From 0936b5e18cfaedef980419f5164618305fd72e03 Mon Sep 17 00:00:00 2001
From: Mourner <agafonkin@gmail.com>
Date: Tue, 12 Jul 2011 20:18:22 +0300
Subject: [PATCH] map#hasLayer, ability to add tile layers below all others

---
 CHANGELOG.md                |  2 ++
 src/layer/tile/TileLayer.js | 17 ++++++++++++-----
 src/map/Map.js              | 10 ++++++++--
 3 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b89f2776..e1a0a351 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,8 @@ Leaflet Changelog
  * Improved circles performance by not drawing them if they're off the clip region.  
  * Improved browser-specific code to rely more on feature detection rather than user agent string.
  * Improved superclass access mechanism to work with inheritance chains of 3 or more classes; now you should use `Klass.superclass` instead of `this.superclass` (by [@anru](https://github.com/anru)). [#179](https://github.com/CloudMade/Leaflet/pull/179)
+ * Added ability to add a tile layer below all others (`map.addLayer(layer, true)`) (useful for switching base tile layers).
+ * Added `hasLayer` method to `Map`.
 
 ### Bugfixes
 
diff --git a/src/layer/tile/TileLayer.js b/src/layer/tile/TileLayer.js
index d69fa16c..8c2fcc1d 100644
--- a/src/layer/tile/TileLayer.js
+++ b/src/layer/tile/TileLayer.js
@@ -30,11 +30,11 @@ L.TileLayer = L.Class.extend({
 		}
 	},
 	
-	onAdd: function(map) {
+	onAdd: function(map, insertAtTheTop) {
 		this._map = map;
 		
 		// create a container div for tiles
-		this._initContainer();
+		this._initContainer(insertAtTheTop);
 		
 		// create an image to clone for tiles
 		this._createTileProto();
@@ -89,11 +89,18 @@ L.TileLayer = L.Class.extend({
 		}
 	},
 	
-	_initContainer: function() {
-		var tilePane = this._map.getPanes().tilePane;
+	_initContainer: function(insertAtTheTop) {
+		var tilePane = this._map.getPanes().tilePane,
+			first = tilePane.firstChild;
 		
 		if (!this._container || tilePane.empty) {
-			this._container = L.DomUtil.create('div', 'leaflet-layer', tilePane);
+			this._container = L.DomUtil.create('div', 'leaflet-layer');
+			
+			if (insertAtTheTop && first) {
+				tilePane.insertBefore(this._container, first);
+			} else {
+				tilePane.appendChild(this._container);
+			}
 			
 			this._setOpacity(this.options.opacity);
 		}
diff --git a/src/map/Map.js b/src/map/Map.js
index 0c5cb501..4de88444 100644
--- a/src/map/Map.js
+++ b/src/map/Map.js
@@ -113,7 +113,7 @@ L.Map = L.Class.extend({
 		return this;
 	},
 	
-	addLayer: function(layer) {
+	addLayer: function(layer, insertAtTheTop) {
 		var id = L.Util.stamp(layer);
 		
 		if (this._layers[id]) return this;
@@ -137,7 +137,7 @@ L.Map = L.Class.extend({
 		}
 		
 		var onMapLoad = function() {
-			layer.onAdd(this);
+			layer.onAdd(this, insertAtTheTop);
 			this.fire('layeradd', {layer: layer});
 		};
 		
@@ -170,6 +170,12 @@ L.Map = L.Class.extend({
 		return this;
 	},
 	
+	hasLayer: function(layer) {
+		var id = L.Util.stamp(layer);
+		
+		return (id in this._layers);
+	},
+	
 	invalidateSize: function() {
 		this._sizeChanged = true;