diff -r 7e132e2a48ca -r 267d67791e05 server/src/main/webapp/static/js/paper-renderer.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/server/src/main/webapp/static/js/paper-renderer.js	Tue Dec 25 21:29:11 2012 +0100
@@ -0,0 +1,1400 @@
+Rkns.Renderer = {
+    _MARGIN_X: 80,
+    _MARGIN_Y: 50,
+    _MIN_DRAG_DISTANCE: 2,
+    _NODE_RADIUS: 25,
+    _NODE_BUTTON_INNER: 26,
+    _NODE_BUTTON_OUTER: 60,
+    _EDGE_BUTTON_INNER: 1,
+    _EDGE_BUTTON_OUTER: 40,
+    _NODE_FONT_SIZE: 10,
+    _EDGE_FONT_SIZE: 9,
+    _NODE_MAX_CHAR: 50,
+    _EDGE_MAX_CHAR: 40,
+    _ARROW_LENGTH: 16,
+    _ARROW_WIDTH: 8,
+    _EDITOR_ARROW_LENGTH : 20,
+    _EDITOR_ARROW_WIDTH : 40,
+    _EDITOR_MARGIN : 15,
+    _EDITOR_PADDING : 10,
+    _EDITOR_GRADIENT : new paper.Gradient(['#f0f0f0', '#d0d0d0']),
+    _CLICKMODE_ADDNODE : 1,
+    _CLICKMODE_STARTEDGE : 2,
+    _CLICKMODE_ENDEDGE : 3
+}
+
+Rkns.Renderer.Utils = {
+    drawEditBox : function(_coords, _path, _width, _xmargin, _selector) {
+        _selector.css({
+            width: (_width - 2* Rkns.Renderer._EDITOR_PADDING),
+        })
+        var _height = _selector.outerHeight() + 2* Rkns.Renderer._EDITOR_PADDING,
+            _isLeft = (_coords.x < paper.view.center.x ? 1 : -1),
+            _left = _coords.x + _isLeft * ( _xmargin + Rkns.Renderer._EDITOR_ARROW_LENGTH ),
+            _right = _coords.x + _isLeft * ( _xmargin + Rkns.Renderer._EDITOR_ARROW_LENGTH + _width ),
+            _top = _coords.y - _height / 2;
+        if (_top < Rkns.Renderer._EDITOR_MARGIN) {
+            _top = Math.min( Rkns.Renderer._EDITOR_MARGIN, _coords.y - Rkns.Renderer._EDITOR_ARROW_WIDTH / 2 );
+        }
+        var _bottom = _top + _height;
+        if (_bottom > (paper.view.size.height - Rkns.Renderer._EDITOR_MARGIN)) {
+            _bottom = Math.max( paper.view.size.height - Rkns.Renderer._EDITOR_MARGIN, _coords.y + Rkns.Renderer._EDITOR_ARROW_WIDTH / 2 );
+            _top = _bottom - _height;
+        }
+        _path.segments[0].point
+            = _path.segments[7].point
+            = _coords.add([_isLeft * _xmargin, 0]);
+        _path.segments[1].point.x
+            = _path.segments[2].point.x
+            = _path.segments[5].point.x
+            = _path.segments[6].point.x
+            = _left;
+        _path.segments[3].point.x
+            = _path.segments[4].point.x
+            = _right;
+        _path.segments[2].point.y
+            = _path.segments[3].point.y
+            = _top;
+        _path.segments[4].point.y
+            = _path.segments[5].point.y
+            = _bottom;
+        _path.segments[1].point.y = _coords.y - Rkns.Renderer._EDITOR_ARROW_WIDTH / 2;
+        _path.segments[6].point.y = _coords.y + Rkns.Renderer._EDITOR_ARROW_WIDTH / 2;
+        _path.closed = true;
+        _path.fillColor = new paper.GradientColor(Rkns.Renderer._EDITOR_GRADIENT, [0,_top], [0, _bottom]);
+        _selector.css({
+            left: (Rkns.Renderer._EDITOR_PADDING + Math.min(_left, _right)),
+            top: (Rkns.Renderer._EDITOR_PADDING + _top)
+        });
+    },
+    sector : function(_repr, _inR, _outR, _startAngle, _endAngle, _padding, _imgsrc, _caption) {
+        var _startRads = _startAngle * Math.PI / 180,
+            _endRads = _endAngle * Math.PI / 180,
+            _img = new Image(),
+            _span = _endRads - _startRads,
+            _k = .0879 * _span,
+            _kin = _k * _inR,
+            _kout = _k * _outR,
+            _startdx = - Math.sin(_startRads),
+            _startdy = Math.cos(_startRads),
+            _startXIn = Math.cos(_startRads) * _inR + _padding * _startdx,
+            _startYIn = Math.sin(_startRads) * _inR + _padding * _startdy,
+            _startXOut = Math.cos(_startRads) * _outR + _padding * _startdx,
+            _startYOut = Math.sin(_startRads) * _outR + _padding * _startdy,
+            _enddx = - Math.sin(_endRads),
+            _enddy = Math.cos(_endRads),
+            _endXIn = Math.cos(_endRads) * _inR - _padding * _enddx,
+            _endYIn = Math.sin(_endRads) * _inR - _padding * _enddy,
+            _endXOut = Math.cos(_endRads) * _outR - _padding * _enddx,
+            _endYOut = Math.sin(_endRads) * _outR - _padding * _enddy,
+            _centerR = (_inR + _outR)/2,
+            _centerRads = (_startRads + _endRads) / 2,
+            _centerX = Math.cos(_centerRads) * _centerR,
+            _centerY = Math.sin(_centerRads) * _centerR,
+            _textX = Math.cos(_centerRads) * (_outR + 3),
+            _textY = Math.sin(_centerRads) * (_outR + 3),
+            _segments = [];
+        _segments.push([[_startXIn, _startYIn], [0, 0], [ _kin * _startdx, _kin * _startdy ]]);
+        for (var i = 1; i < 4; i++) {
+            var _rads = i * _span / 4 + _startRads,
+                _dx = - Math.sin(_rads),
+                _dy = Math.cos(_rads),
+                _x = Math.cos(_rads) * _inR,
+                _y = Math.sin(_rads) * _inR;
+            _segments.push([[_x, _y], [ - _kin * _dx, - _kin * _dy], [ _kin * _dx, _kin * _dy ]]);
+        }
+        _segments.push([[_endXIn, _endYIn], [ - _kin * _enddx, - _kin * _enddy ], [0,0]]);
+        _segments.push([[_endXOut, _endYOut], [ 0,0 ], [ - _kout * _enddx, - _kout * _enddy ]]);
+        for (var i = 3; i > 0; i--) {
+            var _rads = i * _span / 4 + _startRads,
+                _dx = - Math.sin(_rads),
+                _dy = Math.cos(_rads),
+                _x = Math.cos(_rads) * _outR,
+                _y = Math.sin(_rads) * _outR;
+            _segments.push([[_x, _y], [ _kout * _dx, _kout * _dy], [ - _kout * _dx, - _kout * _dy ]]);
+        }
+        _segments.push([[_startXOut, _startYOut], [ _kout * _startdx, _kout * _startdy ], [0, 0]]);
+        var _path = new paper.Path();
+        _path.add.apply(_path, _segments);
+        _path.fillColor = "#333333";
+        _path.opacity = .5;
+        _path.closed = true;
+        _path.__representation = _repr;
+        if (_textX >= -2 && _textX <= 2) {
+            if (_textY > 0) {
+                _textY += 6;
+            }
