Let developers get a list of valid serial ports, which is the same set of ports that we'll accept on a serial.open() call.

Refactored AsyncIOAPIFunction to AsyncAPIFunction, and let inheriting classes specify which thread the Work() operation should happen on (e.g., FILE rather than IO).

BUG=121466
TEST=added

Review URL: https://chromiumcodereview.appspot.com/10317032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@135895 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 58 insertions, 12 deletions

diff --git a/chrome/browser/extensions/api/serial/serial_api.cc b/chrome/browser/extensions/api/serial/serial_api.cc
index e25b8cf..93855f2 100644
--- a/chrome/browser/extensions/api/serial/serial_api.cc
+++ b/chrome/browser/extensions/api/serial/serial_api.cc
@@ -9,14 +9,43 @@
 #include "base/values.h"
 #include "chrome/browser/extensions/api/api_resource_controller.h"
 #include "chrome/browser/extensions/api/serial/serial_connection.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
 
 namespace extensions {
 
 const char kConnectionIdKey[] = "connectionId";
+const char kPortsKey[] = "ports";
 const char kDataKey[] = "data";
 const char kBytesReadKey[] = "bytesRead";
 const char kBytesWrittenKey[] = "bytesWritten";
 
+SerialGetPortsFunction::SerialGetPortsFunction() {}
+
+bool SerialGetPortsFunction::Prepare() {
+  work_thread_id_ = BrowserThread::FILE;
+  return true;
+}
+
+void SerialGetPortsFunction::Work() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+
+  ListValue* ports = new ListValue();
+  SerialConnection::StringSet port_names =
+      SerialConnection::GenerateValidSerialPortNames();
+  SerialConnection::StringSet::const_iterator i = port_names.begin();
+  while (i != port_names.end()) {
+    ports->Append(Value::CreateStringValue(*i++));
+  }
+
+  result_.reset(ports);
+}
+
+bool SerialGetPortsFunction::Respond() {
+  return true;
+}
+
 SerialOpenFunction::SerialOpenFunction() : src_id_(-1) {}
 
 bool SerialOpenFunction::Prepare() {
diff --git a/chrome/browser/extensions/api/serial/serial_api.h b/chrome/browser/extensions/api/serial/serial_api.h
index 902d641..7965d87 100644
--- a/chrome/browser/extensions/api/serial/serial_api.h
+++ b/chrome/browser/extensions/api/serial/serial_api.h
@@ -16,7 +16,22 @@ namespace extensions {
 
 extern const char kConnectionIdKey[];
 
-class SerialOpenFunction : public AsyncIOAPIFunction {
+class SerialGetPortsFunction : public AsyncAPIFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION_NAME("experimental.serial.getPorts")
+
+  SerialGetPortsFunction();
+
+ protected:
+  virtual ~SerialGetPortsFunction() {}
+
+  // AsyncAPIFunction:
+  virtual bool Prepare() OVERRIDE;
+  virtual void Work() OVERRIDE;
+  virtual bool Respond() OVERRIDE;
+};
+
+class SerialOpenFunction : public AsyncAPIFunction {
  public:
   DECLARE_EXTENSION_FUNCTION_NAME("experimental.serial.open")
 
@@ -25,7 +40,7 @@ class SerialOpenFunction : public AsyncIOAPIFunction {
  protected:
   virtual ~SerialOpenFunction() {}
 
-  // AsyncIOAPIFunction:
+  // AsyncAPIFunction:
   virtual bool Prepare() OVERRIDE;
   virtual void Work() OVERRIDE;
   virtual bool Respond() OVERRIDE;
@@ -35,14 +50,14 @@ class SerialOpenFunction : public AsyncIOAPIFunction {
   std::string port_;
 };
 
