text: // 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.
  
  #ifndef CHROME_RENDERER_PRINTING_PRINT_WEB_VIEW_HELPER_H_
  #define CHROME_RENDERER_PRINTING_PRINT_WEB_VIEW_HELPER_H_
  
  #include <memory>
  #include <vector>
  
  #include "base/callback.h"
  #include "base/gtest_prod_util.h"
  #include "base/memory/shared_memory.h"
  #include "base/memory/weak_ptr.h"
  #include "base/time/time.h"
  #include "content/public/renderer/render_view_observer.h"
  #include "content/public/renderer/render_view_observer_tracker.h"
  #include "printing/pdf_metafile_skia.h"
  #include "third_party/WebKit/public/platform/WebCanvas.h"
  #include "third_party/WebKit/public/web/WebNode.h"
  #include "third_party/WebKit/public/web/WebPrintParams.h"
  #include "ui/gfx/geometry/size.h"
  
  struct PrintMsg_Print_Params;
  struct PrintMsg_PrintPage_Params;
  struct PrintMsg_PrintPages_Params;
  struct PrintHostMsg_SetOptionsFromDocument_Params;
  
  namespace base {
  class DictionaryValue;
  }
  
  namespace blink {
  class WebFrame;
  class WebView;
  }
  
  namespace printing {
  
  struct PageSizeMargins;
  class PrepareFrameAndViewForPrint;
  
  // Stores reference to frame using WebVew and unique name.
  // Workaround to modal dialog issue on Linux. crbug.com/236147.
  // If WebFrame someday supports WeakPtr, we should use it here.
  class FrameReference {
   public:
    explicit FrameReference(blink::WebLocalFrame* frame);
    FrameReference();
    ~FrameReference();
  
    void Reset(blink::WebLocalFrame* frame);
  
    blink::WebLocalFrame* GetFrame();
    blink::WebView* view();
  
   private:
    blink::WebView* view_;
    blink::WebLocalFrame* frame_;
  };
  
  // PrintWebViewHelper handles most of the printing grunt work for RenderView.
  // We plan on making print asynchronous and that will require copying the DOM
  // of the document and creating a new WebView with the contents.
  class PrintWebViewHelper
      : public content::RenderViewObserver,
        public content::RenderViewObserverTracker<PrintWebViewHelper> {
   public:
    explicit PrintWebViewHelper(content::RenderView* render_view);
    virtual ~PrintWebViewHelper();
  
    void PrintNode(const blink::WebNode& node);
  
   private:
    enum PrintingResult {
      OK,
      FAIL_PRINT_INIT,
      FAIL_PRINT,
      FAIL_PREVIEW,
    };
  
    enum PrintPreviewErrorBuckets {
      PREVIEW_ERROR_NONE,  // Always first.
      PREVIEW_ERROR_BAD_SETTING,
      PREVIEW_ERROR_METAFILE_COPY_FAILED,
      PREVIEW_ERROR_METAFILE_INIT_FAILED_DEPRECATED,
      PREVIEW_ERROR_ZERO_PAGES,
      PREVIEW_ERROR_MAC_DRAFT_METAFILE_INIT_FAILED_DEPRECATED,
      PREVIEW_ERROR_PAGE_RENDERED_WITHOUT_METAFILE,
      PREVIEW_ERROR_INVALID_PRINTER_SETTINGS,
      PREVIEW_ERROR_LAST_ENUM  // Always last.
    };
  
    // RenderViewObserver implementation.
    bool OnMessageReceived(const IPC::Message& message) override;
    void PrintPage(blink::WebLocalFrame* frame, bool user_initiated) override;
    void OnDestruct() override;
  
    // Message handlers ---------------------------------------------------------
  #if !defined(DISABLE_BASIC_PRINTING)
    void OnPrintPages(bool silent, bool print_background);
    void OnPrintingDone(bool success);
  #endif  // !DISABLE_BASIC_PRINTING
    void OnPrintPreview(const base::DictionaryValue& settings);
  
  
    // Get |page_size| and |content_area| information from
    // |page_layout_in_points|.
    void GetPageSizeAndContentAreaFromPageLayout(
        const PageSizeMargins& page_layout_in_points,
        gfx::Size* page_size,
        gfx::Rect* content_area);
  
    // Update |ignore_css_margins_| based on settings.
    void UpdateFrameMarginsCssInfo(const base::DictionaryValue& settings);
  
    // Prepare frame for creating preview document.
    void PrepareFrameForPreviewDocument();
  
    // Continue creating preview document.
    void OnFramePreparedForPreviewDocument();
  
    // Finalize the print ready preview document.
    bool FinalizePrintReadyDocument();
  
