Initial stub version of Async Clipboard API

third_party/WebKit/Source/core/clipboard/ClipboardPromise.cpp

+// Copyright 2017 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 "core/clipboard/ClipboardPromise.h"
+
+#include "bindings/core/v8/ScriptPromiseResolver.h"
+#include "core/clipboard/DataObject.h"
+#include "core/clipboard/DataTransfer.h"
+#include "core/clipboard/DataTransferItem.h"
+#include "core/clipboard/DataTransferItemList.h"
+#include "core/dom/TaskRunnerHelper.h"
+#include "platform/CrossThreadFunctional.h"
+#include "platform/clipboard/ClipboardMimeTypes.h"
+#include "public/platform/Platform.h"
+
+namespace blink {
+
+ScriptPromise ClipboardPromise::CreateForRead(ScriptState* script_state) {
+  ClipboardPromise* clipboard_promise = new ClipboardPromise(script_state);
+  clipboard_promise->GetTaskRunner()->PostTask(
+      BLINK_FROM_HERE, WTF::Bind(&ClipboardPromise::HandleRead,
+                                 WrapPersistent(clipboard_promise)));
+  return clipboard_promise->script_promise_resolver_->Promise();
+}
+
+ScriptPromise ClipboardPromise::CreateForReadText(ScriptState* script_state) {
+  ClipboardPromise* clipboard_promise = new ClipboardPromise(script_state);
+  clipboard_promise->GetTaskRunner()->PostTask(
+      BLINK_FROM_HERE, WTF::Bind(&ClipboardPromise::HandleReadText,
+                                 WrapPersistent(clipboard_promise)));
+  return clipboard_promise->script_promise_resolver_->Promise();
+}
+
+ScriptPromise ClipboardPromise::CreateForWrite(ScriptState* script_state,
+                                               DataTransfer* data) {
+  ClipboardPromise* clipboard_promise = new ClipboardPromise(script_state);
+  clipboard_promise->GetTaskRunner()->PostTask(
+      BLINK_FROM_HERE,
+      WTF::Bind(&ClipboardPromise::HandleWrite,
+                WrapPersistent(clipboard_promise), WrapPersistent(data)));
+  return clipboard_promise->script_promise_resolver_->Promise();
+}
+
+ScriptPromise ClipboardPromise::CreateForWriteText(ScriptState* script_state,
+                                                   const String& data) {
+  ClipboardPromise* clipboard_promise = new ClipboardPromise(script_state);
+  clipboard_promise->GetTaskRunner()->PostTask(
+      BLINK_FROM_HERE, WTF::Bind(&ClipboardPromise::HandleWriteText,
+                                 WrapPersistent(clipboard_promise), data));
+  return clipboard_promise->script_promise_resolver_->Promise();
+}
+
+ClipboardPromise::ClipboardPromise(ScriptState* script_state)
+    : ContextLifecycleObserver(blink::ExecutionContext::From(script_state)),
+      script_promise_resolver_(ScriptPromiseResolver::Create(script_state)),
+      buffer_(WebClipboard::kBufferStandard) {}
+
+WebTaskRunner* ClipboardPromise::GetTaskRunner() {
+  // TODO(garykac): Replace MiscPlatformAPI with TaskType specific to clipboard.
+  return TaskRunnerHelper::Get(TaskType::kMiscPlatformAPI,
+                               GetExecutionContext())
+      .Get();
+}
+
+// TODO(garykac): This currently only handles plain text.
+void ClipboardPromise::HandleRead() {
+  DCHECK(script_promise_resolver_);
+  String plainText = Platform::Current()->Clipboard()->ReadPlainText(buffer_);

[dcheng, 2017/06/14 18:56:22]

Nit: plain_text

[garykac, 2017/06/29 01:37:26]

Done.

+
+  DataTransfer::DataTransferType type =
+      DataTransfer::DataTransferType::kCopyAndPaste;
+  DataTransferAccessPolicy access =

[dcheng, 2017/06/14 18:56:22]

Nit: the compiler should be able to optimize this, but considering hinting it by
marking these as const here.

[garykac, 2017/06/29 01:37:26]

Done.

+      DataTransferAccessPolicy::kDataTransferReadable;
+  DataObject* data = DataObject::CreateFromString(plainText);
+  DataTransfer* dt = DataTransfer::Create(type, access, data);
+  script_promise_resolver_->Resolve(dt);
+}
+
+void ClipboardPromise::HandleReadText() {
+  DCHECK(script_promise_resolver_);
+  String text = Platform::Current()->Clipboard()->ReadPlainText(buffer_);
+  script_promise_resolver_->Resolve(text);
+}
+
+// TODO(garykac): This currently only handles plain text.
+void ClipboardPromise::HandleWrite(DataTransfer* data) {
+  DCHECK(script_promise_resolver_);
+  size_t num_items = data->items()->length();
+  for (unsigned long i = 0; i < num_items; i++) {
+    DataTransferItem* item = data->items()->item(i);
+    DataObjectItem* objectItem = item->GetDataObjectItem();
+    if (objectItem->Kind() == DataObjectItem::kStringKind &&
+        objectItem->GetType() == kMimeTypeTextPlain) {
+      String text = objectItem->GetAsString();
+      Platform::Current()->Clipboard()->WritePlainText(text);
+      script_promise_resolver_->Resolve();
+      return;
+    }
+  }
+  script_promise_resolver_->Reject();
+}
+
+void ClipboardPromise::HandleWriteText(const String& data) {
+  DCHECK(script_promise_resolver_);
+  Platform::Current()->Clipboard()->WritePlainText(data);
+  script_promise_resolver_->Resolve();
+}
+
+DEFINE_TRACE(ClipboardPromise) {
+  visitor->Trace(script_promise_resolver_);
+  ContextLifecycleObserver::Trace(visitor);
+}
+
+}  // namespace blink