chrome/renderer/extensions/event_bindings.cc

   1 // Copyright (c) 2012 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 #include "chrome/renderer/extensions/event_bindings.h"
   6
   7 #include <vector>
   8
   9 #include "base/bind.h"
  10 #include "base/basictypes.h"
  11 #include "base/lazy_instance.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/message_loop.h"
  14 #include "chrome/common/extensions/background_info.h"
  15 #include "chrome/common/extensions/extension.h"
  16 #include "chrome/common/extensions/extension_messages.h"
  17 #include "chrome/common/extensions/extension_set.h"
  18 #include "chrome/common/extensions/value_counter.h"
  19 #include "chrome/common/url_constants.h"
  20 #include "chrome/renderer/extensions/chrome_v8_context.h"
  21 #include "chrome/renderer/extensions/chrome_v8_context_set.h"
  22 #include "chrome/renderer/extensions/chrome_v8_extension.h"
  23 #include "chrome/renderer/extensions/dispatcher.h"
  24 #include "chrome/renderer/extensions/event_bindings.h"
  25 #include "chrome/renderer/extensions/extension_helper.h"
  26 #include "chrome/renderer/extensions/user_script_slave.h"
  27 #include "content/public/renderer/render_thread.h"
  28 #include "content/public/renderer/v8_value_converter.h"
  29 #include "extensions/common/event_filter.h"
  30 #include "extensions/common/view_type.h"
  31 #include "googleurl/src/gurl.h"
  32 #include "grit/renderer_resources.h"
  33 #include "third_party/WebKit/Source/Platform/chromium/public/WebURL.h"
  34 #include "third_party/WebKit/Source/Platform/chromium/public/WebURLRequest.h"
  35 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
  36 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
  37 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
  38 #include "v8/include/v8.h"
  39
  40 using WebKit::WebFrame;
  41 using WebKit::WebURL;
  42 using content::RenderThread;
  43
  44 namespace extensions {
  45
  46 namespace {
  47
  48 // A map of event names to the number of contexts listening to that event.
  49 // We notify the browser about event listeners when we transition between 0
  50 // and 1.
  51 typedef std::map<std::string, int> EventListenerCounts;
  52
  53 // A map of extension IDs to listener counts for that extension.
  54 base::LazyInstance<std::map<std::string, EventListenerCounts> >
  55     g_listener_counts = LAZY_INSTANCE_INITIALIZER;
  56
  57 // A map of event names to a (filter -> count) map. The map is used to keep
  58 // track of which filters are in effect for which events.
  59 // We notify the browser about filtered event listeners when we transition
  60 // between 0 and 1.
  61 typedef std::map<std::string, linked_ptr<ValueCounter> >
  62     FilteredEventListenerCounts;
  63
  64 // A map of extension IDs to filtered listener counts for that extension.
  65 base::LazyInstance<std::map<std::string, FilteredEventListenerCounts> >
  66     g_filtered_listener_counts = LAZY_INSTANCE_INITIALIZER;
  67
  68 base::LazyInstance<EventFilter> g_event_filter = LAZY_INSTANCE_INITIALIZER;
  69
  70 // TODO(koz): Merge this into EventBindings.
  71 class ExtensionImpl : public ChromeV8Extension {
  72  public:
  73   explicit ExtensionImpl(Dispatcher* dispatcher,
  74                          v8::Handle<v8::Context> v8_context)
  75       : ChromeV8Extension(dispatcher, v8_context) {
  76     RouteFunction("AttachEvent",
  77         base::Bind(&ExtensionImpl::AttachEvent, base::Unretained(this)));
  78     RouteFunction("DetachEvent",
  79         base::Bind(&ExtensionImpl::DetachEvent, base::Unretained(this)));
  80     RouteFunction("AttachFilteredEvent",
  81         base::Bind(&ExtensionImpl::AttachFilteredEvent,
  82                    base::Unretained(this)));
  83     RouteFunction("DetachFilteredEvent",
  84         base::Bind(&ExtensionImpl::DetachFilteredEvent,
  85                    base::Unretained(this)));
  86     RouteFunction("MatchAgainstEventFilter",
  87         base::Bind(&ExtensionImpl::MatchAgainstEventFilter,
  88                    base::Unretained(this)));
  89   }
  90
  91   virtual ~ExtensionImpl() {}
  92
  93   // Attach an event name to an object.
