author Emilio Cobos Álvarez <>
Fri, 12 Feb 2021 15:42:38 +0000
changeset 567288 69206f2dea0052195e131a32d7601acd40c98f68
parent 559757 8c8bbda7c6fa9270765c306512aed129c470b6d6
permissions -rw-r--r--
Bug 1691858 - Minor cleanup of our @page rule setup. r=AlaskanEmily Actually, there's not so much we can improve right now, in the sense that: * We need the ::-moz-page-content pseudo-element to be able to set `display` on the page, since that's a style rule rather than a @page rule. We could get away without it. * Keeping the current code-path (slightly cleaned up) is less code, for now at least. We can have a separate code-path or what not that actually performs the @page rule selector-matching and what not if needed when we get to named pages or other page selectors. Selectors like :first should be pretty trivial to implement, actually. We make some paged mode anon boxes non-inheriting anon boxes. This allows us to share the styles and is generally nicer. They don't need to inherit from anywhere. We could remove the origin handling and don't look at UA rules or what not, but it seems pretty harmless to do that. We also fix the name of the pseudo-elements to match the capitalization. Differential Revision:

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at */

/* Rendering object for a printed or print-previewed sheet of paper */


#include "nsContainerFrame.h"
#include "nsHTMLParts.h"

class nsSharedPageData;

namespace mozilla {

class PrintedSheetFrame final : public nsContainerFrame {

  friend PrintedSheetFrame* ::NS_NewPrintedSheetFrame(
      mozilla::PresShell* aPresShell, ComputedStyle* aStyle);

  void SetSharedPageData(nsSharedPageData* aPD) { mPD = aPD; }

  // nsIFrame overrides
  void Reflow(nsPresContext* aPresContext, ReflowOutput& aReflowOutput,
              const ReflowInput& aReflowInput,
              nsReflowStatus& aStatus) override;

  void BuildDisplayList(nsDisplayListBuilder* aBuilder,
                        const nsDisplayListSet& aLists) override;

  nsresult GetFrameName(nsAString& aResult) const override;

  uint32_t GetNumPages() const { return mNumPages; }

  // Private construtor & destructor, to avoid accidental (non-FrameArena)
  // instantiation/deletion:
  PrintedSheetFrame(ComputedStyle* aStyle, nsPresContext* aPresContext)
      : nsContainerFrame(aStyle, aPresContext, kClassID) {}
  ~PrintedSheetFrame() = default;

  // Helper function to populate some pages-per-sheet metrics in our
  // nsSharedPageData.
  void ComputePagesPerSheetOriginAndScale();

  // Note: this will be set before reflow, and it's strongly owned by our
  // nsPageSequenceFrame, which outlives us.
  nsSharedPageData* mPD = nullptr;
  // The number of visible pages in this sheet.
  uint32_t mNumPages = 0;

}  // namespace mozilla