gdata: Fix "save as pdf" to work on Google Drive.

chrome/browser/chromeos/gdata/gdata_file_writing.cc

+// 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 "chrome/browser/chromeos/gdata/gdata_file_writing.h"
+
+#include "base/threading/sequenced_worker_pool.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+namespace gdata {
+
+GDataFileWriting::GDataFileWriting(GDataFileSystemInterface* file_system)
+    : file_system_(file_system),
+      ui_weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)),
+      ui_weak_ptr_(ui_weak_ptr_factory_.GetWeakPtr()) {
+  // Must be created in GDataSystemService.
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+}
+
+GDataFileWriting::~GDataFileWriting() {
+  // Must be destroyed in GDataSystemService.
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+}
+
+void GDataFileWriting::PrepareWritableFileAndRun(
+    const FilePath& file_path,
+    const OpenFileCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI) ||
+         BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  // TODO(kinaba): factor out RunTaskOnThread family from gdata_file_system.cc
+  // and use it.
+  if (BrowserThread::CurrentlyOn(BrowserThread::UI)) {
+    PrepareWritableFileAndRunOnUIThread(file_path, callback);
+  } else {
+    BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI)->PostTask(
+        FROM_HERE,
+        base::Bind(&GDataFileWriting::PrepareWritableFileAndRunOnUIThread,
+                   ui_weak_ptr_,
+                   file_path,
+                   callback));
+  }
+}
+
+void GDataFileWriting::PrepareWritableFileAndRunOnUIThread(
+    const FilePath& file_path,
+    const OpenFileCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  file_system_->CreateFile(
+      file_path,
+      false, // it is not an error, even if the path already exists.
+      base::Bind(&GDataFileWriting::PrepareWritableFileAndRunAfterCreateFile,
+                 ui_weak_ptr_,
+                 file_path,
+                 callback));
+}
+
+void GDataFileWriting::PrepareWritableFileAndRunAfterCreateFile(
+    const FilePath& file_path,
+    const OpenFileCallback& callback,
+    GDataFileError error) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  if (error != gdata::GDATA_FILE_OK) {
+    if (!callback.is_null()) {
+      content::BrowserThread::GetBlockingPool()->PostTask(
+          FROM_HERE,
+          base::Bind(callback, error, FilePath()));
+    }
+    return;
+  }
+  file_system_->OpenFile(
+      file_path,
+      base::Bind(&GDataFileWriting::PrepareWritableFileAndRunAfterOpenFile,
+                 ui_weak_ptr_,
+                 file_path,
+                 callback));
+}
+
+void GDataFileWriting::PrepareWritableFileAndRunAfterOpenFile(
+    const FilePath& file_path,
+    const OpenFileCallback& callback,
+    GDataFileError error,
+    const FilePath& local_cache_path) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  if (error != gdata::GDATA_FILE_OK) {
+    if (!callback.is_null()) {
+      content::BrowserThread::GetBlockingPool()->PostTask(
+          FROM_HERE,
+          base::Bind(callback, error, FilePath()));
+    }
+    return;
+  }
+
+  if (!callback.is_null()) {
+    content::BrowserThread::GetBlockingPool()->PostTaskAndReply(
+        FROM_HERE,
+        base::Bind(callback, GDATA_FILE_OK, local_cache_path),
+        base::Bind(&GDataFileWriting::PrepareWritableFileAndRunAfterCallback,
+                   ui_weak_ptr_,
+                   file_path));
+  } else {
+    PrepareWritableFileAndRunAfterCallback(file_path);
+  }
+}
+
+void GDataFileWriting::PrepareWritableFileAndRunAfterCallback(
+    const FilePath& file_path) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  file_system_->CloseFile(file_path, FileOperationCallback());
+}
+
+}  // namespace gdata