    // Renders a print preview page. |page_number| is 0-based.
    // Returns true if print preview should continue, false on failure.
    bool RenderPreviewPage(int page_number,
                           const PrintMsg_Print_Params& print_params);
  
  
    // Initialize the print preview document.
    bool CreatePreviewDocument();
  
    // Main printing code -------------------------------------------------------
  
    void Print(blink::WebLocalFrame* frame,
               const blink::WebNode& node,
               bool silent = false,
               bool print_background = false);
  
    // Notification when printing is done - signal tear-down/free resources.
    void DidFinishPrinting(PrintingResult result);
  
    // Print Settings -----------------------------------------------------------
  
    // Initialize print page settings with default settings.
    // Used only for native printing workflow.
    bool InitPrintSettings(bool fit_to_paper_size);
  
    // Calculate number of pages in source document.
    bool CalculateNumberOfPages(blink::WebLocalFrame* frame,
                                const blink::WebNode& node,
                                int* number_of_pages);
  
    // Update the current print settings with new |passed_job_settings|.
    // |passed_job_settings| dictionary contains print job details such as printer
    // name, number of copies, page range, etc.
    bool UpdatePrintSettings(blink::WebLocalFrame* frame,
                             const blink::WebNode& node,
                             const base::DictionaryValue& passed_job_settings);
  
  
    // Get final print settings from the user.
    // Return false if the user cancels or on error.
    bool GetPrintSettingsFromUser(blink::WebFrame* frame,
                                  const blink::WebNode& node,
                                  int expected_pages_count);
  
    // Page Printing / Rendering ------------------------------------------------
  
    void OnFramePreparedForPrintPages();
    void PrintPages();
    bool PrintPagesNative(blink::WebFrame* frame, int page_count);
    void FinishFramePrinting();
  
    // Prints the page listed in |params|.
  #if defined(OS_LINUX) || defined(OS_ANDROID)
    void PrintPageInternal(const PrintMsg_PrintPage_Params& params,
                           blink::WebFrame* frame,
                           PdfMetafileSkia* metafile);
  #elif defined(OS_WIN)
    void PrintPageInternal(const PrintMsg_PrintPage_Params& params,
                           blink::WebFrame* frame,
                           PdfMetafileSkia* metafile,
                           gfx::Size* page_size_in_dpi,
                           gfx::Rect* content_area_in_dpi);
  #else
    void PrintPageInternal(const PrintMsg_PrintPage_Params& params,
                           blink::WebFrame* frame);
  #endif
  
    // Render the frame for printing.
    bool RenderPagesForPrint(blink::WebLocalFrame* frame,
                             const blink::WebNode& node);
  
    // Platform specific helper function for rendering page(s) to |metafile|.
  #if defined(OS_MACOSX)
    void RenderPage(const PrintMsg_Print_Params& params,
                    int page_number,
                    blink::WebFrame* frame,
                    bool is_preview,
                    PdfMetafileSkia* metafile,
                    gfx::Size* page_size,
                    gfx::Rect* content_rect);
  #endif  // defined(OS_MACOSX)
  
    // Renders page contents from |frame| to |content_area| of |canvas|.
    // |page_number| is zero-based.
    // When method is called, canvas should be setup to draw to |canvas_area|
    // with |scale_factor|.
    static float RenderPageContent(blink::WebFrame* frame,
                                   int page_number,
                                   const gfx::Rect& canvas_area,
                                   const gfx::Rect& content_area,
                                   double scale_factor,
                                   blink::WebCanvas* canvas);
  
    // Helper methods -----------------------------------------------------------
  
    bool CopyMetafileDataToSharedMem(const PdfMetafileSkia& metafile,
                                     base::SharedMemoryHandle* shared_mem_handle);
  
    // Helper method to get page layout in points and fit to page if needed.
    static void ComputePageLayoutInPointsForCss(
        blink::WebFrame* frame,
        int page_index,
        const PrintMsg_Print_Params& default_params,
        bool ignore_css_margins,
        double* scale_factor,
        PageSizeMargins* page_layout_in_points);
  
    bool GetPrintFrame(blink::WebLocalFrame** frame);
  
    // Script Initiated Printing ------------------------------------------------
  
    // Notifies the browser a print preview page has been rendered.
    // |page_number| is 0-based.
    // For a valid |page_number| with modifiable content,
    // |metafile| is the rendered page. Otherwise |metafile| is NULL.
    // Returns true if print preview should continue, false on failure.
    bool PreviewPageRendered(int page_number, PdfMetafileSkia* metafile);
  
    void SetPrintPagesParams(const PrintMsg_PrintPages_Params& settings);
  
    // WebView used only to print the selection.
    std::unique_ptr<PrepareFrameAndViewForPrint> prep_frame_view_;
    bool reset_prep_frame_view_;
  
    std::unique_ptr<PrintMsg_PrintPages_Params> print_pages_params_;
    bool is_print_ready_metafile_sent_;
    bool ignore_css_margins_;
  
