Refactoring; switch the |filter| parameter into something that is more amenab...

chrome/common/win_util.cc

Index: chrome/common/win_util.cc
===================================================================
--- chrome/common/win_util.cc	(revision 13572)
+++ chrome/common/win_util.cc	(working copy)
@@ -219,107 +219,63 @@
   return false;
 }
 
-// Set up a filter for a Save/Open dialog, which will consist of 'file_ext'
-// file extension, 'ext_desc' as the text description of the 'file_ext' type,
-// and (optionally) the default 'All Files' view. The purpose of the filter is
-// to show only files of a particular type in a Windows Save/Open dialog box.
-// The resulting filter is stored in 'buffer', which is a vector since multiple
-// NULLs are embedded. The  filters created here are:
-//   1. only files that have 'file_ext' as their extension
-//   2. all files (only added if 'include_all_files' is true)
-// Example:
-//   file_ext: ".txt"
-//   ext_desc: "Text Document"
-//   returned (in buffer): "Text Document\0*.txt\0All Files\0*.*\0\0"
-// This is painful to build, as you will soon see.
-static void FormatFilterForExtension(const std::wstring& file_ext,
-                                     const std::wstring& ext_desc,
-                                     bool include_all_files,
-                                     std::vector<wchar_t>* buffer) {
-  DCHECK(buffer);
-
-  // Force something reasonable to appear in the dialog box if there is no
-  // description provided.
-  if (file_ext.empty() || ext_desc.empty())
-    include_all_files = true;
-
-  size_t size;
-  size_t offset = 0;
+std::wstring FormatFilterForExtensions(
+    const std::vector<std::wstring>& file_ext,
+    const std::vector<std::wstring>& ext_desc,
+    bool include_all_files) {
   const std::wstring all_ext = L"*.*";
   const std::wstring all_desc = l10n_util::GetString(IDS_SAVEAS_ALL_FILES);
 
-  // Includes 2 internal NULLs + "*".
-  const size_t ext_size = ext_desc.length() + file_ext.length() + 3;
-  // Includes 2 internal NULLs.
-  const size_t all_size = all_desc.length() + all_ext.length() + 2;
-  // Includes double terminating NULL.
-  const size_t buf_size = (!ext_desc.empty() ? ext_size : 0) +
-                          (include_all_files ? all_size : 0) + 1;
-  buffer->resize(buf_size);
+  DCHECK(file_ext.size()>=ext_desc.size());
 
-  if (!file_ext.empty() && !ext_desc.empty()) {
-    // Copy in the text description ("JPEG Image") + NULL.
-    size = ext_desc.length() + 1;
-    memcpy(&(*buffer)[offset], ext_desc.c_str(), size * sizeof(wchar_t));
-    offset += size;
+  std::wstring result;
 
-    // Copy in the file type ("*.jpg") + NULL.
-    const std::wstring wildcard_ext = L"*" + file_ext;
-    size = wildcard_ext.length() + 1;
-    memcpy(&(*buffer)[offset], wildcard_ext.c_str(), size * sizeof(wchar_t));
-    offset += size;
-  }
+  for (size_t i=0; i<file_ext.size(); ++i) {
+    std::wstring ext = file_ext[i];
+    std::wstring desc;
+    if (i<ext_desc.size())
+      desc = ext_desc[i];
 
-  if (include_all_files) {
-    // Copy in the default description ("All Files") + NULL.
-    size = all_desc.length() + 1;
-    memcpy(&(*buffer)[offset], all_desc.c_str(), size * sizeof(wchar_t));
-    offset += size;
+    if (ext.empty()) {
+      // Force something reasonable to appear in the dialog box if there is no
+      // extension provided.
+      include_all_files = true;
+      continue;
+    }
 
-    // Copy in the default file extension ("*.*") + NULL.
-    size = all_ext.length() + 1;
-    memcpy(&(*buffer)[offset], all_ext.c_str(), size * sizeof(wchar_t));
-    offset += size;
+    if (desc.empty()) {
+      DCHECK(ext.find(L'.') != std::wstring::npos);
+      std::wstring first_extension = ext.substr(ext.find(L'.'));
+      size_t first_separator_index = first_extension.find(L';');
+      if (first_separator_index != std::wstring::npos)
+        first_extension = first_extension.substr(0, first_separator_index);
+      GetRegistryDescriptionFromExtension(first_extension, &desc);
+      if (desc.empty())
+        desc = L"*." + first_extension;
+    }
+
+    result.append(desc.c_str(), desc.size()+1);  // Append NULL too.
+    result.append(ext.c_str(), ext.size()+1);
   }
 
-  (*buffer)[offset] = L'\0';  // Double NULL required.
-}
-
-std::wstring GetFileFilterFromPath(const std::wstring& file_name) {
-  std::wstring reg_description;
-  std::wstring file_ext = file_util::GetFileExtensionFromPath(file_name);
-  if (!file_ext.empty()) {
-    file_ext = L"." + file_ext;
-    GetRegistryDescriptionFromExtension(file_ext, &reg_description);
+  if (include_all_files) {
+    result.append(all_desc.c_str(), all_desc.size()+1);
+    result.append(all_ext.c_str(), all_ext.size()+1);
   }
 
-  std::vector<wchar_t> filter;
-  FormatFilterForExtension(file_ext, reg_description, true, &filter);
-  return std::wstring(&filter[0], filter.size());
+  result.append(1, '\0');  // Double NULL required.
+  return result;
 }
 
-std::wstring GetFileFilterFromExtensions(const std::wstring& extensions,
-                                         bool include_all_files) {
-  DCHECK(extensions.find(L'.') != std::wstring::npos);
-  std::wstring first_extension = extensions.substr(extensions.find(L'.'));
-  size_t first_separator_index = first_extension.find(L';');
-  if (first_separator_index != std::wstring::npos)
-    first_extension = first_extension.substr(0, first_separator_index);
-
-  std::wstring description;
-  GetRegistryDescriptionFromExtension(first_extension, &description);
-  if (description.empty())
-    description = L"*." + first_extension;
-
-  std::vector<wchar_t> filter;
-  FormatFilterForExtension(extensions, description, true, &filter);
-  return std::wstring(&filter[0], filter.size());
-}
-
 bool SaveFileAs(HWND owner,
                 const std::wstring& suggested_name,
                 std::wstring* final_name) {
-  std::wstring filter = GetFileFilterFromPath(suggested_name);
+  std::wstring file_ext = file_util::GetFileExtensionFromPath(suggested_name);
+  file_ext.insert(L'.', 0);
+  std::wstring filter = FormatFilterForExtensions(
+    std::vector<std::wstring>(1, file_ext),
+    std::vector<std::wstring>(),
+    true);
   unsigned index = 1;
   return SaveFileAsWithFilter(owner,
                               suggested_name,