Issue 24 : Layers

!! NOT STABLE !!
Initial implementation. No UI update yet.
Check js/model/Piskel.js and js/model/Layer.js for an overview of the new
API.

Piskels can be saved on the existing service.

Previous piskels cannot be loaded. This should be fixed soon.

js/controller/PiskelController.js

@@ -0,0 +1,125 @@
+(function () {
+  var ns = $.namespace('pskl.controller');
+
+  ns.PiskelController = function (piskel) {
+    this.setPiskel(piskel);
+  };
+
+  ns.PiskelController.prototype.setPiskel = function (piskel) {
+    this.piskel = piskel;
+    this.currentLayerIndex = 0;
+    this.currentFrameIndex = 0;
+
+    $.publish(Events.FRAMESHEET_RESET);
+    $.publish(Events.FRAME_SIZE_CHANGED);
+  };
+
+  ns.PiskelController.prototype.getHeight = function () {
+    return this.piskel.getHeight();
+  };
+
+  ns.PiskelController.prototype.getWidth = function () {
+    return this.piskel.getWidth();
+  };
+
+  ns.PiskelController.prototype.getCurrentLayer = function () {
+    return this.piskel.getLayerAt(this.currentLayerIndex);
+  };
+
+  ns.PiskelController.prototype.getCurrentFrame = function () {
+    var layer = this.getCurrentLayer();
+    return layer.getFrameAt(this.currentFrameIndex);
+  };
+
+  ns.PiskelController.prototype.getFrameAt = function (index) {
+    var frames = this.piskel.getLayers().map(function (l) {
+      return l.getFrameAt(index);
+    });
+    return pskl.utils.FrameUtils.merge(frames);
+  };
+
+  ns.PiskelController.prototype.hasFrameAt = function (index) {
+    return !!this.getCurrentLayer().getFrameAt(index);
+  };
+
+  // backward from framesheet
+  ns.PiskelController.prototype.getFrameByIndex = 
+    ns.PiskelController.prototype.getMergedFrameAt;
+
+  ns.PiskelController.prototype.addEmptyFrame = function () {
+    var layers = this.piskel.getLayers();
+    layers.forEach(function (l) {
+      l.addFrame(this.createEmptyFrame_());
+    }.bind(this));
+  };
+
+  ns.PiskelController.prototype.createEmptyFrame_ = function () {
+    var w = this.piskel.getWidth(), h = this.piskel.getHeight();
+    return new pskl.model.Frame(w, h);
+  };
+
+  ns.PiskelController.prototype.removeFrameAt = function (index) {
+    var layers = this.piskel.getLayers();
+    layers.forEach(function (l) {
+      l.removeFrameAt(index);
+    });
+    // Current frame index is impacted if the removed frame was before the current frame
+    if (this.currentFrameIndex >= index) {
+      this.setCurrentFrameIndex(this.currentFrameIndex - 1);
+    }
+
+    $.publish(Events.FRAMESHEET_RESET);
+  };
+
+  ns.PiskelController.prototype.duplicateFrameAt = function (index) {
+    var layers = this.piskel.getLayers();
+    layers.forEach(function (l) {
+      l.duplicateFrameAt(index);
+    });
+  };
+
+  ns.PiskelController.prototype.moveFrame = function (fromIndex, toIndex) {
+    var layers = this.piskel.getLayers();
+    layers.forEach(function (l) {
+      l.moveFrame(fromIndex, toIndex);
+    });
+  };
+
+  ns.PiskelController.prototype.getFrameCount = function () {
+    var layer = this.piskel.getLayerAt(0);
+    return layer.length();
+  };
+
+  ns.PiskelController.prototype.setCurrentFrameIndex = function (index) {
+    this.currentFrameIndex = index;
+    $.publish(Events.FRAMESHEET_RESET);
+  };
+
+  ns.PiskelController.prototype.setCurrentLayerIndex = function (index) {
+    this.currentLayerIndex = index;
+    $.publish(Events.FRAMESHEET_RESET);
+  };
+
+  ns.PiskelController.prototype.createLayer = function (name) {
+    var layer = new pskl.model.Layer(name);
+    for (var i = 0 ; i < this.getFrameCount() ; i++) {
+      layer.addFrame(this.createEmptyFrame_());
+    }
+    this.piskel.addLayer(layer);
+    this.setCurrentLayerIndex(this.piskel.getLayers().length - 1);
+  };
+
+  ns.PiskelController.prototype.serialize = function () {
+    return pskl.utils.Serializer.serializePiskel(this.piskel);
+  };
+
+  ns.PiskelController.prototype.deserialize = function (json) {
+    try {
+      var piskel = pskl.utils.Serializer.deserializePiskel(json);
+      this.setPiskel(piskel);
+    } catch (e) {
+      console.error('Failed to deserialize');
+      console.error(e.stack);
+    }
+  };
+})();