Add support for switching PaperScope contexts in PaperScript code exeuction and callback handling. This should add proper support for multiple PaperScript instances in one site.

src/core/PaperScope.js

@@ -38,5 +38,19 @@ var PaperScope = this.PaperScope = Base.extend({
 		return Base.each(this, function(value, key) {
 			this[key] = value;
 		}, scope);
+	},
+
+	// Methods for setting and restoring paper scopes:
+	statics: {
+		scopes: [],
+
+		set: function(scope) {
+			this.scopes.push(paper);
+			paper = scope;
+		},
+
+		restore: function() {
+			paper = this.scopes.pop();
+		}
 	}
 });

src/document/Document.js

@@ -18,7 +18,7 @@ var Document = this.Document = Base.extend({
 	beans: true,
 
 	initialize: function(canvas) {
-		// Store reference to currently active global paper scope:
+		// Store reference to the currently active global paper scope:
 		this._scope = paper;
 		if (canvas && canvas instanceof HTMLCanvasElement) {
 			this.canvas = canvas;

src/tool/Tool.js

@@ -24,18 +24,22 @@ var Tool = this.Tool = ToolHandler.extend(new function() {
 		beans: true,
 
 		initialize: function(handlers, doc) {
-			this.base(handlers);
-			// Create events once, so they can be removed easily too.
-			var that = this, curPoint;
+			this.base(handlers, doc._scope);
+			this._document = doc;
+
+			var curPoint;
 			var dragging = false;
-			this.events = {
+			var that = this;
+			// TODO: Move event handling to DocumentView
+			var events = {
 				mousedown: function(event) {
 					curPoint = viewToArtwork(event, that._document);
 					that.onHandleEvent('mousedown', curPoint, event);
-					if (that.onMouseDown)
+					if (that.onMouseDown) {
 						that._document.redraw();
+					}
 					if (that.eventInterval != null) {
-						this.timer = setInterval(that.events.mousemove,
+						this.timer = setInterval(events.mousemove,
 								that.eventInterval);
 					}
 					dragging = true;
@@ -45,54 +49,55 @@ var Tool = this.Tool = ToolHandler.extend(new function() {
 					// If the event was triggered by a touch screen device,
 					// prevent the default behaviour, as it will otherwise
 					// scroll the page:
-					if (event && event.targetTouches)
-						event.preventDefault();
+					if (event && event.targetTouches) {
+						DomEvent.preventDefault(event);
+					}
 					var point = event && viewToArtwork(event, that._document);
 					// If there is only an onMouseMove handler, call it when
 					// the user is dragging
 					var onlyMove = !!(!that.onMouseDrag && that.onMouseMove);
 					if (dragging && !onlyMove) {
 						curPoint = point || curPoint;
-						if (curPoint)
+						if (curPoint) {
 							that.onHandleEvent('mousedrag', curPoint, event);
+						}
 					} else if (!dragging || onlyMove) {
 						that.onHandleEvent('mousemove', point, event);
 					}
-					if (that.onMouseMove || that.onMouseDrag)
+					if (that.onMouseMove || that.onMouseDrag) {
 						that._document.redraw();
+					}
 				},
 
 				mouseup: function(event) {
 					if (dragging) {
 						curPoint = null;
-						if (that.eventInterval != null)
+						if (that.eventInterval != null) {
 							clearInterval(this.timer);
+						}
 						that.onHandleEvent('mouseup',
 								viewToArtwork(event, that._document), event);
-						if (that.onMouseUp)
+						if (that.onMouseUp) {
 							that._document.redraw();
+						}
 						dragging = false;
 					}
 				},
 
 				touchmove: function(event) {
-					that.events.mousemove(event);
+					events.mousemove(event);
 				},
 
 				touchstart: function(event) {
-					that.events.mousedown(event);
+					events.mousedown(event);
 				},
 
 				touchend: function(event) {
-					that.events.mouseup(event);
+					events.mouseup(event);
 				}
 			};
 
-			// Remove old events first.
-			if (this._document)
-				DomEvent.remove(this._document.canvas, this.events);
-			this._document = doc;
-			DomEvent.add(doc.canvas, this.events);
+			DomEvent.add(doc.canvas, events);
 		},
 
 		getDocument: function() {

src/tool/ToolHandler.js

@@ -21,6 +21,7 @@ var ToolHandler = this.ToolHandler = Base.extend({
 	 * Initializes the tool's settings, so a new tool can be assigned to it
 	 */
 	initialize: function(handlers, scope) {
+		this._scope = scope;
 		this._firstMove = true;
 		this._count = 0;
 		this._downCount = 0;
@@ -120,6 +121,7 @@ var ToolHandler = this.ToolHandler = Base.extend({
 	},
 
 	onHandleEvent: function(type, pt, event) {
+		PaperScope.set(this._scope);
 		switch (type) {
 		case 'mousedown':
 			this.updateEvent(type, pt, null, null, true, false, false);
@@ -176,5 +178,6 @@ var ToolHandler = this.ToolHandler = Base.extend({
 			}
 			break;
 		}
+		PaperScope.restore();
 	}
 });

src/util/PaperScript.js

@@ -129,14 +129,19 @@ var PaperScript = this.PaperScript = new function() {
 		return parse_js.stringify(ast, true);
 	}
 
