1 files changed, 248 insertions, 0 deletions
diff --git a/js/dojo/dojox/geo/openlayers/TouchInteractionSupport.js b/js/dojo/dojox/geo/openlayers/TouchInteractionSupport.js
new file mode 100644
index 0000000..0ea58f6
--- /dev/null
+++ b/js/dojo/dojox/geo/openlayers/TouchInteractionSupport.js
@@ -0,0 +1,248 @@
+//>>built
+define("dojox/geo/openlayers/TouchInteractionSupport", ["dojo/_base/kernel",
+				"dojo/_base/declare",
+				"dojo/_base/connect",
+				"dojo/_base/html",
+				"dojo/_base/lang",
+				"dojo/_base/event",
+				"dojo/_base/window"], function(dojo, declare, connect, html, lang, event, window){
+
+	return declare("dojox.geo.openlayers.TouchInteractionSupport", null, {
+		//	summary: 
+		//		class to handle touch interactions on a OpenLayers.Map widget
+		//	tags:
+		//		private
+
+		_map : null,
+		_centerTouchLocation : null,
+		_touchMoveListener : null,
+		_touchEndListener : null,
+		_initialFingerSpacing : null,
+		_initialScale : null,
+		_tapCount : null,
+		_tapThreshold : null,
+		_lastTap : null,
+
+		constructor : function(/* OpenLayers.Map */map){
+			//	summary: 
+			//		Constructs a new TouchInteractionSupport instance
+			//	map: OpenLayers.Map
+			//		the Map widget this class provides touch navigation for.
+			this._map = map;
+			this._centerTouchLocation = new OpenLayers.LonLat(0, 0);
+
+			var div = this._map.div;
+
+			// install touch listeners
+			connect.connect(div, "touchstart", this, this._touchStartHandler);
+			connect.connect(div, "touchmove", this, this._touchMoveHandler);
+			connect.connect(div, "touchend", this, this._touchEndHandler);
+
+			this._tapCount = 0;
+			this._lastTap = {
+				x : 0,
+				y : 0
+			};
+			this._tapThreshold = 100; // square distance in pixels
+
+		},
+
+		_getTouchBarycenter : function(touchEvent){
+			//	summary: 
+			//		returns the midpoint of the two first fingers (or the first finger location if only one)
+			//	touchEvent: Event
+			//		a touch event
+			//	returns: dojox.gfx.Point
+			//		the midpoint
+			//	tags:
+			//		private
+			var touches = touchEvent.touches;
+			var firstTouch = touches[0];
+			var secondTouch = null;
+			if (touches.length > 1) {
+				secondTouch = touches[1];
+			} else {
+				secondTouch = touches[0];
+			}
+
+			var marginBox = html.marginBox(this._map.div);
+
+			var middleX = (firstTouch.pageX + secondTouch.pageX) / 2.0 - marginBox.l;
+			var middleY = (firstTouch.pageY + secondTouch.pageY) / 2.0 - marginBox.t;
+
+			return {
+				x : middleX,
+				y : middleY
+			};
+
+		},
+
+		_getFingerSpacing : function(touchEvent){
+			//	summary: 
+			//		computes the distance between the first two fingers
+			//	touchEvent: Event
+			//		a touch event
+			//	returns: float
+			//		a distance. -1 if less that 2 fingers
+			//	tags:
+			//		private
+			var touches = touchEvent.touches;
+			var spacing = -1;
+			if (touches.length >= 2) {
+				var dx = (touches[1].pageX - touches[0].pageX);
+				var dy = (touches[1].pageY - touches[0].pageY);
+				spacing = Math.sqrt(dx * dx + dy * dy);
+			}
+			return spacing;
+		},
+
+		_isDoubleTap : function(touchEvent){
+			//	summary: 
+			//		checks whether the specified touchStart event is a double tap 
+			//		(i.e. follows closely a previous touchStart at approximately the same location)
+			//	touchEvent: Event
+			//		a touch event
+			//	returns: boolean
+			//		true if this event is considered a double tap
+			//	tags:
+			//		private
+			var isDoubleTap = false;
+			var touches = touchEvent.touches;
+			if ((this._tapCount > 0) && touches.length == 1) {
+				// test distance from last tap
+				var dx = (touches[0].pageX - this._lastTap.x);
+				var dy = (touches[0].pageY - this._lastTap.y);
+				var distance = dx * dx + dy * dy;
+				if (distance < this._tapThreshold) {
+					isDoubleTap = true;
+				} else {
+					this._tapCount = 0;
+				}
+			}
+			this._tapCount++;
+			this._lastTap.x = touches[0].pageX;
+			this._lastTap.y = touches[0].pageY;
+			setTimeout(lang.hitch(this, function(){
+				this._tapCount = 0;
+			}), 300);
