Implement new strategy regarding Project#activeLayer:

- By default, no layer is created for any project.
- Project#activeLayer is a getter for the hidden #_activeLayer property. When it is called and no layer exists, one is created on the fly.
- Creating any other items creates a layer if none exists (was already the case).

src/item/Layer.js

@@ -86,8 +86,8 @@ var Layer = Group.extend(/** @lends Layer# */{
             return _remove.base.call(this, notify);
         if (this._index != null) {
             var project = this._project;
-            if (project.activeLayer === this)
-                project.activeLayer = this.getNextSibling()
+            if (project._activeLayer === this)
+                project._activeLayer = this.getNextSibling()
                         || this.getPreviousSibling();
             Base.splice(project.layers, null, this._index, 1);
             this._installEvents(false);
@@ -124,7 +124,7 @@ var Layer = Group.extend(/** @lends Layer# */{
      * console.log(project.activeLayer == firstLayer); // true
      */
     activate: function() {
-        this._project.activeLayer = this;
+        this._project._activeLayer = this;
     },
 
     // Private helper for #insertAbove() / #insertBelow()

src/project/Project.js

@@ -53,9 +53,9 @@ var Project = PaperScopeItem.extend(/** @lends Project# */{
         // constructors.
         PaperScopeItem.call(this, true);
         this.layers = [];
+        this._activeLayer = null;
         this.symbols = [];
         this._currentStyle = new Style(null, null, this);
-        this.activeLayer = new Layer();
         // If no view is provided, we create a 1x1 px canvas view just so we
         // have something to do size calculations with.
         // (e.g. PointText#_getBounds)
@@ -98,15 +98,12 @@ var Project = PaperScopeItem.extend(/** @lends Project# */{
     },
 
     /**
-     * Checks whether the project has any content or not. Note that since
-     * projects by default are created with one empty layer, this returns also
-     * {@code true} if that layer exists but is itself empty.
+     * Checks whether the project has any content or not.
      *
      * @return Boolean
      */
     isEmpty: function() {
-        return this.layers.length <= 1
-            && (!this.activeLayer || this.activeLayer.isEmpty());
+        return this.layers.length === 0;
     },
 
     /**
@@ -183,11 +180,11 @@ var Project = PaperScopeItem.extend(/** @lends Project# */{
         if (child instanceof Layer) {
             Base.splice(this.layers, [child]);
             // Also activate this layer if there was none before
-            if (!this.activeLayer)
-                this.activeLayer = child;
+            if (!this._activeLayer)
+                this._activeLayer = child;
         } else if (child instanceof Item) {
             // Anything else than layers needs to be added to a layer first
-            (this.activeLayer
+            (this._activeLayer
                 // NOTE: If there is no layer and this project is not the active
                 // one, passing insert: false and calling addChild on the
                 // project will handle it correctly.
@@ -772,7 +769,7 @@ var Project = PaperScopeItem.extend(/** @lends Project# */{
         this.activate();
         // Provide the activeLayer as a possible target for layers, but only if
         // it's empty.
-        var layer = this.activeLayer;
+        var layer = this._activeLayer;
         return Base.importJSON(json, layer && layer.isEmpty() && layer);
     },
 
@@ -815,7 +812,7 @@ var Project = PaperScopeItem.extend(/** @lends Project# */{
      */
 
     /**
-     * {@grouptitle Project Hierarchy}
+     * {@grouptitle Project Content}
      *
      * The layers contained within the project.
      *
@@ -827,9 +824,12 @@ var Project = PaperScopeItem.extend(/** @lends Project# */{
      * The layer which is currently active. New items will be created on this
      * layer by default.
      *
-     * @name Project#activeLayer
      * @type Layer
+     * @bean
      */
+    getActiveLayer: function() {
+        return this._activeLayer || new Layer({ project: this });
+    },
 
     /**
      * The symbols contained within the project.

test/tests/Item_Getting.js

@@ -45,18 +45,20 @@ test('Item#matches()', function() {
 });
 
 test('Project#getItems()', function() {
+    var layer = new Layer();
+
     equals(function() {
         var matches = paper.project.getItems({
             type: 'layer'
         });
-        return matches.length == 1 && matches[0] == paper.project.activeLayer;
+        return matches.length == 1 && matches[0] == layer;
     }, true);
 
     equals(function() {
         var matches = paper.project.getItems({
-            'class': Item
+            class: Item
         });
-        return matches.length == 1 && matches[0] == paper.project.activeLayer;
+        return matches.length == 1 && matches[0] == layer;
     }, true);
 
     var path = new Path();
@@ -69,12 +71,11 @@ test('Project#getItems()', function() {
 
     equals(function() {
         var matches = paper.project.getItems({
-            'constructor': Path
+            constructor: Path
         });
         return matches.length == 1 && matches[0] === path;
     }, true);
 
-
     var group = new Group();
     equals(function() {
         var matches = paper.project.getItems({

test/tests/Project.js

@@ -29,6 +29,7 @@ test('clear()', function() {
     var project = new Project();
     new Layer();
     new Layer();
+    new Layer();
     equals(project.layers.length, 3);
     project.clear();
     equals(project.layers.length, 0);