/**
* @name MarkerClusterer
* @version 1.0
* @author Xiaoxi Wu
* @copyright (c) 2009 Xiaoxi Wu
* @fileoverview
* This javascript library creates and manages per-zoom-level
* clusters for large amounts of markers (hundreds or thousands).
* This library was inspired by the
* Maptimize hosted clustering solution.
*
* How it works:
* The MarkerClusterer will group markers into clusters according to
* their distance from a cluster's center. When a marker is added,
* the marker cluster will find a position in all the clusters, and
* if it fails to find one, it will create a new cluster with the marker.
* The number of markers in a cluster will be displayed
* on the cluster marker. When the map viewport changes,
* MarkerClusterer will destroy the clusters in the viewport
* and regroup them into new clusters.
*
*/
/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @name MarkerClustererOptions
* @class This class represents optional arguments to the {@link MarkerClusterer}
* constructor.
* @property {Number} [maxZoom] The max zoom level monitored by a
* marker cluster. If not given, the marker cluster assumes the maximum map
* zoom level. When maxZoom is reached or exceeded all markers will be shown
* without cluster.
* @property {Number} [gridSize=60] The grid size of a cluster in pixel. Each
* cluster will be a square. If you want the algorithm to run faster, you can set
* this value larger.
* @property {Array of MarkerStyleOptions} [styles]
* Custom styles for the cluster markers.
* The array should be ordered according to increasing cluster size,
* with the style for the smallest clusters first, and the style for the
* largest clusters last.
*/
/**
* @name MarkerStyleOptions
* @class An array of these is passed into the {@link MarkerClustererOptions}
* styles option.
* @property {String} [url] Image url.
* @property {Number} [height] Image height.
* @property {Number} [height] Image width.
* @property {Array of Number} [opt_anchor] Anchor for label text, like [24, 12].
* If not set, the text will align center and middle.
* @property {String} [opt_textColor="black"] Text color.
*/
/**
* Creates a new MarkerClusterer to cluster markers on the map.
*
* @constructor
* @param {GMap2} map The map that the markers should be added to.
* @param {Array of GMarker} opt_markers Initial set of markers to be clustered.
* @param {MarkerClustererOptions} opt_opts A container for optional arguments.
*/
function MarkerClusterer(map, opt_markers, opt_opts) {
// private members
var clusters_ = [];
var map_ = map;
var maxZoom_ = null;
var me_ = this;
var gridSize_ = 60;
var sizes = [53, 56, 66, 78, 90];
var styles_ = [];
var leftMarkers_ = [];
var mcfn_ = null;
var i = 0;
for (i = 1; i <= 5; ++i) {
styles_.push({
'url': "http://gmaps-utility-library.googlecode.com/svn/trunk/markerclusterer/images/m" + i + ".png",
'height': sizes[i - 1],
'width': sizes[i - 1]
});
}
if (typeof opt_opts === "object" && opt_opts !== null) {
if (typeof opt_opts.gridSize === "number" && opt_opts.gridSize > 0) {
gridSize_ = opt_opts.gridSize;
}
if (typeof opt_opts.maxZoom === "number") {
maxZoom_ = opt_opts.maxZoom;
}
if (typeof opt_opts.styles === "object" && opt_opts.styles !== null && opt_opts.styles.length !== 0) {
styles_ = opt_opts.styles;
}
}
/**
* When we add a marker, the marker may not in the viewport of map, then we don't deal with it, instead
* we add the marker into a array called leftMarkers_. When we reset MarkerClusterer we should add the
* leftMarkers_ into MarkerClusterer.
*/
function addLeftMarkers_() {
if (leftMarkers_.length === 0) {
return;
}
var leftMarkers = [];
for (i = 0; i < leftMarkers_.length; ++i) {
me_.addMarker(leftMarkers_[i], true, null, null, true);
}
leftMarkers_ = leftMarkers;
}
/**
* Get cluster marker images of this marker cluster. Mostly used by {@link Cluster}
* @private
* @return {Array of String}
*/
this.getStyles_ = function () {
return styles_;
};
/**
* Remove all markers from MarkerClusterer.