+
+			return isDoubleTap;
+		},
+
+		_doubleTapHandler : function(touchEvent){
+			//	summary: 
+			//		action performed on the map when a double tap was triggered 
+			//	touchEvent: Event 
+			//		a touch event
+			//	tags:
+			//		private
+			// perform a basic 2x zoom on touch
+			var touches = touchEvent.touches;
+			var marginBox = html.marginBox(this._map.div);
+			var offX = touches[0].pageX - marginBox.l;
+			var offY = touches[0].pageY - marginBox.t;
+			// clicked map point before zooming
+			var mapPoint = this._map.getLonLatFromPixel(new OpenLayers.Pixel(offX, offY));
+			// zoom increment power
+			this._map.setCenter(new OpenLayers.LonLat(mapPoint.lon, mapPoint.lat), this._map.getZoom() + 1);
+		},
+
+		_touchStartHandler : function(touchEvent){
+			//	summary: 
+			//		action performed on the map when a touch start was triggered 
+			//	touchEvent: Event 
+			// 		a touch event
+			//	tags:
+			//		private
+			event.stop(touchEvent);
+
+			// test double tap
+			if (this._isDoubleTap(touchEvent)) {
+				this._doubleTapHandler(touchEvent);
+				return;
+			}
+
+			// compute map midpoint between fingers		
+			var middlePoint = this._getTouchBarycenter(touchEvent);
+
+			this._centerTouchLocation = this._map.getLonLatFromPixel(new OpenLayers.Pixel(middlePoint.x, middlePoint.y));
+
+			// store initial finger spacing to compute zoom later
+			this._initialFingerSpacing = this._getFingerSpacing(touchEvent);
+
+			// store initial map scale
+			this._initialScale = this._map.getScale();
+
+			// install touch move and up listeners (if not done by other fingers before)
+			if (!this._touchMoveListener)
+				this._touchMoveListener = connect.connect(window.global, "touchmove", this, this._touchMoveHandler);
+			if (!this._touchEndListener)
+				this._touchEndListener = connect.connect(window.global, "touchend", this, this._touchEndHandler);
+
+		},
+
+		_touchEndHandler : function(touchEvent){
+			//	summary: 
+			//		action performed on the map when a touch end was triggered 
+			//	touchEvent: Event 
+			//		a touch event
+			//	tags:
+			//		private
+			event.stop(touchEvent);
+
+			var touches = touchEvent.touches;
+
+			if (touches.length == 0) {
+				// disconnect listeners only when all fingers are up
+				if (this._touchMoveListener) {
+					connect.disconnect(this._touchMoveListener);
+					this._touchMoveListener = null;
+				}
+				if (this._touchEndListener) {
+					connect.disconnect(this._touchEndListener);
+					this._touchEndListener = null;
+				}
+			} else {
+				// recompute touch center
+				var middlePoint = this._getTouchBarycenter(touchEvent);
+
+				this._centerTouchLocation = this._map.getLonLatFromPixel(new OpenLayers.Pixel(middlePoint.x, middlePoint.y));
+			}
+		},
+
+		_touchMoveHandler : function(touchEvent){
+			//	summary: 
+			//		action performed on the map when a touch move was triggered 
+			//	touchEvent: Event
+			//		a touch event
+			//	tags:
+			//		private
+
+			// prevent browser interaction
+			event.stop(touchEvent);
+
+			var middlePoint = this._getTouchBarycenter(touchEvent);
+
+			// compute map offset
+			var mapPoint = this._map.getLonLatFromPixel(new OpenLayers.Pixel(middlePoint.x, middlePoint.y));
+			var mapOffsetLon = mapPoint.lon - this._centerTouchLocation.lon;
+			var mapOffsetLat = mapPoint.lat - this._centerTouchLocation.lat;
+
+			// compute scale factor
+			var scaleFactor = 1;
+			var touches = touchEvent.touches;
+			if (touches.length >= 2) {
+				var fingerSpacing = this._getFingerSpacing(touchEvent);
+				scaleFactor = fingerSpacing / this._initialFingerSpacing;
+				// weird openlayer bug : setting several times the same scale value lead to visual zoom...
+				this._map.zoomToScale(this._initialScale / scaleFactor);
+			}
+
+			// adjust map center on barycenter
+			var currentMapCenter = this._map.getCenter();
+			this._map.setCenter(new OpenLayers.LonLat(currentMapCenter.lon - mapOffsetLon, currentMapCenter.lat
+																																											- mapOffsetLat));
+
+		}
+	});
+});