  94   v8::Handle<v8::Value> AttachEvent(const v8::Arguments& args) {
  95     DCHECK(args.Length() == 1);
  96     // TODO(erikkay) should enforce that event name is a string in the bindings
  97     DCHECK(args[0]->IsString() || args[0]->IsUndefined());
  98
  99     if (args[0]->IsString()) {
 100       std::string event_name = *v8::String::AsciiValue(args[0]->ToString());
 101       const ChromeV8ContextSet& context_set = dispatcher_->v8_context_set();
 102       ChromeV8Context* context = context_set.GetByV8Context(v8_context());
 103       CHECK(context);
 104
 105       if (!dispatcher_->CheckContextAccessToExtensionAPI(event_name, context))
 106         return v8::Undefined();
 107
 108       std::string extension_id = context->GetExtensionID();
 109       EventListenerCounts& listener_counts =
 110           g_listener_counts.Get()[extension_id];
 111       if (++listener_counts[event_name] == 1) {
 112         content::RenderThread::Get()->Send(
 113             new ExtensionHostMsg_AddListener(extension_id, event_name));
 114       }
 115
 116       // This is called the first time the page has added a listener. Since
 117       // the background page is the only lazy page, we know this is the first
 118       // time this listener has been registered.
 119       if (IsLazyBackgroundPage(GetRenderView(), context->extension())) {
 120         content::RenderThread::Get()->Send(
 121             new ExtensionHostMsg_AddLazyListener(extension_id, event_name));
 122       }
 123     }
 124     return v8::Undefined();
 125   }
 126
 127   v8::Handle<v8::Value> DetachEvent(const v8::Arguments& args) {
 128     DCHECK(args.Length() == 2);
 129     // TODO(erikkay) should enforce that event name is a string in the bindings
 130     DCHECK(args[0]->IsString() || args[0]->IsUndefined());
 131
 132     if (args[0]->IsString() && args[1]->IsBoolean()) {
 133       std::string event_name = *v8::String::AsciiValue(args[0]->ToString());
 134       bool is_manual = args[1]->BooleanValue();
 135
 136       const ChromeV8ContextSet& context_set = dispatcher_->v8_context_set();
 137       ChromeV8Context* context = context_set.GetByV8Context(v8_context());
 138       if (!context)
 139         return v8::Undefined();
 140
 141       std::string extension_id = context->GetExtensionID();
 142       EventListenerCounts& listener_counts =
 143           g_listener_counts.Get()[extension_id];
 144
 145       if (--listener_counts[event_name] == 0) {
 146         content::RenderThread::Get()->Send(
 147             new ExtensionHostMsg_RemoveListener(extension_id, event_name));
 148       }
 149
 150       // DetachEvent is called when the last listener for the context is
 151       // removed. If the context is the background page, and it removes the
 152       // last listener manually, then we assume that it is no longer interested
 153       // in being awakened for this event.
 154       if (is_manual && IsLazyBackgroundPage(GetRenderView(),
 155                                             context->extension())) {
 156         content::RenderThread::Get()->Send(
 157             new ExtensionHostMsg_RemoveLazyListener(extension_id, event_name));
 158       }
 159     }
 160     return v8::Undefined();
 161   }
 162
 163   // MatcherID AttachFilteredEvent(string event_name, object filter)
 164   // event_name - Name of the event to attach.
 165   // filter - Which instances of the named event are we interested in.
