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

chrome/common/attributed_string_coder.mm

+// 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.
+
+#include "chrome/common/attributed_string_coder.h"
+
+#include <AppKit/AppKit.h>
+
+#include "base/logging.h"
+#include "base/memory/scoped_nsobject.h"
+#include "base/sys_string_conversions.h"
+#include "base/utf_string_conversions.h"
+#include "content/common/common_param_traits.h"
+#include "ipc/ipc_message_utils.h"
+
+namespace mac {
+
+// static
+const AttributedStringCoder::EncodedString* AttributedStringCoder::Encode(
+    NSAttributedString* str) {
+  // Create the return value.
+  EncodedString* encoded_string =
+      new EncodedString(base::SysNSStringToUTF16([str string]));
+  // Iterate over all the attributes in the string.
+  NSUInteger length = [str length];
+  for (NSUInteger i = 0; i < length; ) {
+    NSRange effective_range;
+    NSDictionary* ns_attributes = [str attributesAtIndex:i
+                                          effectiveRange:&effective_range];
+    // Convert the attributes to IPC-friendly types.
+    FontAttribute attrs(ns_attributes, ui::Range(effective_range));
+    // Only encode the attributes if the filtered set contains font information.
+    if (attrs.ShouldEncode()) {
+      encoded_string->attributes()->push_back(attrs);
+    }
+    // Advance the iterator to the position outside of the effective range.
+    i = NSMaxRange(effective_range);
+  }
+  return encoded_string;
+}
+
+// static
+NSAttributedString* AttributedStringCoder::Decode(
+    const AttributedStringCoder::EncodedString* str) {
+  // Create the return value.
+  NSString* plain_text = base::SysUTF16ToNSString(str->string());
+  scoped_nsobject<NSMutableAttributedString> decoded_string(
+      [[NSMutableAttributedString alloc] initWithString:plain_text]);
+  // Iterate over all the encoded attributes, attaching each to the string.
+  const std::vector<FontAttribute> attributes = str->attributes();
+  for (std::vector<FontAttribute>::const_iterator it = attributes.begin();
+       it != attributes.end(); ++it) {
+    [decoded_string addAttributes:it->ToAttributesDictionary()
+                            range:it->effective_range().ToNSRange()];
+  }
+  return [decoded_string.release() autorelease];
+}
+
+// Data Types //////////////////////////////////////////////////////////////////
+
+AttributedStringCoder::EncodedString::EncodedString(string16 string)
+    : string_(string) {
+}
+
+AttributedStringCoder::EncodedString::EncodedString()
+    : string_() {
+}
+
+AttributedStringCoder::FontAttribute::FontAttribute(NSDictionary* dict,
+                                                    ui::Range effective_range)
+    : font_name_(),
+      font_size_(0),
+      effective_range_(effective_range) {
+  NSFont* font = [dict objectForKey:NSFontAttributeName];
+  if (font) {
+    font_name_ = base::SysNSStringToUTF8([font fontName]);

[jeremy, 2011/04/12 09:44:06]

Could you use a FontDescriptor (content/common/font_descriptor_mac.mm) here,
since that class is supposed to encapsulate sending an NSFont over IPC.

[Robert Sesek, 2011/04/25 20:58:18]

Done.

+    font_size_ = [font pointSize];
+  }
+}
+
+AttributedStringCoder::FontAttribute::FontAttribute(std::string name,
+                                                    float size,
+                                                    ui::Range range)
+    : font_name_(name),
+      font_size_(size),
+      effective_range_(range) {
+}
+
+AttributedStringCoder::FontAttribute::FontAttribute()
+    : font_name_(),
+      font_size_(0),
+      effective_range_() {
+}
+
+NSDictionary* AttributedStringCoder::FontAttribute::ToAttributesDictionary(
+    void) const {
+  DCHECK(ShouldEncode());
+  NSFont* font = [NSFont fontWithName:base::SysUTF8ToNSString(font_name_)
+                                 size:font_size_];
+  return [NSDictionary dictionaryWithObject:font forKey:NSFontAttributeName];
+}
+
+bool AttributedStringCoder::FontAttribute::ShouldEncode() const {
+  return !font_name_.empty();
+}
+
+}  // namespace mac
+
+// IPC ParamTraits specialization //////////////////////////////////////////////

[jeremy, 2011/04/12 09:44:06]

When deserializing values here, could you add some paranoid sanity checks?  If
the renderer sends junk over, we don't want it getting to Cocoa...

esp. probably worth checking that the range is legal, font sizes, etc.

[Robert Sesek, 2011/04/25 20:58:18]

ui::Range protects against this in its own ParamTraits<> deserialization and
initialization. Does FontDescriptor do the same?

[jeremy, 2011/05/01 09:25:56]

FontDescriptor's code uses the standard macros and is defined in
content/common/view_messages.h, I'll add some more protection there.

Is there any that verifies that the ui:Range's passed around are within the
strings bounds?

[Robert Sesek, 2011/05/02 15:43:31]

Added a check that Range::GetMin() and GetMax() are both less than the string's
length.

+
+namespace IPC {
+
+using mac::AttributedStringCoder;
+
+void ParamTraits<AttributedStringCoder::EncodedString>::Write(
+    Message* m, const param_type& p) {
+  WriteParam(m, p.string());
+  WriteParam(m, p.attributes());
+}
+
+bool ParamTraits<AttributedStringCoder::EncodedString>::Read(
+    const Message* m, void** iter, param_type* p) {
+  bool success = true;
+
+  string16 result;
+  success &= ReadParam(m, iter, &result);
+  *p = AttributedStringCoder::EncodedString(result);
+
+  success &= ReadParam(m, iter, p->attributes());
+  return success;
+}
+
+void ParamTraits<AttributedStringCoder::EncodedString>::Log(
+    const param_type& p, std::string* l) {
+  l->append(UTF16ToUTF8(p.string()));
+}
+
+void ParamTraits<AttributedStringCoder::FontAttribute>::Write(
+    Message* m, const param_type& p) {
+  WriteParam(m, p.font_name());
+  WriteParam(m, p.font_size());
+  WriteParam(m, p.effective_range());
+}
+
+bool ParamTraits<AttributedStringCoder::FontAttribute>::Read(
+    const Message* m, void** iter, param_type* p) {
+  bool success = true;
+
+  std::string name;
+  success &= ReadParam(m, iter, &name);
+
+  float size;
+  success &= ReadParam(m, iter, &size);
+
+  ui::Range range;
+  success &= ReadParam(m, iter, &range);
+
+  if (success) {
+    *p = AttributedStringCoder::FontAttribute(name, size, range);
+  }
+  return success;
+}
+
+void ParamTraits<AttributedStringCoder::FontAttribute>::Log(
+    const param_type& p, std::string* l) {
+}
+
+}  // namespace IPC