Initial import of the Chrome Frame codebase. Integration in chrome.gyp coming in a separate CL.

BUG=None
TEST=None

Review URL: http://codereview.chromium.org/218019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@27042 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 281 insertions, 0 deletions

diff --git a/chrome_frame/html_utils.cc b/chrome_frame/html_utils.cc
new file mode 100644
index 0000000..60fdd7e
--- /dev/null
+++ b/chrome_frame/html_utils.cc
@@ -0,0 +1,281 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.

+// Use of this source code is governed by a BSD-style license that can be

+// found in the LICENSE file.

+//

+#include "chrome_frame/html_utils.h"

+

+#include "base/string_util.h"

+#include "base/string_tokenizer.h"

+

+const wchar_t* kQuotes = L"\"'";

+

+HTMLScanner::StringRange::StringRange() {

+}

+

+HTMLScanner::StringRange::StringRange(StrPos start, StrPos end)

+    : start_(start), end_(end) {

+}

+

+bool HTMLScanner::StringRange::LowerCaseEqualsASCII(const char* other) const {

+  return ::LowerCaseEqualsASCII(start_, end_, other);

+}

+

+bool HTMLScanner::StringRange::Equals(const wchar_t* other) const {

+  int ret = wcsncmp(&start_[0], other, end_ - start_);

+  if (ret == 0)

+    ret = (other[end_ - start_] == L'\0') ? 0 : -1;

+  return ret == 0;

+}

+

+std::wstring HTMLScanner::StringRange::Copy() const {

+  return std::wstring(start_, end_);

+}

+

+bool HTMLScanner::StringRange::GetTagName(std::wstring* tag_name) const {

+  if (*start_ != L'<') {

+    LOG(ERROR) << "Badly formatted tag found";

+    return false;

+  }

+

+  StrPos name_start = start_;

+  name_start++;

+  while (name_start < end_ && IsWhitespace(*name_start))

+    name_start++;

+

+  if (name_start >= end_) {

+    // We seem to have a degenerate tag (i.e. <   >). Return false here.

+    return false;

+  }

+

+  StrPos name_end = name_start + 1;

+  while (name_end < end_ && !IsWhitespace(*name_end))

+    name_end++;

+

+  if (name_end > end_) {

+    // This looks like an improperly formatted tab ('<foo'). Return false here.

+    return false;

+  }

+

+  tag_name->assign(name_start, name_end);

+  return true;

+}

+

+

+bool HTMLScanner::StringRange::GetTagAttribute(const wchar_t* attribute_name,

+    StringRange* attribute_value) const {

+  if (NULL == attribute_name || NULL == attribute_value) {

+    NOTREACHED();

+    return false;

+  }

+

+  // Use this so we can use the convenience method LowerCaseEqualsASCII()

+  // from string_util.h.

+  std::string search_name_ascii(WideToASCII(attribute_name));

+

+  WStringTokenizer tokenizer(start_, end_, L" =/");

+  tokenizer.set_options(WStringTokenizer::RETURN_DELIMS);

+

+  // Set up the quote chars so that we get quoted attribute values as single

+  // tokens.

+  tokenizer.set_quote_chars(L"\"'");

+

+  const bool PARSE_STATE_NAME = true;

+  const bool PARSE_STATE_VALUE = false;

+  bool parse_state = PARSE_STATE_NAME;

+

+  // Used to skip the first token, which is the tag name.

+  bool first_token_skipped = false;

+

+  // This is set during a loop iteration in which an '=' sign was spotted.

+  // It is used to filter out degenerate tags such as:

+  // <meta foo==bar>

+  bool last_token_was_delim = false;

+

+  // Set this if the attribute name has been found that we might then

+  // pick up the value in the next loop iteration.

+  bool attribute_name_found = false;

+

+  while (tokenizer.GetNext()) {

+    // If we have a whitespace delimiter, just keep going. Cases of this should

+    // be reduced by the CollapseWhitespace call. If we have an '=' character,

+    // we update our state and reiterate.

+    if (tokenizer.token_is_delim()) {

+      if (*tokenizer.token_begin() == L'=') {

+        if (last_token_was_delim) {

+          // Looks like we have a badly formed tag, just stop parsing now.

+          return false;

+        }

+        parse_state = !parse_state;

+        last_token_was_delim = true;

+      }

+      continue;

+    }

+

+    last_token_was_delim = false;

+

+    // The first non-delimiter token is the tag name, which we don't want.

+    if (!first_token_skipped) {

+      first_token_skipped = true;

+      continue;

+    }

+

+    if (PARSE_STATE_NAME == parse_state) {

+      // We have a tag name, check to see if it matches our target name:

+      if (::LowerCaseEqualsASCII(tokenizer.token_begin(), tokenizer.token_end(),

+                                 search_name_ascii.c_str())) {

+        attribute_name_found = true;

+        continue;

+      }

+    } else if (PARSE_STATE_VALUE == parse_state && attribute_name_found) {

+      attribute_value->start_ = tokenizer.token_begin();

+      attribute_value->end_ = tokenizer.token_end();

+

+      // Unquote the attribute value if need be.

