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// Copyright 2013 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/extensions/api/braille_display_private/brlapi_connection.h"
#include <errno.h>
#include "base/macros.h"
#include "base/message_loop/message_loop.h"
#include "base/sys_info.h"
#include "build/build_config.h"
namespace extensions {
using base::MessageLoopForIO;
namespace api {
namespace braille_display_private {
namespace {
// Default virtual terminal. This can be overriden by setting the
// WINDOWPATH environment variable. This is only used when not running
// under Crhome OS (that is in aura for a Linux desktop).
// TODO(plundblad): Find a way to detect the controlling terminal of the
// X server.
static const int kDefaultTtyLinux = 7;
#if defined(OS_CHROMEOS)
// The GUI is always running on vt1 in Chrome OS.
static const int kDefaultTtyChromeOS = 1;
#endif
} // namespace
class BrlapiConnectionImpl : public BrlapiConnection,
MessageLoopForIO::Watcher {
public:
explicit BrlapiConnectionImpl(LibBrlapiLoader* loader) :
libbrlapi_loader_(loader) {}
~BrlapiConnectionImpl() override { Disconnect(); }
ConnectResult Connect(const OnDataReadyCallback& on_data_ready) override;
void Disconnect() override;
bool Connected() override { return handle_ != nullptr; }
brlapi_error_t* BrlapiError() override;
std::string BrlapiStrError() override;
bool GetDisplaySize(size_t* size) override;
bool WriteDots(const unsigned char* cells) override;
int ReadKey(brlapi_keyCode_t* keyCode) override;
// MessageLoopForIO::Watcher
void OnFileCanReadWithoutBlocking(int fd) override { on_data_ready_.Run(); }
void OnFileCanWriteWithoutBlocking(int fd) override {}
private:
bool CheckConnected();
ConnectResult ConnectResultForError();
LibBrlapiLoader* libbrlapi_loader_;
scoped_ptr<brlapi_handle_t, base::FreeDeleter> handle_;
MessageLoopForIO::FileDescriptorWatcher fd_controller_;
OnDataReadyCallback on_data_ready_;
DISALLOW_COPY_AND_ASSIGN(BrlapiConnectionImpl);
};
BrlapiConnection::BrlapiConnection() {
}
BrlapiConnection::~BrlapiConnection() {
}
scoped_ptr<BrlapiConnection> BrlapiConnection::Create(
LibBrlapiLoader* loader) {
DCHECK(loader->loaded());
return scoped_ptr<BrlapiConnection>(new BrlapiConnectionImpl(loader));
}
BrlapiConnection::ConnectResult BrlapiConnectionImpl::Connect(
const OnDataReadyCallback& on_data_ready) {
DCHECK(!handle_);
handle_.reset((brlapi_handle_t*) malloc(
libbrlapi_loader_->brlapi_getHandleSize()));
int fd = libbrlapi_loader_->brlapi__openConnection(handle_.get(), NULL, NULL);
if (fd < 0) {
handle_.reset();
VLOG(1) << "Error connecting to brlapi: " << BrlapiStrError();
return ConnectResultForError();
}
int path[2] = {0, 0};
int pathElements = 0;
#if defined(OS_CHROMEOS)
if (base::SysInfo::IsRunningOnChromeOS())
path[pathElements++] = kDefaultTtyChromeOS;
#endif
if (pathElements == 0 && getenv("WINDOWPATH") == NULL)
path[pathElements++] = kDefaultTtyLinux;
if (libbrlapi_loader_->brlapi__enterTtyModeWithPath(
handle_.get(), path, pathElements, NULL) < 0) {
LOG(ERROR) << "brlapi: couldn't enter tty mode: " << BrlapiStrError();
Disconnect();
return CONNECT_ERROR_RETRY;
}
size_t size;
if (!GetDisplaySize(&size)) {
// Error already logged.
Disconnect();
return CONNECT_ERROR_RETRY;
}
// A display size of 0 means no display connected. We can't reliably
// detect when a display gets connected, so fail and let the caller
// retry connecting.
if (size == 0) {
VLOG(1) << "No braille display connected";
Disconnect();
return CONNECT_ERROR_RETRY;
}
const brlapi_keyCode_t extraKeys[] = {
BRLAPI_KEY_TYPE_CMD | BRLAPI_KEY_CMD_OFFLINE,
// brltty 5.1 converts dot input to Unicode characters unless we
// explicitly accept this command.
BRLAPI_KEY_TYPE_CMD | BRLAPI_KEY_CMD_PASSDOTS,
};
if (libbrlapi_loader_->brlapi__acceptKeys(
handle_.get(), brlapi_rangeType_command, extraKeys,
arraysize(extraKeys)) < 0) {
LOG(ERROR) << "Couldn't acceptKeys: " << BrlapiStrError();
Disconnect();
return CONNECT_ERROR_RETRY;
}
if (!MessageLoopForIO::current()->WatchFileDescriptor(
fd, true, MessageLoopForIO::WATCH_READ, &fd_controller_, this)) {
LOG(ERROR) << "Couldn't watch file descriptor " << fd;
Disconnect();
return CONNECT_ERROR_RETRY;
}
on_data_ready_ = on_data_ready;
return CONNECT_SUCCESS;
}
void BrlapiConnectionImpl::Disconnect() {
if (!handle_) {
return;
}
fd_controller_.StopWatchingFileDescriptor();
libbrlapi_loader_->brlapi__closeConnection(
handle_.get());
handle_.reset();
}
brlapi_error_t* BrlapiConnectionImpl::BrlapiError() {
return libbrlapi_loader_->brlapi_error_location();
}
std::string BrlapiConnectionImpl::BrlapiStrError() {
return libbrlapi_loader_->brlapi_strerror(BrlapiError());
}
bool BrlapiConnectionImpl::GetDisplaySize(size_t* size) {
if (!CheckConnected()) {
return false;
}
unsigned int columns, rows;
if (libbrlapi_loader_->brlapi__getDisplaySize(
handle_.get(), &columns, &rows) < 0) {
LOG(ERROR) << "Couldn't get braille display size " << BrlapiStrError();
return false;
}
*size = columns * rows;
return true;
}
bool BrlapiConnectionImpl::WriteDots(const unsigned char* cells) {
if (!CheckConnected())
return false;
if (libbrlapi_loader_->brlapi__writeDots(handle_.get(), cells) < 0) {
VLOG(1) << "Couldn't write to brlapi: " << BrlapiStrError();
return false;
}
return true;
}
int BrlapiConnectionImpl::ReadKey(brlapi_keyCode_t* key_code) {
if (!CheckConnected())
return -1;
return libbrlapi_loader_->brlapi__readKey(
handle_.get(), 0 /*wait*/, key_code);
}
bool BrlapiConnectionImpl::CheckConnected() {
if (!handle_) {
BrlapiError()->brlerrno = BRLAPI_ERROR_ILLEGAL_INSTRUCTION;
return false;
}
return true;
}
BrlapiConnection::ConnectResult BrlapiConnectionImpl::ConnectResultForError() {
const brlapi_error_t* error = BrlapiError();
// For the majority of users, the socket file will never exist because
// the daemon is never run. Avoid retrying in this case, relying on
// the socket directory to change and trigger further tries if the
// daemon comes up later on.
if (error->brlerrno == BRLAPI_ERROR_LIBCERR
&& error->libcerrno == ENOENT) {
return CONNECT_ERROR_NO_RETRY;
}
return CONNECT_ERROR_RETRY;
}
} // namespace braille_display_private
} // namespace api
} // namespace extensions
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