Add SetImageData api to chrome.clipboard.

chrome/browser/extensions/clipboard_extension_helper.cc

+// Copyright 2016 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/extensions/clipboard_extension_helper.h"
+
+#include "base/macros.h"
+#include "base/metrics/histogram_macros.h"
+#include "base/synchronization/cancellation_flag.h"
+#include "chrome/browser/image_decoder.h"
+#include "extensions/browser/api/clipboard/clipboard_api.h"
+#include "ui/base/clipboard/scoped_clipboard_writer.h"
+
+using content::BrowserThread;
+
+namespace extensions {
+
+class ClipboardExtensionHelper::ClipboardImageDataDecoder
+    : public ImageDecoder::ImageRequest {
+ public:
+  explicit ClipboardImageDataDecoder(ClipboardExtensionHelper* owner)
+      : owner_(owner) {}
+
+  void Start(const std::vector<char>& image_data, clipboard::ImageType type) {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+    std::string image_data_str(image_data.begin(), image_data.end());
+
+    ImageDecoder::ImageCodec codec = ImageDecoder::DEFAULT_CODEC;
+#if defined(OS_CHROMEOS)
+    if (type == clipboard::IMAGE_TYPE_PNG) {
+      codec = ImageDecoder::ROBUST_PNG_CODEC;
+    } else if (type == clipboard::IMAGE_TYPE_JPEG) {
+      codec = ImageDecoder::ROBUST_JPEG_CODEC;
+    } else {
+      OnDecodeImageFailed();
+      return;
+    }
+#endif
+
+    ImageDecoder::StartWithOptions(this, image_data_str, codec, true);
+  }
+
+  void Cancel() {
+    cancel_flag_.Set();
+    owner_->OnImageDecodeCancel();
+  }
+
+  void OnImageDecoded(const SkBitmap& decoded_image) override {
+    if (!cancel_flag_.IsSet())
+      owner_->OnImageDecoded(decoded_image);
+    delete this;
+  }
+
+  void OnDecodeImageFailed() override {
+    if (!cancel_flag_.IsSet())
+      owner_->OnImageDecodeFailure();
+    delete this;
+  }
+
+ private:

[Devlin, 2016/11/16 02:34:33]

private dtor?

[jennyz, 2016/12/07 01:21:47]

Done.

+  ClipboardExtensionHelper* owner_;
+  base::CancellationFlag cancel_flag_;
+
+  DISALLOW_COPY_AND_ASSIGN(ClipboardImageDataDecoder);
+};
+
+ClipboardExtensionHelper::ClipboardImageDataDecoder*
+    ClipboardExtensionHelper::clipboard_image_data_decoder_;
+
+ClipboardExtensionHelper::ClipboardExtensionHelper()
+    : image_save_success_callback_(nullptr),

[Devlin, 2016/11/16 02:34:33]

are these initializations needed?

[jennyz, 2016/12/07 01:21:47]

removed.

+      image_save_error_callback_(nullptr),
+      clipboard_writer_(
+          new ui::ScopedClipboardWriter(ui::CLIPBOARD_TYPE_COPY_PASTE)) {}
+
+ClipboardExtensionHelper::~ClipboardExtensionHelper() {}

[Devlin, 2016/11/16 02:34:33]

What if the clipboard_image_data_decoder_ outlives the ClipboardExtensionHelper?

[jennyz, 2016/12/07 01:21:47]

Good catch. Make ClipboardExtensionHelper a WeakPtr and pass to
clipboard_image_data_decoder_, check if it is still valid before calling its
function.

+
+void ClipboardExtensionHelper::DecodeAndSaveImageData(
+    const std::vector<char>& data,
+    clipboard::ImageType type,
+    const base::Closure& success_callback,
+    const base::Closure& error_callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  // If there is a previous image decoding request still running, cancel it
+  // first. We only need the most recent image save request be completed.
+  if (clipboard_image_data_decoder_)
+    clipboard_image_data_decoder_->Cancel();
+
+  clipboard_image_data_decoder_ = new ClipboardImageDataDecoder(this);

[Devlin, 2016/11/16 02:34:33]

Add a note that this manages its own lifetime.

[dcheng, 2016/11/17 01:13:32]

Maybe it'd be better to just have the lifetime managed here? We have to null out
the pointer anyway, so it seems like we can just make it a std::unique_ptr here.

[jennyz, 2016/12/07 01:21:47]

Done.

[jennyz, 2016/12/07 01:21:47]

Changed to pass WeakPtr into clipboard_image_data_decoder_ to take care of the
case clipboard_image_data_decoder_ outlives ClipboardExtensionHelper object.

[jennyz, 2016/12/14 01:15:35]

Yes, changed to make it td::unique_ptr. Thanks for advice.

+  image_save_success_callback_ = success_callback;
+  image_save_error_callback_ = error_callback;
+  clipboard_image_data_decoder_->Start(data, type);
+}
+
+void ClipboardExtensionHelper::OnImageDecodeFailure() {
+  clipboard_image_data_decoder_ = NULL;

[Devlin, 2016/11/16 02:34:33]

nullptr in new code

[jennyz, 2016/12/07 01:21:47]

Done.

+  image_save_error_callback_.Run();
+}
+
+void ClipboardExtensionHelper::OnImageDecoded(const SkBitmap& bitmap) {
+  clipboard_image_data_decoder_ = NULL;
+
+  // Write the decoded image data to clipboard.
+  if (!bitmap.empty() && !bitmap.isNull())
+    clipboard_writer_->WriteImage(bitmap);
+  clipboard_writer_.reset(
+      new ui::ScopedClipboardWriter(ui::CLIPBOARD_TYPE_COPY_PASTE));
+
+  image_save_success_callback_.Run();
+}
+
+void ClipboardExtensionHelper::OnImageDecodeCancel() {
+  image_save_error_callback_.Run();
+}
+
+}  // namespace extensions