Leaflet/src/map/Map.js

/*
 * L.Map is the central class of the API - it is used to create a map.
 */

L.Map = L.Class.extend({

	includes: L.Mixin.Events,

	options: {
		crs: L.CRS.EPSG3857,

		/*
		center: LatLng,
		zoom: Number,
		layers: Array,
		*/

		fadeAnimation: L.DomUtil.TRANSITION && !L.Browser.android23,
		trackResize: true,
		markerZoomAnimation: L.DomUtil.TRANSITION && L.Browser.any3d
	},

	initialize: function (id, options) { // (HTMLElement or String, Object)
		options = L.setOptions(this, options);

		this._initContainer(id);
		this._initLayout();
		this.callInitHooks();
		this._initEvents();

		if (options.maxBounds) {
			this.setMaxBounds(options.maxBounds);
		}

		if (options.center && options.zoom !== undefined) {
			this.setView(L.latLng(options.center), options.zoom, true);
		}

		this._initLayers(options.layers);
	},


	// public methods that modify map state

	// replaced by animation-powered implementation in Map.PanAnimation.js
	setView: function (center, zoom) {
		this._resetView(L.latLng(center), this._limitZoom(zoom));
		return this;
	},

	setZoom: function (zoom) { // (Number)
		return this.setView(this.getCenter(), zoom);
	},

	zoomIn: function (delta) {
		return this.setZoom(this._zoom + (delta || 1));
	},

	zoomOut: function (delta) {
		return this.setZoom(this._zoom - (delta || 1));
	},

	setZoomAround: function (latlng, zoom) {
		var scale = this.getZoomScale(zoom),
		    viewHalf = this.getSize().divideBy(2),
		    containerPoint = latlng instanceof L.Point ? latlng : this.latLngToContainerPoint(latlng),

		    centerOffset = containerPoint.subtract(viewHalf).multiplyBy(1 - 1 / scale),
		    newCenter = this.containerPointToLatLng(viewHalf.add(centerOffset));

		return this.setView(newCenter, zoom);
	},

	fitBounds: function (bounds, paddingTopLeft, paddingBottomRight) { // (LatLngBounds || ILayer[, Point, Point])

		bounds = bounds.getBounds ? bounds.getBounds() : L.latLngBounds(bounds);

		paddingTopLeft = L.point(paddingTopLeft || [0, 0]);
		paddingBottomRight = L.point(paddingBottomRight || paddingTopLeft);

		var zoom = this.getBoundsZoom(bounds, false, paddingTopLeft.add(paddingBottomRight)),
		    paddingOffset = paddingBottomRight.subtract(paddingTopLeft).divideBy(2),
		    swPoint = this.project(bounds.getSouthWest(), zoom),
		    nePoint = this.project(bounds.getNorthEast(), zoom),
		    center = this.unproject(swPoint.add(nePoint).divideBy(2).add(paddingOffset), zoom);

		return this.setView(center, zoom);
	},

	fitWorld: function () {
		return this.fitBounds([[-90, -180], [90, 180]]);
	},

	panTo: function (center) { // (LatLng)
		return this.setView(center, this._zoom);
	},

	panBy: function (offset) { // (Point)
		// replaced with animated panBy in Map.Animation.js
		this.fire('movestart');

		this._rawPanBy(L.point(offset));

		this.fire('move');
		return this.fire('moveend');
	},

	setMaxBounds: function (bounds) {
		bounds = L.latLngBounds(bounds);

		this.options.maxBounds = bounds;

		if (!bounds) {
			this._boundsMinZoom = null;
			return this;
		}

		var minZoom = this.getBoundsZoom(bounds, true);

		this._boundsMinZoom = minZoom;

		if (this._loaded) {
			if (this._zoom < minZoom) {
				this.setView(bounds.getCenter(), minZoom);
			} else {
				this.panInsideBounds(bounds);
			}
		}

		this.on('moveend', this._panInsideMaxBounds, this);

		return this;
	},

	panInsideBounds: function (bounds) {
		bounds = L.latLngBounds(bounds);

		var viewBounds = this.getPixelBounds(),
		    viewSw = viewBounds.getBottomLeft(),
		    viewNe = viewBounds.getTopRight(),
		    sw = this.project(bounds.getSouthWest()),
		    ne = this.project(bounds.getNorthEast()),
		    dx = 0,
		    dy = 0;

