win8/metro_driver/file_picker.cc - chromium/src - Git at Google

 // Copyright (c) 2012 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 "stdafx.h"
 #include "win8/metro_driver/file_picker.h"

 #include <stddef.h>
 #include <stdint.h>
 #include <windows.storage.pickers.h>

 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_util.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/win/metro.h"
 #include "base/win/scoped_comptr.h"
 #include "win8/metro_driver/chrome_app_view.h"
 #include "win8/metro_driver/winrt_utils.h"

 namespace {

 namespace winstorage = ABI::Windows::Storage;
 typedef winfoundtn::Collections::IVector<HSTRING> StringVectorItf;

 // TODO(siggi): Complete this implementation and move it to a common place.
 class StringVectorImpl : public mswr::RuntimeClass<StringVectorItf> {
  public:
   ~StringVectorImpl() {
     std::for_each(strings_.begin(), strings_.end(), ::WindowsDeleteString);
   }

   HRESULT RuntimeClassInitialize(const std::vector<base::string16>& list) {
     for (size_t i = 0; i < list.size(); ++i)
       strings_.push_back(MakeHString(list[i]));

     return S_OK;
   }

   // IVector<HSTRING> implementation.
   STDMETHOD(GetAt)(unsigned index, HSTRING* item) {
     if (index >= strings_.size())
       return E_INVALIDARG;

     return ::WindowsDuplicateString(strings_[index], item);
   }
   STDMETHOD(get_Size)(unsigned *size) {
     if (strings_.size() > UINT_MAX)
       return E_UNEXPECTED;
     *size = static_cast<unsigned>(strings_.size());
     return S_OK;
   }
   STDMETHOD(GetView)(winfoundtn::Collections::IVectorView<HSTRING> **view) {
     return E_NOTIMPL;
   }
   STDMETHOD(IndexOf)(HSTRING value, unsigned *index, boolean *found) {
     return E_NOTIMPL;
   }

   // write methods
   STDMETHOD(SetAt)(unsigned index, HSTRING item) {
     return E_NOTIMPL;
   }
   STDMETHOD(InsertAt)(unsigned index, HSTRING item) {
     return E_NOTIMPL;
   }
   STDMETHOD(RemoveAt)(unsigned index) {
     return E_NOTIMPL;
   }
   STDMETHOD(Append)(HSTRING item) {
     return E_NOTIMPL;
   }
   STDMETHOD(RemoveAtEnd)() {
     return E_NOTIMPL;
   }
   STDMETHOD(Clear)() {
     return E_NOTIMPL;
   }

  private:
   std::vector<HSTRING> strings_;
 };

 class FilePickerSessionBase {
  public:
   // Creates a file picker for open_file_name.
   explicit FilePickerSessionBase(OPENFILENAME* open_file_name);

   // Runs the picker, returns true on success.
   bool Run();

  protected:
   // Creates, configures and starts a file picker.
   // If the HRESULT returned is a failure code the file picker has not started,
   // so no callbacks should be expected.
   virtual HRESULT StartFilePicker() = 0;

   // The parameters to our picker.
   OPENFILENAME* open_file_name_;
   // The event Run waits on.
   base::WaitableEvent event_;
   // True iff a file picker has successfully finished.
   bool success_;

  private:
   // Initiate a file picker, must be called on the metro dispatcher's thread.
   void DoFilePicker();

   DISALLOW_COPY_AND_ASSIGN(FilePickerSessionBase);
 };

 class OpenFilePickerSession : public FilePickerSessionBase {
  public:
   explicit OpenFilePickerSession(OPENFILENAME* open_file_name);

  private:
   HRESULT StartFilePicker() override;

   typedef winfoundtn::IAsyncOperation<winstorage::StorageFile*>
       SingleFileAsyncOp;
   typedef winfoundtn::Collections::IVectorView<
       winstorage::StorageFile*> StorageFileVectorCollection;
   typedef winfoundtn::IAsyncOperation<StorageFileVectorCollection*>
       MultiFileAsyncOp;

   // Called asynchronously when a single file picker is done.
   HRESULT SinglePickerDone(SingleFileAsyncOp* async, AsyncStatus status);

   // Called asynchronously when a multi file picker is done.
   HRESULT MultiPickerDone(MultiFileAsyncOp* async, AsyncStatus status);

   // Composes a multi-file result string suitable for returning to a
   // from a storage file collection.
   static HRESULT ComposeMultiFileResult(StorageFileVectorCollection* files,
                                         base::string16* result);
  private:
   DISALLOW_COPY_AND_ASSIGN(OpenFilePickerSession);
 };

 class SaveFilePickerSession : public FilePickerSessionBase {
  public:
   explicit SaveFilePickerSession(OPENFILENAME* open_file_name);

  private:
   HRESULT StartFilePicker() override;

   typedef winfoundtn::IAsyncOperation<winstorage::StorageFile*>
       SaveFileAsyncOp;

   // Called asynchronously when the save file picker is done.
   HRESULT FilePickerDone(SaveFileAsyncOp* async, AsyncStatus status);
 };

 FilePickerSessionBase::FilePickerSessionBase(OPENFILENAME* open_file_name)
     : open_file_name_(open_file_name),
       event_(true, false),
       success_(false) {
 }

 bool FilePickerSessionBase::Run() {
   DCHECK(globals.appview_msg_loop != NULL);

