/* -*- 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 "mozilla/TextEditRules.h"

#include "mozilla/TextEditor.h"

#include "mozilla/dom/Selection.h"

#include "nsCOMPtr.h"

#include "nsDebug.h"

#include "nsError.h"

#include "nsFrameSelection.h"

#include "nsIContent.h"

#include "nsIEditor.h"

#include "nsIPresShell.h"

#include "nsISupportsImpl.h"

#include "nsPresContext.h"

#include "nscore.h"

namespace mozilla {

using namespace dom;

// Test for distance between caret and text that will be deleted

nsresult

TextEditRules::CheckBidiLevelForDeletion(

                 const EditorRawDOMPoint& aSelectionPoint,

                 nsIEditor::EDirection aAction,

                 bool* aCancel)

{

  MOZ_ASSERT(IsEditorDataAvailable());

  if (NS_WARN_IF(!aCancel)) {

    return NS_ERROR_INVALID_ARG;

  }

  *aCancel = false;

  RefPtr<nsPresContext> presContext = TextEditorRef().GetPresContext();

  if (NS_WARN_IF(!presContext)) {

    return NS_ERROR_FAILURE;

  }

  if (!presContext->BidiEnabled()) {

    return NS_OK;

  }

  if (!aSelectionPoint.GetContainerAsContent()) {

    return NS_ERROR_FAILURE;

  }

  RefPtr<nsFrameSelection> frameSelection = SelectionRef().GetFrameSelection();

  if (NS_WARN_IF(!frameSelection)) {

    return NS_ERROR_FAILURE;

  }

  nsPrevNextBidiLevels levels = frameSelection->

    GetPrevNextBidiLevels(aSelectionPoint.GetContainerAsContent(),

                          aSelectionPoint.Offset(), true);

  nsBidiLevel levelBefore = levels.mLevelBefore;

  nsBidiLevel levelAfter = levels.mLevelAfter;

  nsBidiLevel currentCaretLevel = frameSelection->GetCaretBidiLevel();

  nsBidiLevel levelOfDeletion;

  levelOfDeletion =

    (nsIEditor::eNext==aAction || nsIEditor::eNextWord==aAction) ?

    levelAfter : levelBefore;

  if (currentCaretLevel == levelOfDeletion) {

    return NS_OK; // perform the deletion

  }

  if (!mDeleteBidiImmediately && levelBefore != levelAfter) {

    *aCancel = true;

  }

  // Set the bidi level of the caret to that of the

  // character that will be (or would have been) deleted

  frameSelection->SetCaretBidiLevel(levelOfDeletion);

  return NS_OK;

}

void

TextEditRules::UndefineCaretBidiLevel()

{

  MOZ_ASSERT(IsEditorDataAvailable());

  /**

   * After inserting text the caret Bidi level must be set to the level of the

   * inserted text.This is difficult, because we cannot know what the level is

   * until after the Bidi algorithm is applied to the whole paragraph.

   *

   * So we set the caret Bidi level to UNDEFINED here, and the caret code will

   * set it correctly later

   */

  RefPtr<nsFrameSelection> frameSelection = SelectionRef().GetFrameSelection();

  if (frameSelection) {

    frameSelection->UndefineCaretBidiLevel();

  }

}

} // namespace mozilla