Line data    Source code

       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 "nsComplexBreaker.h"
       7             : 
       8             : #include <pango/pango-break.h>
       9             : #include "nsUTF8Utils.h"
      10             : #include "nsString.h"
      11             : #include "nsTArray.h"
      12             : 
      13             : void
      14           0 : NS_GetComplexLineBreaks(const char16_t* aText, uint32_t aLength,
      15             :                         uint8_t* aBreakBefore)
      16             : {
      17           0 :   NS_ASSERTION(aText, "aText shouldn't be null");
      18             : 
      19           0 :   memset(aBreakBefore, false, aLength * sizeof(uint8_t));
      20             : 
      21           0 :   AutoTArray<PangoLogAttr, 2000> attrBuffer;
      22           0 :   if (!attrBuffer.AppendElements(aLength + 1))
      23           0 :     return;
      24             : 
      25           0 :   NS_ConvertUTF16toUTF8 aUTF8(aText, aLength);
      26             : 
      27           0 :   const gchar* p = aUTF8.Data();
      28           0 :   const gchar* end = p + aUTF8.Length();
      29           0 :   uint32_t     u16Offset = 0;
      30             : 
      31           0 :   static PangoLanguage* language = pango_language_from_string("en");
      32             : 
      33           0 :   while (p < end)
      34             :   {
      35           0 :     PangoLogAttr* attr = attrBuffer.Elements();
      36           0 :     pango_get_log_attrs(p, end - p, -1, language, attr, attrBuffer.Length());
      37             : 
      38           0 :     while (p < end)
      39             :     {
      40           0 :       aBreakBefore[u16Offset] = attr->is_line_break;
      41           0 :       if (NS_IS_LOW_SURROGATE(aText[u16Offset]))
      42           0 :         aBreakBefore[++u16Offset] = false; // Skip high surrogate
      43           0 :       ++u16Offset;
      44             : 
      45             :       bool err;
      46           0 :       uint32_t ch = UTF8CharEnumerator::NextChar(&p, end, &err);
      47           0 :       ++attr;
      48             : 
      49           0 :       if (ch == 0 || err) {
      50             :         // pango_break (pango 1.16.2) only analyses text before the
      51             :         // first NUL (but sets one extra attr). Workaround loop to call
      52             :         // pango_break again to analyse after the NUL is done somewhere else
      53             :         // (gfx/thebes/gfxFontconfigFonts.cpp: SetupClusterBoundaries()).
      54             :         // So, we do the same here for pango_get_log_attrs.
      55             :         break;
      56             :       }
      57             :     }
      58             :   }
      59             : }
      60             :