Sunday 15 July 2018

'Home' button Leaflet map


Is there a possibility to have a kind of home button on my Leaflet map which will zoom to my initial map view or a specific defined position, respectively?



Answer




The following will add a custom zoom control with a home button to a Leaflet map. The home icon is from font-awesome, so be sure to include that reference.


Working fiddle here.


html:












css:


#map { height: 340px; }
.leaflet-bar a { background-color: #fff; border-bottom: 1px solid #ccc; color: #444; display: block; height: 26px; width: 26px; line-height: 1.45 !important; text-align: center; text-decoration: none; font: bold 18px 'Lucida Console', Monaco, monospace; }

javascript:


var lat = 51.505;
var lng = -0.09;
var zoom = 12;


// set up the map and remove the default zoomControl
var map = L.map('map', {
zoomControl: false
});

map.setView([lat, lng], zoom);
L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
maxZoom: 18
}).addTo(map);


// custom zoom bar control that includes a Zoom Home function
L.Control.zoomHome = L.Control.extend({
options: {
position: 'topright',
zoomInText: '+',
zoomInTitle: 'Zoom in',
zoomOutText: '-',
zoomOutTitle: 'Zoom out',
zoomHomeText: '',

zoomHomeTitle: 'Zoom home'
},

onAdd: function (map) {
var controlName = 'gin-control-zoom',
container = L.DomUtil.create('div', controlName + ' leaflet-bar'),
options = this.options;

this._zoomInButton = this._createButton(options.zoomInText, options.zoomInTitle,
controlName + '-in', container, this._zoomIn);

this._zoomHomeButton = this._createButton(options.zoomHomeText, options.zoomHomeTitle,
controlName + '-home', container, this._zoomHome);
this._zoomOutButton = this._createButton(options.zoomOutText, options.zoomOutTitle,
controlName + '-out', container, this._zoomOut);

this._updateDisabled();
map.on('zoomend zoomlevelschange', this._updateDisabled, this);

return container;
},


onRemove: function (map) {
map.off('zoomend zoomlevelschange', this._updateDisabled, this);
},

_zoomIn: function (e) {
this._map.zoomIn(e.shiftKey ? 3 : 1);
},

_zoomOut: function (e) {

this._map.zoomOut(e.shiftKey ? 3 : 1);
},

_zoomHome: function (e) {
map.setView([lat, lng], zoom);
},

_createButton: function (html, title, className, container, fn) {
var link = L.DomUtil.create('a', className, container);
link.innerHTML = html;

link.href = '#';
link.title = title;

L.DomEvent.on(link, 'mousedown dblclick', L.DomEvent.stopPropagation)
.on(link, 'click', L.DomEvent.stop)
.on(link, 'click', fn, this)
.on(link, 'click', this._refocusOnMap, this);

return link;
},


_updateDisabled: function () {
var map = this._map,
className = 'leaflet-disabled';

L.DomUtil.removeClass(this._zoomInButton, className);
L.DomUtil.removeClass(this._zoomOutButton, className);

if (map._zoom === map.getMinZoom()) {
L.DomUtil.addClass(this._zoomOutButton, className);

}
if (map._zoom === map.getMaxZoom()) {
L.DomUtil.addClass(this._zoomInButton, className);
}
}
});
// add the new control to the map
var zoomHome = new L.Control.zoomHome();
zoomHome.addTo(map);

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