Files App: Enable future generation of thumbnails for local files

Adds basic scaffolding for local file thumbnail generation:
- Moves GetThumbnail function from private_api_drive to private_api_misc
- Adds code that directs the flow of thumbnail generation based on file
  system type
- Adds a place holder for local thumbnail generation.

Bug: 903742
Change-Id: I4b4326d9b28b81a5b46266a7ee03dede5878119e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2246209
Commit-Queue: Bo Majewski <majewski@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Cr-Commit-Position: refs/heads/master@{#780165}

chrome/browser/chromeos/extensions/file_manager/private_api_drive.cc

@@ -506,16 +506,6 @@ class SingleEntryPropertiesGetterForDocumentsProvider {
       weak_ptr_factory_{this};
 };  // class SingleEntryPropertiesGetterForDocumentsProvider
 
-std::string MakeThumbnailDataUrlOnThreadPool(
-    const std::vector<uint8_t>& png_data) {
-  std::string encoded;
-  base::Base64Encode(
-      base::StringPiece(reinterpret_cast<const char*>(png_data.data()),
-                        png_data.size()),
-      &encoded);
-  return base::StrCat({"data:image/png;base64,", encoded});
-}
-
 void OnSearchDriveFs(
     scoped_refptr<ExtensionFunction> function,
     bool filter_dirs,
@@ -1105,71 +1095,4 @@ void FileManagerPrivateInternalGetDownloadUrlFunction::OnGotMetadata(
   OnGotDownloadUrl(metadata ? GURL(metadata->download_url) : GURL());
 }
 
-FileManagerPrivateInternalGetThumbnailFunction::
-    FileManagerPrivateInternalGetThumbnailFunction() {
-  SetWarningThresholds(kDriveSlowOperationThreshold,
-                       kDriveVerySlowOperationThreshold);
-}
-
-FileManagerPrivateInternalGetThumbnailFunction::
-    ~FileManagerPrivateInternalGetThumbnailFunction() = default;
-
-ExtensionFunction::ResponseAction
-FileManagerPrivateInternalGetThumbnailFunction::Run() {
-  using extensions::api::file_manager_private_internal::GetThumbnail::Params;
-  const std::unique_ptr<Params> params(Params::Create(*args_));
-  EXTENSION_FUNCTION_VALIDATE(params);
-
-  const ChromeExtensionFunctionDetails chrome_details(this);
-  scoped_refptr<storage::FileSystemContext> file_system_context =
-      file_manager::util::GetFileSystemContextForRenderFrameHost(
-          chrome_details.GetProfile(), render_frame_host());
-  const GURL url = GURL(params->url);
-  const storage::FileSystemURL file_system_url =
-      file_system_context->CrackURL(url);
-
-  if (file_system_url.type() != storage::kFileSystemTypeDriveFs) {
-    return RespondNow(Error("Invalid URL"));
-  }
-  drive::DriveIntegrationService* integration_service =
-      drive::DriveIntegrationServiceFactory::FindForProfile(
-          chrome_details.GetProfile());
-  base::FilePath path;
-  if (!integration_service || !integration_service->GetRelativeDrivePath(
-                                  file_system_url.path(), &path)) {
-    return RespondNow(Error("Drive not available"));
-  }
-  auto* drivefs_interface = integration_service->GetDriveFsInterface();
-  if (!drivefs_interface) {
-    return RespondNow(Error("Drive not available"));
-  }
-  drivefs_interface->GetThumbnail(
-      path, params->crop_to_square,
-      mojo::WrapCallbackWithDefaultInvokeIfNotRun(
-          base::BindOnce(
-              &FileManagerPrivateInternalGetThumbnailFunction::GotThumbnail,
-              this),
-          base::Optional<std::vector<uint8_t>>()));
-  return RespondLater();
-}
-
-void FileManagerPrivateInternalGetThumbnailFunction::GotThumbnail(
-    const base::Optional<std::vector<uint8_t>>& data) {
-  if (!data) {
-    Respond(OneArgument(std::make_unique<base::Value>("")));
-    return;
-  }
-  base::ThreadPool::PostTaskAndReplyWithResult(
-      FROM_HERE, base::BindOnce(&MakeThumbnailDataUrlOnThreadPool, *data),
-      base::BindOnce(
-          &FileManagerPrivateInternalGetThumbnailFunction::SendEncodedThumbnail,
-          this));
-}
-
-void FileManagerPrivateInternalGetThumbnailFunction::SendEncodedThumbnail(
-    std::string thumbnail_data_url) {
-  Respond(OneArgument(
-      std::make_unique<base::Value>(std::move(thumbnail_data_url))));
-}
-
 }  // namespace extensions

chrome/browser/chromeos/extensions/file_manager/private_api_drive.h

@@ -178,26 +178,6 @@ class FileManagerPrivateInternalGetDownloadUrlFunction
   std::unique_ptr<google_apis::AuthService> auth_service_;
 };
 