   // Post the picker request over to the metro thread.
   bool posted = globals.appview_msg_loop->PostTask(FROM_HERE,
       base::Bind(&FilePickerSessionBase::DoFilePicker, base::Unretained(this)));
   if (!posted)
     return false;

   // Wait for the file picker to complete.
   event_.Wait();

   return success_;
 }

 void FilePickerSessionBase::DoFilePicker() {
   // The file picker will fail if spawned from a snapped application,
   // so let's attempt to unsnap first if we're in that state.
   HRESULT hr = ChromeAppView::Unsnap();
   if (FAILED(hr)) {
     LOG(ERROR) << "Failed to unsnap for file picker, error 0x" << hr;
   }

   if (SUCCEEDED(hr))
     hr = StartFilePicker();

   if (FAILED(hr)) {
     LOG(ERROR) << "Failed to start file picker, error 0x"
                << std::hex << hr;

     event_.Signal();
   }
 }

 OpenFilePickerSession::OpenFilePickerSession(OPENFILENAME* open_file_name)
     : FilePickerSessionBase(open_file_name) {
 }

 HRESULT OpenFilePickerSession::SinglePickerDone(SingleFileAsyncOp* async,
                                                 AsyncStatus status) {
   if (status == Completed) {
     mswr::ComPtr<winstorage::IStorageFile> file;
     HRESULT hr = async->GetResults(file.GetAddressOf());

     if (file) {
       mswr::ComPtr<winstorage::IStorageItem> storage_item;
       if (SUCCEEDED(hr))
         hr = file.As(&storage_item);

       mswrw::HString file_path;
       if (SUCCEEDED(hr))
         hr = storage_item->get_Path(file_path.GetAddressOf());

       if (SUCCEEDED(hr)) {
         UINT32 path_len = 0;
         const wchar_t* path_str =
             ::WindowsGetStringRawBuffer(file_path.Get(), &path_len);

         // If the selected file name is longer than the supplied buffer,
         // we return false as per GetOpenFileName documentation.
         if (path_len < open_file_name_->nMaxFile) {
           base::wcslcpy(open_file_name_->lpstrFile,
                         path_str,
                         open_file_name_->nMaxFile);
           success_ = true;
         }
       }
     } else {
       LOG(ERROR) << "NULL IStorageItem";
     }
   } else {
     LOG(ERROR) << "Unexpected async status " << static_cast<int>(status);
   }

   event_.Signal();

   return S_OK;
 }

 HRESULT OpenFilePickerSession::MultiPickerDone(MultiFileAsyncOp* async,
                                                  AsyncStatus status) {
   if (status == Completed) {
     mswr::ComPtr<StorageFileVectorCollection> files;
     HRESULT hr = async->GetResults(files.GetAddressOf());

     if (files) {
       base::string16 result;
       if (SUCCEEDED(hr))
         hr = ComposeMultiFileResult(files.Get(), &result);

       if (SUCCEEDED(hr)) {
         if (result.size() + 1 < open_file_name_->nMaxFile) {
           // Because the result has embedded nulls, we must memcpy.
           memcpy(open_file_name_->lpstrFile,
                  result.c_str(),
                  (result.size() + 1) * sizeof(result[0]));
           success_ = true;
         }
       }
     } else {
       LOG(ERROR) << "NULL StorageFileVectorCollection";
     }
   } else {
     LOG(ERROR) << "Unexpected async status " << static_cast<int>(status);
   }

   event_.Signal();

   return S_OK;
 }

 HRESULT OpenFilePickerSession::StartFilePicker() {
   DCHECK(globals.appview_msg_loop->BelongsToCurrentThread());
   DCHECK(open_file_name_ != NULL);

   mswrw::HStringReference class_name(
       RuntimeClass_Windows_Storage_Pickers_FileOpenPicker);

   // Create the file picker.
   mswr::ComPtr<winstorage::Pickers::IFileOpenPicker> picker;
   HRESULT hr = ::Windows::Foundation::ActivateInstance(
       class_name.Get(), picker.GetAddressOf());
   CheckHR(hr);

   // Set the file type filter
   mswr::ComPtr<winfoundtn::Collections::IVector<HSTRING>> filter;
   hr = picker->get_FileTypeFilter(filter.GetAddressOf());
   if (FAILED(hr))
     return hr;

   if (open_file_name_->lpstrFilter == NULL) {
     hr = filter->Append(mswrw::HStringReference(L"*").Get());
     if (FAILED(hr))
       return hr;
   } else {
     // The filter is a concatenation of zero terminated string pairs,
     // where each pair is {description, extension}. The concatenation ends
     // with a zero length string - e.g. a double zero terminator.
     const wchar_t* walk = open_file_name_->lpstrFilter;
     while (*walk != L'\0') {
       // Walk past the description.
       walk += wcslen(walk) + 1;

       // We should have an extension, but bail on malformed filters.
       if (*walk == L'\0')
         break;

       // There can be a single extension, or a list of semicolon-separated ones.
       std::vector<base::string16> extensions_win32_style = base::SplitString(
           walk, L";", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);