*/
this.clearMarkers = function () {
for (var i = 0; i < clusters_.length; ++i) {
if (typeof clusters_[i] !== "undefined" && clusters_[i] !== null) {
clusters_[i].clearMarkers();
}
}
clusters_ = [];
leftMarkers_ = [];
GEvent.removeListener(mcfn_);
};
/**
* Check a marker, whether it is in current map viewport.
* @private
* @return {Boolean} if it is in current map viewport
*/
function isMarkerInViewport_(marker) {
return map_.getBounds().containsLatLng(marker.getLatLng());
}
/**
* When reset MarkerClusterer, there will be some markers get out of its cluster.
* These markers should be add to new clusters.
* @param {Array of GMarker} markers Markers to add.
*/
function reAddMarkers_(markers) {
var len = markers.length;
var clusters = [];
for (var i = len - 1; i >= 0; --i) {
me_.addMarker(markers[i].marker, true, markers[i].isAdded, clusters, true);
}
addLeftMarkers_();
}
/**
* Add a marker.
* @private
* @param {GMarker} marker Marker you want to add
* @param {Boolean} opt_isNodraw Whether redraw the cluster contained the marker
* @param {Boolean} opt_isAdded Whether the marker is added to map. Never use it.
* @param {Array of Cluster} opt_clusters Provide a list of clusters, the marker
* cluster will only check these cluster where the marker should join.
*/
this.addMarker = function (marker, opt_isNodraw, opt_isAdded, opt_clusters, opt_isNoCheck) {
if (opt_isNoCheck !== true) {
if (!isMarkerInViewport_(marker)) {
leftMarkers_.push(marker);
return;
}
}
var isAdded = opt_isAdded;
var clusters = opt_clusters;
var pos = map_.fromLatLngToDivPixel(marker.getLatLng());
if (typeof isAdded !== "boolean") {
isAdded = false;
}
if (typeof clusters !== "object" || clusters === null) {
clusters = clusters_;
}
var length = clusters.length;
var cluster = null;
for (var i = length - 1; i >= 0; i--) {
cluster = clusters[i];
var center = cluster.getCenter();
if (center === null) {
continue;
}
center = map_.fromLatLngToDivPixel(center);
// Found a cluster which contains the marker.
if (pos.x >= center.x - gridSize_ && pos.x <= center.x + gridSize_ &&
pos.y >= center.y - gridSize_ && pos.y <= center.y + gridSize_) {
cluster.addMarker({
'isAdded': isAdded,
'marker': marker
});
if (!opt_isNodraw) {
cluster.redraw_();
}
return;
}
}
// No cluster contain the marker, create a new cluster.
cluster = new Cluster(this, map);
cluster.addMarker({
'isAdded': isAdded,
'marker': marker
});
if (!opt_isNodraw) {
cluster.redraw_();
}
// Add this cluster both in clusters provided and clusters_
clusters.push(cluster);
if (clusters !== clusters_) {
clusters_.push(cluster);
}
};
/**
* Remove a marker.
*
* @param {GMarker} marker The marker you want to remove.
*/
this.removeMarker = function (marker) {
for (var i = 0; i < clusters_.length; ++i) {
if (clusters_[i].remove(marker)) {
clusters_[i].redraw_();
return;
}
}
};
/**
* Redraw all clusters in viewport.
*/
this.redraw_ = function () {
var clusters = this.getClustersInViewport_();
for (var i = 0; i < clusters.length; ++i) {
clusters[i].redraw_(true);
}
};
/**
* Get all clusters in viewport.
* @return {Array of Cluster}
*/
this.getClustersInViewport_ = function () {
var clusters = [];
var curBounds = map_.getBounds();
for (var i = 0; i < clusters_.length; i ++) {
if (clusters_[i].isInBounds(curBounds)) {
clusters.push(clusters_[i]);
}
}
return clusters;
};
/**
* Get max zoom level.
* @private
* @return {Number}
*/
this.getMaxZoom_ = function () {
return maxZoom_;
};
/**
* Get map object.
* @private
* @return {GMap2}
*/
this.getMap_ = function () {
return map_;
};
/**
* Get grid size
* @private
* @return {Number}
*/
this.getGridSize_ = function () {
return gridSize_;
};
/**
* Get total number of markers.
