From 106054140b18e94d8a19bcba59a1a734c74a95ce Mon Sep 17 00:00:00 2001
From: mourner <agafonkin@gmail.com>
Date: Fri, 23 Sep 2011 16:55:47 +0300
Subject: [PATCH] A better attempt at the copy world problem, hopefully closed
 #273, fixed #293, fixed #294, closed #288

---
 src/dom/Draggable.js            |  1 +
 src/handler/MapDrag.js          | 29 +++++++++++++++++++++++------
 src/map/Map.js                  |  3 ++-
 src/map/ext/Map.PanAnimation.js |  4 +++-
 4 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/src/dom/Draggable.js b/src/dom/Draggable.js
index 66f48d30..4e1a2b28 100644
--- a/src/dom/Draggable.js
+++ b/src/dom/Draggable.js
@@ -76,6 +76,7 @@ L.Draggable = L.Class.extend({
 	},
 
 	_updatePosition: function() {
+		this.fire('predrag');
 		L.DomUtil.setPosition(this._element, this._newPos);
 		this.fire('drag');
 	},
diff --git a/src/handler/MapDrag.js b/src/handler/MapDrag.js
index b5620b88..ed016ac6 100644
--- a/src/handler/MapDrag.js
+++ b/src/handler/MapDrag.js
@@ -12,6 +12,11 @@ L.Handler.MapDrag = L.Handler.extend({
 			this._draggable.on('dragstart', this._onDragStart, this);
 			this._draggable.on('drag', this._onDrag, this);
 			this._draggable.on('dragend', this._onDragEnd, this);
+
+			if (this._map.options.worldCopyJump) {
+				this._draggable.on('predrag', this._onPreDrag, this);
+				this._map.on('viewreset', this._onViewReset, this);
+			}
 		}
 		this._draggable.enable();
 		this._enabled = true;
@@ -37,15 +42,27 @@ L.Handler.MapDrag = L.Handler.extend({
 		this._map.fire('drag');
 	},
 
-	_onDragEnd: function() {
+	_onViewReset: function() {
+		var pxCenter = this._map.getSize().divideBy(2),
+			pxWorldCenter = this._map.latLngToLayerPoint(new L.LatLng(0,0));
+
+		this._initialWorldOffset = pxWorldCenter.subtract(pxCenter);
+	},
+
+	_onPreDrag: function() {
 		var map = this._map,
-			pane = map._panes.objectsPane,
-			left = map._getTopLeftPoint().x,
-			worldWidth = map.options.scale(this._map.getZoom()),
-			rest = ((left % worldWidth) + worldWidth) % worldWidth;
+			worldWidth = map.options.scale(map.getZoom()),
+			halfWidth = Math.round(worldWidth / 2),
+			dx = this._initialWorldOffset.x,
+			x = this._draggable._newPos.x,
+			newX1 = (x - halfWidth + dx) % worldWidth + halfWidth - dx,
+			newX2 = (x + halfWidth + dx) % worldWidth - halfWidth - dx,
+			newX = Math.abs(newX1 + dx) < Math.abs(newX2 + dx) ? newX1 : newX2;
 
-		pane.style.left = (left - rest) + 'px';
+		this._draggable._newPos.x = newX;
+	},
 
+	_onDragEnd: function() {
 		map.fire('moveend');
 		map.fire('dragend');
 	}
diff --git a/src/map/Map.js b/src/map/Map.js
index 0d6b9063..21ebcfc9 100644
--- a/src/map/Map.js
+++ b/src/map/Map.js
@@ -32,7 +32,8 @@ L.Map = L.Class.extend({
 
 		// misc
 		trackResize: true,
-		closePopupOnClick: true
+		closePopupOnClick: true,
+		worldCopyJump: true
 	},
 
 
diff --git a/src/map/ext/Map.PanAnimation.js b/src/map/ext/Map.PanAnimation.js
index 02ccfd15..fbdb9a4c 100644
--- a/src/map/ext/Map.PanAnimation.js
+++ b/src/map/ext/Map.PanAnimation.js
@@ -5,7 +5,9 @@ L.Map.include(!(L.Transition && L.Transition.implemented()) ? {} : {
 
 		if (this._loaded && !forceReset && this._layers) {
 			// difference between the new and current centers in pixels
-			var offset = this._getNewTopLeftPoint(center).subtract(this._getTopLeftPoint()); 
+			var offset = this._getNewTopLeftPoint(center).subtract(this._getTopLeftPoint());
+
+			center = new L.LatLng(center.lat, center.lng);
 			
 			var done = (zoomChanged ? 
 						!!this._zoomToIfCenterInView && this._zoomToIfCenterInView(center, zoom, offset) :