+        }
+        var _text = new paper.PointText(_textX,_textY);
+        _text.characterStyle = {
+            fontSize: 9,
+            fillColor: '#c000c0'
+        };
+        if (_textX > 2) {
+            _text.paragraphStyle.justification = 'left';
+        } else if (_textX < -2) {
+            _text.paragraphStyle.justification = 'right';
+        } else {
+            _text.paragraphStyle.justification = 'center';
+        }
+        _text.visible = false;
+        var _visible = false,
+            _restPos = new paper.Point(-200, -200),
+            _grp = new paper.Group([_path, _text]),
+            _delta = _grp.position,
+            _imgdelta = new paper.Point([_centerX, _centerY]),
+            _currentPos = new paper.Point(0,0);
+        _text.content = _caption;
+        _grp.visible = false;
+        _grp.position = _restPos;
+        var _res = {
+            show: function() {
+                _visible = true;
+                _grp.position = _currentPos.add(_delta);
+                _grp.visible = true;
+            },
+            moveTo: function(_point) {
+                _currentPos = _point;
+                if (_visible) {
+                    _grp.position = _point.add(_delta);
+                }
+            },
+            hide: function() {
+                _visible = false;
+                _grp.visible = false;
+                _grp.position = _restPos;
+            },
+            select: function() {
+                _path.opacity = .8;
+                _text.visible = true;
+            },
+            unselect: function() {
+                _path.opacity = .5;
+                _text.visible = false;
+            },
+            destroy: function() {
+                _grp.remove();
+            }
+        }
+        _img.onload = function() {
+            var _h = _img.height;
+            var _raster = new paper.Raster(_img);
+            _raster.position = _imgdelta.add(_grp.position).subtract(_delta);
+            _grp.addChild(_raster);
+        }
+        _img.src = _imgsrc;
+        return _res
+    }
+}
+
+Rkns.Renderer._BaseRepresentation = function(_renderer, _model) {
+    if (typeof _renderer !== "undefined") {
+        this.renderer = _renderer;
+        this.project = _renderer.renkan.project;
+        this.model = _model;
+        if (this.model) {
+            var _this = this;
+            this._changeBinding = function() {
+                _this.redraw();
+            }
+            this._removeBinding = function() {
+                _renderer.removeRepresentation(_this);
+                _renderer.redraw();
+            }
+            this.model.on("change", this._changeBinding );
+            this.model.on("remove", this._removeBinding );
+        }
+    }
+}
+
+Rkns.Renderer._BaseRepresentation.prototype.super = function(_func) {
+    Rkns.Renderer._BaseRepresentation.prototype[_func].apply(this, Array.prototype.slice.call(arguments, 1));
+}
+
+Rkns.Renderer._BaseRepresentation.prototype.select = function() {}
+
+Rkns.Renderer._BaseRepresentation.prototype.unselect = function() {}
+
+Rkns.Renderer._BaseRepresentation.prototype.highlight = function() {}
+
+Rkns.Renderer._BaseRepresentation.prototype.unhighlight = function() {}
+
+Rkns.Renderer._BaseRepresentation.prototype.mouseup = function() {}
+
+Rkns.Renderer._BaseRepresentation.prototype.destroy = function() {
+    if (this.model) {
+        this.model.off("change", this._changeBinding );
+        this.model.off("remove", this._removeBinding );
+    }
+}
+
+Rkns.Renderer.Node = Rkns.Utils.inherit(Rkns.Renderer._BaseRepresentation);
+
+Rkns.Renderer.Node.prototype._init = function() {
+    this.renderer.node_layer.activate();
+    this.type = "Node";
+    this.circle = new paper.Path.Circle([0, 0], Rkns.Renderer._NODE_RADIUS);
+    this.circle.fillColor = '#ffffff';
+    this.circle.__representation = this;
+    this.title = new paper.PointText([0,0]);
+    this.title.characterStyle = {
+        fontSize: Rkns.Renderer._NODE_FONT_SIZE,
+        fillColor: 'black'
+    };
+    this.edit_button = new Rkns.Renderer.NodeEditButton(this.renderer, null);
+    this.edit_button.node_representation = this;
+    this.remove_button = new Rkns.Renderer.NodeRemoveButton(this.renderer, null);
+    this.remove_button.node_representation = this;
+    this.link_button = new Rkns.Renderer.NodeLinkButton(this.renderer, null);
+    this.link_button.node_representation = this;
+    this.title.paragraphStyle.justification = 'center';
+}
+
+Rkns.Renderer.Node.prototype.redraw = function() {
+    var _model_coords = new paper.Point(this.model.get("position"));
+    this.paper_coords = this.renderer.toPaperCoords(_model_coords);
+    this.circle.position = this.paper_coords;
+    this.title.content = this.model.get("title");
+    this.title.position = this.paper_coords.add([0, Rkns.Renderer._NODE_RADIUS + 1.5 *Rkns.Renderer._NODE_FONT_SIZE]);
+    this.circle.strokeColor = this.model.get("created_by").get("color");
+    this.edit_button.moveTo(this.paper_coords);
+    this.remove_button.moveTo(this.paper_coords);
+    this.link_button.moveTo(this.paper_coords);
+    var _img = this.model.get("image");
+    if (_img && _img !== this.img) {
+        var _image = new Image(),
+            _this = this;
+        _image.onload = function() {
+            if (_this.node_image) {
+                _this.node_image.remove();
+            }
+            _this.renderer.node_layer.activate();
+            var _ratio = Math.min(1, 2 * Rkns.Renderer._NODE_RADIUS / _image.width, 2 * Rkns.Renderer._NODE_RADIUS / _image.height );
+            var _raster = new paper.Raster(_image);
+            var _clip = new paper.Path.Circle([0, 0], Rkns.Renderer._NODE_RADIUS);
+            _raster.scale(_ratio);
+            _this.node_image = new paper.Group(_clip, _raster);
+            _this.node_image.opacity = .9;
+            /* This is a workaround to allow clipping at group level
+             * If opacity was set to 1, paper.js would merge all clipping groups in one (known bug).