* @return {Number}
*/
this.getTotalMarkers = function () {
var result = 0;
for (var i = 0; i < clusters_.length; ++i) {
result += clusters_[i].getTotalMarkers();
}
return result;
};
/**
* Get total number of clusters.
* @return {int}
*/
this.getTotalClusters = function () {
return clusters_.length;
};
/**
* Collect all markers of clusters in viewport and regroup them.
*/
this.resetViewport = function () {
var clusters = this.getClustersInViewport_();
var tmpMarkers = [];
var removed = 0;
for (var i = 0; i < clusters.length; ++i) {
var cluster = clusters[i];
var oldZoom = cluster.getCurrentZoom();
if (oldZoom === null) {
continue;
}
var curZoom = map_.getZoom();
if (curZoom !== oldZoom) {
// If the cluster zoom level changed then destroy the cluster
// and collect its markers.
var mks = cluster.getMarkers();
for (var j = 0; j < mks.length; ++j) {
var newMarker = {
'isAdded': false,
'marker': mks[j].marker
};
tmpMarkers.push(newMarker);
}
cluster.clearMarkers();
removed++;
for (j = 0; j < clusters_.length; ++j) {
if (cluster === clusters_[j]) {
clusters_.splice(j, 1);
}
}
}
}
// Add the markers collected into marker cluster to reset
reAddMarkers_(tmpMarkers);
this.redraw_();
};
/**
* Add a set of markers.
*
* @param {Array of GMarker} markers The markers you want to add.
*/
this.addMarkers = function (markers) {
for (var i = 0; i < markers.length; ++i) {
this.addMarker(markers[i], true);
}
this.redraw_();
};
// initialize
if (typeof opt_markers === "object" && opt_markers !== null) {
this.addMarkers(opt_markers);
}
// when map move end, regroup.
mcfn_ = GEvent.addListener(map_, "moveend", function () {
me_.resetViewport();
});
}
/**
* Create a cluster to collect markers.
* A cluster includes some markers which are in a block of area.
* If there are more than one markers in cluster, the cluster
* will create a {@link ClusterMarker_} and show the total number
* of markers in cluster.
*
* @constructor
* @private
* @param {MarkerClusterer} markerClusterer The marker cluster object
*/
function Cluster(markerClusterer) {
var center_ = null;
var markers_ = [];
var markerClusterer_ = markerClusterer;
var map_ = markerClusterer.getMap_();
var clusterMarker_ = null;
var zoom_ = map_.getZoom();
/**
* Get markers of this cluster.
*
* @return {Array of GMarker}
*/
this.getMarkers = function () {
return markers_;
};
/**
* If this cluster intersects certain bounds.
*
* @param {GLatLngBounds} bounds A bounds to test
* @return {Boolean} Is this cluster intersects the bounds
*/
this.isInBounds = function (bounds) {
if (center_ === null) {
return false;
}
if (!bounds) {
bounds = map_.getBounds();
}
var sw = map_.fromLatLngToDivPixel(bounds.getSouthWest());
var ne = map_.fromLatLngToDivPixel(bounds.getNorthEast());
var centerxy = map_.fromLatLngToDivPixel(center_);
var inViewport = true;
var gridSize = markerClusterer.getGridSize_();
if (zoom_ !== map_.getZoom()) {
var dl = map_.getZoom() - zoom_;
gridSize = Math.pow(2, dl) * gridSize;
}
if (ne.x !== sw.x && (centerxy.x + gridSize < sw.x || centerxy.x - gridSize > ne.x)) {
inViewport = false;
}
if (inViewport && (centerxy.y + gridSize < ne.y || centerxy.y - gridSize > sw.y)) {
inViewport = false;
}
return inViewport;
};
/**
* Get cluster center.
*
* @return {GLatLng}
*/
this.getCenter = function () {
return center_;
};
/**
* Add a marker.
*
* @param {Object} marker An object of marker you want to add:
* {Boolean} isAdded If the marker is added on map.
* {GMarker} marker The marker you want to add.