       // Metro wants suffixes only, not patterns.
       mswrw::HString extension;
       for (size_t i = 0; i < extensions_win32_style.size(); ++i) {
         if (extensions_win32_style[i] == L"*.*") {
           // The wildcard filter is "*" for Metro. The string "*.*" produces
           // an "invalid parameter" error.
           hr = extension.Set(L"*");
         } else {
           // Metro wants suffixes only, not patterns.
           base::string16 ext =
               base::FilePath(extensions_win32_style[i]).Extension();
           if ((ext.size() < 2) ||
               (ext.find_first_of(L"*?") != base::string16::npos)) {
             continue;
           }
           hr = extension.Set(ext.c_str());
         }
         if (SUCCEEDED(hr))
           hr = filter->Append(extension.Get());
         if (FAILED(hr))
           return hr;
       }

       // Walk past the extension.
       walk += wcslen(walk) + 1;
     }
   }

   // Spin up a single or multi picker as appropriate.
   if (open_file_name_->Flags & OFN_ALLOWMULTISELECT) {
     mswr::ComPtr<MultiFileAsyncOp> completion;
     hr = picker->PickMultipleFilesAsync(&completion);
     if (FAILED(hr))
       return hr;

     // Create the callback method.
     typedef winfoundtn::IAsyncOperationCompletedHandler<
         StorageFileVectorCollection*> HandlerDoneType;
     mswr::ComPtr<HandlerDoneType> handler(mswr::Callback<HandlerDoneType>(
         this, &OpenFilePickerSession::MultiPickerDone));
     DCHECK(handler.Get() != NULL);
     hr = completion->put_Completed(handler.Get());

     return hr;
   } else {
     mswr::ComPtr<SingleFileAsyncOp> completion;
     hr = picker->PickSingleFileAsync(&completion);
     if (FAILED(hr))
       return hr;

     // Create the callback method.
     typedef winfoundtn::IAsyncOperationCompletedHandler<
         winstorage::StorageFile*> HandlerDoneType;
     mswr::ComPtr<HandlerDoneType> handler(mswr::Callback<HandlerDoneType>(
         this, &OpenFilePickerSession::SinglePickerDone));
     DCHECK(handler.Get() != NULL);
     hr = completion->put_Completed(handler.Get());

     return hr;
   }
 }

 HRESULT OpenFilePickerSession::ComposeMultiFileResult(
     StorageFileVectorCollection* files, base::string16* result) {
   DCHECK(files != NULL);
   DCHECK(result != NULL);

   // Empty the output string.
   result->clear();

   unsigned int num_files = 0;
   HRESULT hr = files->get_Size(&num_files);
   if (FAILED(hr))
     return hr;

   // Make sure we return an error on an empty collection.
   if (num_files == 0) {
     DLOG(ERROR) << "Empty collection on input.";
     return E_UNEXPECTED;
   }

   // This stores the base path that should be the parent of all the files.
   base::FilePath base_path;

   // Iterate through the collection and append the file paths to the result.
   for (unsigned int i = 0; i < num_files; ++i) {
     mswr::ComPtr<winstorage::IStorageFile> file;
     hr = files->GetAt(i, file.GetAddressOf());
     if (FAILED(hr))
       return hr;

     mswr::ComPtr<winstorage::IStorageItem> storage_item;
     hr = file.As(&storage_item);
     if (FAILED(hr))
       return hr;

     mswrw::HString file_path_str;
     hr = storage_item->get_Path(file_path_str.GetAddressOf());
     if (FAILED(hr))
       return hr;

     base::FilePath file_path(MakeStdWString(file_path_str.Get()));
     if (base_path.empty()) {
       DCHECK(result->empty());
       base_path = file_path.DirName();

       // Append the path, including the terminating zero.
       // We do this only for the first file.
       result->append(base_path.value().c_str(), base_path.value().size() + 1);
     }
     DCHECK(!result->empty());
     DCHECK(!base_path.empty());
     DCHECK(base_path == file_path.DirName());

     // Append the base name, including the terminating zero.
     base::FilePath base_name = file_path.BaseName();
     result->append(base_name.value().c_str(), base_name.value().size() + 1);
   }

   DCHECK(!result->empty());

   return S_OK;
 }

 SaveFilePickerSession::SaveFilePickerSession(OPENFILENAME* open_file_name)
     : FilePickerSessionBase(open_file_name) {
 }

 HRESULT SaveFilePickerSession::StartFilePicker() {
   DCHECK(globals.appview_msg_loop->BelongsToCurrentThread());
   DCHECK(open_file_name_ != NULL);

   mswrw::HStringReference class_name(
       RuntimeClass_Windows_Storage_Pickers_FileSavePicker);

   // Create the file picker.
   mswr::ComPtr<winstorage::Pickers::IFileSavePicker> picker;
   HRESULT hr = ::Windows::Foundation::ActivateInstance(
       class_name.Get(), picker.GetAddressOf());
   CheckHR(hr);

   typedef winfoundtn::Collections::IMap<HSTRING, StringVectorItf*>
       StringVectorMap;
   mswr::ComPtr<StringVectorMap> choices;
   hr = picker->get_FileTypeChoices(choices.GetAddressOf());
   if (FAILED(hr))
     return hr;

   if (open_file_name_->lpstrFilter) {
     // The filter is a concatenation of zero terminated string pairs,
     // where each pair is {description, extension list}. The concatenation ends
     // with a zero length string - e.g. a double zero terminator.
     const wchar_t* walk = open_file_name_->lpstrFilter;
     while (*walk != L'\0') {
       mswrw::HString description;
       hr = description.Set(walk);
       if (FAILED(hr))
         return hr;