+            */
+            _this.node_image.clipped = true;
+            _this.node_image.position = _this.paper_coords;
+            _this.node_image.__representation = _this;
+            _clip.__representation = _this;
+            paper.view.draw();
+        }
+        _image.src = _img;
+    }
+    this.img = _img;
+    if (this.node_image) {
+        if (!this.img) {
+            this.node_image.remove();
+            delete this.node_image;
+        } else {
+            this.node_image.position = this.paper_coords;
+        }
+    }
+}
+
+Rkns.Renderer.Node.prototype.paperShift = function(_delta) {
+    var _coords = this.renderer.toModelCoords(this.paper_coords.add(_delta)),
+        _data = {
+            position: {
+                x: _coords.x,
+                y: _coords.y
+            }
+        };
+    this.model.set(_data);
+    this.renderer.redraw();
+}
+
+Rkns.Renderer.Node.prototype.openEditor = function() {
+    this.renderer.removeRepresentationsOfType("editor");
+    var _editor = this.renderer.addRepresentation("NodeEditor",null);
+    _editor.node_representation = this;
+    _editor.draw();
+}
+
+Rkns.Renderer.Node.prototype.select = function() {
+    this.circle.strokeWidth = 3;
+    this.edit_button.show();
+    this.remove_button.show();
+    this.link_button.show();
+    var _uri = this.model.get("uri");
+    Rkns.$('.Rk-Bin-Item').each(function() {
+        var _el = Rkns.$(this);
+        if (_el.attr("data-uri") == _uri) {
+            _el.addClass("selected");
+        }
+    });
+}
+
+Rkns.Renderer.Node.prototype.unselect = function(_newTarget) {
+    if (!_newTarget || _newTarget.node_representation !== this) {
+        this.edit_button.hide();
+        this.remove_button.hide();
+        this.link_button.hide();
+        this.circle.strokeWidth = 1;
+        Rkns.$('.Rk-Bin-Item').removeClass("selected");
+    }
+}
+
+Rkns.Renderer.Node.prototype.highlight = function() {
+    this.circle.fillColor = "#ffff80";
+    if (this.node_image) {
+        this.node_image.opacity = .5;
+    }
+}
+
+Rkns.Renderer.Node.prototype.unhighlight = function(_newTarget) {
+    this.circle.fillColor = "#ffffff";
+    if (this.node_image) {
+        this.node_image.opacity = .9;
+    }
+}
+
+Rkns.Renderer.Node.prototype.mouseup = function(_event) {
+    if (!this.renderer.is_dragging) {
+        this.openEditor();
+    }
+    this.renderer.click_target = null;
+    this.renderer.is_dragging = false;
+}
+
+Rkns.Renderer.Node.prototype.destroy = function(_event) {
+    this.super("destroy");
+    this.edit_button.destroy();
+    this.remove_button.destroy();
+    this.link_button.destroy();
+    this.circle.remove();
+    this.title.remove();
+    if (this.node_image) {
+        this.node_image.remove();
+    }
+}
+
+/* */
+
+Rkns.Renderer.Edge = Rkns.Utils.inherit(Rkns.Renderer._BaseRepresentation);
+
+Rkns.Renderer.Edge.prototype._init = function() {
+    this.renderer.edge_layer.activate();
+    this.type = "Edge";
+    this.from_representation = this.renderer.getRepresentationByModel(this.model.get("from"));
+    this.to_representation = this.renderer.getRepresentationByModel(this.model.get("to"));
+    this.bundle = this.renderer.addToBundles(this);
+    this.line = new paper.Path();
+    this.line.add([0,0],[0,0],[0,0]);
+    this.line.__representation = this;
+    this.arrow = new paper.Path();
+    this.arrow.add([0,0],[Rkns.Renderer._ARROW_LENGTH,Rkns.Renderer._ARROW_WIDTH / 2],[0,Rkns.Renderer._ARROW_WIDTH]);
+    this.arrow.__representation = this;
+    this.text = new paper.PointText();
+    this.text.characterStyle = {
+        fontSize: Rkns.Renderer._EDGE_FONT_SIZE,
+        fillColor: 'black'
+    };
+    this.text.paragraphStyle.justification = 'center';
+    this.text_angle = 0;
+    this.arrow_angle = 0;
+    this.edit_button = new Rkns.Renderer.EdgeEditButton(this.renderer, null);
+    this.edit_button.edge_representation = this;
+    this.remove_button = new Rkns.Renderer.EdgeRemoveButton(this.renderer, null);
+    this.remove_button.edge_representation = this;
+}
+
+Rkns.Renderer.Edge.prototype.redraw = function() {
+    var _p0a = this.from_representation.paper_coords,
+        _p1a = this.to_representation.paper_coords,
+        _v = _p1a.subtract(_p0a),
+        _r = _v.length,
+        _u = _v.divide(_r),
+        _group_pos = this.bundle.getPosition(this),
+        _delta = new paper.Point([- _u.y, _u.x]).multiply( 12 * _group_pos ),
+        _p0b = _p0a.add(_delta), /* Adding a 4 px difference */
+        _p1b = _p1a.add(_delta), /* to differentiate inbound and outbound links */
+        _a = _v.angle,
+        _handle = _v.divide(3),
+        _color = this.model.get("created_by").get("color");
+    this.paper_coords = _p0b.add(_p1b).divide(2);
+    this.line.strokeColor = _color;
+    this.line.segments[0].point = _p0a;
+    this.line.segments[1].point = this.paper_coords;
+    this.line.segments[1].handleIn = _handle.multiply(-1);
+    this.line.segments[1].handleOut = _handle;
+    this.line.segments[2].point = _p1a;
+    this.arrow.rotate(_a - this.arrow_angle);
+    this.arrow.fillColor = _color;
+    this.arrow.position = this.paper_coords.subtract(_u.multiply(4));
+    this.arrow_angle = _a;
+    if (_a > 90) {
+        _a -= 180;
+    }
+    if (_a < -90) {
+        _a += 180;
+    }
+    this.text.rotate(_a - this.text_angle);
+    this.text.content = this.model.get("title");
+    this.text.position = this.paper_coords;
+    this.text_angle = _a;
+    this.edit_button.moveTo(this.paper_coords);
+    this.remove_button.moveTo(this.paper_coords);
+}
+
+Rkns.Renderer.Edge.prototype.openEditor = function() {
+    this.renderer.removeRepresentationsOfType("editor");
+    var _editor = this.renderer.addRepresentation("EdgeEditor",null);
+    _editor.edge_representation = this;
+    _editor.draw();
+}
+
+Rkns.Renderer.Edge.prototype.select = function() {
+    this.line.strokeWidth = 3;
+    this.edit_button.show();
+    this.remove_button.show();
+}
+
+Rkns.Renderer.Edge.prototype.unselect = function(_newTarget) {
+    if (!_newTarget || _newTarget.edge_representation !== this) {
+        this.edit_button.hide();
+        this.remove_button.hide();
+        this.line.strokeWidth = 1;
+    }
+}
+
+Rkns.Renderer.Edge.prototype.mouseup = function(_event) {
+    if (!this.renderer.is_dragging) {
+        this.openEditor();
+    }
+    this.renderer.click_target = null;
+    this.renderer.is_dragging = false;
+}
+
+Rkns.Renderer.Edge.prototype.paperShift = function(_delta) {
+    this.from_representation.paperShift(_delta);
+    this.to_representation.paperShift(_delta);
+    this.renderer.redraw();
+}
+
+Rkns.Renderer.Edge.prototype.destroy = function() {
+    this.super("destroy");
+    this.line.remove();
+    this.arrow.remove();
+    this.text.remove();
+    this.edit_button.destroy();
+    this.remove_button.destroy();
+    var _this = this;
+    this.bundle.edges = Rkns._(this.bundle.edges).reject(function(_edge) {
+        return _edge === _this;
