Implemented the undo translation in the renderer.

This reverts the page's text to its original (pre-translation) value. 

BUG=None 
TEST=None 

Review http://codereview.chromium.org/554104/show

Review URL: http://codereview.chromium.org/555175

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@37583 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 50 insertions, 0 deletions

diff --git a/chrome/renderer/render_view.cc b/chrome/renderer/render_view.cc
index a27792f4..48e5ebf 100644
--- a/chrome/renderer/render_view.cc
+++ b/chrome/renderer/render_view.cc
@@ -1146,6 +1146,9 @@ void RenderView::UpdateURL(WebFrame* frame) {
       host_zoom_levels_.erase(host);
     }
 
+    // Drop the translated nodes.
+    page_translator_->NavigatedToNewPage();
+
     // Update contents MIME type for main frame.
     params.contents_mime_type = ds->response().mimeType().utf8();
 
@@ -3333,6 +3336,13 @@ void RenderView::OnTranslateTextResponse(
   text_translator_.OnTranslationResponse(work_id, error_id, text_chunks);
 }
 
+void RenderView::OnUndoTranslate(int page_id) {
+  if (page_id != page_id_)
+    return;  // Not the page we expected, nothing to do.
+
+  page_translator_->UndoTranslation();
+}
+
 void RenderView::OnInstallMissingPlugin() {
   // This could happen when the first default plugin is deleted.
   if (first_default_plugin_)
diff --git a/chrome/renderer/render_view.h b/chrome/renderer/render_view.h
index dfc4cdb..3ca5baa 100644
--- a/chrome/renderer/render_view.h
+++ b/chrome/renderer/render_view.h
@@ -699,6 +699,10 @@ class RenderView : public RenderWidget,
                        const std::string& source_lang,
                        const std::string& target_lang);
 
+  // Tells the renderer to revert the page contents to its original
+  // non-translated content.
+  void OnUndoTranslate(int page_id);
+
   // Message that provides the translated text for a request.
   void OnTranslateTextResponse(int work_id,
                                int error_id,
diff --git a/chrome/renderer/translate/page_translator.cc b/chrome/renderer/translate/page_translator.cc
index 8119a8d..df0a59b 100644
--- a/chrome/renderer/translate/page_translator.cc
+++ b/chrome/renderer/translate/page_translator.cc
@@ -79,6 +79,8 @@ void PageTranslator::Translate(WebKit::WebFrame* web_frame,
       string16 text = static_cast<string16>(text_nodes_iter->nodeValue());
       DCHECK(!ContainsOnlyWhitespace(text));
       text_chunks.push_back(text);
+      // Store the original text so we can undo the translation if requested.
+      text_nodes_.push_back(NodeTextPair(*text_nodes_iter, text));
     }
     // Send the text for translation.
     bool secure = static_cast<GURL>(web_frame->top()->url()).SchemeIsSecure();
@@ -89,6 +91,21 @@ void PageTranslator::Translate(WebKit::WebFrame* web_frame,
   }
 }
 
+void PageTranslator::NavigatedToNewPage() {
+  // We can drop all our states, they were related to the previous page.
+  ResetPageState();
+}
+
+void PageTranslator::UndoTranslation() {
+  // Revert all text nodes to their original contents.
+  std::vector<NodeTextPair>::iterator iter;
+  for (iter = text_nodes_.begin(); iter != text_nodes_.end(); ++iter)
+    iter->first.setNodeValue(iter->second);
+
+  // The page is back to its original content, we can dop all our states.
+  ResetPageState();
+}
+
 bool PageTranslator::ShouldElementBeTraversed(WebKit::WebElement element) {
   return ignored_tags_.find(element.tagName()) == ignored_tags_.end();
 }
@@ -108,6 +125,11 @@ void PageTranslator::ClearNodeZone(int work_id) {
   pending_translations_.erase(iter);
 }
 
+void PageTranslator::ResetPageState() {
+  pending_translations_.clear();
+  text_nodes_.clear();
+}
+
 void PageTranslator::TranslationError(int work_id, int error_id) {
   // TODO(jcampan): may be we should show somehow that something went wrong to
   //                the user?
diff --git a/chrome/renderer/translate/page_translator.h b/chrome/renderer/translate/page_translator.h
index f7135be..14139227 100644
--- a/chrome/renderer/translate/page_translator.h
+++ b/chrome/renderer/translate/page_translator.h
@@ -41,6 +41,12 @@ class PageTranslator : public TextTranslator::Delegate {
                  std::string from_lang,
                  std::string to_lang);
 
+  // Notification that the associated RenderView has navigated to a new page.
+  void NavigatedToNewPage();
+
+  // Reverts the page to its original non-translated contents.
+  void UndoTranslation();
+
   // TextTranslator::Delegate implentation:
   virtual void TranslationError(int work_id, int error_id);
   virtual void TextTranslated(
@@ -73,6 +79,9 @@ class PageTranslator : public TextTranslator::Delegate {
   // Removes and deletes the NodeZone for |work_id| in pending_translations_.
   void ClearNodeZone(int work_id);
 
+  // Clears all the states related to the page's contents.
+  void ResetPageState();
+
   // The RenderView we are providing translations for.
   RenderView* render_view_;
 
@@ -89,6 +98,11 @@ class PageTranslator : public TextTranslator::Delegate {
   // Mapping from a translation engine work id to the associated nodes.
   std::map<int, NodeList*> pending_translations_;
 
+  // The list of text nodes in the current page with their original text.
+  // Used to undo the translation.
+  typedef std::pair<WebKit::WebNode, WebKit::WebString> NodeTextPair;
+  std::vector<NodeTextPair> text_nodes_;
+
   DISALLOW_COPY_AND_ASSIGN(PageTranslator);
 };