       // Walk past the description.
       walk += wcslen(walk) + 1;

       // We should have an extension, but bail on malformed filters.
       if (*walk == L'\0')
         break;

       // There can be a single extension, or a list of semicolon-separated ones.
       std::vector<base::string16> extensions_win32_style = base::SplitString(
           walk, L";", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);

       // Metro wants suffixes only, not patterns.  Also, metro does not support
       // the all files ("*") pattern in the save picker.
       std::vector<base::string16> extensions;
       for (size_t i = 0; i < extensions_win32_style.size(); ++i) {
         base::string16 ext =
             base::FilePath(extensions_win32_style[i]).Extension();
         if ((ext.size() < 2) ||
             (ext.find_first_of(L"*?") != base::string16::npos))
           continue;
         extensions.push_back(ext);
       }

       if (!extensions.empty()) {
         // Convert to a Metro collection class.
         mswr::ComPtr<StringVectorItf> list;
         hr = mswr::MakeAndInitialize<StringVectorImpl>(
             list.GetAddressOf(), extensions);
         if (FAILED(hr))
           return hr;

         // Finally set the filter.
         boolean replaced = FALSE;
         hr = choices->Insert(description.Get(), list.Get(), &replaced);
         if (FAILED(hr))
           return hr;
         DCHECK_EQ(FALSE, replaced);
       }

       // Walk past the extension(s).
       walk += wcslen(walk) + 1;
     }
   }

   // The save picker requires at least one choice.  Callers are strongly advised
   // to provide sensible choices.  If none were given, fallback to .dat.
   uint32_t num_choices = 0;
   hr = choices->get_Size(&num_choices);
   if (FAILED(hr))
     return hr;

   if (num_choices == 0) {
     mswrw::HString description;
     // TODO(grt): Get a properly translated string.  This can't be done from
     // within metro_driver.  Consider preprocessing the filter list in Chrome
     // land to ensure it has this entry if all others are patterns.  In that
     // case, this whole block of code can be removed.
     hr = description.Set(L"Data File");
     if (FAILED(hr))
       return hr;

     mswr::ComPtr<StringVectorItf> list;
     hr = mswr::MakeAndInitialize<StringVectorImpl>(
         list.GetAddressOf(), std::vector<base::string16>(1, L".dat"));
     if (FAILED(hr))
       return hr;

     boolean replaced = FALSE;
     hr = choices->Insert(description.Get(), list.Get(), &replaced);
     if (FAILED(hr))
       return hr;
     DCHECK_EQ(FALSE, replaced);
   }

   if (open_file_name_->lpstrFile != NULL) {
     hr = picker->put_SuggestedFileName(
         mswrw::HStringReference(
             const_cast<const wchar_t*>(open_file_name_->lpstrFile)).Get());
     if (FAILED(hr))
       return hr;
   }

   mswr::ComPtr<SaveFileAsyncOp> completion;
   hr = picker->PickSaveFileAsync(&completion);
   if (FAILED(hr))
     return hr;

   // Create the callback method.
   typedef winfoundtn::IAsyncOperationCompletedHandler<
       winstorage::StorageFile*> HandlerDoneType;
   mswr::ComPtr<HandlerDoneType> handler(mswr::Callback<HandlerDoneType>(
       this, &SaveFilePickerSession::FilePickerDone));
   DCHECK(handler.Get() != NULL);
   hr = completion->put_Completed(handler.Get());

   return hr;
 }

 HRESULT SaveFilePickerSession::FilePickerDone(SaveFileAsyncOp* async,
                                               AsyncStatus status) {
   if (status == Completed) {
     mswr::ComPtr<winstorage::IStorageFile> file;
     HRESULT hr = async->GetResults(file.GetAddressOf());

     if (file) {
       mswr::ComPtr<winstorage::IStorageItem> storage_item;
       if (SUCCEEDED(hr))
         hr = file.As(&storage_item);

       mswrw::HString file_path;
       if (SUCCEEDED(hr))
         hr = storage_item->get_Path(file_path.GetAddressOf());

       if (SUCCEEDED(hr)) {
         base::string16 path_str = MakeStdWString(file_path.Get());

         // If the selected file name is longer than the supplied buffer,
         // we return false as per GetOpenFileName documentation.
         if (path_str.size() < open_file_name_->nMaxFile) {
           base::wcslcpy(open_file_name_->lpstrFile,
                         path_str.c_str(),
                         open_file_name_->nMaxFile);
           success_ = true;
         }
       }
     } else {
       LOG(ERROR) << "NULL IStorageItem";
     }
   } else {
     LOG(ERROR) << "Unexpected async status " << static_cast<int>(status);
   }

   event_.Signal();

   return S_OK;
 }

 }  // namespace

 BOOL MetroGetOpenFileName(OPENFILENAME* open_file_name) {
   OpenFilePickerSession session(open_file_name);

   return session.Run();
 }

 BOOL MetroGetSaveFileName(OPENFILENAME* open_file_name) {
   SaveFilePickerSession session(open_file_name);

   return session.Run();
 }
	// Copyright (c) 2012 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 "stdafx.h"
	#include "win8/metro_driver/file_picker.h"