+    });
+}
+
+/* */
+
+Rkns.Renderer.TempEdge = Rkns.Utils.inherit(Rkns.Renderer._BaseRepresentation);
+
+Rkns.Renderer.TempEdge.prototype._init = function() {
+    this.renderer.edge_layer.activate();
+    this.type = "temp-edge";
+    
+    var _color = this.project.get("users").get(this.renderer.renkan.current_user).get("color");
+    this.line = new paper.Path();
+    this.line.strokeColor = _color;
+    this.line.add([0,0],[0,0]);
+    this.line.__representation = this;
+    this.arrow = new paper.Path();
+    this.arrow.fillColor = _color;
+    this.arrow.add([0,0],[Rkns.Renderer._ARROW_LENGTH,Rkns.Renderer._ARROW_WIDTH / 2],[0,Rkns.Renderer._ARROW_WIDTH]);
+    this.arrow.__representation = this;
+    this.arrow_angle = 0;
+}
+
+Rkns.Renderer.TempEdge.prototype.redraw = function() {
+    var _p0 = this.from_representation.paper_coords,
+        _p1 = this.end_pos,
+        _a = _p1.subtract(_p0).angle,
+        _c = _p0.add(_p1).divide(2);
+    this.line.segments[0].point = _p0;
+    this.line.segments[1].point = _p1;
+    this.arrow.rotate(_a - this.arrow_angle);
+    this.arrow.position = _c;
+    this.arrow_angle = _a;
+}
+
+Rkns.Renderer.TempEdge.prototype.paperShift = function(_delta) {
+    this.end_pos = this.end_pos.add(_delta);
+    var _hitResult = paper.project.hitTest(this.end_pos);
+    this.renderer.findTarget(_hitResult);
+    this.redraw();
+}
+
+Rkns.Renderer.TempEdge.prototype.mouseup = function(_event) {
+    var _hitResult = paper.project.hitTest(_event.point),
+        _model = this.from_representation.model,
+        _endDrag = true;
+    if (_hitResult && typeof _hitResult.item.__representation !== "undefined") {
+        var _target = _hitResult.item.__representation;
+        if (_target.type === "Node" && _model !== _target.model) {
+            var _data = {
+                id: Rkns.Utils.getUID('edge'),
+                created_by: this.renderer.renkan.current_user,
+                from: _model.get("_id"),
+                to: _target.model.get("_id")
+            };
+            this.project.addEdge(_data);
+        }
+        if (_model === _target.model || (_target.node_representation && _target.node_representation.model === _model)) {
+            _endDrag = false;
+            this.renderer.is_dragging = true;
+        }
+    }
+    if (_endDrag) {
+        this.renderer.click_target = null;
+        this.renderer.is_dragging = false;
+        this.renderer.removeRepresentation(this);
+        paper.view.draw();
+    }
+}
+
+Rkns.Renderer.TempEdge.prototype.destroy = function() {
+    this.arrow.remove();
+    this.line.remove();
+}
+
+/* */
+
+Rkns.Renderer.NodeEditor = Rkns.Utils.inherit(Rkns.Renderer._BaseRepresentation);
+
+Rkns.Renderer.NodeEditor.prototype._init = function() {
+    this.renderer.overlay_layer.activate();
+    this.type = "editor";
+    this.editor_block = new paper.Path();
+    var _pts = Rkns._(Rkns._.range(8)).map(function() {return [0,0]});
+    this.editor_block.add.apply(this.editor_block, _pts);
+    this.editor_block.strokeWidth = 2;
+    this.editor_block.strokeColor = "#999999";
+    this.editor_block.fillColor = "#e0e0e0";
+    this.editor_block.opacity = .8;
+    this.editor_$ = Rkns.$('<div>')
+        .appendTo(this.renderer.editor_$)
+        .css({
+            position: "absolute",
+            opacity: .8
+        })
+        .hide();
+}
+
+Rkns.Renderer.NodeEditor.prototype.template = Rkns._.template(
+    '<h2><span class="Rk-CloseX">&times;</span><%=l10n.edit_node%></span></h2>'
+    + '<p><label><%=l10n.edit_title%></label><input class="Rk-Edit-Title" type="text" value="<%=node.title%>"/></p>'
+    + '<p><label><%=l10n.edit_uri%></label><input class="Rk-Edit-URI" type="text" value="<%=node.uri%>"/><a class="Rk-Edit-Goto" href="<%=node.uri%>" target="_blank"></a></p>'
+    + '<p><label><%=l10n.edit_description%></label><textarea class="Rk-Edit-Description"><%=node.description%></textarea></p>'
+    + '<p><label><%=l10n.edit_image%></label><input class="Rk-Edit-Image" type="text" value="<%=node.image%>"/><img class="Rk-Edit-ImgPreview" src="<%=node.image%>" /></p>'
+    + '<p><label><%=l10n.created_by%></label> <span class="Rk-UserColor" style="background:<%=node.created_by_color%>;"></span><%=node.created_by_title%></p>'
+);
+
+Rkns.Renderer.NodeEditor.prototype.draw = function() {
+    var _model = this.node_representation.model;
+    this.editor_$
+        .html(this.template({
+            node: {
+                title: _model.get("title"),
+                uri: _model.get("uri"),
+                description: _model.get("description"),
+                image: _model.get("image") || "",
+                created_by_color: _model.get("created_by").get("color"),
+                created_by_title: _model.get("created_by").get("title")
+            },
+            l10n: this.renderer.renkan.l10n
+        }));
+    this.redraw();
+    var _this = this;
+    this.editor_$.find(".Rk-CloseX").click(function() {
+        _this.renderer.removeRepresentation(_this);
+        paper.view.draw();
+    });
+    this.editor_$.find("input, textarea").bind("keyup change", function() {
+        var _uri = _this.editor_$.find(".Rk-Edit-URI").val(),
+            _image = _this.editor_$.find(".Rk-Edit-Image").val();
+        _this.editor_$.find(".Rk-Edit-ImgPreview").attr("src", _image);
+        _this.editor_$.find(".Rk-Edit-Goto").attr("href",_uri);
+        var _data = {
+            title: _this.editor_$.find(".Rk-Edit-Title").val(),
+            description: _this.editor_$.find(".Rk-Edit-Description").val(),
+            uri: _uri,
+            image: _image
+        }
+        _model.set(_data);
+        _this.redraw();
+    });
+    this.editor_$.find("img").load(function() {
+        _this.redraw();
+    })
+    this.editor_$.find(".Rk-Edit-Title")[0].focus();
+}
+
+Rkns.Renderer.NodeEditor.prototype.redraw = function() {
+    var _coords = this.node_representation.paper_coords;
+    Rkns.Renderer.Utils.drawEditBox(_coords, this.editor_block, 250, 20, this.editor_$);
+    this.editor_$.show();
+    paper.view.draw();
+}
+
+Rkns.Renderer.NodeEditor.prototype.destroy = function() {
+    this.editor_block.remove();
+    this.editor_$.detach();
+}
+
+/* */
+
+Rkns.Renderer.EdgeEditor = Rkns.Utils.inherit(Rkns.Renderer._BaseRepresentation);
+
+Rkns.Renderer.EdgeEditor.prototype._init = function() {
+    this.renderer.overlay_layer.activate();
+    this.type = "editor";
+    this.editor_block = new paper.Path();
+    var _pts = Rkns._(Rkns._.range(8)).map(function() {return [0,0]});
+    this.editor_block.add.apply(this.editor_block, _pts);
+    this.editor_block.strokeWidth = 2;
+    this.editor_block.strokeColor = "#999999";
+    this.editor_block.fillColor = "#e0e0e0";
+    this.editor_block.opacity = .8;
+    this.editor_$ = Rkns.$('<div>')
+        .appendTo(this.renderer.editor_$)
+        .css({
+            position: "absolute",
+            opacity: .8
+        })
+        .hide();
+}
+