*/
this.addMarker = function (marker) {
if (center_ === null) {
/*var pos = marker['marker'].getLatLng();
pos = map.fromLatLngToContainerPixel(pos);
pos.x = parseInt(pos.x - pos.x % (GRIDWIDTH * 2) + GRIDWIDTH);
pos.y = parseInt(pos.y - pos.y % (GRIDWIDTH * 2) + GRIDWIDTH);
center = map.fromContainerPixelToLatLng(pos);*/
center_ = marker.marker.getLatLng();
}
markers_.push(marker);
};
/**
* Remove a marker from cluster.
*
* @param {GMarker} marker The marker you want to remove.
* @return {Boolean} Whether find the marker to be removed.
*/
this.removeMarker = function (marker) {
for (var i = 0; i < markers_.length; ++i) {
if (marker === markers_[i].marker) {
if (markers_[i].isAdded) {
map_.removeOverlay(markers_[i].marker);
}
markers_.splice(i, 1);
return true;
}
}
return false;
};
/**
* Get current zoom level of this cluster.
* Note: the cluster zoom level and map zoom level not always the same.
*
* @return {Number}
*/
this.getCurrentZoom = function () {
return zoom_;
};
/**
* Redraw a cluster.
* @private
* @param {Boolean} isForce If redraw by force, no matter if the cluster is
* in viewport.
*/
this.redraw_ = function (isForce) {
if (!isForce && !this.isInBounds()) {
return;
}
// Set cluster zoom level.
zoom_ = map_.getZoom();
var i = 0;
var mz = markerClusterer.getMaxZoom_();
if (mz === null) {
mz = map_.getCurrentMapType().getMaximumResolution();
}
if (zoom_ >= mz || this.getTotalMarkers() === 1) {
// If current zoom level is beyond the max zoom level or the cluster
// have only one marker, the marker(s) in cluster will be showed on map.
for (i = 0; i < markers_.length; ++i) {
if (markers_[i].isAdded) {
if (markers_[i].marker.isHidden()) {
markers_[i].marker.show();
}
} else {
map_.addOverlay(markers_[i].marker);
markers_[i].isAdded = true;
}
}
if (clusterMarker_ !== null) {
clusterMarker_.hide();
}
} else {
// Else add a cluster marker on map to show the number of markers in
// this cluster.
for (i = 0; i < markers_.length; ++i) {
if (markers_[i].isAdded && (!markers_[i].marker.isHidden())) {
markers_[i].marker.hide();
}
}
if (clusterMarker_ === null) {
clusterMarker_ = new ClusterMarker_(center_, this.getTotalMarkers(), markerClusterer_.getStyles_(), markerClusterer_.getGridSize_());
map_.addOverlay(clusterMarker_);
} else {
if (clusterMarker_.isHidden()) {
clusterMarker_.show();
}
clusterMarker_.redraw(true);
}
}
};
/**
* Remove all the markers from this cluster.
*/
this.clearMarkers = function () {
if (clusterMarker_ !== null) {
map_.removeOverlay(clusterMarker_);
}
for (var i = 0; i < markers_.length; ++i) {
if (markers_[i].isAdded) {
map_.removeOverlay(markers_[i].marker);
}
}
markers_ = [];
};
/**
* Get number of markers.
* @return {Number}
*/
this.getTotalMarkers = function () {
return markers_.length;
};
}
/**
* ClusterMarker_ creates a marker that shows the number of markers that
* a cluster contains.
*
* @constructor
* @private
* @param {GLatLng} latlng Marker's lat and lng.
* @param {Number} count Number to show.
* @param {Array of Object} styles The image list to be showed:
* {String} url Image url.
* {Number} height Image height.
* {Number} width Image width.
* {Array of Number} anchor Text anchor of image left and top.
* {String} textColor text color.
* @param {Number} padding Padding of marker center.