	#include <stddef.h>
	#include <stdint.h>
	#include <windows.storage.pickers.h>

	#include "base/bind.h"
	#include "base/files/file_path.h"
	#include "base/logging.h"
	#include "base/macros.h"
	#include "base/message_loop/message_loop.h"
	#include "base/strings/string_util.h"
	#include "base/synchronization/waitable_event.h"
	#include "base/win/metro.h"
	#include "base/win/scoped_comptr.h"
	#include "win8/metro_driver/chrome_app_view.h"
	#include "win8/metro_driver/winrt_utils.h"

	namespace {

	namespace winstorage = ABI::Windows::Storage;
	typedef winfoundtn::Collections::IVector<HSTRING> StringVectorItf;

	// TODO(siggi): Complete this implementation and move it to a common place.
	class StringVectorImpl : public mswr::RuntimeClass<StringVectorItf> {
	public:
	~StringVectorImpl() {
	std::for_each(strings_.begin(), strings_.end(), ::WindowsDeleteString);
	}

	HRESULT RuntimeClassInitialize(const std::vector<base::string16>& list) {
	for (size_t i = 0; i < list.size(); ++i)
	strings_.push_back(MakeHString(list[i]));

	return S_OK;
	}

	// IVector<HSTRING> implementation.
	STDMETHOD(GetAt)(unsigned index, HSTRING* item) {
	if (index >= strings_.size())
	return E_INVALIDARG;

	return ::WindowsDuplicateString(strings_[index], item);
	}
	STDMETHOD(get_Size)(unsigned *size) {
	if (strings_.size() > UINT_MAX)
	return E_UNEXPECTED;
	*size = static_cast<unsigned>(strings_.size());
	return S_OK;
	}
	STDMETHOD(GetView)(winfoundtn::Collections::IVectorView<HSTRING> **view) {
	return E_NOTIMPL;
	}
	STDMETHOD(IndexOf)(HSTRING value, unsigned index, boolean found) {
	return E_NOTIMPL;
	}

	// write methods
	STDMETHOD(SetAt)(unsigned index, HSTRING item) {
	return E_NOTIMPL;
	}
	STDMETHOD(InsertAt)(unsigned index, HSTRING item) {
	return E_NOTIMPL;
	}
	STDMETHOD(RemoveAt)(unsigned index) {
	return E_NOTIMPL;
	}
	STDMETHOD(Append)(HSTRING item) {
	return E_NOTIMPL;
	}
	STDMETHOD(RemoveAtEnd)() {
	return E_NOTIMPL;
	}
	STDMETHOD(Clear)() {
	return E_NOTIMPL;
	}

	private:
	std::vector<HSTRING> strings_;
	};

	class FilePickerSessionBase {
	public:
	// Creates a file picker for open_file_name.
	explicit FilePickerSessionBase(OPENFILENAME* open_file_name);

	// Runs the picker, returns true on success.
	bool Run();

	protected:
	// Creates, configures and starts a file picker.
	// If the HRESULT returned is a failure code the file picker has not started,
	// so no callbacks should be expected.
	virtual HRESULT StartFilePicker() = 0;

	// The parameters to our picker.
	OPENFILENAME* open_file_name_;
	// The event Run waits on.
	base::WaitableEvent event_;
	// True iff a file picker has successfully finished.
	bool success_;

	private:
	// Initiate a file picker, must be called on the metro dispatcher's thread.
	void DoFilePicker();

	DISALLOW_COPY_AND_ASSIGN(FilePickerSessionBase);
	};

	class OpenFilePickerSession : public FilePickerSessionBase {
	public:
	explicit OpenFilePickerSession(OPENFILENAME* open_file_name);

	private:
	HRESULT StartFilePicker() override;

	typedef winfoundtn::IAsyncOperation<winstorage::StorageFile*>
	SingleFileAsyncOp;
	typedef winfoundtn::Collections::IVectorView<
	winstorage::StorageFile*> StorageFileVectorCollection;
	typedef winfoundtn::IAsyncOperation<StorageFileVectorCollection*>
	MultiFileAsyncOp;

	// Called asynchronously when a single file picker is done.
	HRESULT SinglePickerDone(SingleFileAsyncOp* async, AsyncStatus status);

	// Called asynchronously when a multi file picker is done.
	HRESULT MultiPickerDone(MultiFileAsyncOp* async, AsyncStatus status);

	// Composes a multi-file result string suitable for returning to a
	// from a storage file collection.
	static HRESULT ComposeMultiFileResult(StorageFileVectorCollection* files,
	base::string16* result);
	private:
	DISALLOW_COPY_AND_ASSIGN(OpenFilePickerSession);
	};

	class SaveFilePickerSession : public FilePickerSessionBase {
	public:
	explicit SaveFilePickerSession(OPENFILENAME* open_file_name);

	private:
	HRESULT StartFilePicker() override;

	typedef winfoundtn::IAsyncOperation<winstorage::StorageFile*>
	SaveFileAsyncOp;

	// Called asynchronously when the save file picker is done.
	HRESULT FilePickerDone(SaveFileAsyncOp* async, AsyncStatus status);
	};

