editor/libeditor/text/nsTextEditRulesBidi.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsAutoPtr.h"
   7 #include "nsCOMPtr.h"
   8 #include "nsDebug.h"
   9 #include "nsError.h"
  10 #include "nsFrameSelection.h"
  11 #include "nsIContent.h"
  12 #include "nsIDOMNode.h"
  13 #include "nsIEditor.h"
  14 #include "nsIPresShell.h"
  15 #include "nsISelection.h"
  16 #include "nsISelectionPrivate.h"
  17 #include "nsISupportsImpl.h"
  18 #include "nsPlaintextEditor.h"
  19 #include "nsPresContext.h"
  20 #include "nsTextEditRules.h"
  21 #include "nscore.h"
  22
  23 // Test for distance between caret and text that will be deleted
  24 nsresult
  25 nsTextEditRules::CheckBidiLevelForDeletion(nsISelection         *aSelection,
  26                                            nsIDOMNode           *aSelNode,
  27                                            int32_t               aSelOffset,
  28                                            nsIEditor::EDirection aAction,
  29                                            bool                 *aCancel)
  30 {
  31   NS_ENSURE_ARG_POINTER(aCancel);
  32   *aCancel = false;
  33
  34   nsCOMPtr<nsIPresShell> shell = mEditor->GetPresShell();
  35   NS_ENSURE_TRUE(shell, NS_ERROR_NOT_INITIALIZED);
  36
  37   nsPresContext *context = shell->GetPresContext();
  38   NS_ENSURE_TRUE(context, NS_ERROR_NULL_POINTER);
  39
  40   if (!context->BidiEnabled())
  41     return NS_OK;
  42
  43   nsCOMPtr<nsIContent> content = do_QueryInterface(aSelNode);
  44   NS_ENSURE_TRUE(content, NS_ERROR_NULL_POINTER);
  45
  46   uint8_t levelBefore;
  47   uint8_t levelAfter;
  48
  49   nsCOMPtr<nsISelectionPrivate> privateSelection(do_QueryInterface(aSelection));
  50   NS_ENSURE_TRUE(privateSelection, NS_ERROR_NULL_POINTER);
  51
  52   nsRefPtr<nsFrameSelection> frameSelection;
  53   privateSelection->GetFrameSelection(getter_AddRefs(frameSelection));
  54   NS_ENSURE_TRUE(frameSelection, NS_ERROR_NULL_POINTER);
  55
  56   nsPrevNextBidiLevels levels = frameSelection->
  57     GetPrevNextBidiLevels(content, aSelOffset, true);
  58
  59   levelBefore = levels.mLevelBefore;
  60   levelAfter = levels.mLevelAfter;
  61
  62   uint8_t currentCaretLevel = frameSelection->GetCaretBidiLevel();
  63
  64   uint8_t levelOfDeletion;
  65   levelOfDeletion =
  66     (nsIEditor::eNext==aAction || nsIEditor::eNextWord==aAction) ?
  67     levelAfter : levelBefore;
  68
  69   if (currentCaretLevel == levelOfDeletion)
  70     ; // perform the deletion
  71   else
  72   {
  73     if (mDeleteBidiImmediately || levelBefore == levelAfter)
  74       ; // perform the deletion
  75     else
  76       *aCancel = true;
  77
  78     // Set the bidi level of the caret to that of the
  79     // character that will be (or would have been) deleted
  80     frameSelection->SetCaretBidiLevel(levelOfDeletion);
  81   }
  82   return NS_OK;
  83 }
  84