+Rkns.Renderer.EdgeEditor.prototype.template = Rkns._.template(
+    '<h2><span class="Rk-CloseX">&times;</span><%=l10n.edit_edge%></span></h2>'
+    + '<p><label><%=l10n.edit_title%></label><input class="Rk-Edit-Title" type="text" value="<%=edge.title%>"/></p>'
+    + '<p><label><%=l10n.edit_uri%></label><input class="Rk-Edit-URI" type="text" value="<%=edge.uri%>"/><a class="Rk-Edit-Goto" href="<%=edge.uri%>" target="_blank"></a></p>'
+    + '<p><label><%=l10n.edit_from%></label><span class="Rk-UserColor" style="background:<%=edge.from_created_by_color%>;"></span><%=edge.from_title%></p>'
+    + '<p><label><%=l10n.edit_to%></label><span class="Rk-UserColor" style="background:<%=edge.to_created_by_color%>;"></span><%=edge.to_title%></p>'
+    + '<p><label><%=l10n.created_by%> </label><span class="Rk-UserColor" style="background:<%=edge.created_by_color%>;"></span><%=edge.created_by_title%></p>'
+);
+
+Rkns.Renderer.EdgeEditor.prototype.draw = function() {
+    var _model = this.edge_representation.model;
+    this.editor_$
+        .html(this.template({
+            edge: {
+                title: _model.get("title"),
+                uri: _model.get("uri"),
+                description: _model.get("description"),
+                from_title: _model.get("from").get("title"),
+                to_title: _model.get("to").get("title"),
+                from_created_by_color: _model.get("from").get("created_by").get("color"),
+                to_created_by_color: _model.get("to").get("created_by").get("color"),
+                created_by_color: _model.get("created_by").get("color"),
+                created_by_title: _model.get("created_by").get("title")
+            },
+            l10n: this.renderer.renkan.l10n
+        }));
+    this.redraw();
+    var _this = this;
+    this.editor_$.find(".Rk-CloseX").click(function() {
+        _this.renderer.removeRepresentation(_this);
+        paper.view.draw();
+    });
+    this.editor_$.find("input, textarea").bind("keyup change", function() {
+        _this.editor_$.find(".Rk-Edit-Goto").attr("href",_this.editor_$.find(".Rk-Edit-URI").val());
+        var _data = {
+            title: _this.editor_$.find(".Rk-Edit-Title").val(),
+            uri: _this.editor_$.find(".Rk-Edit-URI").val()
+        }
+        _model.set(_data);
+        _this.redraw();
+    });
+}
+Rkns.Renderer.EdgeEditor.prototype.redraw = function() {
+    var _coords = this.edge_representation.paper_coords;
+    Rkns.Renderer.Utils.drawEditBox(_coords, this.editor_block, 250, 5, this.editor_$);
+    this.editor_$.show();
+    paper.view.draw();
+}
+
+Rkns.Renderer.EdgeEditor.prototype.destroy = function() {
+    this.editor_block.remove();
+    this.editor_$.detach();
+}
+
+/* */
+
+Rkns.Renderer.NodeEditButton = Rkns.Utils.inherit(Rkns.Renderer._BaseRepresentation);
+
+Rkns.Renderer.NodeEditButton.prototype._init = function() {
+    this.renderer.overlay_layer.activate();
+    this.type = "Node-edit-button";
+    this.sector = Rkns.Renderer.Utils.sector(this, Rkns.Renderer._NODE_BUTTON_INNER, Rkns.Renderer._NODE_BUTTON_OUTER, - 90, 30, 1, this.renderer.renkan.static_url+'img/edit.png', this.renderer.renkan.l10n.caption_edit);
+}
+
+Rkns.Renderer.NodeEditButton.prototype.moveTo = function(_pos) {
+    this.sector.moveTo(_pos);
+}
+
+Rkns.Renderer.NodeEditButton.prototype.show = function() {
+    this.sector.show();
+}
+
+Rkns.Renderer.NodeEditButton.prototype.hide = function() {
+    this.sector.hide();
+}
+
+Rkns.Renderer.NodeEditButton.prototype.select = function() {
+    this.sector.select();
+}
+
+Rkns.Renderer.NodeEditButton.prototype.unselect = function(_newTarget) {
+    this.sector.unselect();
+    if (!_newTarget || (_newTarget !== this.node_representation && _newTarget.node_representation !== this.node_representation)) {
+        this.node_representation.unselect();
+    }
+}
+
+Rkns.Renderer.NodeEditButton.prototype.mouseup = function() {
+    if (!this.renderer.is_dragging) {
+        this.node_representation.openEditor();
+    }
+}
+
+Rkns.Renderer.NodeEditButton.prototype.destroy = function() {
+    this.sector.destroy();
+}
+
+/* */
+
+Rkns.Renderer.NodeRemoveButton = Rkns.Utils.inherit(Rkns.Renderer._BaseRepresentation);
+
+Rkns.Renderer.NodeRemoveButton.prototype._init = function() {
+    this.renderer.overlay_layer.activate();
+    this.type = "Node-remove-button";
+    this.sector = Rkns.Renderer.Utils.sector(this, Rkns.Renderer._NODE_BUTTON_INNER, Rkns.Renderer._NODE_BUTTON_OUTER, -210, -90, 1, this.renderer.renkan.static_url+'img/remove.png', this.renderer.renkan.l10n.caption_remove);
+}
+
+Rkns.Renderer.NodeRemoveButton.prototype.moveTo = function(_pos) {
+    this.sector.moveTo(_pos);
+}
+
+Rkns.Renderer.NodeRemoveButton.prototype.show = function() {
+    this.sector.show();
+}
+
+Rkns.Renderer.NodeRemoveButton.prototype.hide = function() {
+    this.sector.hide();
+}
+
+Rkns.Renderer.NodeRemoveButton.prototype.select = function() {
+    this.sector.select();
+}
+
+Rkns.Renderer.NodeRemoveButton.prototype.unselect = function(_newTarget) {
+    this.sector.unselect();
+    if (!_newTarget || (_newTarget !== this.node_representation && _newTarget.node_representation !== this.node_representation)) {
+        this.node_representation.unselect();
+    }
+}
+
+Rkns.Renderer.NodeRemoveButton.prototype.mouseup = function() {
+    this.renderer.removeRepresentationsOfType("editor");
+    if (confirm('Do you really wish to remove node "' + this.node_representation.model.get("title") + '"?')) {
+        this.project.removeNode(this.node_representation.model);
+    }
+}
+
+Rkns.Renderer.NodeRemoveButton.prototype.destroy = function() {
+    this.sector.destroy();
+}
+
+/* */
+
+Rkns.Renderer.NodeLinkButton = Rkns.Utils.inherit(Rkns.Renderer._BaseRepresentation);
+
+Rkns.Renderer.NodeLinkButton.prototype._init = function() {
+    this.renderer.overlay_layer.activate();
+    this.type = "Node-link-button";
+    this.sector = Rkns.Renderer.Utils.sector(this, Rkns.Renderer._NODE_BUTTON_INNER, Rkns.Renderer._NODE_BUTTON_OUTER, 30, 150, 1, this.renderer.renkan.static_url+'img/link.png', this.renderer.renkan.l10n.caption_link);
+}
+
+Rkns.Renderer.NodeLinkButton.prototype.moveTo = function(_pos) {
+    this.sector.moveTo(_pos);
+}
+
+Rkns.Renderer.NodeLinkButton.prototype.show = function() {
+    this.sector.show();
+}
+
+Rkns.Renderer.NodeLinkButton.prototype.hide = function() {
+    this.sector.hide();
+}
+
+Rkns.Renderer.NodeLinkButton.prototype.select = function() {
+    this.sector.select();
+}
+
+Rkns.Renderer.NodeLinkButton.prototype.unselect = function(_newTarget) {
+    this.sector.unselect();
+    if (!_newTarget || (_newTarget !== this.node_representation && _newTarget.node_representation !== this.node_representation)) {
+        this.node_representation.unselect();
+    }
+}
+
+Rkns.Renderer.NodeLinkButton.prototype.destroy = function() {
+    this.sector.destroy();
+}
+
+/* */
+
+Rkns.Renderer.EdgeEditButton = Rkns.Utils.inherit(Rkns.Renderer._BaseRepresentation);
+