	FilePickerSessionBase::FilePickerSessionBase(OPENFILENAME* open_file_name)
	: open_file_name_(open_file_name),
	event_(true, false),
	success_(false) {
	}

	bool FilePickerSessionBase::Run() {
	DCHECK(globals.appview_msg_loop != NULL);

	// Post the picker request over to the metro thread.
	bool posted = globals.appview_msg_loop->PostTask(FROM_HERE,
	base::Bind(&FilePickerSessionBase::DoFilePicker, base::Unretained(this)));
	if (!posted)
	return false;

	// Wait for the file picker to complete.
	event_.Wait();

	return success_;
	}

	void FilePickerSessionBase::DoFilePicker() {
	// The file picker will fail if spawned from a snapped application,
	// so let's attempt to unsnap first if we're in that state.
	HRESULT hr = ChromeAppView::Unsnap();
	if (FAILED(hr)) {
	LOG(ERROR) << "Failed to unsnap for file picker, error 0x" << hr;
	}

	if (SUCCEEDED(hr))
	hr = StartFilePicker();

	if (FAILED(hr)) {
	LOG(ERROR) << "Failed to start file picker, error 0x"
	<< std::hex << hr;

	event_.Signal();
	}
	}

	OpenFilePickerSession::OpenFilePickerSession(OPENFILENAME* open_file_name)
	: FilePickerSessionBase(open_file_name) {
	}

	HRESULT OpenFilePickerSession::SinglePickerDone(SingleFileAsyncOp* async,
	AsyncStatus status) {
	if (status == Completed) {
	mswr::ComPtr<winstorage::IStorageFile> file;
	HRESULT hr = async->GetResults(file.GetAddressOf());

	if (file) {
	mswr::ComPtr<winstorage::IStorageItem> storage_item;
	if (SUCCEEDED(hr))
	hr = file.As(&storage_item);

	mswrw::HString file_path;
	if (SUCCEEDED(hr))
	hr = storage_item->get_Path(file_path.GetAddressOf());

	if (SUCCEEDED(hr)) {
	UINT32 path_len = 0;
	const wchar_t* path_str =
	::WindowsGetStringRawBuffer(file_path.Get(), &path_len);

	// If the selected file name is longer than the supplied buffer,
	// we return false as per GetOpenFileName documentation.
	if (path_len < open_file_name_->nMaxFile) {
	base::wcslcpy(open_file_name_->lpstrFile,
	path_str,
	open_file_name_->nMaxFile);
	success_ = true;
	}
	}
	} else {
	LOG(ERROR) << "NULL IStorageItem";
	}
	} else {
	LOG(ERROR) << "Unexpected async status " << static_cast<int>(status);
	}

	event_.Signal();

	return S_OK;
	}

	HRESULT OpenFilePickerSession::MultiPickerDone(MultiFileAsyncOp* async,
	AsyncStatus status) {
	if (status == Completed) {
	mswr::ComPtr<StorageFileVectorCollection> files;
	HRESULT hr = async->GetResults(files.GetAddressOf());

	if (files) {
	base::string16 result;
	if (SUCCEEDED(hr))
	hr = ComposeMultiFileResult(files.Get(), &result);

	if (SUCCEEDED(hr)) {
	if (result.size() + 1 < open_file_name_->nMaxFile) {
	// Because the result has embedded nulls, we must memcpy.
	memcpy(open_file_name_->lpstrFile,
	result.c_str(),
	(result.size() + 1) * sizeof(result[0]));
	success_ = true;
	}
	}
	} else {
	LOG(ERROR) << "NULL StorageFileVectorCollection";
	}
	} else {
	LOG(ERROR) << "Unexpected async status " << static_cast<int>(status);
	}

	event_.Signal();

	return S_OK;
	}

	HRESULT OpenFilePickerSession::StartFilePicker() {
	DCHECK(globals.appview_msg_loop->BelongsToCurrentThread());
	DCHECK(open_file_name_ != NULL);

	mswrw::HStringReference class_name(
	RuntimeClass_Windows_Storage_Pickers_FileOpenPicker);

	// Create the file picker.
	mswr::ComPtr<winstorage::Pickers::IFileOpenPicker> picker;
	HRESULT hr = ::Windows::Foundation::ActivateInstance(
	class_name.Get(), picker.GetAddressOf());
	CheckHR(hr);

	// Set the file type filter
	mswr::ComPtr<winfoundtn::Collections::IVector<HSTRING>> filter;
	hr = picker->get_FileTypeFilter(filter.GetAddressOf());
	if (FAILED(hr))
	return hr;

	if (open_file_name_->lpstrFilter == NULL) {
	hr = filter->Append(mswrw::HStringReference(L"*").Get());
	if (FAILED(hr))
	return hr;
	} else {
	// The filter is a concatenation of zero terminated string pairs,
	// where each pair is {description, extension}. The concatenation ends
	// with a zero length string - e.g. a double zero terminator.
	const wchar_t* walk = open_file_name_->lpstrFilter;
	while (*walk != L'\0') {
	// Walk past the description.
	walk += wcslen(walk) + 1;

	// We should have an extension, but bail on malformed filters.
	if (*walk == L'\0')
	break;

	// There can be a single extension, or a list of semicolon-separated ones.
	std::vector<base::string16> extensions_win32_style = base::SplitString(
	walk, L";", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);

