leaflet-canvas-layer
v1.0.8
Published
Leaflet plugin for showing a canvas overlay in a leaflet map. This project is a fork and a typescript translation from https://github.com/Sumbera/gLayers.Leaflet
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Readme
gLayers.Leaflet
generic map layers for leaflet 0.7 and 1.0-rc, moving from original GIST here https://gist.github.com/Sumbera/11114288 to this repo.
L.CanvasLayer - full screen generic canvas layer for leaflet
##API
|methods | description | | ------------- |:-------------| |needRedraw | will schedule next frame call for drawLayer| |delegate(object) | optionaly set receiver of the events if not 'inheriting' from L.CanvasLayer |
events | description | | ------------- |:-------------| |onLayerDidMount | after layer is attached/added to the map| |onLayerWillUnmount | before layer is removed from the map| |onDrawLayer(info) | when layer is drawn , info contains view parameters like bounds, size, canvas etc. note : events will be called only if presented on the 'subclass' or if delegate(receiver) is set
Examples
Basic usage
L.canvasLayer()
.delegate(this) // -- if we do not inherit from L.CanvasLayer we can setup a delegate to receive events from L.CanvasLayer
.addTo(leafletMap);
function onDrawLayer(info) {
var ctx = info.canvas.getContext('2d');
ctx.clearRect(0, 0, info.canvas.width, info.canvas.height);
ctx.fillStyle = "rgba(255,116,0, 0.2)";
for (var i = 0; i < data.length; i++) {
var d = data[i];
if (info.bounds.contains([d[0], d[1]])) {
dot = info.layer._map.latLngToContainerPoint([d[0], d[1]]);
ctx.beginPath();
ctx.arc(dot.x, dot.y, 3, 0, Math.PI * 2);
ctx.fill();
ctx.closePath();
}
}
};
Custom layer
myCustomCanvasDraw= function(){
this.onLayerDidMount = function (){
// -- prepare custom drawing
};
this.onLayerWillUnmount = function(){
// -- custom cleanup
};
this.setData = function (data){
// -- custom data set
this.needRedraw(); // -- call to drawLayer
};
this.onDrawLayer = function (viewInfo){
// -- custom draw
}
}
myCustomCanvasDraw.prototype = new L.CanvasLayer(); // -- setup prototype
var myLayer = new myCustomCanvasDraw();
myLayer.addTo(leafletMap);
Other useful full view Leaflet Canvas sources here:
- leaflet.heat
- [Full Canvas] (https://github.com/cyrilcherian/Leaflet-Fullcanvas)