 166   // returns the id assigned to the listener, which will be returned from calls
 167   // to MatchAgainstEventFilter where this listener matches.
 168   v8::Handle<v8::Value> AttachFilteredEvent(const v8::Arguments& args) {
 169     DCHECK_EQ(2, args.Length());
 170     DCHECK(args[0]->IsString());
 171     DCHECK(args[1]->IsObject());
 172
 173     const ChromeV8ContextSet& context_set = dispatcher_->v8_context_set();
 174     ChromeV8Context* context = context_set.GetByV8Context(v8_context());
 175     DCHECK(context);
 176     if (!context)
 177       return v8::Integer::New(-1);
 178
 179     std::string event_name = *v8::String::AsciiValue(args[0]);
 180     // This method throws an exception if it returns false.
 181     if (!dispatcher_->CheckContextAccessToExtensionAPI(event_name, context))
 182       return v8::Undefined();
 183
 184     std::string extension_id = context->GetExtensionID();
 185     if (extension_id.empty())
 186       return v8::Integer::New(-1);
 187
 188     scoped_ptr<base::DictionaryValue> filter;
 189     scoped_ptr<content::V8ValueConverter> converter(
 190         content::V8ValueConverter::create());
 191
 192     base::DictionaryValue* filter_dict = NULL;
 193     base::Value* filter_value =
 194         converter->FromV8Value(args[1]->ToObject(), context->v8_context());
 195     if (!filter_value)
 196       return v8::Integer::New(-1);
 197     if (!filter_value->GetAsDictionary(&filter_dict)) {
 198       delete filter_value;
 199       return v8::Integer::New(-1);
 200     }
 201
 202     filter.reset(filter_dict);
 203     EventFilter& event_filter = g_event_filter.Get();
 204     int id = event_filter.AddEventMatcher(event_name, ParseEventMatcher(
 205         filter.get()));
 206
 207     // Only send IPCs the first time a filter gets added.
 208     if (AddFilter(event_name, extension_id, filter.get())) {
 209       bool lazy = IsLazyBackgroundPage(GetRenderView(), context->extension());
 210       content::RenderThread::Get()->Send(
 211           new ExtensionHostMsg_AddFilteredListener(extension_id, event_name,
 212                                                    *filter, lazy));
 213     }
 214
 215     return v8::Integer::New(id);
 216   }
 217
 218   // Add a filter to |event_name| in |extension_id|, returning true if it
 219   // was the first filter for that event in that extension.
 220   static bool AddFilter(const std::string& event_name,
 221                         const std::string& extension_id,
 222                         base::DictionaryValue* filter) {
 223     FilteredEventListenerCounts& counts =
 224         g_filtered_listener_counts.Get()[extension_id];
 225     FilteredEventListenerCounts::iterator it = counts.find(event_name);
 226     if (it == counts.end())
 227       counts[event_name].reset(new ValueCounter);
 228
 229     int result = counts[event_name]->Add(*filter);
 230     return 1 == result;
 231   }
 232
 233   // Remove a filter from |event_name| in |extension_id|, returning true if it
 234   // was the last filter for that event in that extension.
 235   static bool RemoveFilter(const std::string& event_name,
 236                            const std::string& extension_id,
 237                            base::DictionaryValue* filter) {
 238     FilteredEventListenerCounts& counts =
 239         g_filtered_listener_counts.Get()[extension_id];
 240     FilteredEventListenerCounts::iterator it = counts.find(event_name);
 241     if (it == counts.end())
 242       return false;
 243     return 0 == it->second->Remove(*filter);
 244   }
 245
 246   // void DetachFilteredEvent(int id, bool manual)
 247   // id     - Id of the event to detach.
 248   // manual - false if this is part of the extension unload process where all
 249   //          listeners are automatically detached.