	// Metro wants suffixes only, not patterns.
	mswrw::HString extension;
	for (size_t i = 0; i < extensions_win32_style.size(); ++i) {
	if (extensions_win32_style[i] == L".") {
	// The wildcard filter is "" for Metro. The string ".*" produces
	// an "invalid parameter" error.
	hr = extension.Set(L"*");
	} else {
	// Metro wants suffixes only, not patterns.
	base::string16 ext =
	base::FilePath(extensions_win32_style[i]).Extension();
	if ((ext.size() < 2) \|\|
	(ext.find_first_of(L"*?") != base::string16::npos)) {
	continue;
	}
	hr = extension.Set(ext.c_str());
	}
	if (SUCCEEDED(hr))
	hr = filter->Append(extension.Get());
	if (FAILED(hr))
	return hr;
	}

	// Walk past the extension.
	walk += wcslen(walk) + 1;
	}
	}

	// Spin up a single or multi picker as appropriate.
	if (open_file_name_->Flags & OFN_ALLOWMULTISELECT) {
	mswr::ComPtr<MultiFileAsyncOp> completion;
	hr = picker->PickMultipleFilesAsync(&completion);
	if (FAILED(hr))
	return hr;

	// Create the callback method.
	typedef winfoundtn::IAsyncOperationCompletedHandler<
	StorageFileVectorCollection*> HandlerDoneType;
	mswr::ComPtr<HandlerDoneType> handler(mswr::Callback<HandlerDoneType>(
	this, &OpenFilePickerSession::MultiPickerDone));
	DCHECK(handler.Get() != NULL);
	hr = completion->put_Completed(handler.Get());

	return hr;
	} else {
	mswr::ComPtr<SingleFileAsyncOp> completion;
	hr = picker->PickSingleFileAsync(&completion);
	if (FAILED(hr))
	return hr;

	// Create the callback method.
	typedef winfoundtn::IAsyncOperationCompletedHandler<
	winstorage::StorageFile*> HandlerDoneType;
	mswr::ComPtr<HandlerDoneType> handler(mswr::Callback<HandlerDoneType>(
	this, &OpenFilePickerSession::SinglePickerDone));
	DCHECK(handler.Get() != NULL);
	hr = completion->put_Completed(handler.Get());

	return hr;
	}
	}

	HRESULT OpenFilePickerSession::ComposeMultiFileResult(
	StorageFileVectorCollection* files, base::string16* result) {
	DCHECK(files != NULL);
	DCHECK(result != NULL);

	// Empty the output string.
	result->clear();

	unsigned int num_files = 0;
	HRESULT hr = files->get_Size(&num_files);
	if (FAILED(hr))
	return hr;

	// Make sure we return an error on an empty collection.
	if (num_files == 0) {
	DLOG(ERROR) << "Empty collection on input.";
	return E_UNEXPECTED;
	}

	// This stores the base path that should be the parent of all the files.
	base::FilePath base_path;

	// Iterate through the collection and append the file paths to the result.
	for (unsigned int i = 0; i < num_files; ++i) {
	mswr::ComPtr<winstorage::IStorageFile> file;
	hr = files->GetAt(i, file.GetAddressOf());
	if (FAILED(hr))
	return hr;

	mswr::ComPtr<winstorage::IStorageItem> storage_item;
	hr = file.As(&storage_item);
	if (FAILED(hr))
	return hr;

	mswrw::HString file_path_str;
	hr = storage_item->get_Path(file_path_str.GetAddressOf());
	if (FAILED(hr))
	return hr;

	base::FilePath file_path(MakeStdWString(file_path_str.Get()));
	if (base_path.empty()) {
	DCHECK(result->empty());
	base_path = file_path.DirName();

	// Append the path, including the terminating zero.
	// We do this only for the first file.
	result->append(base_path.value().c_str(), base_path.value().size() + 1);
	}
	DCHECK(!result->empty());
	DCHECK(!base_path.empty());
	DCHECK(base_path == file_path.DirName());

	// Append the base name, including the terminating zero.
	base::FilePath base_name = file_path.BaseName();
	result->append(base_name.value().c_str(), base_name.value().size() + 1);
	}

	DCHECK(!result->empty());

	return S_OK;
	}

	SaveFilePickerSession::SaveFilePickerSession(OPENFILENAME* open_file_name)
	: FilePickerSessionBase(open_file_name) {
	}

	HRESULT SaveFilePickerSession::StartFilePicker() {
	DCHECK(globals.appview_msg_loop->BelongsToCurrentThread());
	DCHECK(open_file_name_ != NULL);

	mswrw::HStringReference class_name(
	RuntimeClass_Windows_Storage_Pickers_FileSavePicker);

	// Create the file picker.
	mswr::ComPtr<winstorage::Pickers::IFileSavePicker> picker;
	HRESULT hr = ::Windows::Foundation::ActivateInstance(
	class_name.Get(), picker.GetAddressOf());
	CheckHR(hr);

	typedef winfoundtn::Collections::IMap<HSTRING, StringVectorItf*>
	StringVectorMap;
	mswr::ComPtr<StringVectorMap> choices;
	hr = picker->get_FileTypeChoices(choices.GetAddressOf());
	if (FAILED(hr))
	return hr;

	if (open_file_name_->lpstrFilter) {
	// The filter is a concatenation of zero terminated string pairs,
	// where each pair is {description, extension list}. The concatenation ends
	// with a zero length string - e.g. a double zero terminator.
	const wchar_t* walk = open_file_name_->lpstrFilter;
	while (*walk != L'\0') {
	mswrw::HString description;
	hr = description.Set(walk);
	if (FAILED(hr))
	return hr;