-class FileManagerPrivateInternalGetThumbnailFunction
-    : public LoggedExtensionFunction {
- public:
-  DECLARE_EXTENSION_FUNCTION("fileManagerPrivateInternal.getThumbnail",
-                             FILEMANAGERPRIVATEINTERNAL_GETTHUMBNAIL)
-
-  FileManagerPrivateInternalGetThumbnailFunction();
-
- protected:
-  ~FileManagerPrivateInternalGetThumbnailFunction() override;
-
-  // ExtensionFunction overrides.
-  ResponseAction Run() override;
-
- private:
-  void GotThumbnail(const base::Optional<std::vector<uint8_t>>& data);
-
-  void SendEncodedThumbnail(std::string thumbnail_data_url);
-};
-
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_MANAGER_PRIVATE_API_DRIVE_H_

chrome/browser/chromeos/extensions/file_manager/private_api_misc.cc

@@ -19,6 +19,7 @@
 #include "base/files/file_path.h"
 #include "base/i18n/encoding_detection.h"
 #include "base/memory/ref_counted.h"
+#include "base/strings/strcat.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
@@ -73,6 +74,7 @@
 #include "extensions/browser/app_window/app_window.h"
 #include "extensions/browser/app_window/app_window_registry.h"
 #include "google_apis/drive/auth_service.h"
+#include "mojo/public/cpp/bindings/callback_helpers.h"
 #include "services/network/public/cpp/shared_url_loader_factory.h"
 #include "storage/common/file_system/file_system_types.h"
 #include "storage/common/file_system/file_system_util.h"
@@ -195,6 +197,17 @@ bool IsAllowedSource(storage::FileSystemType type,
   }
 }
 
+// Encodes PNG data as a dataURL.
+std::string MakeThumbnailDataUrlOnThreadPool(
+    const std::vector<uint8_t>& png_data) {
+  std::string encoded;
+  base::Base64Encode(
+      base::StringPiece(reinterpret_cast<const char*>(png_data.data()),
+                        png_data.size()),
+      &encoded);
+  return base::StrCat({"data:image/png;base64,", encoded});
+}
+
 }  // namespace
 
 ExtensionFunction::ResponseAction
@@ -1110,4 +1123,105 @@ FileManagerPrivateDetectCharacterEncodingFunction::Run() {
       success ? std::move(encoding) : std::string())));
 }
 
+FileManagerPrivateInternalGetThumbnailFunction::
+    FileManagerPrivateInternalGetThumbnailFunction() {}
+
+FileManagerPrivateInternalGetThumbnailFunction::
+    ~FileManagerPrivateInternalGetThumbnailFunction() = default;
+
+ExtensionFunction::ResponseAction
+FileManagerPrivateInternalGetThumbnailFunction::Run() {
+  using extensions::api::file_manager_private_internal::GetThumbnail::Params;
+  const std::unique_ptr<Params> params(Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params);
+
+  const ChromeExtensionFunctionDetails chrome_details(this);
+  scoped_refptr<storage::FileSystemContext> file_system_context =
+      file_manager::util::GetFileSystemContextForRenderFrameHost(
+          chrome_details.GetProfile(), render_frame_host());
+  const GURL url = GURL(params->url);
+  const storage::FileSystemURL file_system_url =
+      file_system_context->CrackURL(url);
+
+  switch (file_system_url.type()) {
+    case storage::kFileSystemTypeNativeLocal:
+      return GetLocalThumbnail(chrome_details, file_system_url,
+                               params->crop_to_square);
+    case storage::kFileSystemTypeDriveFs:
+      return GetDrivefsThumbnail(chrome_details, file_system_url,
+                                 params->crop_to_square);
+    default:
+      return RespondNow(Error(base::StringPrintf(
+          "Unsupported file system type: %d", file_system_url.type())));
+  }
+}
+
+ExtensionFunction::ResponseAction
+FileManagerPrivateInternalGetThumbnailFunction::GetLocalThumbnail(
+    const ChromeExtensionFunctionDetails& chrome_details,
+    const storage::FileSystemURL& url,
+    bool crop_to_square) {
+  base::FilePath path = file_manager::util::GetLocalPathFromURL(
+      render_frame_host(), chrome_details.GetProfile(), url.ToGURL());
+  if (path.empty() ||
+      base::FilePath::CompareIgnoreCase(path.Extension(), ".pdf") != 0) {
+    return RespondNow(Error("Can only handle PDF files"));
+  }
+  return RespondNow(Error("Not implemented"));
+}
+
+ExtensionFunction::ResponseAction
+FileManagerPrivateInternalGetThumbnailFunction::GetDrivefsThumbnail(
+    const ChromeExtensionFunctionDetails& chrome_details,
+    const storage::FileSystemURL& url,
+    bool crop_to_square) {
+  // If the thumbnail is generated by drivefs give it a bit more time
+  // before issuing warnings about slow operation.
+  SetWarningThresholds(base::TimeDelta::FromSeconds(5),
+                       base::TimeDelta::FromMinutes(1));
+  if (url.type() != storage::kFileSystemTypeDriveFs) {
+    return RespondNow(Error("Invalid URL"));
+  }
+  auto* drive_integration_service =
+      drive::DriveIntegrationServiceFactory::FindForProfile(
+          chrome_details.GetProfile());
+  if (!drive_integration_service) {
+    return RespondNow(Error("Drive service not available"));
+  }
+  base::FilePath path;
+  if (!drive_integration_service->GetRelativeDrivePath(url.path(), &path)) {
+    return RespondNow(Error("File not found"));
+  }
+  auto* drivefs_interface = drive_integration_service->GetDriveFsInterface();
+  if (!drivefs_interface) {
+    return RespondNow(Error("Drivefs not available"));
+  }
+  drivefs_interface->GetThumbnail(
+      path, crop_to_square,
+      mojo::WrapCallbackWithDefaultInvokeIfNotRun(
+          base::BindOnce(
+              &FileManagerPrivateInternalGetThumbnailFunction::GotThumbnail,
+              this),
+          base::Optional<std::vector<uint8_t>>()));
+  return RespondLater();
+}
+
+void FileManagerPrivateInternalGetThumbnailFunction::GotThumbnail(
+    const base::Optional<std::vector<uint8_t>>& data) {
+  if (!data) {
+    Respond(OneArgument(std::make_unique<base::Value>("")));
+    return;
+  }
+  base::ThreadPool::PostTaskAndReplyWithResult(
+      FROM_HERE, base::BindOnce(&MakeThumbnailDataUrlOnThreadPool, *data),
+      base::BindOnce(
+          &FileManagerPrivateInternalGetThumbnailFunction::SendEncodedThumbnail,
+          this));
+}
+
+void FileManagerPrivateInternalGetThumbnailFunction::SendEncodedThumbnail(
+    std::string thumbnail_data_url) {
+  Respond(OneArgument(
+      std::make_unique<base::Value>(std::move(thumbnail_data_url))));
+}
 }  // namespace extensions

