[Experimental] Supporting OOPIF printing

services/pdf_compositor/public/cpp/pdf_compositor_client.cc

+// 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 "services/pdf_compositor/public/cpp/pdf_compositor_client.h"
+
+#include <vector>
+
+#include "content/public/common/service_manager_connection.h"
+#include "mojo/public/cpp/system/platform_handle.h"
+#include "services/pdf_compositor/public/interfaces/constants.mojom.h"
+
+namespace pdf_compositor {
+
+namespace {
+
+// Helper callback which owns an PdfCompositorPtr until invoked. This keeps the
+// PdfCompositor pipe open just long enough to dispatch a reply, at which point
+// the reply is forwarded to the wrapped |callback|.
+void OnCompositePdf(
+    mojom::PdfCompositorPtr compositor,
+    const pdf_compositor::mojom::PdfCompositor::CompositePdfCallback& callback,
+    scoped_refptr<base::SequencedTaskRunner> task_runner,
+    mojo::ScopedSharedBufferHandle pdf_handle) {
+  task_runner->PostTask(FROM_HERE,
+                        base::Bind(callback, base::Passed(&pdf_handle)));
+}
+
+void OnIsReadyToComposite(
+    mojom::PdfCompositorPtr compositor,
+    const pdf_compositor::mojom::PdfCompositor::IsReadyToCompositeCallback&
+        callback,
+    scoped_refptr<base::SequencedTaskRunner> task_runner,
+    bool status) {
+  task_runner->PostTask(FROM_HERE, base::Bind(callback, base::Passed(&status)));
+}
+
+}  // namespace
+
+void PdfCompositorClient::DisconnectFromPdfCompositor() {
+  compositor_.reset();
+}
+
+void PdfCompositorClient::ConnectionWithPdfCompositor() {
+  DCHECK(!compositor_.is_bound());
+  if (compositor_.is_bound())
+    return;
+
+  service_manager::mojom::ConnectorRequest connector_request;
+  std::unique_ptr<service_manager::Connector> connector =
+      service_manager::Connector::Create(&connector_request);
+  content::ServiceManagerConnection::GetForProcess()
+      ->GetConnector()
+      ->BindConnectorRequest(std::move(connector_request));
+  connector->BindInterface(mojom::kServiceName, &compositor_);
+}
+
+void PdfCompositorClient::Composite(
+    base::SharedMemoryHandle handle,
+    uint32_t data_size,
+    const pdf_compositor::mojom::PdfCompositor::CompositePdfCallback& callback,
+    scoped_refptr<base::SequencedTaskRunner> callback_task_runner) {
+  if (!compositor_.get()) {
+    ConnectionWithPdfCompositor();
+  }
+
+  mojo::ScopedSharedBufferHandle buffer_handle =
+      mojo::WrapSharedMemoryHandle(handle, data_size, true);
+
+  compositor_.get()->CompositePdf(
+      std::move(buffer_handle),
+      base::Bind(&OnCompositePdf, base::Passed(&compositor_), callback,
+                 callback_task_runner));
+}
+
+void PdfCompositorClient::PrepareSubframe(int id, int page_num) {
+  if (!compositor_.get()) {
+    ConnectionWithPdfCompositor();
+  }
+
+  compositor_.get()->PrepareSubframe(id, page_num);
+}
+
+void PdfCompositorClient::IsReadyToComposite(
+    int page_num,
+    const pdf_compositor::mojom::PdfCompositor::IsReadyToCompositeCallback&
+        callback,
+    scoped_refptr<base::SequencedTaskRunner> callback_task_runner) {
+  if (!compositor_.get()) {
+    ConnectionWithPdfCompositor();
+  }
+
+  compositor_.get()->IsReadyToComposite(
+      page_num, base::Bind(&OnIsReadyToComposite, base::Passed(&compositor_),
+                           callback, callback_task_runner));
+}
+
+void PdfCompositorClient::AddSubFrameContent(int id,
+                                             base::SharedMemoryHandle handle,
+                                             uint32_t data_size) {
+  if (!compositor_.get()) {
+    ConnectionWithPdfCompositor();
+  }
+
+  mojo::ScopedSharedBufferHandle buffer_handle =
+      mojo::WrapSharedMemoryHandle(handle, data_size, true);
+  compositor_.get()->AddSubFrameContent(id, std::move(buffer_handle));
+}
+
+}  // namespace pdf_compositor