-class SerialCloseFunction : public AsyncIOAPIFunction {
+class SerialCloseFunction : public AsyncAPIFunction {
  public:
   DECLARE_EXTENSION_FUNCTION_NAME("experimental.serial.close")
 
  protected:
   virtual ~SerialCloseFunction() {}
 
-  // AsyncIOAPIFunction:
+  // AsyncAPIFunction:
   virtual bool Prepare() OVERRIDE;
   virtual void Work() OVERRIDE;
   virtual bool Respond() OVERRIDE;
@@ -51,14 +66,14 @@ class SerialCloseFunction : public AsyncIOAPIFunction {
   int connection_id_;
 };
 
-class SerialReadFunction : public AsyncIOAPIFunction {
+class SerialReadFunction : public AsyncAPIFunction {
  public:
   DECLARE_EXTENSION_FUNCTION_NAME("experimental.serial.read")
 
  protected:
   virtual ~SerialReadFunction() {}
 
-  // AsyncIOAPIFunction:
+  // AsyncAPIFunction:
   virtual bool Prepare() OVERRIDE;
   virtual void Work() OVERRIDE;
   virtual bool Respond() OVERRIDE;
@@ -67,7 +82,7 @@ class SerialReadFunction : public AsyncIOAPIFunction {
   int connection_id_;
 };
 
-class SerialWriteFunction : public AsyncIOAPIFunction {
+class SerialWriteFunction : public AsyncAPIFunction {
  public:
   DECLARE_EXTENSION_FUNCTION_NAME("experimental.serial.write")
 
@@ -76,7 +91,7 @@ class SerialWriteFunction : public AsyncIOAPIFunction {
  protected:
   virtual ~SerialWriteFunction();
 
-  // AsyncIOAPIFunction:
+  // AsyncAPIFunction:
   virtual bool Prepare() OVERRIDE;
   virtual void Work() OVERRIDE;
   virtual bool Respond() OVERRIDE;
diff --git a/chrome/browser/extensions/api/serial/serial_connection.cc b/chrome/browser/extensions/api/serial/serial_connection.cc
index ed9314b..d17a707 100644
--- a/chrome/browser/extensions/api/serial/serial_connection.cc
+++ b/chrome/browser/extensions/api/serial/serial_connection.cc
@@ -8,7 +8,7 @@
 
 namespace extensions {
 
-const char kSerialConnectionNotFoundError[] = "Serial conenction not found";
+const char kSerialConnectionNotFoundError[] = "Serial connection not found";
 
 // static
 bool SerialConnection::DoesPortExist(const StringSet& name_set,
diff --git a/chrome/browser/extensions/api/serial/serial_connection.h b/chrome/browser/extensions/api/serial/serial_connection.h
index d62189d..7dca2aa 100644
--- a/chrome/browser/extensions/api/serial/serial_connection.h
+++ b/chrome/browser/extensions/api/serial/serial_connection.h
@@ -44,11 +44,9 @@ class SerialConnection : public APIResource {
   static bool DoesPortExist(const StringSet& port_patterns,
                             const std::string& port_name);
 
- private:
-  // TODO(miket): expose this functionality via API. Otherwise developers have
-  // to guess at valid names.
   static StringSet GenerateValidSerialPortNames();
 
+ private:
   // Returns a StringSet of patterns to be used with MatchPattern.
   static StringSet GenerateValidPatterns();
 
diff --git a/chrome/browser/extensions/api/serial/serial_connection_posix.cc b/chrome/browser/extensions/api/serial/serial_connection_posix.cc
index 4e1fa5d..8e6e567 100644
--- a/chrome/browser/extensions/api/serial/serial_connection_posix.cc
+++ b/chrome/browser/extensions/api/serial/serial_connection_posix.cc
@@ -14,6 +14,9 @@
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/string_util.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
 
 namespace extensions {
 
@@ -105,6 +108,7 @@ SerialConnection::StringSet SerialConnection::GenerateValidPatterns() {
 // TODO(miket): this might be refactorable into serial_connection.cc, if
 // Windows serial-port enumeration also entails looking through a directory.
 SerialConnection::StringSet SerialConnection::GenerateValidSerialPortNames() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   const FilePath DEV_ROOT("/dev");
   const file_util::FileEnumerator::FileType FILES_AND_SYM_LINKS =
       static_cast<file_util::FileEnumerator::FileType>(