chrome/browser/chromeos/extensions/file_manager/private_api_misc.h

@@ -460,6 +460,48 @@ class FileManagerPrivateDetectCharacterEncodingFunction
   ResponseAction Run() override;
 };
 
+class FileManagerPrivateInternalGetThumbnailFunction
+    : public LoggedExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("fileManagerPrivateInternal.getThumbnail",
+                             FILEMANAGERPRIVATEINTERNAL_GETTHUMBNAIL)
+
+  FileManagerPrivateInternalGetThumbnailFunction();
+
+ protected:
+  ~FileManagerPrivateInternalGetThumbnailFunction() override;
+
+  // ExtensionFunction overrides.
+  ResponseAction Run() override;
+
+ private:
+  // Attempts to generate a thumbnail for the given url. This method
+  // checks that the URL references a Google Drive file.
+  ResponseAction GetDrivefsThumbnail(
+      const ChromeExtensionFunctionDetails& chrome_details,
+      const storage::FileSystemURL& url,
+      bool crop_to_square);
+
+  // Attempts to generate a thumbnail for the given url. This method checks
+  // that the URL references a local PDF file. If so, it attempts to generate
+  // a one page thumbnail.
+  ResponseAction GetLocalThumbnail(
+      const ChromeExtensionFunctionDetails& chrome_details,
+      const storage::FileSystemURL& url,
+      bool crop_to_square);
+
+  // A function that performs IO operations to read and render PDF thumbnail
+  // Must be run on the IO Thread.
+  void GetLocalThumbnailOnIOThread(const base::FilePath& path,
+                                   bool crop_to_square);
+
+  // A callback invoked when thumbnail data has been generated.
+  void GotThumbnail(const base::Optional<std::vector<uint8_t>>& data);
+
+  // Responds with a base64 encoded PNG thumbnail data.
+  void SendEncodedThumbnail(std::string thumbnail_data_url);
+};
+
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_MANAGER_PRIVATE_API_MISC_H_

chrome/common/extensions/api/file_manager_private.idl

@@ -1186,7 +1186,7 @@ interface Functions {
   [nocompile]
   static void importCrostiniImage([instanceof=Entry] object entry);
 
-  // For a file in DriveFS, retrieves its thumbnail. If |cropToSquare| is true,
+  // For a given file entry, retrieves its thumbnail. If |cropToSquare| is true,
   // returns a thumbnail appropriate for file list or grid views; otherwise,
   // returns a thumbnail appropriate for quickview.
   [nocompile]