Only send SelectionChanged events when the selection has actually changed....

chrome/renderer/render_view.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/render_view.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 2469 matching lines @@
   }
 }
 
 void RenderView::SetTooltipText(WebView* webview,
                                 const std::wstring& tooltip_text) {
   Send(new ViewHostMsg_SetTooltipText(routing_id_, tooltip_text));
 }
 
 void RenderView::DidChangeSelection(bool is_empty_selection) {
 #if defined(OS_LINUX)
+  // TODO(estade): investigate incremental updates to the selection so that we
+  // don't send the entire selection over IPC every time.
   if (!is_empty_selection) {
+    // Sometimes we get repeated DidChangeSelection calls from webkit when
+    // the selection hasn't actually changed. We don't want to report these
+    // because it will cause us to continually claim the X clipboard.
+    std::string this_selection =

[darin (slow to review), 2009/05/18 17:09:28]

minor nit:  "const std::string& this_selection ="

[Evan Stade, 2009/05/18 17:14:23]

I had that at first, but GetSelection() returns a string (not string&), so isn't
it pointless?

+        webview()->GetFocusedFrame()->GetSelection(false);
+    if (this_selection == last_selection_)
+      return;
+
     Send(new ViewHostMsg_SelectionChanged(routing_id_,
-         webview()->GetFocusedFrame()->GetSelection(false)));
+         this_selection));
+    last_selection_ = this_selection;
   }
 #endif
 }
 
 void RenderView::DownloadUrl(const GURL& url, const GURL& referrer) {
   Send(new ViewHostMsg_DownloadUrl(routing_id_, url, referrer));
 }
 
 WebDevToolsAgentDelegate* RenderView::GetWebDevToolsAgentDelegate() {
   return devtools_agent_.get();
@@ skipping 503 matching lines @@
     }
   }
   UMA_HISTOGRAM_TIMES("Renderer.All.StartToFinishDoc", start_to_finish_doc);
   UMA_HISTOGRAM_TIMES("Renderer.All.FinishDocToFinish", finish_doc_to_finish);
   UMA_HISTOGRAM_TIMES("Renderer.All.StartToFinish", start_to_finish);
   if (start_to_first_layout.ToInternalValue() >= 0) {
     UMA_HISTOGRAM_TIMES(
       "Renderer.All.StartToFirstLayout", start_to_first_layout);
   }
 }