is `"Arial,sans-serif"`.
`fontStyle`	`number`	The value of the CSS `font-style` property for the label text shown on the cluster icon. The default value is `"normal"`.
`fontWeight`	`number`	The value of the CSS `font-weight` property for the label text shown on the cluster icon. The default value is `"bold"`.
`height`	`number`	The height (in pixels) of the cluster icon. Required.
`textColor`	`string`	The color of the label text shown on the cluster icon. The default value is `"black"`.
`textDecoration`	`number`	The value of the CSS `text-decoration` property for the label text shown on the cluster icon. The default value is `"none"`.
`textSize`	`number`	The size (in pixels) of the label text shown on the cluster icon. The default value is `11`.
`url`	`string`	The URL of the cluster icon image file. Required.
`width`	`number`	The width (in pixels) of the cluster icon. Required.

class MarkerClusterer

This class extends google.maps.OverlayView.

Constructor

Constructor	Description
`MarkerClusterer(map:google.maps.Map, opt_markers?:Array.<google.maps.Marker>, opt_options?:MarkerClustererOptions)`	Creates a MarkerClusterer object with the options specified in `MarkerClustererOptions`.

Methods

Methods	Return Value	Description
`addMarker(marker:google.maps.Marker, opt_nodraw?:boolean)`	`None`	Adds a marker to the clusterer. The clusters are redrawn unless `opt_nodraw` is set to `true`.
`addMarkers(markers:Array.<google.maps.Marker>, opt_nodraw?:boolean)`	`None`	Adds an array of markers to the clusterer. The clusters are redrawn unless `opt_nodraw` is set to `true`.
`clearMarkers()`	`None`	Removes all clusters and markers from the map and also removes all markers managed by the clusterer.
`fitMapToMarkers()`	`None`	Fits the map to the bounds of the markers managed by the clusterer.
`getAverageCenter()`	`boolean`	Returns the value of the `averageCenter` property.
`getBatchSizeIE()`	`number`	Returns the value of the `batchSizeIE` property.
`getCalculator()`	`function`	Returns the value of the `calculator` property.
`getGridSize()`	`number`	Returns the value of the `gridSize` property.
`getIgnoreHidden()`	`boolean`	Returns the value of the `ignoreHidden` property.
`getImageExtension()`	`string`	Returns the value of the `imageExtension` property.
`getImagePath()`	`string`	Returns the value of the `imagePath` property.
`getImageSizes()`	`Array`	Returns the value of the `imageSizes` property.
`getMarkers()`	`Array`	Returns the array of markers managed by the clusterer.
`getMaxZoom()`	`number`	Returns the value of the `maxZoom` property.
`getMinimumClusterSize()`	`number`	Returns the value of the `minimumClusterSize` property.
`getPrintable()`	`boolean`	Returns the value of the `printable` property.
`getStyles()`	`Array`	Returns the value of the `styles` property.
`getTitle()`	`string`	Returns the value of the `title` property.
`getTotalClusters()`	`number`	Returns the number of clusters formed by the clusterer.
`getTotalMarkers()`	`number`	Returns the number of markers managed by the clusterer.
`getZoomOnClick()`	`boolean`	Returns the value of the `zoomOnClick` property.
`removeMarker(marker:google.maps.Marker, opt_nodraw?:boolean)`	`boolean`	Removes a marker from the cluster. The clusters are redrawn unless `opt_nodraw` is set to `true`. Returns `true` if the marker was removed from the clusterer.
`removeMarkers(markers:Array.<google.maps.Marker>, opt_nodraw?:boolean)`	`boolean`	Removes an array of markers from the cluster. The clusters are redrawn unless `opt_nodraw` is set to `true`. Returns `true` if markers were removed from the clusterer.
`repaint()`	`None`	Recalculates and redraws all the marker clusters from scratch. Call this after changing any properties.
`setAverageCenter(averageCenter:boolean)`	`None`	Sets the value of the `averageCenter` property.
`setBatchSizeIE(batchSizeIE:number)`	`None`	Sets the value of the `batchSizeIE` property.
`setCalculator(calculator:function(Array.<google.maps.Marker>\|number))`	`None`	Sets the value of the `calculator` property.
`setGridSize(gridSize:number)`	`None`	Sets the value of the `gridSize` property.
`setIgnoreHidden(ignoreHidden:boolean)`	`None`	Sets the value of the `ignoreHidden` property.
`setImageExtension(imageExtension:string)`	`None`	Sets the value of the `imageExtension` property.
`setImagePath(imagePath:string)`	`None`	Sets the value of the `imagePath` property.
`setImageSizes(imageSizes:Array)`	`None`	Sets the value of the `imageSizes` property.
`setMaxZoom(maxZoom:number)`	`None`	Sets the value of the `maxZoom` property.
`setMinimumClusterSize(minimumClusterSize:number)`	`None`	Sets the value of the `minimumClusterSize` property.
`setPrintable(printable:boolean)`	`None`	Sets the value of the `printable` property.
`setStyles(styles:Array.<ClusterIconStyle>)`	`None`	Sets the value of the `styles` property.
`setTitle(title:string)`	`None`	Sets the value of the `title` property.
`setZoomOnClick(zoomOnClick:boolean)`	`None`	Sets the value of the `zoomOnClick` property.