-	function run(code) {
-		with (paper) {
-			var doc = paper.document,
-				tool = paper.tool = /on(?:Key|Mouse)(?:Up|Down|Move|Drag)/.test(code)
-					&& new Tool(null, doc),
-				onEditOptions, onSelect, onDeselect, onReselect, onMouseDown,
-				onMouseUp, onMouseDrag, onMouseMove, onKeyDown, onKeyUp,
-				res = eval(compile(code));
+	function run(code, scope) {
+		try { with (scope) { // Safe one indentation by grouping try and with
+			PaperScope.set(scope);
+			var doc = scope.document;
+				// TODO: Add support for multiple tools
+			var tool = scope.tool =
+					/on(?:Key|Mouse)(?:Up|Down|Move|Drag)/.test(code)
+					&& new Tool(null, doc);
+			// Define variables for potential handlers, so eval() calls below to 
+			// fetch their values do not require try-catch around them.
+			var onEditOptions, onSelect, onDeselect, onReselect, onMouseDown,
+				onMouseUp, onMouseDrag, onMouseMove, onKeyDown, onKeyUp, onFrame;
+			var res = eval(compile(code));
 			if (tool) {
 				Base.each(['onEditOptions', 'onSelect', 'onDeselect',
 						'onReselect', 'onMouseDown', 'onMouseUp', 'onMouseDrag',
@@ -146,44 +151,44 @@ var PaperScript = this.PaperScript = new function() {
 					}
 				);
 			}
-			try {
-				var onFrame = eval('onFrame');
-				if (onFrame) {
-					var lastTime;
-					var totalTime = 0;
-					function frame() {
-						// Request next frame already
-						DomEvent.requestAnimationFrame(frame, doc && doc.canvas);
-						var time = Date.now() / 1000;
-						// Time elapsed since last redraw in seconds:
-						var delta = lastTime ? time - lastTime : 0;
-						// Time since first call of frame() in seconds:
-						totalTime += delta;
-						onFrame({
-							delta: delta,
-							time: totalTime
-						});
-						// Automatically redraw document each frame.
-						if (doc)
-							doc.redraw();
-						lastTime = time;
-					};
-					// Call the onFrame handler and redraw the document:
-					frame();
-				} else {
-					// Automatically redraw document at the end.
+			// TODO: Move onFrame support to DocumentView
+			var onFrame = eval('onFrame');
+			if (onFrame) {
+				var lastTime;
+				var totalTime = 0;
+				function frame() {
+					// Request next frame already
+					DomEvent.requestAnimationFrame(frame, doc && doc.canvas);
+					var time = Date.now() / 1000;
+					// Time elapsed since last redraw in seconds:
+					var delta = lastTime ? time - lastTime : 0;
+					// Time since first call of frame() in seconds:
+					totalTime += delta;
+					onFrame({
+						delta: delta,
+						time: totalTime
+					});
+					// Automatically redraw document each frame.
 					if (doc)
 						doc.redraw();
-				}
-			} catch (e) {
+					lastTime = time;
+				};
+				// Call the onFrame handler and redraw the document:
+				frame();
+			} else {
+				// Automatically redraw document at the end.
+				if (doc)
+					doc.redraw();
 			}
 			return res;
+		} } finally {
+			PaperScope.restore();
 		}
 	}
 
 //#ifdef BROWSER
 	// Code borrowed from Coffee Script:
-	function request(url) {
+	function request(url, scope) {
 		var xhr = new (window.ActiveXObject || XMLHttpRequest)(
 				'Microsoft.XMLHTTP');
 		xhr.open('GET', url, true);
@@ -192,7 +197,7 @@ var PaperScript = this.PaperScript = new function() {
 		}
 		xhr.onreadystatechange = function() {
 			if (xhr.readyState === 4) {
-				return run(xhr.responseText);
+				return run(xhr.responseText, scope);
 			}
 		};
 		return xhr.send(null);
@@ -205,16 +210,23 @@ var PaperScript = this.PaperScript = new function() {
 			// Only load this cript if it not loaded already.
 			if (script.type === 'text/paperscript'
 					&& !script.getAttribute('loaded')) {
+				// Produce a new PaperScope for this script now. Scopes are
+				// cheap so let's not worry about the initial one that was
+				// already created.
+				var scope = new PaperScope();
 				// If a canvas id is provided, create a document for it now,
 				// so the active document is defined.
 				var canvas = script.getAttribute('canvas');
 				if (canvas = canvas && document.getElementById(canvas)) {
+					// Create a Document for this canvas, using the right scope
+					PaperScope.set(scope);
 					new Document(canvas);
+					PaperScope.restore();
 				}
 				if (script.src) {
-					request(script.src);
+					request(script.src, scope);
 				} else {
-					run(script.innerHTML);
+					run(script.innerHTML, scope);
 				}
 				// Mark script as loaded now.
 				script.setAttribute('loaded', true);