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// Copyright (c) 2011 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/browser/sync/js_event_handler_list.h"
#include <cstddef>
#include "base/logging.h"
#include "chrome/browser/sync/js_backend.h"
#include "chrome/browser/sync/js_event_handler.h"
namespace browser_sync {
JsEventHandlerList::PendingMessage::PendingMessage(
const std::string& name, const JsArgList& args,
const JsEventHandler* sender)
: name(name), args(args), sender(sender) {}
JsEventHandlerList::JsEventHandlerList() : backend_(NULL) {}
JsEventHandlerList::~JsEventHandlerList() {
RemoveBackend();
}
// We connect to the backend only when necessary, i.e. when there is
// at least one handler.
void JsEventHandlerList::AddHandler(JsEventHandler* handler) {
handlers_.AddObserver(handler);
if (backend_) {
backend_->SetParentJsEventRouter(this);
}
}
void JsEventHandlerList::RemoveHandler(JsEventHandler* handler) {
handlers_.RemoveObserver(handler);
if (backend_ && handlers_.size() == 0) {
backend_->RemoveParentJsEventRouter();
}
}
void JsEventHandlerList::SetBackend(JsBackend* backend) {
DCHECK(!backend_);
DCHECK(backend);
backend_ = backend;
if (handlers_.size() > 0) {
backend_->SetParentJsEventRouter(this);
// Process any queued messages.
PendingMessageList pending_messages;
pending_messages_.swap(pending_messages);
for (PendingMessageList::const_iterator it = pending_messages.begin();
it != pending_messages.end(); ++it) {
backend_->ProcessMessage(it->name, it->args, it->sender);
}
}
}
void JsEventHandlerList::RemoveBackend() {
if (backend_) {
backend_->RemoveParentJsEventRouter();
backend_ = NULL;
}
}
void JsEventHandlerList::ProcessMessage(
const std::string& name, const JsArgList& args,
const JsEventHandler* sender) {
if (backend_) {
backend_->ProcessMessage(name, args, sender);
} else {
pending_messages_.push_back(PendingMessage(name, args, sender));
}
}
void JsEventHandlerList::RouteJsEvent(const std::string& name,
const JsArgList& args,
const JsEventHandler* target) {
if (target) {
JsEventHandler* non_const_target(const_cast<JsEventHandler*>(target));
if (handlers_.HasObserver(non_const_target)) {
non_const_target->HandleJsEvent(name, args);
} else {
VLOG(1) << "Unknown target; dropping event " << name
<< " with args " << args.ToString();
}
} else {
FOR_EACH_OBSERVER(JsEventHandler, handlers_, HandleJsEvent(name, args));
}
}
} // namespace browser_sync
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