	// Walk past the description.
	walk += wcslen(walk) + 1;

	// We should have an extension, but bail on malformed filters.
	if (*walk == L'\0')
	break;

	// There can be a single extension, or a list of semicolon-separated ones.
	std::vector<base::string16> extensions_win32_style = base::SplitString(
	walk, L";", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);

	// Metro wants suffixes only, not patterns. Also, metro does not support
	// the all files ("*") pattern in the save picker.
	std::vector<base::string16> extensions;
	for (size_t i = 0; i < extensions_win32_style.size(); ++i) {
	base::string16 ext =
	base::FilePath(extensions_win32_style[i]).Extension();
	if ((ext.size() < 2) \|\|
	(ext.find_first_of(L"*?") != base::string16::npos))
	continue;
	extensions.push_back(ext);
	}

	if (!extensions.empty()) {
	// Convert to a Metro collection class.
	mswr::ComPtr<StringVectorItf> list;
	hr = mswr::MakeAndInitialize<StringVectorImpl>(
	list.GetAddressOf(), extensions);
	if (FAILED(hr))
	return hr;

	// Finally set the filter.
	boolean replaced = FALSE;
	hr = choices->Insert(description.Get(), list.Get(), &replaced);
	if (FAILED(hr))
	return hr;
	DCHECK_EQ(FALSE, replaced);
	}

	// Walk past the extension(s).
	walk += wcslen(walk) + 1;
	}
	}

	// The save picker requires at least one choice. Callers are strongly advised
	// to provide sensible choices. If none were given, fallback to .dat.
	uint32_t num_choices = 0;
	hr = choices->get_Size(&num_choices);
	if (FAILED(hr))
	return hr;

	if (num_choices == 0) {
	mswrw::HString description;
	// TODO(grt): Get a properly translated string. This can't be done from
	// within metro_driver. Consider preprocessing the filter list in Chrome
	// land to ensure it has this entry if all others are patterns. In that
	// case, this whole block of code can be removed.
	hr = description.Set(L"Data File");
	if (FAILED(hr))
	return hr;

	mswr::ComPtr<StringVectorItf> list;
	hr = mswr::MakeAndInitialize<StringVectorImpl>(
	list.GetAddressOf(), std::vector<base::string16>(1, L".dat"));
	if (FAILED(hr))
	return hr;

	boolean replaced = FALSE;
	hr = choices->Insert(description.Get(), list.Get(), &replaced);
	if (FAILED(hr))
	return hr;
	DCHECK_EQ(FALSE, replaced);
	}

	if (open_file_name_->lpstrFile != NULL) {
	hr = picker->put_SuggestedFileName(
	mswrw::HStringReference(
	const_cast<const wchar_t*>(open_file_name_->lpstrFile)).Get());
	if (FAILED(hr))
	return hr;
	}

	mswr::ComPtr<SaveFileAsyncOp> completion;
	hr = picker->PickSaveFileAsync(&completion);
	if (FAILED(hr))
	return hr;

	// Create the callback method.
	typedef winfoundtn::IAsyncOperationCompletedHandler<
	winstorage::StorageFile*> HandlerDoneType;
	mswr::ComPtr<HandlerDoneType> handler(mswr::Callback<HandlerDoneType>(
	this, &SaveFilePickerSession::FilePickerDone));
	DCHECK(handler.Get() != NULL);
	hr = completion->put_Completed(handler.Get());

	return hr;
	}

	HRESULT SaveFilePickerSession::FilePickerDone(SaveFileAsyncOp* async,
	AsyncStatus status) {
	if (status == Completed) {
	mswr::ComPtr<winstorage::IStorageFile> file;
	HRESULT hr = async->GetResults(file.GetAddressOf());

	if (file) {
	mswr::ComPtr<winstorage::IStorageItem> storage_item;
	if (SUCCEEDED(hr))
	hr = file.As(&storage_item);

	mswrw::HString file_path;
	if (SUCCEEDED(hr))
	hr = storage_item->get_Path(file_path.GetAddressOf());

	if (SUCCEEDED(hr)) {
	base::string16 path_str = MakeStdWString(file_path.Get());

	// If the selected file name is longer than the supplied buffer,
	// we return false as per GetOpenFileName documentation.
	if (path_str.size() < open_file_name_->nMaxFile) {
	base::wcslcpy(open_file_name_->lpstrFile,
	path_str.c_str(),
	open_file_name_->nMaxFile);
	success_ = true;
	}
	}
	} else {
	LOG(ERROR) << "NULL IStorageItem";
	}
	} else {
	LOG(ERROR) << "Unexpected async status " << static_cast<int>(status);
	}

	event_.Signal();

	return S_OK;
	}

	} // namespace

	BOOL MetroGetOpenFileName(OPENFILENAME* open_file_name) {
	OpenFilePickerSession session(open_file_name);

	return session.Run();
	}

	BOOL MetroGetSaveFileName(OPENFILENAME* open_file_name) {
	SaveFilePickerSession session(open_file_name);

	return session.Run();
	}