    // Used for scripted initiated printing blocking.
    bool is_scripted_printing_blocked_;
  
    // Let the browser process know of a printing failure. Only set to false when
    // the failure came from the browser in the first place.
    bool notify_browser_of_print_failure_;
  
    // True, when printing from print preview.
    bool print_for_preview_;
  
    // Keeps track of the state of print preview between messages.
    // TODO(vitalybuka): Create PrintPreviewContext when needed and delete after
    // use. Now it's interaction with various messages is confusing.
    class PrintPreviewContext {
     public:
      PrintPreviewContext();
      ~PrintPreviewContext();
  
      // Initializes the print preview context. Need to be called to set
      // the |web_frame| / |web_node| to generate the print preview for.
      void InitWithFrame(blink::WebLocalFrame* web_frame);
      void InitWithNode(const blink::WebNode& web_node);
  
      // Does bookkeeping at the beginning of print preview.
      void OnPrintPreview();
  
      // Create the print preview document. |pages| is empty to print all pages.
      // Takes ownership of |prepared_frame|.
      bool CreatePreviewDocument(PrepareFrameAndViewForPrint* prepared_frame,
                                 const std::vector<int>& pages);
  
      // Called after a page gets rendered. |page_time| is how long the
      // rendering took.
      void RenderedPreviewPage(const base::TimeDelta& page_time);
  
      // Updates the print preview context when the required pages are rendered.
      void AllPagesRendered();
  
      // Finalizes the print ready preview document.
      void FinalizePrintReadyDocument();
  
      // Cleanup after print preview finishes.
      void Finished();
  
      // Cleanup after print preview fails.
      void Failed(bool report_error);
  
      // Helper functions
      int GetNextPageNumber();
      bool IsRendering() const;
      bool IsModifiable();
      bool HasSelection();
      bool IsLastPageOfPrintReadyMetafile() const;
      bool IsFinalPageRendered() const;
  
      // Setters
      void set_generate_draft_pages(bool generate_draft_pages);
      void set_error(enum PrintPreviewErrorBuckets error);
  
      // Getters
      // Original frame for which preview was requested.
      blink::WebLocalFrame* source_frame();
      // Original node for which preview was requested.
      const blink::WebNode& source_node() const;
  
      // Frame to be use to render preview. May be the same as source_frame(), or
      // generated from it, e.g. copy of selected block.
      blink::WebLocalFrame* prepared_frame();
      // Node to be use to render preview. May be the same as source_node(), or
      // generated from it, e.g. copy of selected block.
      const blink::WebNode& prepared_node() const;
  
      int total_page_count() const;
      bool generate_draft_pages() const;
      PdfMetafileSkia* metafile();
      int last_error() const;
  
     private:
      enum State {
        UNINITIALIZED,  // Not ready to render.
        INITIALIZED,    // Ready to render.
        RENDERING,      // Rendering.
        DONE            // Finished rendering.
      };
  
      // Reset some of the internal rendering context.
      void ClearContext();
  
      // Specifies what to render for print preview.
      FrameReference source_frame_;
      blink::WebNode source_node_;
  
      std::unique_ptr<PrepareFrameAndViewForPrint> prep_frame_view_;
      std::unique_ptr<PdfMetafileSkia> metafile_;
  
      // Total page count in the renderer.
      int total_page_count_;
  
      // The current page to render.
      int current_page_index_;
  
      // List of page indices that need to be rendered.
      std::vector<int> pages_to_render_;
  
      // True, when draft pages needs to be generated.
      bool generate_draft_pages_;
  
      // Specifies the total number of pages in the print ready metafile.
      int print_ready_metafile_page_count_;
  
      base::TimeDelta document_render_time_;
      base::TimeTicks begin_time_;
  
      enum PrintPreviewErrorBuckets error_;
  
      State state_;
    };
  
  
    bool print_node_in_progress_;
    bool is_loading_;
    bool is_scripted_preview_delayed_;
  
    PrintPreviewContext print_preview_context_;
  
    // Used to fix a race condition where the source is a PDF and print preview
    // hangs because RequestPrintPreview is called before DidStopLoading() is
    // called. This is a store for the RequestPrintPreview() call and its
    // parameters so that it can be invoked after DidStopLoading.
    base::Closure on_stop_loading_closure_;
  
    base::WeakPtrFactory<PrintWebViewHelper> weak_ptr_factory_;
  
    DISALLOW_COPY_AND_ASSIGN(PrintWebViewHelper);
  };
  
  }  // namespace printing
  
  #endif  // CHROME_RENDERER_PRINTING_PRINT_WEB_VIEW_HELPER_H_
  