editor/libeditor/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 "mozilla/dom/Selection.h"
  16 #include "nsISupportsImpl.h"
  17 #include "nsPlaintextEditor.h"
  18 #include "nsPresContext.h"
  19 #include "nsTextEditRules.h"
  20 #include "nscore.h"
  21
  22 using namespace mozilla;
  23 using namespace mozilla::dom;
  24
  25 // Test for distance between caret and text that will be deleted
  26 nsresult
  27 nsTextEditRules::CheckBidiLevelForDeletion(Selection* aSelection,
  28                                            nsIDOMNode           *aSelNode,
  29                                            int32_t               aSelOffset,
  30                                            nsIEditor::EDirection aAction,
  31                                            bool                 *aCancel)
  32 {
  33   NS_ENSURE_ARG_POINTER(aCancel);
  34   *aCancel = false;
  35
  36   nsCOMPtr<nsIPresShell> shell = mEditor->GetPresShell();
  37   NS_ENSURE_TRUE(shell, NS_ERROR_NOT_INITIALIZED);
  38
  39   nsPresContext *context = shell->GetPresContext();
  40   NS_ENSURE_TRUE(context, NS_ERROR_NULL_POINTER);
  41
  42   if (!context->BidiEnabled())
  43     return NS_OK;
  44
  45   nsCOMPtr<nsIContent> content = do_QueryInterface(aSelNode);
  46   NS_ENSURE_TRUE(content, NS_ERROR_NULL_POINTER);
  47
  48   nsBidiLevel levelBefore;
  49   nsBidiLevel levelAfter;
  50   RefPtr<nsFrameSelection> frameSelection =
  51     static_cast<Selection*>(aSelection)->GetFrameSelection();
  52   NS_ENSURE_TRUE(frameSelection, NS_ERROR_NULL_POINTER);
  53
  54   nsPrevNextBidiLevels levels = frameSelection->
  55     GetPrevNextBidiLevels(content, aSelOffset, true);
  56
  57   levelBefore = levels.mLevelBefore;
  58   levelAfter = levels.mLevelAfter;
  59
  60   nsBidiLevel currentCaretLevel = frameSelection->GetCaretBidiLevel();
  61
  62   nsBidiLevel levelOfDeletion;
  63   levelOfDeletion =
  64     (nsIEditor::eNext==aAction || nsIEditor::eNextWord==aAction) ?
  65     levelAfter : levelBefore;
  66
  67   if (currentCaretLevel == levelOfDeletion)
  68     ; // perform the deletion
  69   else
  70   {
  71     if (mDeleteBidiImmediately || levelBefore == levelAfter)
  72       ; // perform the deletion
  73     else
  74       *aCancel = true;
  75
  76     // Set the bidi level of the caret to that of the
  77     // character that will be (or would have been) deleted
  78     frameSelection->SetCaretBidiLevel(levelOfDeletion);
  79   }
  80   return NS_OK;
  81 }
  82
  83 void
  84 nsTextEditRules::UndefineCaretBidiLevel(Selection* aSelection)
  85 {
  86   /**
  87    * After inserting text the caret Bidi level must be set to the level of the
  88    * inserted text.This is difficult, because we cannot know what the level is
  89    * until after the Bidi algorithm is applied to the whole paragraph.
  90    *
  91    * So we set the caret Bidi level to UNDEFINED here, and the caret code will
  92    * set it correctly later
  93    */
  94   RefPtr<nsFrameSelection> frameSelection = aSelection->GetFrameSelection();
  95   if (frameSelection) {
  96     frameSelection->UndefineCaretBidiLevel();
  97   }
  98 }