		if (viewNe.y < ne.y) { // north
			dy = Math.ceil(ne.y - viewNe.y);
		}
		if (viewNe.x > ne.x) { // east
			dx = Math.floor(ne.x - viewNe.x);
		}
		if (viewSw.y > sw.y) { // south
			dy = Math.floor(sw.y - viewSw.y);
		}
		if (viewSw.x < sw.x) { // west
			dx = Math.ceil(sw.x - viewSw.x);
		}

		if (dx || dy) {
			return this.panBy([dx, dy]);
		}

		return this;
	},

	addLayer: function (layer) {
		// TODO method is too big, refactor

		var id = L.stamp(layer);

		if (this._layers[id]) { return this; }

		this._layers[id] = layer;

		// TODO getMaxZoom, getMinZoom in ILayer (instead of options)
		if (layer.options && (!isNaN(layer.options.maxZoom) || !isNaN(layer.options.minZoom))) {
			this._zoomBoundLayers[id] = layer;
			this._updateZoomLevels();
		}

		// TODO looks ugly, refactor!!!
		if (this.options.zoomAnimation && L.TileLayer && (layer instanceof L.TileLayer)) {
			this._tileLayersNum++;
            this._tileLayersToLoad++;
            layer.on('load', this._onTileLayerLoad, this);
		}

		this.whenReady(function () {
			layer.onAdd(this);
			this.fire('layeradd', {layer: layer});
		}, this);

		return this;
	},

	removeLayer: function (layer) {
		var id = L.stamp(layer);

		if (!this._layers[id]) { return; }

		layer.onRemove(this);

		delete this._layers[id];
		if (this._zoomBoundLayers[id]) {
			delete this._zoomBoundLayers[id];
			this._updateZoomLevels();
		}

		// TODO looks ugly, refactor
		if (this.options.zoomAnimation && L.TileLayer && (layer instanceof L.TileLayer)) {
			this._tileLayersNum--;
            this._tileLayersToLoad--;
            layer.off('load', this._onTileLayerLoad, this);
		}

		return this.fire('layerremove', {layer: layer});
	},

	hasLayer: function (layer) {
		if (!layer) { return false; }

		return (L.stamp(layer) in this._layers);
	},

	eachLayer: function (method, context) {
		for (var i in this._layers) {
			method.call(context, this._layers[i]);
		}
		return this;
	},

	invalidateSize: function (animate) {
		var oldSize = this.getSize();

		this._sizeChanged = true;

		if (this.options.maxBounds) {
			this.setMaxBounds(this.options.maxBounds);
		}

		if (!this._loaded) { return this; }

		var newSize = this.getSize(),
		    offset = oldSize.subtract(newSize).divideBy(2).round();

		if ((offset.x !== 0) || (offset.y !== 0)) {
			if (animate === true) {
				this.panBy(offset);
			} else {
				this._rawPanBy(offset);

				this.fire('move');

				clearTimeout(this._sizeTimer);
				this._sizeTimer = setTimeout(L.bind(this.fire, this, 'moveend'), 200);
			}
			this.fire('resize', {
				oldSize: oldSize,
				newSize: newSize
			});
		}
		return this;
	},

	// TODO handler.addTo
	addHandler: function (name, HandlerClass) {
		if (!HandlerClass) { return; }

		this[name] = new HandlerClass(this);

		if (this.options[name]) {
			this[name].enable();
		}

		return this;
	},

	remove: function () {
		if (this._loaded) {
			this.fire('unload');
		}
		this._initEvents('off');
		delete this._container._leaflet;
		return this;
	},


