diff -r 000000000000 -r 6474c204b198 dom/base/CompositionStringSynthesizer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/base/CompositionStringSynthesizer.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,160 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CompositionStringSynthesizer.h"
+#include "nsContentUtils.h"
+#include "nsIDocShell.h"
+#include "nsIFrame.h"
+#include "nsIPresShell.h"
+#include "nsIWidget.h"
+#include "nsPIDOMWindow.h"
+#include "nsView.h"
+#include "mozilla/TextEvents.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_ISUPPORTS(CompositionStringSynthesizer,
+                  nsICompositionStringSynthesizer)
+
+CompositionStringSynthesizer::CompositionStringSynthesizer(
+                                nsPIDOMWindow* aWindow)
+{
+  mWindow = do_GetWeakReference(aWindow);
+  mClauses = new TextRangeArray();
+  ClearInternal();
+}
+
+CompositionStringSynthesizer::~CompositionStringSynthesizer()
+{
+}
+
+void
+CompositionStringSynthesizer::ClearInternal()
+{
+  mString.Truncate();
+  mClauses->Clear();
+  mCaret.mRangeType = 0;
+}
+
+nsIWidget*
+CompositionStringSynthesizer::GetWidget()
+{
+  nsCOMPtr<nsPIDOMWindow> window = do_QueryReferent(mWindow);
+  if (!window) {
+    return nullptr;
+  }
+  nsIDocShell *docShell = window->GetDocShell();
+  if (!docShell) {
+    return nullptr;
+  }
+  nsCOMPtr<nsIPresShell> presShell = docShell->GetPresShell();
+  if (!presShell) {
+    return nullptr;
+  }
+  nsIFrame* frame = presShell->GetRootFrame();
+  if (!frame) {
+    return nullptr;
+  }
+  return frame->GetView()->GetNearestWidget(nullptr);
+}
+
+NS_IMETHODIMP
+CompositionStringSynthesizer::SetString(const nsAString& aString)
+{
+  nsCOMPtr<nsIWidget> widget = GetWidget();
+  NS_ENSURE_TRUE(widget && !widget->Destroyed(), NS_ERROR_NOT_AVAILABLE);
+
+  mString = aString;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CompositionStringSynthesizer::AppendClause(uint32_t aLength,
+                                           uint32_t aAttribute)
+{
+  nsCOMPtr<nsIWidget> widget = GetWidget();
+  NS_ENSURE_TRUE(widget && !widget->Destroyed(), NS_ERROR_NOT_AVAILABLE);
+
+  switch (aAttribute) {
+    case ATTR_RAWINPUT:
+    case ATTR_SELECTEDRAWTEXT:
+    case ATTR_CONVERTEDTEXT:
+    case ATTR_SELECTEDCONVERTEDTEXT: {
+      TextRange textRange;
+      textRange.mStartOffset =
+        mClauses->IsEmpty() ? 0 : mClauses->LastElement().mEndOffset;
+      textRange.mEndOffset = textRange.mStartOffset + aLength;
+      textRange.mRangeType = aAttribute;
+      mClauses->AppendElement(textRange);
+      return NS_OK;
+    }
+    default:
+      return NS_ERROR_INVALID_ARG;
+  }
+}
+
+NS_IMETHODIMP
+CompositionStringSynthesizer::SetCaret(uint32_t aOffset, uint32_t aLength)
+{
+  nsCOMPtr<nsIWidget> widget = GetWidget();
+  NS_ENSURE_TRUE(widget && !widget->Destroyed(), NS_ERROR_NOT_AVAILABLE);
+
+  mCaret.mStartOffset = aOffset;
+  mCaret.mEndOffset = mCaret.mStartOffset + aLength;
+  mCaret.mRangeType = NS_TEXTRANGE_CARETPOSITION;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CompositionStringSynthesizer::DispatchEvent(bool* aDefaultPrevented)
+{
+  NS_ENSURE_ARG_POINTER(aDefaultPrevented);
+  nsCOMPtr<nsIWidget> widget = GetWidget();
+  NS_ENSURE_TRUE(widget && !widget->Destroyed(), NS_ERROR_NOT_AVAILABLE);
+
+  if (!nsContentUtils::IsCallerChrome()) {
+    return NS_ERROR_DOM_SECURITY_ERR;
+  }
+
+  if (!mClauses->IsEmpty() &&
+      mClauses->LastElement().mEndOffset != mString.Length()) {
+    NS_WARNING("Sum of length of the all clauses must be same as the string "
+               "length");
+    ClearInternal();
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
+  if (mCaret.mRangeType == NS_TEXTRANGE_CARETPOSITION) {
+    if (mCaret.mEndOffset > mString.Length()) {
+      NS_WARNING("Caret position is out of the composition string");
+      ClearInternal();
+      return NS_ERROR_ILLEGAL_VALUE;
+    }
+    mClauses->AppendElement(mCaret);
+  }
+
+  WidgetTextEvent textEvent(true, NS_TEXT_TEXT, widget);
+  textEvent.time = PR_IntervalNow();
+  textEvent.theText = mString;
+  if (!mClauses->IsEmpty()) {
+    textEvent.mRanges = mClauses;
+  }
+
+  // XXX How should we set false for this on b2g?
+  textEvent.mFlags.mIsSynthesizedForTests = true;
+
+  nsEventStatus status = nsEventStatus_eIgnore;
+  nsresult rv = widget->DispatchEvent(&textEvent, status);
+  *aDefaultPrevented = (status == nsEventStatus_eConsumeNoDefault);
+
+  ClearInternal();
+
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+} // namespace dom
+} // namespace mozilla