Implement Composition interface for IME API

Source/core/html/ime/Composition.cpp

 /*
  * Copyright (C) 2013 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 13 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/html/ime/Composition.h"
 
+#include "core/html/ime/InputMethodContext.h"
+
 namespace WebCore {
 
 Composition::~Composition()
 {
 }
 
-PassRefPtr<Composition> Composition::create()
+PassRefPtr<Composition> Composition::create(InputMethodContext* context)
 {
-    return adoptRef(new Composition());
+    return adoptRef(new Composition(context));
 }
 
-Composition::Composition()
-    : m_selectionStart(0)
-    , m_selectionEnd(0)
+Composition::Composition(InputMethodContext* context)
+    : m_inputMethodContext(context)
 {
     ScriptWrappable::init(this);
 }
 
+String Composition::text() const
+{
+    return m_inputMethodContext->compositionText();
+}
+
+int Composition::selectionStart() const
+{
+    return m_inputMethodContext->selectionStart();
+}
+
+int Composition::selectionEnd() const
+{
+    return m_inputMethodContext->selectionEnd();
+}
+
 const Vector<unsigned>& Composition::getSegments() const
 {
-    return m_segments;
+    return m_inputMethodContext->segments();
 }
 
 } // namespace WebCore