1 files changed, 229 insertions, 0 deletions
diff --git a/gfx/thebes/gfxScriptItemizer.cpp b/gfx/thebes/gfxScriptItemizer.cpp
new file mode 100644
index 000000000..b9426ee6f
--- /dev/null
+++ b/gfx/thebes/gfxScriptItemizer.cpp
@@ -0,0 +1,229 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * This file is based on usc_impl.c from ICU 4.2.0.1, slightly adapted
+ * for use within Mozilla Gecko, separate from a standard ICU build.
+ *
+ * The original ICU license of the code follows:
+ *
+ * ICU License - ICU 1.8.1 and later
+ *
+ * COPYRIGHT AND PERMISSION NOTICE
+ * 
+ * Copyright (c) 1995-2009 International Business Machines Corporation and
+ * others
+ *
+ * All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, provided that the above copyright notice(s) and this
+ * permission notice appear in all copies of the Software and that both the
+ * above copyright notice(s) and this permission notice appear in supporting
+ * documentation.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS NOTICE
+ * BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES,
+ * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+ * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of a copyright holder shall
+ * not be used in advertising or otherwise to promote the sale, use or other
+ * dealings in this Software without prior written authorization of the
+ * copyright holder.
+ *
+ * All trademarks and registered trademarks mentioned herein are the property
+ * of their respective owners. 
+ */
+
+#include "gfxScriptItemizer.h"
+#include "nsUnicodeProperties.h"
+#include "nsCharTraits.h"
+#include "harfbuzz/hb.h"
+
+#define MOD(sp) ((sp) % PAREN_STACK_DEPTH)
+#define LIMIT_INC(sp) (((sp) < PAREN_STACK_DEPTH)? (sp) + 1 : PAREN_STACK_DEPTH)
+#define INC(sp,count) (MOD((sp) + (count)))
+#define INC1(sp) (INC(sp, 1))
+#define DEC(sp,count) (MOD((sp) + PAREN_STACK_DEPTH - (count)))
+#define DEC1(sp) (DEC(sp, 1))
+#define STACK_IS_EMPTY() (pushCount <= 0)
+#define STACK_IS_NOT_EMPTY() (! STACK_IS_EMPTY())
+#define TOP() (parenStack[parenSP])
+#define SYNC_FIXUP() (fixupCount = 0)
+
+void
+gfxScriptItemizer::push(uint32_t endPairChar, Script newScriptCode)
+{
+    pushCount  = LIMIT_INC(pushCount);
+    fixupCount = LIMIT_INC(fixupCount);
+
+    parenSP = INC1(parenSP);
+    parenStack[parenSP].endPairChar = endPairChar;
+    parenStack[parenSP].scriptCode = newScriptCode;
+}
+
+void
+gfxScriptItemizer::pop()
+{
+    if (STACK_IS_EMPTY()) {
+        return;
+    }
+
+    if (fixupCount > 0) {
+        fixupCount -= 1;
+    }
+
+    pushCount -= 1;
+    parenSP = DEC1(parenSP);
+  
+    /* If the stack is now empty, reset the stack
+       pointers to their initial values.
+     */
+    if (STACK_IS_EMPTY()) {
+        parenSP = -1;
+    }
+}
+
+void
+gfxScriptItemizer::fixup(Script newScriptCode)
+{
+    int32_t fixupSP = DEC(parenSP, fixupCount);
+
+    while (fixupCount-- > 0) {
+        fixupSP = INC1(fixupSP);
+        parenStack[fixupSP].scriptCode = newScriptCode;
+    }
+}
+
+static inline bool
+SameScript(Script runScript, Script currCharScript)
+{
+    return runScript <= Script::INHERITED ||
+           currCharScript <= Script::INHERITED ||
+           currCharScript == runScript;
+}
+
+gfxScriptItemizer::gfxScriptItemizer(const char16_t *src, uint32_t length)
+    : textPtr(src), textLength(length)
+{
+    reset();
+}
+
+void
+gfxScriptItemizer::SetText(const char16_t *src, uint32_t length)
+{
+    textPtr  = src;
+    textLength = length;
+
+    reset();
+}
+
+bool
+gfxScriptItemizer::Next(uint32_t& aRunStart, uint32_t& aRunLimit,
+                        Script& aRunScript)
+{
+    /* if we've fallen off the end of the text, we're done */
+    if (scriptLimit >= textLength) {
+        return false;
+    }
+
+    SYNC_FIXUP();
+    scriptCode = Script::COMMON;
+
+    for (scriptStart = scriptLimit; scriptLimit < textLength; scriptLimit += 1) {
+        uint32_t ch;
+        Script sc;
+        uint32_t startOfChar = scriptLimit;
+
+        ch = textPtr[scriptLimit];
+
+        /* decode UTF-16 (may be surrogate pair) */
+        if (NS_IS_HIGH_SURROGATE(ch) && scriptLimit < textLength - 1) {
+            uint32_t low = textPtr[scriptLimit + 1];
+            if (NS_IS_LOW_SURROGATE(low)) {
+                ch = SURROGATE_TO_UCS4(ch, low);
+                scriptLimit += 1;
+            }
+        }
+
+        // Initialize gc to UNASSIGNED; we'll only set it to the true GC
+        // if the character has script=COMMON, otherwise we don't care.
+        uint8_t gc = HB_UNICODE_GENERAL_CATEGORY_UNASSIGNED;
+
+        sc = GetScriptCode(ch);
+        if (sc == Script::COMMON) {
+            /*
+             * Paired character handling:
+             *
+             * if it's an open character, push it onto the stack.
+             * if it's a close character, find the matching open on the
+             * stack, and use that script code. Any non-matching open
+             * characters above it on the stack will be popped.
+             *
+             * We only do this if the script is COMMON; for chars with
+             * specific script assignments, we just use them as-is.
+             */
+            gc = GetGeneralCategory(ch);
+            if (gc == HB_UNICODE_GENERAL_CATEGORY_OPEN_PUNCTUATION) {
+                uint32_t endPairChar = mozilla::unicode::GetMirroredChar(ch);
+                if (endPairChar != ch) {
+                    push(endPairChar, scriptCode);
+                }
+            } else if (gc == HB_UNICODE_GENERAL_CATEGORY_CLOSE_PUNCTUATION &&
+                HasMirroredChar(ch))
+            {
+                while (STACK_IS_NOT_EMPTY() && TOP().endPairChar != ch) {
+                    pop();
+                }
+
+                if (STACK_IS_NOT_EMPTY()) {
+                    sc = TOP().scriptCode;
+                }
+            }
+        }
+
+        if (SameScript(scriptCode, sc)) {
+            if (scriptCode <= Script::INHERITED &&
+                sc > Script::INHERITED)
+            {
+                scriptCode = sc;
+                fixup(scriptCode);
+            }
+
+            /*
+             * if this character is a close paired character,
+             * pop the matching open character from the stack
+             */
+            if (gc == HB_UNICODE_GENERAL_CATEGORY_CLOSE_PUNCTUATION &&
+                HasMirroredChar(ch)) {
+                pop();
+            }
+        } else {
+            /*
+             * reset scriptLimit in case it was advanced during reading a
+             * multiple-code-unit character
+             */
+            scriptLimit = startOfChar;
+
+            break;
+        }
+    }
+
+    aRunStart = scriptStart;
+    aRunLimit = scriptLimit;
+    aRunScript = scriptCode;
+
+    return true;
+}