Implement Item#get/setDocument and Document#selectedItems.

src/document/Document.js

@@ -37,6 +37,7 @@ var Document = this.Document = Base.extend({
 		this.symbols = [];
 		this.views = [new DocumentView(this)];
 		this.activeView = this.views[0];
+		this._selectedItems = [];
 	},
 
 	getCurrentStyle: function() {

src/item/Item.js

@@ -19,7 +19,7 @@ var Item = this.Item = Base.extend({
 
 	initialize: function() {
 		paper.document.activeLayer.appendTop(this);
-		this.setStyle(this.document.getCurrentStyle());
+		this.setStyle(this._document.getCurrentStyle());
 	},
 
 	/**
@@ -60,20 +60,47 @@ var Item = this.Item = Base.extend({
 				child.setSelected(selected);
 			}
 		} else {
-			this._selected = selected;
+			if (selected != this._selected) {
+				// TODO: when an item is removed or moved to another
+				// document, it needs to be removed from _selectedItems
+				this._selected = selected;
+				var selectedItems = this._document._selectedItems;
+				if (selected) {
+					selectedItems.push(this);
+				} else {
+					// TODO: is there a faster way?
+					var index = selectedItems.indexOf(this);
+					if (index != -1)
+						selectedItems.splice(index, 1);
+				}
+			}
 		}
 	},
 	
 	getSelected: function() {
-		if (this._children) {
+		if (this.children) {
-			for (var i = 0, l = this._children.length; i < l; i++) {
+			for (var i = 0, l = this.children.length; i < l; i++) {
-				var child = this._children[i];
+				if (this.children[i].getSelected())
-				if (child.getSelected())
 					return true;
 			}
 		} else {
 			return !!this._selected;
 		}
+		return false;
+	},
+	
+	getDocument: function() {
+		return this._document;
+	},
+	
+	setDocument: function(document) {
+		if (document != this._document) {
+			this._document = document;
+			if (this.children) {
+				for (var i = 0, l = this.children.length; i < l; i++)
+					this.children[i].setDocument(document);
+			}
+		}
 	},
 	
 	// TODO: isFullySelected / setFullySelected
@@ -252,6 +279,8 @@ var Item = this.Item = Base.extend({
 	* Removes the item.
 	*/
 	remove: function() {
+		if(this._selected)
+			this.setSelected(false);
 		return this.removeFromParent();
 	},
 
@@ -749,7 +778,7 @@ var Item = this.Item = Base.extend({
 				item.removeFromParent();
 				this.children.splice(top ? this.children.length : 0, 0, item);
 				item.parent = this;
-				item.document = this.document;
+				item.setDocument(this._document);
 				return true;
 			}
 			return false;
@@ -763,7 +792,7 @@ var Item = this.Item = Base.extend({
 				item.parent.children.splice(item.getIndex()
 						+ (above ? 1 : -1), 0, this);
 				this.parent = item.parent;
-				this.document = item.document;
+				this.setDocument(item._document);
 				return true;
 			}
 			return false;

src/item/Layer.js

@@ -19,13 +19,13 @@ var Layer = this.Layer = Group.extend({
 
 	initialize: function() {
 		this.children = [];
-		this.document = paper.document;
+		this._document = paper.document;
-		this.document.layers.push(this);
+		this._document.layers.push(this);
 		this.activate();
 	},
 
 	getIndex: function() {
-		return this.parent ? this.base() : this.document.layers.indexOf(this);
+		return this.parent ? this.base() : this._document.layers.indexOf(this);
 	},
 
 	/**
@@ -34,7 +34,7 @@ var Layer = this.Layer = Group.extend({
 	*/
 	removeFromParent: function() {
 		if (!this.parent) {
-			return !!this.document.layers.splice(this.getIndex(), 1).length;
+			return !!this._document.layers.splice(this.getIndex(), 1).length;
 		} else {
 			return this.base();
 		}
@@ -42,16 +42,16 @@ var Layer = this.Layer = Group.extend({
 
 	getNextSibling: function() {
 		return this.parent ? this.base()
-				: this.document.layers[this.getIndex() + 1] || null;
+				: this._document.layers[this.getIndex() + 1] || null;
 	},
 
 	getPreviousSibling: function() {
 		return this.parent ? this.base()
-				: this.document.layers[this.getIndex() - 1] || null;
+				: this._document.layers[this.getIndex() - 1] || null;
 	},
 
 	activate: function() {
-		this.document.activeLayer = this;
+		this._document.activeLayer = this;
 	}
 }, new function () {
 	function move(above) {
@@ -59,9 +59,9 @@ var Layer = this.Layer = Group.extend({
 			// if the item is a layer and contained within Document#layers
 			if (item instanceof Layer && !item.parent) {
 				this.removeFromParent();
-				item.document.layers.splice(item.getIndex() + (above ? 1 : -1),
+				item._document.layers.splice(item.getIndex() + (above ? 1 : -1),
 						0, this);
-				this.document = item.document;
+				this.setDocument(item._document);
 				return true;
 			} else {
 				return this.base(item);