Rewrite clipboard write IPC handling to be easier to understand.

content/renderer/clipboard_client.h

-// Copyright (c) 2013 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.
-
-#ifndef CONTENT_RENDERER_CLIPBOARD_CLIENT_H_
-#define CONTENT_RENDERER_CLIPBOARD_CLIENT_H_
-
-#include "content/common/clipboard_format.h"
-#include "ui/base/clipboard/clipboard.h"
-
-class GURL;
-
-namespace content {
-
-// Interface for the content embedder to implement to support clipboard.
-class ClipboardClient {
- public:
-  class WriteContext {
-   public:
-    virtual ~WriteContext() { }
-
-    // Writes bitmap data into the context, updating the ObjectMap.
-    virtual void WriteBitmapFromPixels(ui::Clipboard::ObjectMap* objects,
-                                       const void* pixels,
-                                       const gfx::Size& size) = 0;
-
-    // Flushes all gathered data.
-    virtual void Flush(const ui::Clipboard::ObjectMap& objects) = 0;
-  };
-
-  virtual ~ClipboardClient() { }
-
-  // Get a clipboard that can be used to construct a ScopedClipboardWriterGlue.
-  virtual ui::Clipboard* GetClipboard() = 0;
-
-  // Get a sequence number which uniquely identifies clipboard state.
-  virtual uint64 GetSequenceNumber(ui::ClipboardType type) = 0;
-
-  // Tests whether the clipboard contains a certain format
-  virtual bool IsFormatAvailable(ClipboardFormat format,
-                                 ui::ClipboardType type) = 0;
-
-  // Clear the contents of the clipboard.
-  virtual void Clear(ui::ClipboardType type) = 0;
-
-  // Reads the available types from the clipboard, if available.
-  virtual void ReadAvailableTypes(ui::ClipboardType type,
-                                  std::vector<base::string16>* types,
-                                  bool* contains_filenames) = 0;
-
-  // Reads text from the clipboard, trying UNICODE first, then falling back to
-  // ASCII.
-  virtual void ReadText(ui::ClipboardType type,
-                        base::string16* result) = 0;
-
-  // Reads HTML from the clipboard, if available.
-  virtual void ReadHTML(ui::ClipboardType type,
-                        base::string16* markup,
-                        GURL* url,
-                        uint32* fragment_start,
-                        uint32* fragment_end) = 0;
-
-  // Reads RTF from the clipboard, if available.
-  virtual void ReadRTF(ui::ClipboardType type, std::string* result) = 0;
-
-  // Reads and image from the clipboard, if available.
-  virtual void ReadImage(ui::ClipboardType type, std::string* data) = 0;
-
-  // Reads a custom data type from the clipboard, if available.
-  virtual void ReadCustomData(ui::ClipboardType clipboard_type,
-                              const base::string16& type,
-                              base::string16* data) = 0;
-
-  // Creates a context to write clipboard data. May return NULL.
-  virtual WriteContext* CreateWriteContext() = 0;
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_CLIPBOARD_CLIENT_H_
-