WebKit merge 40668:40722 part 1.

third_party/WebKit/WebCore/rendering/RenderText.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 1049 matching lines @@
         }
         result.setWidth(rightSide - leftSide);
         result.setX(leftSide);
         result.setHeight(lastTextBox()->yPos() + lastTextBox()->height() - firstTextBox()->yPos());
         result.setY(firstTextBox()->yPos());
     }
 
     return result;
 }
 
-IntRect RenderText::clippedOverflowRectForRepaint(RenderBox* repaintContainer)
+IntRect RenderText::clippedOverflowRectForRepaint(RenderBoxModelObject* repaintContainer)
 {
     RenderObject* cb = containingBlock();
     return cb->clippedOverflowRectForRepaint(repaintContainer);
 }
 
-IntRect RenderText::selectionRectForRepaint(RenderBox* repaintContainer, bool clipToVisibleContent)
+IntRect RenderText::selectionRectForRepaint(RenderBoxModelObject* repaintContainer, bool clipToVisibleContent)
 {
     ASSERT(!needsLayout());
 
     if (selectionState() == SelectionNone)
         return IntRect();
     RenderBlock* cb =  containingBlock();
     if (!cb)
         return IntRect();
 
     // Now calculate startPos and endPos for painting selection.
@@ skipping 74 matching lines @@
     if (!iterator)
         return current - 1;
 
     long result = textBreakPreceding(iterator, current);
     if (result == TextBreakDone)
         result = current - 1;
 
     return result;
 }
 
+#define HANGUL_CHOSEONG_START (0x1100)
+#define HANGUL_CHOSEONG_END (0x115F)
+#define HANGUL_JUNGSEONG_START (0x1160)
+#define HANGUL_JUNGSEONG_END (0x11A2)
+#define HANGUL_JONGSEONG_START (0x11A8)
+#define HANGUL_JONGSEONG_END (0x11F9)
+#define HANGUL_SYLLABLE_START (0xAC00)
+#define HANGUL_SYLLABLE_END (0xD7AF)
+#define HANGUL_JONGSEONG_COUNT (28)
+
+enum HangulState {
+    HangulStateL,
+    HangulStateV,
+    HangulStateT,
+    HangulStateLV,
+    HangulStateLVT,
+    HangulStateBreak
+};
+
+inline bool isHangulLVT(UChar32 character)
+{
+    return (character - HANGUL_SYLLABLE_START) % HANGUL_JONGSEONG_COUNT;
+}
+
+int RenderText::previousOffsetForBackwardDeletion(int current) const
+{
+#if PLATFORM(MAC)
+    UChar32 character;
+    while (current > 0) {
+        if (U16_IS_TRAIL((*m_text)[--current]))
+            --current;
+        if (current < 0)
+            break;
+
+        UChar32 character = m_text->characterStartingAt(current);
+
+        // We don't combine characters in Armenian ... Limbu range for backward deletion.
+        if ((character >= 0x0530) && (character < 0x1950))
+            break;
+
+        if (u_isbase(character) && (character != 0xFF9E) && (character != 0xFF9F))
+            break;
+    }
+
+    if (current <= 0)
+        return current;
+
+    // Hangul
+    character = m_text->characterStartingAt(current);
+    if (((character >= HANGUL_CHOSEONG_START) && (character <= HANGUL_JONGSEONG_END)) || ((character >= HANGUL_SYLLABLE_START) && (character <= HANGUL_SYLLABLE_END))) {
+        HangulState state;
+        HangulState initialState;
+
+        if (character < HANGUL_JUNGSEONG_START)
+            state = HangulStateL;
+        else if (character < HANGUL_JONGSEONG_START)
+            state = HangulStateV;
+        else if (character < HANGUL_SYLLABLE_START)
+            state = HangulStateT;
+        else
+            state = isHangulLVT(character) ? HangulStateLVT : HangulStateLV;
+
+        initialState = state;
+
+        while (current > 0 && ((character = m_text->characterStartingAt(current - 1)) >= HANGUL_CHOSEONG_START) && (character <= HANGUL_SYLLABLE_END) && ((character <= HANGUL_JONGSEONG_END) || (character >= HANGUL_SYLLABLE_START))) {
+            switch (state) {
+            case HangulStateV:
+                if (character <= HANGUL_CHOSEONG_END)
+                    state = HangulStateL;
+                else if ((character >= HANGUL_SYLLABLE_START) && (character <= HANGUL_SYLLABLE_END) && !isHangulLVT(character))
+                    state = HangulStateLV;
+                else if (character > HANGUL_JUNGSEONG_END)
+                    state = HangulStateBreak;
+                break;
+            case HangulStateT:
+                if ((character >= HANGUL_JUNGSEONG_START) && (character <= HANGUL_JUNGSEONG_END))
+                    state = HangulStateV;
+                else if ((character >= HANGUL_SYLLABLE_START) && (character <= HANGUL_SYLLABLE_END))
+                    state = (isHangulLVT(character) ? HangulStateLVT : HangulStateLV);
+                else if (character < HANGUL_JUNGSEONG_START)
+                    state = HangulStateBreak;
+                break;
+            default:
+                state = (character < HANGUL_JUNGSEONG_START) ? HangulStateL : HangulStateBreak;
+                break;
+            }
+            if (state == HangulStateBreak)
+                break;
+
+            --current;
+        }
+    }
+
+    return current;
+#else
+    // Platforms other than Mac delete by one code point.
+    return current - 1;
+#endif
+}
+
 int RenderText::nextOffset(int current) const
 {
     StringImpl* si = m_text.get();
     TextBreakIterator* iterator = characterBreakIterator(si->characters(), si->length());
     if (!iterator)
         return current + 1;
 
     long result = textBreakFollowing(iterator, current);
     if (result == TextBreakDone)
         result = current + 1;
@@ skipping 12 matching lines @@
         ASSERT(child->prevTextBox() == prev);
         prev = child;
     }
     ASSERT(prev == m_lastTextBox);
 #endif
 }
 
 #endif
 
 } // namespace WebCore