electron/shell/browser/printing/print_preview_message_handler.h

// Copyright (c) 2018 GitHub, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.

#ifndef SHELL_BROWSER_PRINTING_PRINT_PREVIEW_MESSAGE_HANDLER_H_
#define SHELL_BROWSER_PRINTING_PRINT_PREVIEW_MESSAGE_HANDLER_H_

#include <map>

#include "base/memory/ref_counted_memory.h"
#include "base/memory/weak_ptr.h"
#include "components/services/pdf_compositor/public/mojom/pdf_compositor.mojom.h"
#include "content/public/browser/web_contents_observer.h"
#include "content/public/browser/web_contents_user_data.h"
#include "shell/common/promise_util.h"
#include "v8/include/v8.h"

struct PrintHostMsg_DidPreviewDocument_Params;
struct PrintHostMsg_PreviewIds;

namespace content {
class RenderFrameHost;
}

namespace electron {

// Manages the print preview handling for a WebContents.
class PrintPreviewMessageHandler
    : public content::WebContentsObserver,
      public content::WebContentsUserData<PrintPreviewMessageHandler> {
 public:
  ~PrintPreviewMessageHandler() override;

  void PrintToPDF(base::DictionaryValue options,
                  util::Promise<v8::Local<v8::Value>> promise);

 protected:
  // content::WebContentsObserver implementation.
  bool OnMessageReceived(const IPC::Message& message,
                         content::RenderFrameHost* render_frame_host) override;

 private:
  friend class content::WebContentsUserData<PrintPreviewMessageHandler>;

  explicit PrintPreviewMessageHandler(content::WebContents* web_contents);

  void OnMetafileReadyForPrinting(
      content::RenderFrameHost* render_frame_host,
      const PrintHostMsg_DidPreviewDocument_Params& params,
      const PrintHostMsg_PreviewIds& ids);
  void OnCompositePdfDocumentDone(const PrintHostMsg_PreviewIds& ids,
                                  printing::mojom::PdfCompositor::Status status,
                                  base::ReadOnlySharedMemoryRegion region);
  void OnPrintPreviewFailed(int document_cookie,
                            const PrintHostMsg_PreviewIds& ids);
  void OnPrintPreviewCancelled(int document_cookie,
                               const PrintHostMsg_PreviewIds& ids);

  util::Promise<v8::Local<v8::Value>> GetPromise(int request_id);

  void ResolvePromise(int request_id,
                      scoped_refptr<base::RefCountedMemory> data_bytes);
  void RejectPromise(int request_id);

  using PromiseMap =
      std::map<int, electron::util::Promise<v8::Local<v8::Value>>>;
  PromiseMap promise_map_;

  base::WeakPtrFactory<PrintPreviewMessageHandler> weak_ptr_factory_;

  WEB_CONTENTS_USER_DATA_KEY_DECL();

  DISALLOW_COPY_AND_ASSIGN(PrintPreviewMessageHandler);
};

}  // namespace electron

#endif  // SHELL_BROWSER_PRINTING_PRINT_PREVIEW_MESSAGE_HANDLER_H_