Consider exploring the Leaflet plugins designed for layer switchers to find one that aligns better with your specific needs, rather than relying on default L.Control.Layers with varying icons.
Alternatively: The icon for the layers control is determined by CSS, specified in this section of the code:
.leaflet-control-layers-toggle {
background-image: url(images/layers.png);
width: 36px;
height: 36px;
}
The class name used in the CSS is derived from the _initLayout method within L.Control.Layers:
_initLayout: function () {
var className = 'leaflet-control-layers',
// [snip]
var link = this._layersLink = DomUtil.create('a', className + '-toggle', container);
// [snip]
}
It's worth noting that the toggle element containing the image is stored as a private property this._layersLink, providing scope for manipulation.
Armed with this understanding, it becomes feasible to extend L.Control.Layers through subclass creation:
L.Control.Layers.TogglerIcon = L.Control.Layers.extend({
options: {
// Optional base CSS class name for the toggler element
togglerClassName: undefined
},
_initLayout: function(){
L.Control.Layers.prototype._initLayout.call(this);
if (this.options.togglerClassName) {
L.DomUtil.addClass(this._layersLink, togglerClassName);
}
}
});
This approach allows the establishment of multiple customized layers controls by passing specific options, for instance:
var layers1 =
new L.Control.Layers.TogglerIcon(..., ..., {togglerClassName: 'layers-flowers'});
var layers2 =
new L.Control.Layers.TogglerIcon(..., ..., {togglerClassName: 'layers-cars'});
To complement this setup, corresponding CSS can be applied to define distinct icons for each control:
.layers-flowers {
background-image: url(images/layers-flowers.png);
width: 36px;
height: 36px;
}
.layers-cars {
/* identical process applies */
}
In addition to utilizing CSS classes, it's also viable to adjust the properties of the HTMLElement directly within the code:
_initLayout: function(){
L.Control.Layers.prototype._initLayout.call(this);
if (this.options.backgroundImageUrl) {
this._layersLink.style.backgroundImage = this.options.backgroundImageUrl;
}
}
Note that this alternative method could necessitate more intricate fine-tuning.