*/
function ClusterMarker_(latlng, count, styles, padding) {
var index = 0;
var dv = count;
while (dv !== 0) {
dv = parseInt(dv / 10, 10);
index ++;
}
if (styles.length < index) {
index = styles.length;
}
this.url_ = styles[index - 1].url;
this.height_ = styles[index - 1].height;
this.width_ = styles[index - 1].width;
this.textColor_ = styles[index - 1].opt_textColor;
this.anchor_ = styles[index - 1].opt_anchor;
this.latlng_ = latlng;
this.index_ = index;
this.styles_ = styles;
this.text_ = count;
this.padding_ = padding;
}
ClusterMarker_.prototype = new GOverlay();
/**
* Initialize cluster marker.
* @private
*/
ClusterMarker_.prototype.initialize = function (map) {
this.map_ = map;
var div = document.createElement("div");
var latlng = this.latlng_;
var pos = map.fromLatLngToDivPixel(latlng);
pos.x -= parseInt(this.width_ / 2, 10);
pos.y -= parseInt(this.height_ / 2, 10);
var mstyle = "";
if (document.all) {
mstyle = 'filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src="' + this.url_ + '");';
} else {
mstyle = "background:url(" + this.url_ + ");";
}
if (typeof this.anchor_ === "object") {
if (typeof this.anchor_[0] === "number" && this.anchor_[0] > 0 && this.anchor_[0] < this.height_) {
mstyle += 'height:' + (this.height_ - this.anchor_[0]) + 'px;padding-top:' + this.anchor_[0] + 'px;';
} else {
mstyle += 'height:' + this.height_ + 'px;line-height:' + this.height_ + 'px;';
}
if (typeof this.anchor_[1] === "number" && this.anchor_[1] > 0 && this.anchor_[1] < this.width_) {
mstyle += 'width:' + (this.width_ - this.anchor_[1]) + 'px;padding-left:' + this.anchor_[1] + 'px;';
} else {
mstyle += 'width:' + this.width_ + 'px;text-align:center;';
}
} else {
mstyle += 'height:' + this.height_ + 'px;line-height:' + this.height_ + 'px;';
mstyle += 'width:' + this.width_ + 'px;text-align:center;';
}
var txtColor = this.textColor_ ? this.textColor_ : 'black';
div.style.cssText = mstyle + 'cursor:pointer;top:' + pos.y + "px;left:" +
pos.x + "px;color:" + txtColor + ";position:absolute;font-size:11px;" +
'font-family:Arial,sans-serif;font-weight:bold';
div.innerHTML = this.text_;
map.getPane(G_MAP_MAP_PANE).appendChild(div);
var padding = this.padding_;
GEvent.addDomListener(div, "click", function () {
var pos = map.fromLatLngToDivPixel(latlng);
var sw = new GPoint(pos.x - padding, pos.y + padding);
sw = map.fromDivPixelToLatLng(sw);
var ne = new GPoint(pos.x + padding, pos.y - padding);
ne = map.fromDivPixelToLatLng(ne);
var zoom = map.getBoundsZoomLevel(new GLatLngBounds(sw, ne), map.getSize());
map.setCenter(latlng, zoom);
});
this.div_ = div;
};
/**
* Remove this overlay.
* @private
*/
ClusterMarker_.prototype.remove = function () {
this.div_.parentNode.removeChild(this.div_);
};
/**
* Copy this overlay.
* @private
*/
ClusterMarker_.prototype.copy = function () {
return new ClusterMarker_(this.latlng_, this.index_, this.text_, this.styles_, this.padding_);
};
/**
* Redraw this overlay.
* @private
*/
ClusterMarker_.prototype.redraw = function (force) {
if (!force) {
return;
}
var pos = this.map_.fromLatLngToDivPixel(this.latlng_);
pos.x -= parseInt(this.width_ / 2, 10);
pos.y -= parseInt(this.height_ / 2, 10);
this.div_.style.top = pos.y + "px";
this.div_.style.left = pos.x + "px";
};
/**
* Hide this cluster marker.
*/
ClusterMarker_.prototype.hide = function () {
this.div_.style.display = "none";
};
/**
* Show this cluster marker.
*/
ClusterMarker_.prototype.show = function () {
this.div_.style.display = "";
};
/**
* Get whether the cluster marker is hidden.
* @return {Boolean}
*/
ClusterMarker_.prototype.isHidden = function () {
return this.div_.style.display === "none";
};