+Rkns.Renderer.EdgeEditButton.prototype._init = function() {
+    this.renderer.overlay_layer.activate();
+    this.type = "Edge-edit-button";
+    this.sector = Rkns.Renderer.Utils.sector(this, Rkns.Renderer._EDGE_BUTTON_INNER, Rkns.Renderer._EDGE_BUTTON_OUTER, - 90, 90, 1, this.renderer.renkan.static_url+'img/edit.png', this.renderer.renkan.l10n.caption_edit);
+}
+
+Rkns.Renderer.EdgeEditButton.prototype.moveTo = function(_pos) {
+    this.sector.moveTo(_pos);
+}
+
+Rkns.Renderer.EdgeEditButton.prototype.show = function() {
+    this.sector.show();
+}
+
+Rkns.Renderer.EdgeEditButton.prototype.hide = function() {
+    this.sector.hide();
+}
+
+Rkns.Renderer.EdgeEditButton.prototype.select = function() {
+    this.sector.select();
+}
+
+Rkns.Renderer.EdgeEditButton.prototype.unselect = function(_newTarget) {
+    this.sector.unselect();
+    if (!_newTarget || (_newTarget !== this.edge_representation && _newTarget.edge_representation !== this.edge_representation)) {
+        this.edge_representation.unselect();
+    }
+}
+
+Rkns.Renderer.EdgeEditButton.prototype.mouseup = function() {
+    if (!this.renderer.is_dragging) {
+        this.edge_representation.openEditor();
+    }
+}
+
+Rkns.Renderer.EdgeEditButton.prototype.destroy = function() {
+    this.sector.destroy();
+}
+
+/* */
+
+Rkns.Renderer.EdgeRemoveButton = Rkns.Utils.inherit(Rkns.Renderer._BaseRepresentation);
+
+Rkns.Renderer.EdgeRemoveButton.prototype._init = function() {
+    this.renderer.overlay_layer.activate();
+    this.type = "Edge-remove-button";
+    this.sector = Rkns.Renderer.Utils.sector(this, Rkns.Renderer._EDGE_BUTTON_INNER, Rkns.Renderer._EDGE_BUTTON_OUTER, - 270, -90, 1, this.renderer.renkan.static_url+'img/remove.png', this.renderer.renkan.l10n.caption_remove);
+}
+Rkns.Renderer.EdgeRemoveButton.prototype.moveTo = function(_pos) {
+    this.sector.moveTo(_pos);
+}
+
+Rkns.Renderer.EdgeRemoveButton.prototype.show = function() {
+    this.sector.show();
+}
+
+Rkns.Renderer.EdgeRemoveButton.prototype.hide = function() {
+    this.sector.hide();
+}
+
+Rkns.Renderer.EdgeRemoveButton.prototype.select = function() {
+    this.sector.select();
+}
+
+Rkns.Renderer.EdgeRemoveButton.prototype.unselect = function(_newTarget) {
+    this.sector.unselect();
+    if (!_newTarget || (_newTarget !== this.edge_representation && _newTarget.edge_representation !== this.edge_representation)) {
+        this.edge_representation.unselect();
+    }
+}
+
+Rkns.Renderer.EdgeRemoveButton.prototype.mouseup = function() {
+    this.renderer.removeRepresentationsOfType("editor");
+    if (confirm('Do you really wish to remove edge "' + this.edge_representation.model.get("title") + '"?')) {
+        this.project.removeEdge(this.edge_representation.model);
+    }
+}
+
+Rkns.Renderer.EdgeRemoveButton.prototype.destroy = function() {
+    this.sector.destroy();
+}
+
+/* */
+
+Rkns.Renderer.Scene = function(_renkan) {
+    this.renkan = _renkan;
+    this.$ = Rkns.$(".Rk-Render");
+    this.representations = [];
+    this.$.html(this.template({
+        l10n: _renkan.l10n
+    }))
+    this.canvas_$ = this.$.find(".Rk-Canvas");
+    this.editor_$ = this.$.find(".Rk-Editor");
+    this.notif_$ = this.$.find(".Rk-Notifications");
+    paper.setup(this.canvas_$[0]);
+    this.scale = 1;
+    this.offset = paper.view.center;
+    this.totalScroll = 0;
+    this.click_target = null;
+    this.selected_target = null;
+    this.edge_layer = new paper.Layer();
+    this.node_layer = new paper.Layer();
+    this.overlay_layer = new paper.Layer();
+    this.bundles = [];
+    this.click_mode = false;
+    var _tool = new paper.Tool(),
+        _this = this;
+    _tool.minDistance = Rkns.Renderer._MIN_DRAG_DISTANCE;
+    _tool.onMouseMove = function(_event) {
+        _this.onMouseMove(_event);
+    }
+    _tool.onMouseDown = function(_event) {
+        _this.onMouseDown(_event);
+    }
+    _tool.onMouseDrag = function(_event) {
+        _this.onMouseDrag(_event);
+    }
+    this.canvas_$.mouseup(function(_event) {
+        _this.onMouseUp(_event);
+    });
+    this.canvas_$.mousewheel(function(_event, _delta) {
+        _this.onScroll(_event, _delta);
+    });
+    this.canvas_$.dblclick(function(_event) {
+        _this.onDoubleClick(_event);
+    });
+    this.canvas_$.mouseenter(function(_event) {
+        _this.onMouseEnter(_event);
+    });
+    this.editor_$.find(".Rk-ZoomOut").click(function() {
+        _this.offset = new paper.Point([
+            _this.canvas_$.width(),
+            _this.canvas_$.height()
+        ]).multiply( .5 * ( 1 - Math.SQRT1_2 ) ).add(_this.offset.multiply( Math.SQRT1_2 ));
+        _this.setScale( _this.scale * Math.SQRT1_2 );
+        _this.redraw();
+    });
+    this.editor_$.find(".Rk-ZoomIn").click(function() {
+        _this.offset = new paper.Point([
+            _this.canvas_$.width(),
+            _this.canvas_$.height()
+        ]).multiply( .5 * ( 1 - Math.SQRT2 ) ).add(_this.offset.multiply( Math.SQRT2 ));
+        _this.setScale( _this.scale * Math.SQRT2 );
+        _this.redraw();
+    });
+    this.$.find(".Rk-CurrentUser").mouseenter(
+        function() { _this.$.find(".Rk-UserList").slideDown() }
+    );
+    this.$.find(".Rk-Users").mouseleave(
+        function() { _this.$.find(".Rk-UserList").slideUp(); }
+    );
+    this.$.find(".Rk-FullScreen-Button").click(function() {
+        var _isFull = document.fullScreen || document.mozFullScreen || document.webkitIsFullScreen,
+            _el = _this.renkan.$[0],
+            _requestMethods = ["requestFullScreen","mozRequestFullScreen","webkitRequestFullScreen"],
+            _cancelMethods = ["cancelFullScreen","mozCancelFullScreen","webkitCancelFullScreen"];
+        if (_isFull) {
+            for (var i = 0; i < _cancelMethods.length; i++) {
+                if (typeof document[_cancelMethods[i]] === "function") {
+                    document[_cancelMethods[i]]();
+                    break;
+                }
+            }
+        } else {
+            for (var i = 0; i < _requestMethods.length; i++) {
+                if (typeof _el[_requestMethods[i]] === "function") {
+                    _el[_requestMethods[i]]();
+                    break;
+                }
+            }
+        }
+    });
+    this.$.find(".Rk-AddNode-Button").click(function() {
+        if (_this.click_mode === Rkns.Renderer._CLICKMODE_ADDNODE) {
+            _this.click_mode = false;
+            _this.notif_$.hide();
+        } else {
+            _this.click_mode = Rkns.Renderer._CLICKMODE_ADDNODE;
+            _this.notif_$.html(_renkan.l10n.notif_add_node).fadeIn();
+        }
+    });
+    this.$.find(".Rk-AddEdge-Button").click(function() {
+        if (_this.click_mode === Rkns.Renderer._CLICKMODE_STARTEDGE || _this.click_mode === Rkns.Renderer._CLICKMODE_ENDEDGE) {
+            _this.click_mode = false;
+            _this.notif_$.hide();
+        } else {
+            _this.click_mode = Rkns.Renderer._CLICKMODE_STARTEDGE;
