Mac: Infrastructure for serialization of OS fonts over IPC.

chrome/common/font_loader_mac.mm

+// Copyright (c) 2010 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/font_loader_mac.h"
+
+#import <Cocoa/Cocoa.h>
+
+#include "base/basictypes.h"
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/mac_util.h"
+#include "base/scoped_cftyperef.h"
+#include "base/sys_string_conversions.h"
+
+// static
+bool FontLoader::LoadFontIntoBuffer(const string16& font_name,
+                                    float font_point_size,
+                                    base::SharedMemory* font_data,
+                                    uint32* font_data_size) {
+  CHECK(font_data && font_data_size);
+  *font_data_size = 0;
+
+  // Load appropriate NSFont.
+  NSString* font_name_ns = base::SysUTF16ToNSString(font_name);
+  NSFont* font_to_encode =
+      [NSFont fontWithName:font_name_ns size:font_point_size];
+  if (!font_to_encode) {
+    LOG(ERROR) << "Failed to load font " << font_name;
+    return false;
+  }
+
+  // NSFont -> ATSFontRef.
+  ATSFontRef ats_font =
+      CTFontGetPlatformFont(reinterpret_cast<CTFontRef>(font_to_encode), NULL);
+  if (!ats_font) {
+    LOG(ERROR) << "Conversion to ATSFontRef failed for " << font_name;
+    return false;
+  }
+
+  // ATSFontRef -> File path.
+  FSRef font_fsref;
+  if (ATSFontGetFileReference(ats_font, &font_fsref) != noErr) {
+    LOG(ERROR) << "Failed to find font file for " << font_name;
+    return false;
+  }
+  FilePath font_path = FilePath(mac_util::PathFromFSRef(font_fsref));
+
+  // Load file into shared memory buffer.
+  int64 font_file_size_64 = -1;
+  if (!file_util::GetFileSize(font_path, &font_file_size_64)) {
+    LOG(ERROR) << "Couldn't get font file size for " << font_path.value();
+    return false;
+  }
+
+  if (font_file_size_64 <= 0 || font_file_size_64 >= kint32max) {
+    LOG(ERROR) << "Bad size for font file " << font_path.value();
+    return false;
+  }
+
+  int32 font_file_size_32 = static_cast<int32>(font_file_size_64);
+  if (!font_data->Create(L"", false, false, font_file_size_32)) {
+    LOG(ERROR) << "Failed to create shmem area for " << font_name;
+    return false;
+  }
+
+  if (!font_data->Map(font_file_size_32)) {
+    LOG(ERROR) << "Failed to map shmem area for " << font_name;
+    return false;
+  }
+
+  int32 amt_read = file_util::ReadFile(font_path,
+                       reinterpret_cast<char*>(font_data->memory()),
+                       font_file_size_32);
+  if (amt_read != font_file_size_32) {
+    LOG(ERROR) << "Failed to read font data for " << font_path.value();
+    return false;
+  }
+
+  *font_data_size = font_file_size_32;
+  return true;
+}
+
+// static
+bool FontLoader::CreateCGFontFromBuffer(base::SharedMemoryHandle font_data,
+                                        uint32 font_data_size,
+                                        CGFontRef *font) {
+  using base::SharedMemory;
+  DCHECK(SharedMemory::IsHandleValid(font_data));
+  DCHECK_GT(font_data_size, 0U);
+
+  SharedMemory shm(font_data, true);
+  if (!shm.Map(font_data_size))
+    return false;
+
+  ATSFontContainerRef font_container = 0;
+  OSStatus err = ATSFontActivateFromMemory(shm.memory(), font_data_size,
+                    kATSFontContextLocal, kATSFontFormatUnspecified,
+                    NULL, kATSOptionFlagsDefault, &font_container );
+  if (err != noErr || !font_container)
+    return false;
+
+  // Count the number of fonts that were loaded.
+  ItemCount fontCount = 0;
+  ATSFontFindFromContainer(font_container, kATSOptionFlagsDefault, 0, NULL,
+      &fontCount);
+
+  if (fontCount < 1) {
+    ATSFontDeactivate(font_container, NULL, kATSOptionFlagsDefault);
+    return false;
+  }
+
+  // Load font from container.
+  ATSFontRef font_ref_ats = 0;
+  ATSFontFindFromContainer(font_container, kATSOptionFlagsDefault, 1,
+      &font_ref_ats, NULL);
+
+  if (!font_ref_ats) {
+    ATSFontDeactivate(font_container, NULL, kATSOptionFlagsDefault);
+    return false;
+  }
+
+  // Convert to cgFont.
+  CGFontRef font_ref_cg = CGFontCreateWithPlatformFont(&font_ref_ats);
+
+  if (!font_ref_cg) {
+    ATSFontDeactivate(font_container, NULL, kATSOptionFlagsDefault);
+    return false;
+  }
+
+  *font = font_ref_cg;
+  return true;
+}