DevTools: DOMStorage undo/redo feature

Source/devtools/front_end/DOMStorage.js

Index: Source/devtools/front_end/DOMStorage.js
diff --git a/Source/devtools/front_end/DOMStorage.js b/Source/devtools/front_end/DOMStorage.js
index b209f726c0934ddc46be269c2feb81061a41ae36..4446d7d238fe4553f7e0cdfa11bae94f3d0c8f16 100644
--- a/Source/devtools/front_end/DOMStorage.js
+++ b/Source/devtools/front_end/DOMStorage.js
@@ -36,6 +36,7 @@ WebInspector.DOMStorage = function(securityOrigin, isLocalStorage)
 {
     this._securityOrigin = securityOrigin;
     this._isLocalStorage = isLocalStorage;
+    this._storageHistory = new WebInspector.DOMStorageHistory(this);
 }
 
 /**
@@ -79,20 +80,155 @@ WebInspector.DOMStorage.prototype = {
     /**
      * @param {string} key
      * @param {string} value
-     * @param {function(?Protocol.Error):void=} callback
      */
-    setItem: function(key, value, callback)
+    setItem: function(key, value)
     {
-        DOMStorageAgent.setDOMStorageItem(this.id, key, value, callback);
+        this._storageHistory.perform(new WebInspector.DOMStorageSetItemAction(this, key, value));
     },
 
     /**
      * @param {string} key
-     * @param {function(?Protocol.Error):void=} callback
      */
-    removeItem: function(key, callback)
+    removeItem: function(key)
     {
-        DOMStorageAgent.removeDOMStorageItem(this.id, key, callback);
+        this._storageHistory.perform(new WebInspector.DOMStorageRemoveItemAction(this, key));
+    },
+
+    undo: function()
+    {
+        this._storageHistory.undo();
+    },
+
+    redo: function()
+    {
+        this._storageHistory.redo();
+    }
+}
+
+/**
+ * @constructor
+ */
+WebInspector.DOMStorageAction = function(domStorage)

[apavlov, 2013/05/08 11:41:36]

I would defer the decision on this to pfeldman, but IMHO the lightness of the
solution doesn't warrant copycatting the backend code.

+{
+    this._domStorage = domStorage;
+}
+
+WebInspector.DOMStorageAction.prototype = {
+    perform: function()
+    {
+    },
+
+    undo: function()
+    {
+    },
+
+    redo: function()
+    {
+    }
+}
+
+WebInspector.DOMStorageRemoveItemAction = function(domStorage, key)
+{
+    WebInspector.DOMStorageAction.call(this, domStorage);
+    this._key = key;
+}
+
+WebInspector.DOMStorageRemoveItemAction.prototype = {
+    __proto__: WebInspector.DOMStorageAction.prototype,
+
+    perform: function()
+    {
+        function callback(error, value)
+        {
+            this._value = value;
+            this.redo();
+        }
+        DOMStorageAgent.getDOMStorageItem(this._domStorage.id, this._key, callback.bind(this));
+    },
+
+    undo: function()
+    {
+        DOMStorageAgent.setDOMStorageItem(this._domStorage.id, this._key, this._value);
+    },
+
+    redo: function()
+    {
+        DOMStorageAgent.removeDOMStorageItem(this._domStorage.id, this._key);
+    }
+}
+
+WebInspector.DOMStorageSetItemAction = function(domStorage, key, value)
+{
+    WebInspector.DOMStorageAction.call(this, domStorage);
+    this._key = key;
+    this._value = value;
+}
+
+WebInspector.DOMStorageSetItemAction.prototype = {
+    __proto__: WebInspector.DOMStorageAction.prototype,
+
+    perform: function()
+    {
+        function callback(error, value)
+        {
+            this._oldValue = value;
+            this.redo();
+        }
+        DOMStorageAgent.getDOMStorageItem(this._domStorage.id, this._key, callback.bind(this));
+    },
+
+    undo: function()
+    {
+        DOMStorageAgent.setDOMStorageItem(this._domStorage.id, this._key, this._oldValue);
+    },
+
+    redo: function()
+    {
+        DOMStorageAgent.setDOMStorageItem(this._domStorage.id, this._key, this._value);
+    }
+}
+
+/**
+ * @constructor
+ */
+WebInspector.DOMStorageHistory = function(domStorage)
+{
+    this._domStorage = domStorage;
+    this._actions = [];
+    this._currentActionIndex = -1;
+}
+
+WebInspector.DOMStorageHistory.prototype = {
+    perform: function(action)
+    {
+        if (!action)
+            return;
+
+        action.perform();
+
+        this._actions.push(action);
+        ++this._currentActionIndex;
+    },
+
+    undo: function()
+    {
+        if (this._currentActionIndex < 0)
+            return;
+
+        var action = this._actions[this._currentActionIndex];
+        if (action)
+            action.undo();
+        --this._currentActionIndex;
+    },
+
+    redo: function()
+    {
+        if (this._currentActionIndex > this._actions.length)
+            return;
+
+        var action = this._actions[++this._currentActionIndex];
+        if (action)
+            action.redo();
     }
 }