Cleanup dart to string conversions.

Source/WebCore/bindings/dart/DartUtilities.h

 // Copyright 2011, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //    * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //    * Redistributions in binary form must reproduce the above
@@ skipping 32 matching lines @@
 class DartApplicationLoader;
 class DartDOMData;
 class Dictionary;
 class Frame;
 class ScriptArguments;
 class ScriptCallStack;
 class ScriptExecutionContext;
 class SerializedScriptValue;
 class WebKitFlags;
 
-typedef HashMap<void*, Dart_Handle> DartDOMMap;
+class DartStringAdapter {
+public:
+    explicit DartStringAdapter(PassRefPtr<StringImpl> stringImpl)
+        : m_stringImpl(stringImpl)
+    {
+    }
+
+    operator String() const { return String(m_stringImpl); }
+    operator AtomicString() const { return AtomicString(m_stringImpl); }
+
+private:
+    RefPtr<StringImpl> m_stringImpl;
+};
 
 class DartUtilities {
 public:
     enum ConversionFlag {
         ConvertNone = 0,
         ConvertNullToDefaultValue = 1
     };
 
     static const char* htmlLibraryName;
 
-    static PassRefPtr<StringImpl> toStringImpl(Dart_Handle, ConversionFlag flag, Dart_Handle& exception);
-    // FIXME: we should get rid of this one in favour of toStringImpl.
-    static String dartStringToString(Dart_Handle object)
-    {
-        Dart_Handle exception = 0;
-        RefPtr<StringImpl> impl = toStringImpl(object, ConvertNone, exception);
-        ASSERT(!exception);
-        return String(impl.release());
-    }
-
     static Dart_Handle stringImplToDartString(StringImpl*);
     static Dart_Handle stringToDartString(const String&);
     static Dart_Handle stringToDartString(const AtomicString&);
 
     static Dart_Handle errorToException(Dart_Handle error)
     {
         ASSERT(Dart_IsError(error));
         if (Dart_ErrorHasException(error))
             return Dart_ErrorGetException(error);
         return Dart_NewString(Dart_GetError(error));
     }
 
     static bool checkResult(Dart_Handle result, Dart_Handle& exception)
     {
         if (!Dart_IsError(result))
             return true;
 
         exception = errorToException(result);
         return false;
     }
 
     static void extractListElements(Dart_Handle list, Dart_Handle& exception, Vector<Dart_Handle>& elements);
     static void extractMapElements(Dart_Handle map, Dart_Handle& exception, Vector<Dart_Handle>& keys, Vector<Dart_Handle>& values);
 
     static int64_t toInteger(Dart_Handle object, Dart_Handle& exception);
+    static String toString(Dart_Handle object);
     static void toMessagePortArray(Dart_Handle object, MessagePortArray&, ArrayBufferArray&, Dart_Handle& exception);
     static PassRefPtr<SerializedScriptValue> toSerializedScriptValue(Dart_Handle object, MessagePortArray*, ArrayBufferArray*, Dart_Handle& exception);
     static PassRefPtr<WebKitFlags> toWebKitFlags(Dart_Handle object, Dart_Handle& exception);
     static Dictionary dartToDictionary(Dart_Handle, Dart_Handle& exception);
 
     static DOMWindow* domWindowForCurrentIsolate();
 
     static Dart_Handle htmlLibraryForCurrentIsolate();
     static Dart_Handle pageLibraryForCurrentIsolate();
 
@@ skipping 30 matching lines @@
     }
 
     static Dart_Handle internalErrorException(const char* msg)
     {
         // FIXME: wrap into proper type.
         return Dart_NewString(msg);
     }
 
     static Dart_Handle invokeUtilsMethod(const char* methodName, int argCount, Dart_Handle* args);
 
+    static DartStringAdapter dartToString(Dart_Handle object, Dart_Handle& exception)
+    {
+        // FIXME: [performance] need better treatment of String vs. AtomicString, cf. v8 implementation.
+        return DartStringAdapter(toStringImpl(object, exception));
+    }
+    static DartStringAdapter dartToStringWithNullCheck(Dart_Handle object, Dart_Handle& exception)

[Anton Muhin, 2012/06/26 16:52:28]

wdyt, do we need to distinguish those?  maybe we should just accept nulls?  my
main concern would be v8 may convert nulls to "null" string :)

[podivilov, 2012/06/26 18:07:38]

Passing nulls to c++ methods is a bit scary... Also we do want to throw
exceptions where real string should be provided.

+    {
+        if (Dart_IsNull(object))
+            return DartStringAdapter(0);
+        return dartToString(object, exception);
+    }
     static Dart_Handle stringToDart(const AtomicString& value, ConversionFlag flag = ConvertNone);
     static Dart_Handle stringToDart(const String& value, ConversionFlag flag = ConvertNone);
 
     static bool dartToBool(Dart_Handle, Dart_Handle& exception);
     static Dart_Handle boolToDart(bool value)
     {
         return Dart_NewBoolean(value);
     }
 
     static int dartToInt(Dart_Handle, Dart_Handle& exception);
@@ skipping 29 matching lines @@
         return Dart_NewDouble(value);
     }
 
     static Dart_Handle numberToDart(double value);
 
     static ScriptValue dartToScriptValue(Dart_Handle, Dart_Handle& exception);
     static Dart_Handle scriptValueToDart(const ScriptValue& value);
 
     static PassRefPtr<SerializedScriptValue> dartToSerializedScriptValue(Dart_Handle, Dart_Handle& exception);
     static Dart_Handle serializedScriptValueToDart(SerializedScriptValue* value);
+
+private:
+    static PassRefPtr<StringImpl> toStringImpl(Dart_Handle object, Dart_Handle& exception);
 };
 
 class DartApiScope {
 public:
     DartApiScope() { Dart_EnterScope(); }
     ~DartApiScope() { Dart_ExitScope(); }
 };
 
 #define DART_UNIMPLEMENTED_EXCEPTION() DartUtilities::notImplementedException(__FILE__, __LINE__)
 #define DART_UNIMPLEMENTED() Dart_ThrowException(DART_UNIMPLEMENTED_EXCEPTION());
 
 } // namespace WebCore
 
 #endif // DartUtilities_h