Revert of Rewrite clipboard write IPC handling to be easier to understand.

content/renderer/renderer_clipboard_client.cc

Index: content/renderer/renderer_clipboard_client.cc
diff --git a/content/renderer/renderer_clipboard_client.cc b/content/renderer/renderer_clipboard_client.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1e2953ea9890fab8c203b89a2e3a2f8bfa289b24
--- /dev/null
+++ b/content/renderer/renderer_clipboard_client.cc
@@ -0,0 +1,180 @@
+// Copyright (c) 2012 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.
+
+// This file provides the embedder's side of the Clipboard interface.
+
+#include "content/renderer/renderer_clipboard_client.h"
+
+#include "base/memory/shared_memory.h"
+#include "base/numerics/safe_math.h"
+#include "base/strings/string16.h"
+#include "content/common/clipboard_messages.h"
+#include "content/public/renderer/content_renderer_client.h"
+#include "content/renderer/render_thread_impl.h"
+#include "content/renderer/scoped_clipboard_writer_glue.h"
+#include "ui/base/clipboard/clipboard.h"
+#include "ui/gfx/size.h"
+
+namespace content {
+
+namespace {
+
+class RendererClipboardWriteContext : public ClipboardClient::WriteContext {
+ public:
+  RendererClipboardWriteContext();
+  ~RendererClipboardWriteContext() override;
+  void WriteBitmapFromPixels(ui::Clipboard::ObjectMap* objects,
+                             const void* pixels,
+                             const gfx::Size& size) override;
+  void Flush(const ui::Clipboard::ObjectMap& objects) override;
+
+ private:
+  scoped_ptr<base::SharedMemory> shared_buf_;
+  DISALLOW_COPY_AND_ASSIGN(RendererClipboardWriteContext);
+};
+
+RendererClipboardWriteContext::RendererClipboardWriteContext() {
+}
+
+RendererClipboardWriteContext::~RendererClipboardWriteContext() {
+}
+
+// This definition of WriteBitmapFromPixels uses shared memory to communicate
+// across processes.
+void RendererClipboardWriteContext::WriteBitmapFromPixels(
+    ui::Clipboard::ObjectMap* objects,
+    const void* pixels,
+    const gfx::Size& size) {
+  // Do not try to write a bitmap more than once
+  if (shared_buf_)
+    return;
+
+  base::CheckedNumeric<uint32> checked_buf_size = 4;
+  checked_buf_size *= size.width();
+  checked_buf_size *= size.height();
+  if (!checked_buf_size.IsValid())
+    return;
+
+  uint32 buf_size = checked_buf_size.ValueOrDie();
+
+  // Allocate a shared memory buffer to hold the bitmap bits.
+  shared_buf_.reset(ChildThread::current()->AllocateSharedMemory(buf_size));
+  if (!shared_buf_)
+    return;
+
+  // Copy the bits into shared memory
+  DCHECK(shared_buf_->memory());
+  memcpy(shared_buf_->memory(), pixels, buf_size);
+  shared_buf_->Unmap();
+
+  ui::Clipboard::ObjectMapParam size_param;
+  const char* size_data = reinterpret_cast<const char*>(&size);
+  for (size_t i = 0; i < sizeof(gfx::Size); ++i)
+    size_param.push_back(size_data[i]);
+
+  ui::Clipboard::ObjectMapParams params;
+
+  // The first parameter is replaced on the receiving end with a pointer to
+  // a shared memory object containing the bitmap. We reserve space for it here.
+  ui::Clipboard::ObjectMapParam place_holder_param;
+  params.push_back(place_holder_param);
+  params.push_back(size_param);
+  (*objects)[ui::Clipboard::CBF_SMBITMAP] = params;
+}
+
+// Flushes the objects to the clipboard with an IPC.
+void RendererClipboardWriteContext::Flush(
+    const ui::Clipboard::ObjectMap& objects) {
+  if (shared_buf_) {
+    RenderThreadImpl::current()->Send(
+        new ClipboardHostMsg_WriteObjectsSync(objects, shared_buf_->handle()));
+  } else {
+    RenderThreadImpl::current()->Send(
+        new ClipboardHostMsg_WriteObjectsAsync(objects));
+  }
+}
+
+}  // anonymous namespace
+
+RendererClipboardClient::RendererClipboardClient() {
+}
+
+RendererClipboardClient::~RendererClipboardClient() {
+}
+
+ui::Clipboard* RendererClipboardClient::GetClipboard() {
+  return NULL;
+}
+
+uint64 RendererClipboardClient::GetSequenceNumber(ui::ClipboardType type) {
+  uint64 sequence_number = 0;
+  RenderThreadImpl::current()->Send(
+      new ClipboardHostMsg_GetSequenceNumber(type, &sequence_number));
+  return sequence_number;
+}
+
+bool RendererClipboardClient::IsFormatAvailable(content::ClipboardFormat format,
+                                                ui::ClipboardType type) {
+  bool result = false;
+  RenderThreadImpl::current()->Send(
+      new ClipboardHostMsg_IsFormatAvailable(format, type, &result));
+  return result;
+}
+
+void RendererClipboardClient::Clear(ui::ClipboardType type) {
+  RenderThreadImpl::current()->Send(new ClipboardHostMsg_Clear(type));
+}
+
+void RendererClipboardClient::ReadAvailableTypes(
+    ui::ClipboardType type,
+    std::vector<base::string16>* types,
+    bool* contains_filenames) {
+  RenderThreadImpl::current()->Send(new ClipboardHostMsg_ReadAvailableTypes(
+      type, types, contains_filenames));
+}
+
+void RendererClipboardClient::ReadText(ui::ClipboardType type,
+                                       base::string16* result) {
+  RenderThreadImpl::current()->Send(
+      new ClipboardHostMsg_ReadText(type, result));
+}
+
+void RendererClipboardClient::ReadHTML(ui::ClipboardType type,
+                                       base::string16* markup,
+                                       GURL* url, uint32* fragment_start,
+                                       uint32* fragment_end) {
+  RenderThreadImpl::current()->Send(new ClipboardHostMsg_ReadHTML(
+      type, markup, url, fragment_start, fragment_end));
+}
+
+void RendererClipboardClient::ReadRTF(ui::ClipboardType type,
+                                      std::string* result) {
+  RenderThreadImpl::current()->Send(new ClipboardHostMsg_ReadRTF(type, result));
+}
+
+void RendererClipboardClient::ReadImage(ui::ClipboardType type,
+                                        std::string* data) {
+  base::SharedMemoryHandle image_handle;
+  uint32 image_size = 0;
+  RenderThreadImpl::current()->Send(
+      new ClipboardHostMsg_ReadImage(type, &image_handle, &image_size));
+  if (base::SharedMemory::IsHandleValid(image_handle)) {
+    base::SharedMemory buffer(image_handle, true);
+    buffer.Map(image_size);
+    data->append(static_cast<char*>(buffer.memory()), image_size);
+  }
+}
+
+void RendererClipboardClient::ReadCustomData(ui::ClipboardType clipboard_type,
+                                             const base::string16& type,
+                                             base::string16* data) {
+  RenderThreadImpl::current()->Send(
+      new ClipboardHostMsg_ReadCustomData(clipboard_type, type, data));
+}
+
+ClipboardClient::WriteContext* RendererClipboardClient::CreateWriteContext() {
+  return new RendererClipboardWriteContext;
+}
+
+}  // namespace content