	// public methods for getting map state

	getCenter: function () { // (Boolean) -> LatLng
		this._checkIfLoaded();

		if (!this._moved()) {
			return this._initialCenter;
		}
		return this.layerPointToLatLng(this._getCenterLayerPoint());
	},

	getZoom: function () {
		return this._zoom;
	},

	getBounds: function () {
		var bounds = this.getPixelBounds(),
		    sw = this.unproject(bounds.getBottomLeft()),
		    ne = this.unproject(bounds.getTopRight());

		return new L.LatLngBounds(sw, ne);
	},

	getMinZoom: function () {
		var z1 = this.options.minZoom || 0,
		    z2 = this._layersMinZoom || 0,
		    z3 = this._boundsMinZoom || 0;

		return Math.max(z1, z2, z3);
	},

	getMaxZoom: function () {
		var z1 = this.options.maxZoom === undefined ? Infinity : this.options.maxZoom,
		    z2 = this._layersMaxZoom  === undefined ? Infinity : this._layersMaxZoom;

		return Math.min(z1, z2);
	},

	getBoundsZoom: function (bounds, inside, padding) { // (LatLngBounds[, Boolean, Point]) -> Number
		bounds = L.latLngBounds(bounds);

		var zoom = this.getMinZoom() - (inside ? 1 : 0),
		    maxZoom = this.getMaxZoom(),
		    size = this.getSize(),

		    nw = bounds.getNorthWest(),
		    se = bounds.getSouthEast(),

		    zoomNotFound = true,
		    boundsSize;

		padding = L.point(padding || [0, 0]);

		do {
			zoom++;
			boundsSize = this.project(se, zoom).subtract(this.project(nw, zoom)).add(padding);
			zoomNotFound = !inside ? size.contains(boundsSize) : boundsSize.x < size.x || boundsSize.y < size.y;

		} while (zoomNotFound && zoom <= maxZoom);

		if (zoomNotFound && inside) {
			return null;
		}

		return inside ? zoom : zoom - 1;
	},

	getSize: function () {
		if (!this._size || this._sizeChanged) {
			this._size = new L.Point(
				this._container.clientWidth,
				this._container.clientHeight);

			this._sizeChanged = false;
		}
		return this._size.clone();
	},

	getPixelBounds: function () {
		var topLeftPoint = this._getTopLeftPoint();
		return new L.Bounds(topLeftPoint, topLeftPoint.add(this.getSize()));
	},

	getPixelOrigin: function () {
		this._checkIfLoaded();
		return this._initialTopLeftPoint;
	},

	getPanes: function () {
		return this._panes;
	},

	getContainer: function () {
		return this._container;
	},


	// TODO replace with universal implementation after refactoring projections

	getZoomScale: function (toZoom) {
		var crs = this.options.crs;
		return crs.scale(toZoom) / crs.scale(this._zoom);
	},

	getScaleZoom: function (scale) {
		return this._zoom + (Math.log(scale) / Math.LN2);
	},


	// conversion methods

	project: function (latlng, zoom) { // (LatLng[, Number]) -> Point
		zoom = zoom === undefined ? this._zoom : zoom;
		return this.options.crs.latLngToPoint(L.latLng(latlng), zoom);
	},

	unproject: function (point, zoom) { // (Point[, Number]) -> LatLng
		zoom = zoom === undefined ? this._zoom : zoom;
		return this.options.crs.pointToLatLng(L.point(point), zoom);
	},

	layerPointToLatLng: function (point) { // (Point)
		var projectedPoint = L.point(point).add(this.getPixelOrigin());
		return this.unproject(projectedPoint);
	},

	latLngToLayerPoint: function (latlng) { // (LatLng)
		var projectedPoint = this.project(L.latLng(latlng))._round();
		return projectedPoint._subtract(this.getPixelOrigin());
	},

	containerPointToLayerPoint: function (point) { // (Point)
		return L.point(point).subtract(this._getMapPanePos());
	},

	layerPointToContainerPoint: function (point) { // (Point)
		return L.point(point).add(this._getMapPanePos());
	},

	containerPointToLatLng: function (point) {
		var layerPoint = this.containerPointToLayerPoint(L.point(point));
		return this.layerPointToLatLng(layerPoint);
	},

	latLngToContainerPoint: function (latlng) {
		return this.layerPointToContainerPoint(this.latLngToLayerPoint(L.latLng(latlng)));
	},

	mouseEventToContainerPoint: function (e) { // (MouseEvent)
		return L.DomEvent.getMousePosition(e, this._container);
	},

	mouseEventToLayerPoint: function (e) { // (MouseEvent)
		return this.containerPointToLayerPoint(this.mouseEventToContainerPoint(e));
	},

	mouseEventToLatLng: function (e) { // (MouseEvent)
		return this.layerPointToLatLng(this.mouseEventToLayerPoint(e));
	},


