1// Copyright 2014 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#ifndef EXTENSIONS_RENDERER_CONTENT_WATCHER_H_ 6#define EXTENSIONS_RENDERER_CONTENT_WATCHER_H_ 7 8#include <map> 9#include <set> 10#include <string> 11#include <vector> 12 13#include "third_party/WebKit/public/platform/WebVector.h" 14 15namespace blink { 16class WebFrame; 17class WebString; 18} 19 20namespace extensions { 21class Dispatcher; 22class Extension; 23class NativeHandler; 24 25// Watches the content of WebFrames to notify extensions when they match various 26// patterns. This class tracks the set of relevant patterns (set by 27// ExtensionMsg_WatchPages) and the set that match on each WebFrame, and sends a 28// ExtensionHostMsg_OnWatchedPageChange whenever a RenderView's set changes. 29// 30// There's one ContentWatcher per Dispatcher rather than per RenderView because 31// WebFrames can move between RenderViews through adoptNode. 32class ContentWatcher { 33 public: 34 ContentWatcher(); 35 ~ContentWatcher(); 36 37 // Handler for ExtensionMsg_WatchPages. 38 void OnWatchPages(const std::vector<std::string>& css_selectors); 39 40 // Uses WebDocument::watchCSSSelectors to watch the selectors in 41 // css_selectors_ and get a callback into DidMatchCSS() whenever the set of 42 // matching selectors in |frame| changes. 43 void DidCreateDocumentElement(blink::WebFrame* frame); 44 45 // Records that |newly_matching_selectors| have started matching on |*frame|, 46 // and |stopped_matching_selectors| have stopped matching. 47 void DidMatchCSS( 48 blink::WebFrame* frame, 49 const blink::WebVector<blink::WebString>& newly_matching_selectors, 50 const blink::WebVector<blink::WebString>& stopped_matching_selectors); 51 52 private: 53 // Given that we saw a change in the CSS selectors that |changed_frame| 54 // matched, tell the browser about the new set of matching selectors in its 55 // top-level page. We filter this so that if an extension were to be granted 56 // activeTab permission on that top-level page, we only send CSS selectors for 57 // frames that it could run on. 58 void NotifyBrowserOfChange(blink::WebFrame* changed_frame) const; 59 60 // If any of these selectors match on a page, we need to send an 61 // ExtensionHostMsg_OnWatchedPageChange back to the browser. 62 blink::WebVector<blink::WebString> css_selectors_; 63 64 // Maps live WebFrames to the set of CSS selectors they match. Blink sends 65 // back diffs, which we apply to these sets. 66 std::map<blink::WebFrame*, std::set<std::string> > matching_selectors_; 67}; 68 69} // namespace extensions 70 71#endif // EXTENSIONS_RENDERER_CONTENT_WATCHER_H_ 72