Initial commit

lib/assets/javascripts/builder/data/undo-manager.js

@@ -0,0 +1,91 @@
+var _ = require('underscore');
+var BackboneUndo = require('backbone-undo');
+var MAXIMUM_STACK_LENGTH = 30;
+
+module.exports = {
+  init: function (model, opts) {
+    if (!model) throw new Error('model is required to initialize undoManager');
+
+    opts = opts || {};
+    this.model = model;
+
+    this.model._undoManager = this.undoManager = new BackboneUndo({
+      maximumStackLength: opts.maximumStackLength || MAXIMUM_STACK_LENGTH,
+      register: this.model,
+      track: opts.track
+    });
+
+    this._trackEvents();
+    this._addMethods();
+
+    if (!_.isEmpty(opts.history)) {
+      opts.track && this.undoManager.stopTracking();
+      this._addHistory(opts.history);
+      opts.track && this.undoManager.startTracking();
+    }
+  },
+
+  _trackEvents: function () {
+    _.each(['undo', 'redo'], function (eventType) {
+      this.undoManager.bind(eventType, function () {
+        this.trigger(eventType, this.changed, this);
+      }, this.model);
+    }, this);
+
+    this.undoManager.stack.bind('add remove reset', function () {
+      this.trigger('unredoChanged', this.changed, this);
+    }, this.model);
+  },
+
+  _addHistory: function (history) {
+    var stack = this.undoManager.stack;
+
+    _.each(history, function (attrs, i) {
+      if (history[i + 1]) {
+        stack.add({
+          after: history[i + 1],
+          before: attrs,
+          type: 'change',
+          undoTypes: this.undoManager.undoTypes,
+          object: this.model,
+          magicFusionIndex: 0
+        });
+      }
+    }, this);
+
+    stack.pointer = stack.length - 1;
+  },
+
+  _addMethods: function () {
+    _.extend(
+      this.model,
+      {
+        undo: function () {
+          this._undoManager.undo();
+        },
+
+        redo: function () {
+          this._undoManager.redo();
+        },
+
+        canUndo: function () {
+          return this._undoManager.isAvailable('undo');
+        },
+
+        canRedo: function () {
+          return this._undoManager.isAvailable('redo');
+        },
+
+        getUndoHistory: function () {
+          var list = this._undoManager.stack.toJSON();
+          var data = _.reduce(list, function (memo, attrs, i) {
+            memo.push(attrs.before);
+            return memo;
+          }, [], this);
+          data.push(this.attributes);
+          return data;
+        }
+      }
+    );
+  }
+};