 250   v8::Handle<v8::Value> DetachFilteredEvent(const v8::Arguments& args) {
 251     DCHECK_EQ(2, args.Length());
 252     DCHECK(args[0]->IsInt32());
 253     DCHECK(args[1]->IsBoolean());
 254     bool is_manual = args[1]->BooleanValue();
 255     const ChromeV8ContextSet& context_set = dispatcher_->v8_context_set();
 256     ChromeV8Context* context = context_set.GetByV8Context(v8_context());
 257     if (!context)
 258       return v8::Undefined();
 259
 260     std::string extension_id = context->GetExtensionID();
 261     if (extension_id.empty())
 262       return v8::Undefined();
 263
 264     int matcher_id = args[0]->Int32Value();
 265     EventFilter& event_filter = g_event_filter.Get();
 266     EventMatcher* event_matcher =
 267         event_filter.GetEventMatcher(matcher_id);
 268
 269     const std::string& event_name = event_filter.GetEventName(matcher_id);
 270
 271     // Only send IPCs the last time a filter gets removed.
 272     if (RemoveFilter(event_name, extension_id, event_matcher->value())) {
 273       bool lazy = is_manual && IsLazyBackgroundPage(GetRenderView(),
 274                                                     context->extension());
 275       content::RenderThread::Get()->Send(
 276           new ExtensionHostMsg_RemoveFilteredListener(extension_id, event_name,
 277                                                       *event_matcher->value(),
 278                                                       lazy));
 279     }
 280
 281     event_filter.RemoveEventMatcher(matcher_id);
 282
 283     return v8::Undefined();
 284   }
 285
 286   v8::Handle<v8::Value> MatchAgainstEventFilter(const v8::Arguments& args) {
 287     typedef std::set<EventFilter::MatcherID> MatcherIDs;
 288
 289     EventFilter& event_filter = g_event_filter.Get();
 290     std::string event_name = *v8::String::AsciiValue(args[0]->ToString());
 291     EventFilteringInfo info = ParseFromObject(args[1]->ToObject());
 292     MatcherIDs matched_event_filters = event_filter.MatchEvent(
 293         event_name, info);
 294     v8::Handle<v8::Array> array(v8::Array::New(matched_event_filters.size()));
 295     int i = 0;
 296     for (MatcherIDs::iterator it = matched_event_filters.begin();
 297          it != matched_event_filters.end(); ++it) {
 298       array->Set(v8::Integer::New(i++), v8::Integer::New(*it));
 299     }
 300     return array;
 301   }
 302
 303   static EventFilteringInfo ParseFromObject(v8::Handle<v8::Object> object) {
 304     EventFilteringInfo info;
 305     v8::Handle<v8::String> url(v8::String::New("url"));
 306     if (object->Has(url)) {
 307       v8::Handle<v8::Value> url_value(object->Get(url));
 308       info.SetURL(GURL(*v8::String::AsciiValue(url_value)));
 309     }
 310     return info;
 311   }
 312
 313  private:
 314   static bool IsLazyBackgroundPage(content::RenderView* render_view,
 315                                    const Extension* extension) {
 316     if (!render_view)
 317       return false;
 318     ExtensionHelper* helper = ExtensionHelper::Get(render_view);
 319     return (extension && BackgroundInfo::HasLazyBackgroundPage(extension) &&
 320             helper->view_type() == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE);
 321   }
 322
 323   static scoped_ptr<EventMatcher> ParseEventMatcher(
 324       base::DictionaryValue* filter_dict) {
 325     return scoped_ptr<EventMatcher>(new EventMatcher(
 326         scoped_ptr<base::DictionaryValue>(filter_dict->DeepCopy())));
 327   }
 328 };
 329
 330 }  // namespace
 331
 332 // static
 333 ChromeV8Extension* EventBindings::Create(Dispatcher* dispatcher,
 334                                          v8::Handle<v8::Context> context) {
 335   return new ExtensionImpl(dispatcher, context);
 336 }
 337
 338 }  // namespace extensions