editor/libeditor/text/nsTextEditRulesBidi.cpp

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  37
  38 #include "nsTextEditRules.h"
  39 #include "nsCOMPtr.h"
  40 #include "nsIDOMNode.h"
  41 #include "nsIContent.h"
  42 #include "nsIPresShell.h"
  43 #include "nsPresContext.h"
  44 #include "nsIFrame.h"
  45 #include "nsISelectionPrivate.h"
  46 #include "nsFrameSelection.h"
  47
  48 // Test for distance between caret and text that will be deleted
  49 nsresult
  50 nsTextEditRules::CheckBidiLevelForDeletion(nsISelection         *aSelection,
  51                                            nsIDOMNode           *aSelNode,
  52                                            PRInt32               aSelOffset,
  53                                            nsIEditor::EDirection aAction,
  54                                            PRBool               *aCancel)
  55 {
  56   NS_ENSURE_ARG_POINTER(aCancel);
  57   *aCancel = PR_FALSE;
  58
  59   nsCOMPtr<nsIPresShell> shell;
  60   nsresult res = mEditor->GetPresShell(getter_AddRefs(shell));
  61   NS_ENSURE_SUCCESS(res, res);
  62   NS_ENSURE_TRUE(shell, NS_ERROR_NULL_POINTER);
  63
  64   nsPresContext *context = shell->GetPresContext();
  65   NS_ENSURE_TRUE(context, NS_ERROR_NULL_POINTER);
  66
  67   if (!context->BidiEnabled())
  68     return NS_OK;
  69
  70   nsCOMPtr<nsIContent> content = do_QueryInterface(aSelNode);
  71   NS_ENSURE_TRUE(content, NS_ERROR_NULL_POINTER);
  72
  73   PRUint8 levelBefore;
  74   PRUint8 levelAfter;
  75
  76   nsCOMPtr<nsISelectionPrivate> privateSelection(do_QueryInterface(aSelection));
  77   NS_ENSURE_TRUE(privateSelection, NS_ERROR_NULL_POINTER);
  78
  79   nsCOMPtr<nsFrameSelection> frameSelection;
  80   privateSelection->GetFrameSelection(getter_AddRefs(frameSelection));
  81   NS_ENSURE_TRUE(frameSelection, NS_ERROR_NULL_POINTER);
  82
  83   nsPrevNextBidiLevels levels = frameSelection->
  84     GetPrevNextBidiLevels(content, aSelOffset, PR_TRUE);
  85
  86   levelBefore = levels.mLevelBefore;
  87   levelAfter = levels.mLevelAfter;
  88
  89   PRUint8 currentCaretLevel = frameSelection->GetCaretBidiLevel();
  90
  91   PRUint8 levelOfDeletion;
  92   levelOfDeletion =
  93     (nsIEditor::eNext==aAction || nsIEditor::eNextWord==aAction) ?
  94     levelAfter : levelBefore;
  95
  96   if (currentCaretLevel == levelOfDeletion)
  97     ; // perform the deletion
  98   else
  99   {
 100     if (mDeleteBidiImmediately || levelBefore == levelAfter)
 101       ; // perform the deletion
 102     else
 103       *aCancel = PR_TRUE;
 104
 105     // Set the bidi level of the caret to that of the
 106     // character that will be (or would have been) deleted
 107     frameSelection->SetCaretBidiLevel(levelOfDeletion);
 108   }
 109   return NS_OK;
 110 }
 111