+            _this.notif_$.html(_renkan.l10n.notif_start_edge).fadeIn();
+        }
+    });
+    this.$.find(".Rk-TopBar-Button").mouseover(function() {
+        Rkns.$(this).find(".Rk-TopBar-Tooltip").show();
+    }).mouseout(function() {
+        Rkns.$(this).find(".Rk-TopBar-Tooltip").hide();
+    });
+    
+    paper.view.onResize = function(_event) {
+        _this.offset = _this.offset.add(_event.delta.divide(2));
+        _this.redraw();
+    }
+    
+    var _thRedraw = Rkns._.throttle(function() {
+        _this.redraw();
+    },50);
+    
+    this.addRepresentations("Node", this.renkan.project.get("nodes"));
+    this.addRepresentations("Edge", this.renkan.project.get("edges"));
+    this.renkan.project.get("users").each(function(_user) {
+        _this.addUser(_user);
+    })
+    
+    this.renkan.project.on("add:users", function(_user) {
+        _this.addUser(_user);
+    });
+    this.renkan.project.on("add:nodes", function(_node) {
+        _this.addRepresentation("Node", _node);
+        _thRedraw();
+    });
+    this.renkan.project.on("add:edges", function(_edge) {
+        _this.addRepresentation("Edge", _edge);
+        _thRedraw();
+    });
+    
+    this.redraw();
+}
+
+Rkns.Renderer.Scene.prototype.template = Rkns._.template(
+    '<div class="Rk-TopBar"><h3 class="Rk-PadTitle"><%=l10n.untitled_project%></h3>'
+    + '<div class="Rk-Users"><div class="Rk-CurrentUser"><span class="Rk-CurrentUser-Color"></span><span class="Rk-CurrentUser-Name">&lt;unknown user&gt;</span></div><ul class="Rk-UserList"></ul></div>'
+    + '<div class="Rk-TopBar-Separator"></div><div class="Rk-TopBar-Button Rk-FullScreen-Button"><div class="Rk-TopBar-Tooltip"><div class="Rk-TopBar-Tooltip-Tip"></div><div class="Rk-TopBar-Tooltip-Contents"><%=l10n.full_screen%></div></div></div>'
+    + '<div class="Rk-TopBar-Separator"></div><div class="Rk-TopBar-Button Rk-AddNode-Button"><div class="Rk-TopBar-Tooltip"><div class="Rk-TopBar-Tooltip-Tip"></div><div class="Rk-TopBar-Tooltip-Contents"><%=l10n.add_node%></div></div></div>'
+    + '<div class="Rk-TopBar-Separator"></div><div class="Rk-TopBar-Button Rk-AddEdge-Button"><div class="Rk-TopBar-Tooltip"><div class="Rk-TopBar-Tooltip-Tip"></div><div class="Rk-TopBar-Tooltip-Contents"><%=l10n.add_edge%></div></div></div>'
+    + '<div class="Rk-TopBar-Separator"></div></div>'
+    + '<canvas class="Rk-Canvas" resize></canvas><div class="Rk-Editor"><div class="Rk-Notifications"></div>'
+    + '<div class="Rk-ZoomButtons"><div class="Rk-ZoomIn" title="<%=l10n.zoom_in%>"></div><div class="Rk-ZoomOut" title="<%=l10n.zoom_out%>"></div></div>'
+    + '</div>'
+);
+
+Rkns.Renderer.Scene.prototype.addToBundles = function(_edgeRepr) {
+    var _bundle = Rkns._(this.bundles).find(function(_bundle) {
+        return ( 
+            ( _bundle.from === _edgeRepr.from_representation && _bundle.to === _edgeRepr.to_representation )
+            || ( _bundle.from === _edgeRepr.to_representation && _bundle.to === _edgeRepr.from_representation )
+        );
+    });
+    if (typeof _bundle !== "undefined") {
+        _bundle.edges.push(_edgeRepr)
+    } else {
+        _bundle = {
+            from: _edgeRepr.from_representation,
+            to: _edgeRepr.to_representation,
+            edges: [ _edgeRepr ],
+            getPosition: function(_er) {
+                var _dir = (_er.from_representation === this.from) ? 1 : -1;
+                return _dir * ( Rkns._(this.edges).indexOf(_er) - (this.edges.length - 1) / 2 );
+            }
+        }
+        this.bundles.push(_bundle);
+    }
+    return _bundle;
+}
+
+Rkns.Renderer.Scene.prototype.setScale = function(_newScale) {
+    this.scale = _newScale;
+    this.redraw();
+}
+
+Rkns.Renderer.Scene.prototype.autoScale = function() {
+    var nodes = this.renkan.project.get("nodes")
+    if (nodes.length > 1) {
+        var _xx = nodes.map(function(_node) { return _node.get("position").x }),
+            _yy = nodes.map(function(_node) { return _node.get("position").y }),
+            _minx = Math.min.apply(Math, _xx),
+            _miny = Math.min.apply(Math, _yy),
+            _maxx = Math.max.apply(Math, _xx),
+            _maxy = Math.max.apply(Math, _yy);
+        var _scale = Math.min((paper.view.size.width - 2 * Rkns.Renderer._MARGIN_X) / (_maxx - _minx), (paper.view.size.height - 2 * Rkns.Renderer._MARGIN_Y) / (_maxy - _miny));
+        this.offset = paper.view.center.subtract(new paper.Point([(_maxx + _minx) / 2, (_maxy + _miny) / 2]).multiply(_scale));
+        this.setScale(_scale);
+    }
+    if (nodes.length === 1) {
+        this.offset = paper.view.center.subtract(new paper.Point([nodes.at(0).get("position").x, nodes.at(0).get("position").y]));
+        this.setScale(1);
+    }
+}
+
+Rkns.Renderer.Scene.prototype.toPaperCoords = function(_point) {
+    return _point.multiply(this.scale).add(this.offset);
+}
+
+
+Rkns.Renderer.Scene.prototype.toModelCoords = function(_point) {
+    return _point.subtract(this.offset).divide(this.scale);
+}
+
+Rkns.Renderer.Scene.prototype.addRepresentation = function(_type, _model) {
+    var _repr = new Rkns.Renderer[_type](this, _model);
+    this.representations.push(_repr);
+    return _repr;
+}
+
+Rkns.Renderer.Scene.prototype.addRepresentations = function(_type, _collection) {
+    var _this = this;
+    _collection.forEach(function(_model) {
+        _this.addRepresentation(_type, _model);
+    });
+}
+
+Rkns.Renderer.Scene.prototype.userTemplate = Rkns._.template(
+    '<li class="Rk-User"><span class="Rk-UserColor" style="background:<%=background%>;"></span><%=name%></li>'
+);
+
+Rkns.Renderer.Scene.prototype.addUser = function(_user) {
+    if (_user.get("_id") === this.renkan.current_user) {
+        this.$.find(".Rk-CurrentUser-Name").text(_user.get("title"));
+        this.$.find(".Rk-CurrentUser-Color").css("background", _user.get("color"));
+    } else {
+        this.$.find(".Rk-UserList").append(
+            Rkns.$(
+                this.userTemplate({
+                    name: _user.get("title"),
+                    background: _user.get("color")
+                })
+            )
+        );
+    }
+}
+
+Rkns.Renderer.Scene.prototype.removeRepresentation = function(_representation) {
+    _representation.destroy();
+    this.representations = Rkns._(this.representations).reject(
+        function(_repr) {
+            return _repr == _representation
+        }
+    );
+}
+
+Rkns.Renderer.Scene.prototype.getRepresentationByModel = function(_model) {
+    return Rkns._(this.representations).find(function(_repr) {
+        return _repr.model === _model;
+    });
+}
+
+Rkns.Renderer.Scene.prototype.removeRepresentationsOfType = function(_type) {
+    var _representations = Rkns._(this.representations).filter(function(_repr) {
+            return _repr.type == _type;
+        }),
+        _this = this;
+    Rkns._(_representations).each(function(_repr) {
+        _this.removeRepresentation(_repr);
+    });
+}
+
+Rkns.Renderer.Scene.prototype.highlightModel = function(_model) {
