[Mac] Implement the system dictionary popup by implementing NSTextInput methods.

chrome/common/attributed_string_coder_mac.h

+// Copyright (c) 2011 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.
+
+#ifndef CHROME_COMMON_ATTRIBUTED_STRING_CODER_MAC_H_
+#define CHROME_COMMON_ATTRIBUTED_STRING_CODER_MAC_H_
+
+#include <set>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/string16.h"
+#include "content/common/font_descriptor_mac.h"
+#include "ipc/ipc_message_utils.h"
+#include "ui/base/range/range.h"
+
+#if __OBJC__
+@class NSAttributedString;
+@class NSDictionary;
+#else
+class NSAttributedString;
+class NSDictionary;
+#endif
+
+namespace mac {
+
+// This class will serialize the font information of an NSAttributedString so
+// that it can be sent over IPC. This class only stores the information of the
+// NSFontAttributeName. The motive is that of security: using NSArchiver and
+// friends to send objects from the renderer to the browser could lead to
+// deserialization of arbitrary objects. This class restricts serialization to
+// a specific object class and specific attributes of that object.
+class AttributedStringCoder {
+ public:
+  // A C++ IPC-friendly representation of the NSFontAttributeName attribute
+  // set.
+  class FontAttribute {
+   public:
+    FontAttribute(NSDictionary* ns_attributes, ui::Range effective_range);
+    FontAttribute(FontDescriptor font, ui::Range range);
+    FontAttribute();
+    ~FontAttribute();
+
+    // Creates an autoreleased NSDictionary that can be attached to an
+    // NSAttributedString.
+    NSDictionary* ToAttributesDictionary() const;
+
+    // Whether or not the attribute should be placed in the EncodedString. This
+    // can return false, e.g. if the Cocoa-based constructor can't find any
+    // information to encode.
+    bool ShouldEncode() const;
+
+    // Accessors:
+    FontDescriptor font_descriptor() const { return font_descriptor_; }
+    ui::Range effective_range() const { return effective_range_; }
+
+   private:
+    FontDescriptor font_descriptor_;
+    ui::Range effective_range_;
+  };
+
+  // A class that contains the pertinent information from an NSAttributedString,
+  // which can be serialized over IPC.
+  class EncodedString {
+   public:
+    explicit EncodedString(string16 string);
+    EncodedString();
+    ~EncodedString();
+
+    // Accessors:
+    string16 string() const { return string_; }
+    const std::vector<FontAttribute>& attributes() const {
+      return attributes_;
+    }
+    std::vector<FontAttribute>* attributes() { return &attributes_; }
+
+   private:
+    // The plain-text string.
+    string16 string_;
+    // The set of attributes that style |string_|.
+    std::vector<FontAttribute> attributes_;
+  };
+
+  // Takes an NSAttributedString, extracts the pertinent attributes, and returns
+  // an object that represents it. Caller owns the result.
+  static const EncodedString* Encode(NSAttributedString* str);
+
+  // Returns an autoreleased NSAttributedString from an encoded representation.
+  static NSAttributedString* Decode(const EncodedString* str);
+
+ private:
+  AttributedStringCoder();
+};
+
+}  // namespace mac
+
+// IPC ParamTraits specialization //////////////////////////////////////////////
+
+namespace IPC {
+
+template <>
+struct ParamTraits<mac::AttributedStringCoder::EncodedString> {
+  typedef mac::AttributedStringCoder::EncodedString param_type;
+  static void Write(Message* m, const param_type& p);
+  static bool Read(const Message* m, void** iter, param_type* r);
+  static void Log(const param_type& p, std::string* l);
+};
+
+template <>
+struct ParamTraits<mac::AttributedStringCoder::FontAttribute> {
+  typedef mac::AttributedStringCoder::FontAttribute param_type;
+  static void Write(Message* m, const param_type& p);
+  static bool Read(const Message* m, void** iter, param_type* r);
+  static void Log(const param_type& p, std::string* l);
+};
+
+}  // namespace IPC
+
+#endif  // CHROME_COMMON_ATTRIBUTED_STRING_CODER_MAC_H_