	// map initialization methods

	_initContainer: function (id) {
		var container = this._container = L.DomUtil.get(id);

		if (!container) {
			throw new Error('Map container not found.');
		} else if (container._leaflet) {
			throw new Error('Map container is already initialized.');
		}

		container._leaflet = true;
	},

	_initLayout: function () {
		var container = this._container;

		L.DomUtil.addClass(container, 'leaflet-container');

		if (L.Browser.touch) {
			L.DomUtil.addClass(container, 'leaflet-touch');
		}

		if (this.options.fadeAnimation) {
			L.DomUtil.addClass(container, 'leaflet-fade-anim');
		}

		var position = L.DomUtil.getStyle(container, 'position');

		if (position !== 'absolute' && position !== 'relative' && position !== 'fixed') {
			container.style.position = 'relative';
		}

		this._initPanes();

		if (this._initControlPos) {
			this._initControlPos();
		}
	},

	_initPanes: function () {
		var panes = this._panes = {};

		this._mapPane = panes.mapPane = this._createPane('leaflet-map-pane', this._container);

		this._tilePane = panes.tilePane = this._createPane('leaflet-tile-pane', this._mapPane);
		panes.objectsPane = this._createPane('leaflet-objects-pane', this._mapPane);
		panes.shadowPane = this._createPane('leaflet-shadow-pane');
		panes.overlayPane = this._createPane('leaflet-overlay-pane');
		panes.markerPane = this._createPane('leaflet-marker-pane');
		panes.popupPane = this._createPane('leaflet-popup-pane');

		var zoomHide = ' leaflet-zoom-hide';

		if (!this.options.markerZoomAnimation) {
			L.DomUtil.addClass(panes.markerPane, zoomHide);
			L.DomUtil.addClass(panes.shadowPane, zoomHide);
			L.DomUtil.addClass(panes.popupPane, zoomHide);
		}
	},

	_createPane: function (className, container) {
		return L.DomUtil.create('div', className, container || this._panes.objectsPane);
	},

	_initLayers: function (layers) {
		layers = layers ? (L.Util.isArray(layers) ? layers : [layers]) : [];

		this._layers = {};
		this._zoomBoundLayers = {};
		this._tileLayersNum = 0;

		var i, len;

		for (i = 0, len = layers.length; i < len; i++) {
			this.addLayer(layers[i]);
		}
	},


	// private methods that modify map state

	_resetView: function (center, zoom, preserveMapOffset, afterZoomAnim) {

		var zoomChanged = (this._zoom !== zoom);

		if (!afterZoomAnim) {
			this.fire('movestart');

			if (zoomChanged) {
				this.fire('zoomstart');
			}
		}

		this._zoom = zoom;
		this._initialCenter = center;

		this._initialTopLeftPoint = this._getNewTopLeftPoint(center);

		if (!preserveMapOffset) {
			L.DomUtil.setPosition(this._mapPane, new L.Point(0, 0));
		} else {
			this._initialTopLeftPoint._add(this._getMapPanePos());
		}

		this._tileLayersToLoad = this._tileLayersNum;

		var loading = !this._loaded;
		this._loaded = true;

		if (loading) {
			this.fire('load');
		}

		this.fire('viewreset', {hard: !preserveMapOffset});

		this.fire('move');

		if (zoomChanged || afterZoomAnim) {
			this.fire('zoomend');
		}

		this.fire('moveend', {hard: !preserveMapOffset});
	},

	_rawPanBy: function (offset) {
		L.DomUtil.setPosition(this._mapPane, this._getMapPanePos().subtract(offset));
	},

	_getZoomSpan: function () {
		return this.getMaxZoom() - this.getMinZoom();
	},

	_updateZoomLevels: function () {
		var i,
			minZoom = Infinity,
			maxZoom = -Infinity,
			oldZoomSpan = this._getZoomSpan();

		for (i in this._zoomBoundLayers) {
			var layer = this._zoomBoundLayers[i];
			if (!isNaN(layer.options.minZoom)) {
				minZoom = Math.min(minZoom, layer.options.minZoom);
			}
			if (!isNaN(layer.options.maxZoom)) {
				maxZoom = Math.max(maxZoom, layer.options.maxZoom);
			}
		}

		if (i === undefined) { // we have no tilelayers
			this._layersMaxZoom = this._layersMinZoom = undefined;
		} else {
			this._layersMaxZoom = maxZoom;
			this._layersMinZoom = minZoom;
		}

		if (oldZoomSpan !== this._getZoomSpan()) {
			this.fire('zoomlevelschange');
		}
	},