+    var _repr = this.getRepresentationByModel(_model);
+    if (_repr) {
+        _repr.highlight();
+    }
+}
+
+Rkns.Renderer.Scene.prototype.unhighlightAll = function(_model) {
+    Rkns._(this.representations).each(function(_repr) {
+        _repr.unhighlight();
+    });
+}
+
+Rkns.Renderer.Scene.prototype.redraw = function() {
+    Rkns._(this.representations).each(function(_representation) {
+        _representation.redraw();
+    });
+    paper.view.draw();
+}
+
+Rkns.Renderer.Scene.prototype.addTempEdge = function(_from, _point) {
+    var _tmpEdge = this.addRepresentation("TempEdge",null);
+    _tmpEdge.end_pos = _point;
+    _tmpEdge.from_representation = _from;
+    _tmpEdge.redraw();
+    this.click_target = _tmpEdge;
+}
+
+Rkns.Renderer.Scene.prototype.findTarget = function(_hitResult) {
+    if (_hitResult && typeof _hitResult.item.__representation !== "undefined") {
+        var _newTarget = _hitResult.item.__representation;
+        if (this.selected_target !== _hitResult.item.__representation) {
+            if (this.selected_target) {
+                this.selected_target.unselect(_newTarget);
+            }
+            _newTarget.select(this.selected_target);
+            this.selected_target = _newTarget;
+        }
+    } else {
+        if (this.selected_target) {
+            this.selected_target.unselect(null);
+        }
+        this.selected_target = null;
+    }
+}
+
+Rkns.Renderer.Scene.prototype.onMouseMove = function(_event) {
+    var _hitResult = paper.project.hitTest(_event.point);
+    if (this.is_dragging) {
+        if (this.click_target && typeof this.click_target.paperShift === "function") {
+            this.click_target.paperShift(_event.delta);
+        } else {
+            this.offset = this.offset.add(_event.delta);
+            this.redraw();
+        }
+    } else {
+        this.findTarget(_hitResult);
+    }
+}
+
+Rkns.Renderer.Scene.prototype.onMouseDown = function(_event) {
+    if (!this.click_target || this.click_target.type !== "temp-edge") {
+        this.is_dragging = false;
+        var _hitResult = paper.project.hitTest(_event.point);
+        if (_hitResult && typeof _hitResult.item.__representation !== "undefined") {
+            this.click_target = _hitResult.item.__representation;
+            if (this.click_target.type === "Node-link-button") {
+                this.removeRepresentationsOfType("editor");
+                this.addTempEdge(this.click_target.node_representation, _event.point);
+            }
+        } else {
+            this.click_target = null;
+            if (this.click_mode === Rkns.Renderer._CLICKMODE_ADDNODE) {
+                var _coords = this.toModelCoords(_event.point),
+                    _data = {
+                        id: Rkns.Utils.getUID('node'),
+                        created_by: this.renkan.current_user,
+                        position: {
+                            x: _coords.x,
+                            y: _coords.y
+                        }
+                    };
+                    _node = this.renkan.project.addNode(_data);
+                this.getRepresentationByModel(_node).openEditor();
+            }
+        }
+    }
+    if (this.click_mode) {
+        if (this.click_mode === Rkns.Renderer._CLICKMODE_STARTEDGE && this.click_target && this.click_target.type === "Node") {
+            this.removeRepresentationsOfType("editor");
+            this.addTempEdge(this.click_target, _event.point);
+            this.click_mode = Rkns.Renderer._CLICKMODE_ENDEDGE;
+            this.notif_$.fadeOut(function() {
+                Rkns.$(this).html(_renkan.l10n.notif_end_edge).fadeIn();
+            });
+        } else {
+            this.notif_$.hide();
+            this.click_mode = false;
+        }
+    }
+}
+
+Rkns.Renderer.Scene.prototype.onMouseDrag = function(_event) {
+    this.is_dragging = true;
+    this.onMouseMove(_event);
+}
+
+Rkns.Renderer.Scene.prototype.onMouseUp = function(_event) {
+    if (this.click_target) {
+        var _off = this.canvas_$.offset();
+        this.click_target.mouseup(
+            {
+                point: new paper.Point([
+                    _event.pageX - _off.left,
+                    _event.pageY - _off.top
+                ])
+            }
+        );
+    } else {
+        this.click_target = null;
+        this.is_dragging = false;
+    }
+}
+
+Rkns.Renderer.Scene.prototype.onScroll = function(_event, _scrolldelta) {
+    this.totalScroll += _scrolldelta;
+    if (Math.abs(this.totalScroll) >= 1) {
+        var _off = this.canvas_$.offset(),
+            _delta = new paper.Point([
+                _event.pageX - _off.left,
+                _event.pageY - _off.top
+            ]).subtract(this.offset).multiply( Math.SQRT2 - 1 );
+        if (this.totalScroll > 0) {
+            this.offset = this.offset.subtract(_delta);
+            this.setScale( this.scale * Math.SQRT2 );
+        } else {
+            this.offset = this.offset.add(_delta.divide( Math.SQRT2 ));
+            this.setScale( this.scale * Math.SQRT1_2);
+        }
+        this.totalScroll = 0;
+        this.redraw();
+    }
+}
+
+Rkns.Renderer.Scene.prototype.onDoubleClick = function(_event) {
+    var _off = this.canvas_$.offset(),
+        _point = new paper.Point([
+            _event.pageX - _off.left,
+            _event.pageY - _off.top
+        ]);
+    var _hitResult = paper.project.hitTest(_point);
+    if (!_hitResult || typeof _hitResult.item.__representation === "undefined") {
+        var _coords = this.toModelCoords(_point),
+            _data = {
+                id: Rkns.Utils.getUID('node'),
+                created_by: this.renkan.current_user,
+                position: {
+                    x: _coords.x,
+                    y: _coords.y
+                }
+            };
+            _node = this.renkan.project.addNode(_data);
+            this.getRepresentationByModel(_node).openEditor();
+    }
+    paper.view.draw();
+}
+
+Rkns.Renderer.Scene.prototype.onMouseEnter = function(_event) {
+    var _newEl = this.renkan.selected_bin_item;
+    if (_newEl) {
+        var _off = this.canvas_$.offset(),
+            _point = new paper.Point([
+                _event.pageX - _off.left,
+                _event.pageY - _off.top
+            ]),
+            _coords = this.toModelCoords(_point),
+            _data = {
+                id: Rkns.Utils.getUID('node'),
+                created_by: this.renkan.current_user,
+                uri: _newEl.uri,
+                title: _newEl.title,
+                description: _newEl.description,
+                image: _newEl.image,
+                position: {
+                    x: _coords.x,
+                    y: _coords.y
+                }
+            };
+        var _node = this.renkan.project.addNode(_data);
+        this.renkan.selected_bin_item = null;
+        this.is_dragging = true;
+        this.click_target = this.getRepresentationByModel(_node);
+    }
+}
\ No newline at end of file