[Android] Prompt with infobar on filename conflict

chrome/browser/android/download_overwrite_infobar_delegate.h

+// Copyright 2015 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.
+
+#ifndef CHROME_BROWSER_ANDROID_DOWNLOAD_OVERWRITE_INFOBAR_DELEGATE_H_
+#define CHROME_BROWSER_ANDROID_DOWNLOAD_OVERWRITE_INFOBAR_DELEGATE_H_
+
+#include "base/callback.h"
+#include "base/files/file_path.h"
+#include "chrome/browser/download/download_target_determiner_delegate.h"
+#include "components/infobars/core/infobar_delegate.h"
+
+class InfoBarService;
+
+namespace chrome {
+namespace android {
+
+// An infobar that asks if it is ok to overwrite an
+// existing file. Due to limited disk space on Android, two options are
+// presented to the user when downloading a file whose name conflicts with an
+// already present file:
+//
+// 1. Overwrite the file.
+// 2. Create a new file.
+//
+// Also, the user can dismiss the infobar to abort the download.
+//
+// Note that this infobar does not expire if the user subsequently navigates,
+// since such navigations won't automatically cancel the underlying download.
+class DownloadOverwriteInfoBarDelegate : public infobars::InfoBarDelegate {
+ public:
+  ~DownloadOverwriteInfoBarDelegate() override;
+
+  static void Create(
+      InfoBarService* infobar_service,
+      const base::FilePath& suggested_download_path,
+      const DownloadTargetDeterminerDelegate::FileSelectedCallback&
+          file_selected_callback);
+
+  // This is called when the user chooses to overwrite the existing file.
+  void OverwriteExistingFile();
+
+  // This is called when the user chooses to create a new file.
+  void CreateNewFile();
+
+  base::FilePath suggested_download_path() const {
+    return suggested_download_path_;
+  }
+
+ private:
+  DownloadOverwriteInfoBarDelegate(
+      const base::FilePath& suggested_path,
+      const DownloadTargetDeterminerDelegate::FileSelectedCallback& callback);
+
+  // infobars::InfoBarDelegate:
+  bool ShouldExpire(const NavigationDetails& details) const override;
+  void InfoBarDismissed() override;
+
+  // Creates a new file in content::BrowserThread::FILE thread, and when it's
+  // done, calls |callback| in the UI thread.
+  static void CreateNewFileInternal(
+      const base::FilePath& suggested_download_path,
+      const DownloadTargetDeterminerDelegate::FileSelectedCallback& callback);
+
+  // The suggested download path from download target determiner. This is used
+  // to show users the file name and the directory that will be used.
+  base::FilePath suggested_download_path_;
+
+  // A callback to download target determiner to notify that file selection
+  // is made (or cancelled).
+  DownloadTargetDeterminerDelegate::FileSelectedCallback
+      file_selected_callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(DownloadOverwriteInfoBarDelegate);
+};
+
+}  // namespace android
+}  // namespace chrome
+
+#endif  // CHROME_BROWSER_ANDROID_DOWNLOAD_OVERWRITE_INFOBAR_DELEGATE_H_