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// Copyright (c) 2012 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 "content/browser/geolocation/geolocation_provider.h"
#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/callback.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/memory/singleton.h"
#include "base/message_loop.h"
#include "content/browser/geolocation/location_arbitrator_impl.h"
#include "content/public/browser/browser_thread.h"
namespace content {
void GeolocationProvider::AddObserver(GeolocationObserver* observer,
const GeolocationObserverOptions& update_options) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
observers_[observer] = update_options;
OnClientsChanged();
if (position_.Validate() ||
position_.error_code != Geoposition::ERROR_CODE_NONE)
observer->OnLocationUpdate(position_);
}
bool GeolocationProvider::RemoveObserver(GeolocationObserver* observer) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
size_t removed = observers_.erase(observer);
if (removed)
OnClientsChanged();
return removed > 0;
}
void GeolocationProvider::RequestCallback(
const GeolocationUpdateCallback& callback) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
callbacks_.push_back(callback);
OnClientsChanged();
OnPermissionGranted();
}
void GeolocationProvider::OnPermissionGranted() {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
bool was_permission_granted = is_permission_granted_;
is_permission_granted_ = true;
if (IsRunning() && !was_permission_granted)
InformProvidersPermissionGranted();
}
bool GeolocationProvider::HasPermissionBeenGranted() const {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
return is_permission_granted_;
}
void GeolocationProvider::OnLocationUpdate(const Geoposition& position) {
DCHECK(OnGeolocationThread());
// Will be true only in testing.
if (ignore_location_updates_)
return;
BrowserThread::PostTask(BrowserThread::IO,
FROM_HERE,
base::Bind(&GeolocationProvider::NotifyClients,
base::Unretained(this), position));
}
void GeolocationProvider::OverrideLocationForTesting(
const Geoposition& position) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
position_ = position;
ignore_location_updates_ = true;
NotifyClients(position);
}
GeolocationProvider* GeolocationProvider::GetInstance() {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
return Singleton<GeolocationProvider>::get();
}
GeolocationProvider::GeolocationProvider()
: base::Thread("Geolocation"),
is_permission_granted_(false),
ignore_location_updates_(false),
arbitrator_(NULL) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
}
GeolocationProvider::~GeolocationProvider() {
// All observers should have unregistered before this singleton is destructed.
DCHECK(observers_.empty());
Stop();
DCHECK(!arbitrator_);
}
bool GeolocationProvider::OnGeolocationThread() const {
return MessageLoop::current() == message_loop();
}
void GeolocationProvider::OnClientsChanged() {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
base::Closure task;
if (observers_.empty() && callbacks_.empty()) {
DCHECK(IsRunning());
// We have no more observers, so we clear the cached geoposition so that
// when the next observer is added we will not provide a stale position.
position_ = Geoposition();
task = base::Bind(&GeolocationProvider::StopProviders,
base::Unretained(this));
} else {
if (!IsRunning()) {
Start();
if (HasPermissionBeenGranted())
InformProvidersPermissionGranted();
}
// Determine a set of options that satisfies all clients.
GeolocationObserverOptions options =
GeolocationObserverOptions::Collapse(observers_);
// For callbacks, high accuracy position information is always requested.
if (!callbacks_.empty())
options.Collapse(GeolocationObserverOptions(true));
// Send the current options to the providers as they may have changed.
task = base::Bind(&GeolocationProvider::StartProviders,
base::Unretained(this),
options);
}
message_loop()->PostTask(FROM_HERE, task);
}
void GeolocationProvider::StopProviders() {
DCHECK(OnGeolocationThread());
DCHECK(arbitrator_);
arbitrator_->StopProviders();
}
void GeolocationProvider::StartProviders(
const GeolocationObserverOptions& options) {
DCHECK(OnGeolocationThread());
DCHECK(arbitrator_);
arbitrator_->StartProviders(options);
}
void GeolocationProvider::InformProvidersPermissionGranted() {
DCHECK(IsRunning());
if (!OnGeolocationThread()) {
message_loop()->PostTask(
FROM_HERE,
base::Bind(&GeolocationProvider::InformProvidersPermissionGranted,
base::Unretained(this)));
return;
}
DCHECK(OnGeolocationThread());
DCHECK(arbitrator_);
arbitrator_->OnPermissionGranted();
}
void GeolocationProvider::NotifyClients(const Geoposition& position) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
DCHECK(position.Validate() ||
position.error_code != Geoposition::ERROR_CODE_NONE);
position_ = position;
ObserverMap::const_iterator it = observers_.begin();
while (it != observers_.end()) {
// Advance iterator before calling the observer to guard against synchronous
// unregister.
GeolocationObserver* observer = it->first;
++it;
observer->OnLocationUpdate(position_);
}
if (!callbacks_.empty()) {
// Copy the callback list to guard against synchronous callback requests
// reallocating the vector and invalidating the iterator.
CallbackList callbacks = callbacks_;
callbacks_.clear();
for (CallbackList::iterator it = callbacks.begin();
it != callbacks.end();
++it)
it->Run(position);
OnClientsChanged();
}
}
void GeolocationProvider::Init() {
DCHECK(OnGeolocationThread());
DCHECK(!arbitrator_);
arbitrator_ = CreateArbitrator();
}
void GeolocationProvider::CleanUp() {
DCHECK(OnGeolocationThread());
delete arbitrator_;
arbitrator_ = NULL;
}
GeolocationArbitrator* GeolocationProvider::CreateArbitrator() {
return new GeolocationArbitratorImpl(this);
}
} // namespace content
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