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

chrome_frame/html_utils.h

+// 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.
+
+// This file defines utility functions for working with html.
+
+#ifndef CHROME_FRAME_HTML_UTILS_H_
+#define CHROME_FRAME_HTML_UTILS_H_
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"
+
+// Forward declarations
+class HtmlUtilUnittest;
+
+//
+// Class designed to take a string of HTML and extract from it named
+// attribute values from named tags.
+//
+// Caveat: this class currently doesn't handle multi-word UTF-16 encoded
+// characters. Doesn't handle implies that any data following such a
+// character could possibly be misinterpreted.
+//
+class HTMLScanner {
+ public:
+  typedef std::wstring::const_iterator StrPos;
+
+  // Structure maintaining const_iterators into html_string_.
+  class StringRange {
+    friend class HTMLScanner;
+   public:
+    StringRange();
+    StringRange(StrPos start, StrPos end);
+
+    bool LowerCaseEqualsASCII(const char* other) const;
+    bool Equals(const wchar_t* other) const;
+
+    // Copies the data described by StringRange into destination.
+    std::wstring Copy() const;
+
+    // If this StringRange represents a tag, this method extracts the name of
+    // the tag and sticks it in tag_name.
+    // Returns true if the tag name was successfully extracted.
+    // Returns false if this string doesn't look like a valid tag.
+    bool GetTagName(std::wstring* tag_name) const;
+
+    // From a given string range, uses a string tokenizer to extract the value
+    // of the named attribute if a simple scan finds that the attribute name is
+    // present.
+    //
+    // Returns true if the named attribute can be located and it has a value
+    // which has been placed in attribute_value.
+    //
+    // Note that the attribute value is unquoted here as well, so that
+    // GetTagAttribute(*<foo bar="baz">*, L"bar", *out_value*) will stick
+    // 'bar' in out_value and not '"bar"'.
+    //
+    // Returns false if the named attribute is not present in the tag or if it
+    // did not have a value.
+    //
+    bool GetTagAttribute(const wchar_t* attribute_name,
+                         StringRange* attribute_value) const;
+
+    // Unquotes a StringRange by removing a matching pair of either ' or "
+    // characters from the beginning and end of the string if present.
+    // Returns true if string was modified, false otherwise.
+    bool UnQuote();
+   private:
+     StrPos start_;
+     StrPos end_;
+  };
+
+  typedef std::vector<StringRange> StringRangeList;
+
+  // html_string must be a null-terminated string containing the HTML
+  // to be scanned.
+  explicit HTMLScanner(const wchar_t* html_string);
+
+  // Returns the set of ranges denoting HTML tags that match the given name.
+  // If stop_tag_name is given, then as soon as a tag with this name is
+  // encountered this method will return.
+  void GetTagsByName(const wchar_t* name, StringRangeList* tag_list,
+                     const wchar_t* stop_tag_name);
+
+ private:
+  friend class HtmlUtilUnittest;
+  FRIEND_TEST(HtmlUtilUnittest, BasicTest);
+
+  // Given html_string which represents the remaining html range, this method
+  // returns the next tag in tag and advances html_string to one character after
+  // the end of tag. This method is intended to be called repeatedly to extract
+  // all of the tags in sequence.
+  //
+  // Returns true if another tag was found and 'tag' was populated with a valid
+  // range.
+  // Returns false if we have reached the end of the html data.
+  bool NextTag(StringRange* html_string, StringRange* tag);
+
+  // Returns true if c can be found in quotes_, false otherwise
+  bool IsQuote(wchar_t c);
+
+  // Returns true if pos refers to the last character in an HTML comment in a
+  // string described by html_string, false otherwise.
+  // For example with html_string describing <!-- foo> -->, pos must refer to
+  // the last > for this method to return true.
+  bool IsHTMLCommentClose(StringRange* html_string, StrPos pos);
+
+  // We store a (CollapsedWhitespace'd) copy of the html data.
+  const std::wstring html_string_;
+
+  // Store the string of quote characters to avoid repeated construction.
+  const std::wstring quotes_;
+
+  DISALLOW_COPY_AND_ASSIGN(HTMLScanner);
+};
+
+#endif  // CHROME_FRAME_HTML_UTILS_H_