+      attribute_value->UnQuote();

+

+      return true;

+    } else if (PARSE_STATE_VALUE == parse_state) {

+      // If we haven't found the attribute name we want yet, ignore this token

+      // and go back to looking for our name.

+      parse_state = PARSE_STATE_NAME;

+    }

+  }

+

+  return false;

+}

+

+bool HTMLScanner::StringRange::UnQuote() {

+  if (start_ + 2 > end_) {

+    // String's too short to be quoted, bail.

+    return false;

+  }

+

+  if ((*start_ == L'\'' && *(end_ - 1) == L'\'') ||

+      (*start_ == L'"' && *(end_ - 1) == L'"')) {

+    start_ = start_ + 1;

+    end_ = end_ - 1;

+    return true;

+  }

+

+  return false;

+}

+

+HTMLScanner::HTMLScanner(const wchar_t* html_string)

+    : html_string_(CollapseWhitespace(html_string, true)),

+      quotes_(kQuotes) {

+}

+

+void HTMLScanner::GetTagsByName(const wchar_t* name, StringRangeList* tag_list,

+                                const wchar_t* stop_tag) {

+  DCHECK(NULL != name);

+  DCHECK(NULL != tag_list);

+  DCHECK(NULL != stop_tag);

+

+  StringRange remaining_html(html_string_.begin(), html_string_.end());

+

+  std::wstring search_name(name);

+  TrimWhitespace(search_name, TRIM_ALL, &search_name);

+

+  // Use this so we can use the convenience method LowerCaseEqualsASCII()

+  // from string_util.h.

+  std::string search_name_ascii(WideToASCII(search_name));

+  std::string stop_tag_ascii(WideToASCII(stop_tag));

+

+  StringRange current_tag;

+  std::wstring current_name;

+  while (NextTag(&remaining_html, &current_tag)) {

+    if (current_tag.GetTagName(&current_name)) {

+      if (LowerCaseEqualsASCII(current_name, search_name_ascii.c_str())) {

+        tag_list->push_back(current_tag);

+      } else if (LowerCaseEqualsASCII(current_name, stop_tag_ascii.c_str())) {

+        // We hit the stop tag so it's time to go home.

+        break;

+      }

+    }

+  }

+}

+

+struct ScanState {

+  bool in_quote;

+  bool in_escape;

+  wchar_t quote_char;

+  ScanState() : in_quote(false), in_escape(false) {}

+};

+

+bool HTMLScanner::IsQuote(wchar_t c) {

+  return quotes_.find(c) != std::wstring::npos;

+}

+

+bool HTMLScanner::IsHTMLCommentClose(StringRange* html_string, StrPos pos) {

+  if (pos < html_string->end_ && pos > html_string->start_ + 2 &&

+      *pos == L'>') {

+    return *(pos-1) == L'-' && *(pos-2) == L'-';

+  }

+  return false;

+}

+

+bool HTMLScanner::NextTag(StringRange* html_string, StringRange* tag) {

+  DCHECK(NULL != html_string);

+  DCHECK(NULL != tag);

+

+  tag->start_ = html_string->start_;

+  while (tag->start_ < html_string->end_ && *tag->start_ != L'<') {

+    tag->start_++;

+  }

+

+  // we went past the end of the string.

+  if (tag->start_ >= html_string->end_) {

+    return false;

+  }

+

+  tag->end_ = tag->start_ + 1;

+

+  // Get the tag name to see if we are in an HTML comment. If we are, then

+  // don't consider quotes. This should work for example:

+  // <!-- foo ' --> <meta foo='bar'>

+  std::wstring tag_name;

+  StringRange start_range(tag->start_, html_string->end_);

+  start_range.GetTagName(&tag_name);

+  if (StartsWith(tag_name, L"!--", true)) {

+    // We're inside a comment tag, keep going until we get out of it.

+    while (tag->end_ < html_string->end_ &&

+           !IsHTMLCommentClose(html_string, tag->end_)) {

+      tag->end_++;

+    }

+  } else {

+    // Properly handle quoted strings within non-comment tags by maintaining

+    // some state while scanning. Specifically, we have to maintain state on

+    // whether we are inside a string, what the string terminating character

+    // will be and whether we are inside an escape sequence.

+    ScanState state;

+    while (tag->end_ < html_string->end_) {

+      if (state.in_quote) {

+        if (state.in_escape) {

+          state.in_escape = false;

+        } else if (*tag->end_ == '\\') {

+          state.in_escape = true;

+        } else if (*tag->end_ == state.quote_char) {

+          state.in_quote = false;

+        }

+      } else {

+        state.in_quote = IsQuote(state.quote_char = *tag->end_);

+      }

+

+      if (!state.in_quote && *tag->end_ == L'>') {

+        break;

+      }

+      tag->end_++;

+    }

+  }

+

+  // We hit the end_ but found no matching tag closure. Consider this an

+  // incomplete tag and do not report it.

+  if (tag->end_ >= html_string->end_)

+    return false;

+

+  // Modify html_string to point to just beyond the end_ of the current tag.

+  html_string->start_ = tag->end_ + 1;

+

+  return true;

+}

+