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/printing/common/print.mojom.h"
#include "components/services/print_compositor/public/mojom/print_compositor.mojom.h"
#include "content/public/browser/web_contents_observer.h"
#include "content/public/browser/web_contents_user_data.h"
#include "mojo/public/cpp/bindings/associated_receiver.h"
#include "mojo/public/cpp/bindings/associated_remote.h"
#include "shell/common/gin_helper/promise.h"
#include "v8/include/v8.h"

struct PrintHostMsg_DidPreviewDocument_Params;
struct PrintHostMsg_DidPreviewPage_Params;

namespace content {
class RenderFrameHost;
}

namespace electron {

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

  void PrintToPDF(base::DictionaryValue options,
                  gin_helper::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 printing::mojom::DidPreviewDocumentParams& params,
      const printing::mojom::PreviewIds& ids);
  void OnCompositeDocumentToPdfDone(
      const printing::mojom::PreviewIds& ids,
      printing::mojom::PrintCompositor::Status status,
      base::ReadOnlySharedMemoryRegion region);
  void OnPrepareForDocumentToPdfDone(
      const printing::mojom::PreviewIds& ids,
      printing::mojom::PrintCompositor::Status status);
  void OnDidPrepareForDocumentToPdf(content::RenderFrameHost* render_frame_host,
                                    int document_cookie,
                                    const printing::mojom::PreviewIds& ids);
  void OnCompositePdfPageDone(int page_number,
                              int document_cookie,
                              const printing::mojom::PreviewIds& ids,
                              printing::mojom::PrintCompositor::Status status,
                              base::ReadOnlySharedMemoryRegion region);
  void OnDidPreviewPage(content::RenderFrameHost* render_frame_host,
                        const printing::mojom::DidPreviewPageParams& params,
                        const printing::mojom::PreviewIds& ids);

  // printing::mojo::PrintPreviewUI:
  void SetOptionsFromDocument(
      const printing::mojom::OptionsFromDocumentParamsPtr params,
      int32_t request_id) override {}
  void PrintPreviewFailed(int32_t document_cookie, int32_t request_id) override;
  void PrintPreviewCancelled(int32_t document_cookie,
                             int32_t request_id) override;
  void PrinterSettingsInvalid(int32_t document_cookie,
                              int32_t request_id) override {}

  gin_helper::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, gin_helper::Promise<v8::Local<v8::Value>>>;
  PromiseMap promise_map_;

  mojo::AssociatedRemote<printing::mojom::PrintRenderFrame> print_render_frame_;

  mojo::AssociatedReceiver<printing::mojom::PrintPreviewUI> receiver_{this};

  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_