	_panInsideMaxBounds: function () {
		this.panInsideBounds(this.options.maxBounds);
	},

	_checkIfLoaded: function () {
		if (!this._loaded) {
			throw new Error('Set map center and zoom first.');
		}
	},

	// map events

	_initEvents: function (onOff) {
		if (!L.DomEvent) { return; }

		onOff = onOff || 'on';

		L.DomEvent[onOff](this._container, 'click', this._onMouseClick, this);

		var events = ['dblclick', 'mousedown', 'mouseup', 'mouseenter',
		              'mouseleave', 'mousemove', 'contextmenu'],
		    i, len;

		for (i = 0, len = events.length; i < len; i++) {
			L.DomEvent[onOff](this._container, events[i], this._fireMouseEvent, this);
		}

		if (this.options.trackResize) {
			L.DomEvent[onOff](window, 'resize', this._onResize, this);
		}
	},

	_onResize: function () {
		L.Util.cancelAnimFrame(this._resizeRequest);
		this._resizeRequest = L.Util.requestAnimFrame(
		        this.invalidateSize, this, false, this._container);
	},

	_onMouseClick: function (e) {
		if (!this._loaded || (this.dragging && this.dragging.moved())) { return; }

		this.fire('preclick');
		this._fireMouseEvent(e);
	},

	_fireMouseEvent: function (e) {
		if (!this._loaded) { return; }

		var type = e.type;

		type = (type === 'mouseenter' ? 'mouseover' : (type === 'mouseleave' ? 'mouseout' : type));

		if (!this.hasEventListeners(type)) { return; }

		if (type === 'contextmenu') {
			L.DomEvent.preventDefault(e);
		}

		var containerPoint = this.mouseEventToContainerPoint(e),
		    layerPoint = this.containerPointToLayerPoint(containerPoint),
		    latlng = this.layerPointToLatLng(layerPoint);

		this.fire(type, {
			latlng: latlng,
			layerPoint: layerPoint,
			containerPoint: containerPoint,
			originalEvent: e
		});
	},

	_onTileLayerLoad: function () {
		this._tileLayersToLoad--;
		if (this._tileLayersNum && !this._tileLayersToLoad) {
			this.fire('tilelayersload');
		}
	},

	whenReady: function (callback, context) {
		if (this._loaded) {
			callback.call(context || this, this);
		} else {
			this.on('load', callback, context);
		}
		return this;
	},


	// private methods for getting map state

	_getMapPanePos: function () {
		return L.DomUtil.getPosition(this._mapPane);
	},

	_moved: function () {
		var pos = this._getMapPanePos();
		return pos && !pos.equals([0, 0]);
	},

	_getTopLeftPoint: function () {
		return this.getPixelOrigin().subtract(this._getMapPanePos());
	},

	_getNewTopLeftPoint: function (center, zoom) {
		var viewHalf = this.getSize()._divideBy(2);
		// TODO round on display, not calculation to increase precision?
		return this.project(center, zoom)._subtract(viewHalf)._round();
	},

	_latLngToNewLayerPoint: function (latlng, newZoom, newCenter) {
		var topLeft = this._getNewTopLeftPoint(newCenter, newZoom).add(this._getMapPanePos());
		return this.project(latlng, newZoom)._subtract(topLeft);
	},

	// layer point of the current center
	_getCenterLayerPoint: function () {
		return this.containerPointToLayerPoint(this.getSize()._divideBy(2));
	},

	// offset of the specified place to the current center in pixels
	_getCenterOffset: function (latlng) {
		return this.latLngToLayerPoint(latlng).subtract(this._getCenterLayerPoint());
	},

	_limitZoom: function (zoom) {
		var min = this.getMinZoom(),
		    max = this.getMaxZoom();

		return Math.max(min, Math.min(max, zoom));
	}
});

L.map = function (id, options) {
	return new L.Map(id, options);
};