Events

Events	Arguments	Description
`click`	`c:Cluster`	This event is fired when a cluster marker is clicked.
`clusteringbegin`	`mc:MarkerClusterer`	This event is fired when the `MarkerClusterer` begins clustering markers.
`clusteringend`	`mc:MarkerClusterer`	This event is fired when the `MarkerClusterer` stops clustering markers.
`mouseout`	`c:Cluster`	This event is fired when the mouse moves out of a cluster marker.
`mouseover`	`c:Cluster`	This event is fired when the mouse moves over a cluster marker.

class MarkerClustererOptions

This class represents the optional parameter passed to the MarkerClusterer constructor. There is no constructor for this class. Instead, this class is instantiated as a javascript object literal.

Properties

Properties	Type	Description
`averageCenter`	`boolean`	Whether the position of a cluster marker should be the average position of all markers in the cluster. If set to `false`, the cluster marker is positioned at the location of the first marker added to the cluster. The default value is `false`.
`batchSizeIE`	`number`	When Internet Explorer is being used, markers are processed in several batches with a small delay inserted between each batch in an attempt to avoid Javascript timeout errors. Set this property to the number of markers to be processed in a single batch; select as high a number as you can without causing a timeout error in the browser. This number might need to be as low as 100 if 15,000 markers are being managed, for example. The default value is `MarkerClusterer.BATCH_SIZE_IE`.
`calculator`	`function`	The function used to determine the text to be displayed on a cluster marker and the index indicating which style to use for the cluster marker. The input parameters for the function are (1) the array of markers represented by a cluster marker and (2) the number of cluster icon styles. It returns a `ClusterIconInfo` object. The default `calculator` returns a `text` property which is the number of markers in the cluster and an `index` property which is one higher than the lowest integer such that `10^i` exceeds the number of markers in the cluster, or the size of the styles array, whichever is less. The `styles` array element used has an index of `index` minus 1. For example, the default `calculator` returns a `text` value of `"125"` and an `index` of `3` for a cluster icon representing 125 markers so the element used in the `styles` array is `2`. The default value is `MarkerClusterer.CALCULATOR`.
`gridSize`	`number`	The grid size of a cluster in pixels. The grid is a square. The default value is `60`.
`ignoreHidden`	`boolean`	Whether to ignore hidden markers in clusters. You may want to set this to `true` to ensure that hidden markers are not included in the marker count that appears on a cluster marker (this count is the value of the `text` property of the result returned by the default `calculator`). If set to `true` and you change the visibility of a marker being clustered, be sure to also call `MarkerClusterer.repaint()`. The default value is `false`.
`imageExtension`	`string`	The extension name for the cluster icon image files (e.g., `"png"` or `"jpg"`). The default value is `MarkerClusterer.IMAGE_EXTENSION`.
`imagePath`	`string`	The full URL of the root name of the group of image files to use for cluster icons. The complete file name is of the form `imagePath`n.`imageExtension` where n is the image file number (1, 2, etc.). The default value is `MarkerClusterer.IMAGE_PATH`.
`imageSizes`	`Array`	An array of numbers containing the widths of the group of `imagePath`n.`imageExtension` image files. (The images are assumed to be square.) The default value is `MarkerClusterer.IMAGE_SIZES`.
`maxZoom`	`number`	The maximum zoom level at which clustering is enabled or `null` if clustering is to be enabled at all zoom levels. The default value is `null`.
`minimumClusterSize`	`number`	The minimum number of markers needed in a cluster before the markers are hidden and a cluster marker appears. The default value is `2`.
`printable`	`boolean`	Whether to make the cluster icons printable. Do not set to `true` if the `url` fields in the `styles` array refer to image sprite files. The default value is `false`.
`styles`	`Array`	An array of `ClusterIconStyle` elements defining the styles of the cluster markers to be used. The element to be used to style a given cluster marker is determined by the function defined by the `calculator` property. The default is an array of `ClusterIconStyle` elements whose properties are derived from the values for `imagePath`, `imageExtension`, and `imageSizes`.
`title`	`string`	The tooltip to display when the mouse moves over a cluster marker. The default value is `""`.
`zoomOnClick`	`boolean`	Whether to zoom the map when a cluster marker is clicked. You may want to set this to `false` if you have installed a handler for the `click` event and it deals with zooming on its own. The default value is `true`.