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/* -*- 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 "mozilla/gfx/Point.h"
#include "nsContainerFrame.h"
#include "nsHTMLParts.h"
class nsSharedPageData;
namespace mozilla {
class PrintedSheetFrame final : public nsContainerFrame {
using IntSize = mozilla::gfx::IntSize;
friend PrintedSheetFrame* ::NS_NewPrintedSheetFrame(
mozilla::PresShell* aPresShell, ComputedStyle* aStyle);
void SetSharedPageData(nsSharedPageData* aPD) { mPD = aPD; }
// XXX: this needs a better name, since it also updates style.
// Invokes MoveOverflowToChildList.
// This is intended for use by callers that need to be able to get our first/
// only nsPageFrame from our child list to examine its computed style just
// **prior** to us being reflowed. (If our first nsPageFrame will come from
// our prev-in-flow, we won't otherwise take ownership of it until we are
// reflowed.)
void ClaimPageFrameFromPrevInFlow();
// 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; }
// These methods provide information about the grid that pages should be
// placed into in the case that there are multiple pages-per-sheet.
uint32_t GetGridNumCols() const { return mGridNumCols; }
nsPoint GetGridOrigin() const { return mGridOrigin; }
nscoord GetGridCellWidth() const { return mGridCellWidth; }
nscoord GetGridCellHeight() const { return mGridCellHeight; }
nsSize ComputeSheetSize(const nsPresContext* aPresContext);
* When we're printing one page-per-sheet and `page-orientation` on our
* single nsPageFrame child should cause the page to rotate, then we want to
* essentially rotate the sheet. We implement that by switching the
* dimensions of this sheet (changing its orientation), sizing the
* nsPageFrame to the original dimensions, and then applying the rotation to
* the nsPageFrame child.
* This returns the dimensions that this frame would have without any
* dimension swap we may have done to implement `page-orientation`. If
* there is no rotation caused by `page-orientation`, then the value returned
* and mRect.Size() are identical.
nsSize GetSizeForChildren() const { return mSizeForChildren; }
* This method returns the dimensions of the physical page that the target
* [pseudo-]printer should create. This may be different from our own
* dimensions in the case where CSS `page-orientation` causes us to be
* rotated, but we only support that if the PrintTarget backend supports
* different page sizes/orientations. That's only the case for our Save-to-PDF
* backends (possibly other save-to-file outputs in future).
* The dimensions returned are expected to be passed to
* nsDeviceContext::BeginPage, which will pass them on to
* PrintTarget::BeginPage to use as the physical dimensions of the page.
IntSize GetPrintTargetSizeInPoints(
const int32_t aAppUnitsPerPhysicalInch) const;
// 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.
// XXXjwatt: We should investigate sharing this function for the single
// page-per-sheet case (bug 1835782). The logic for that case
// (nsPageFrame::ComputePageSizeScale) is somewhat different though, since
// that case uses no sheet margins and uses the user/CSS specified margins on
// the page, with any page scaling reverted to keep the margins unchanged.
// We, on the other hand, use the unwriteable margins for the sheet, unscaled,
// and use the user/CSS margins on the pages and allow them to be scaled
// along with any pages-per-sheet scaling. (This behavior makes maximum use
// of the sheet and, by scaling the default on the pages, results in a
// a sensible amount of spacing between pages.)
void ComputePagesPerSheetGridMetrics(const nsSize& aSheetSize);
// See GetSizeForChildren.
nsSize mSizeForChildren;
// 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;
// Number of "columns" in our pages-per-sheet layout. For example: if we're
// printing with 6 pages-per-sheet, then this could be either 3 or 2,
// depending on whether we're printing portrait-oriented pages onto a
// landscape-oriented sheet (3 cols) vs. if we're printing landscape-oriented
// pages onto a portrait-oriented sheet (2 cols).
uint32_t mGridNumCols = 1;
// The offset of the start of the multiple pages-per-sheet grid from the
// top-left of the sheet.
nsPoint mGridOrigin;
// The size of each cell on the sheet into which pages are to be placed.
// (The default values are arbitrary.)
nscoord mGridCellWidth = 1;
nscoord mGridCellHeight = 1;
} // namespace mozilla