Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 307 insertions, 0 deletions

diff --git a/layout/generic/PrintedSheetFrame.cpp b/layout/generic/PrintedSheetFrame.cpp
new file mode 100644
index 0000000000..062ce411f8
--- /dev/null
+++ b/layout/generic/PrintedSheetFrame.cpp
@@ -0,0 +1,307 @@
+/* -*- 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 https://mozilla.org/MPL/2.0/. */
+
+/* Rendering object for a printed or print-previewed sheet of paper */
+
+#include "mozilla/PrintedSheetFrame.h"
+
+#include <tuple>
+
+#include "mozilla/StaticPrefs_print.h"
+#include "nsCSSFrameConstructor.h"
+#include "nsPageFrame.h"
+#include "nsPageSequenceFrame.h"
+
+using namespace mozilla;
+
+PrintedSheetFrame* NS_NewPrintedSheetFrame(PresShell* aPresShell,
+                                           ComputedStyle* aStyle) {
+  return new (aPresShell)
+      PrintedSheetFrame(aStyle, aPresShell->GetPresContext());
+}
+
+namespace mozilla {
+
+NS_QUERYFRAME_HEAD(PrintedSheetFrame)
+  NS_QUERYFRAME_ENTRY(PrintedSheetFrame)
+NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
+
+NS_IMPL_FRAMEARENA_HELPERS(PrintedSheetFrame)
+
+void PrintedSheetFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
+                                         const nsDisplayListSet& aLists) {
+  if (PresContext()->IsScreen()) {
+    // Draw the background/shadow/etc. of a blank sheet of paper, for
+    // print-preview.
+    DisplayBorderBackgroundOutline(aBuilder, aLists);
+  }
+
+  for (auto* frame : mFrames) {
+    if (!frame->HasAnyStateBits(NS_PAGE_SKIPPED_BY_CUSTOM_RANGE)) {
+      BuildDisplayListForChild(aBuilder, frame, aLists);
+    }
+  }
+}
+
+// If the given page is included in the user's page range, this function
+// returns false. Otherwise, it tags the page with the
+// NS_PAGE_SKIPPED_BY_CUSTOM_RANGE state bit and returns true.
+static bool TagIfSkippedByCustomRange(nsPageFrame* aPageFrame, int32_t aPageNum,
+                                      nsSharedPageData* aPD) {
+  if (!nsIPrintSettings::IsPageSkipped(aPageNum, aPD->mPageRanges)) {
+    MOZ_ASSERT(!aPageFrame->HasAnyStateBits(NS_PAGE_SKIPPED_BY_CUSTOM_RANGE),
+               "page frames NS_PAGE_SKIPPED_BY_CUSTOM_RANGE state should "
+               "only be set if we actually want to skip the page");
+    return false;
+  }
+
+  aPageFrame->AddStateBits(NS_PAGE_SKIPPED_BY_CUSTOM_RANGE);
+  return true;
+}
+
+void PrintedSheetFrame::ClaimPageFrameFromPrevInFlow() {
+  MoveOverflowToChildList();
+}
+
+void PrintedSheetFrame::Reflow(nsPresContext* aPresContext,
+                               ReflowOutput& aReflowOutput,
+                               const ReflowInput& aReflowInput,
+                               nsReflowStatus& aStatus) {
+  MarkInReflow();
+  DO_GLOBAL_REFLOW_COUNT("PrintedSheetFrame");
+  DISPLAY_REFLOW(aPresContext, this, aReflowInput, aReflowOutput, aStatus);
+  MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
+
+  // If we have a prev-in-flow, take its overflowing content:
+  MoveOverflowToChildList();
+
+  const WritingMode wm = aReflowInput.GetWritingMode();
+
+  // Count the number of pages that are displayed on this sheet (i.e. how many
+  // child frames we end up laying out, excluding any pages that are skipped
+  // due to not being in the user's page-range selection).
+  uint32_t numPagesOnThisSheet = 0;
+
+  // Target for numPagesOnThisSheet.
+  const uint32_t desiredPagesPerSheet = mPD->PagesPerSheetInfo()->mNumPages;
+
+  if (desiredPagesPerSheet > 1) {
+    ComputePagesPerSheetGridMetrics(
+        nsSize(aReflowInput.AvailableISize(), aReflowInput.AvailableBSize()));
+  }
+
+  // NOTE: I'm intentionally *not* using a range-based 'for' loop here, since
+  // we potentially mutate the frame list (appending to the end) during the
+  // list, which is not generally safe with range-based 'for' loops.
+  for (auto* childFrame = mFrames.FirstChild(); childFrame;
+       childFrame = childFrame->GetNextSibling()) {
+    MOZ_ASSERT(childFrame->IsPageFrame(),
+               "we're only expecting page frames as children");
+    auto* pageFrame = static_cast<nsPageFrame*>(childFrame);
+
+    // Be sure our child has a pointer to the nsSharedPageData and knows its
+    // page number:
+    pageFrame->SetSharedPageData(mPD);
+    pageFrame->DeterminePageNum();
+
+    if (!TagIfSkippedByCustomRange(pageFrame, pageFrame->GetPageNum(), mPD)) {
+      // The page is going to be displayed on this sheet. Tell it its index
+      // among the displayed pages, so we can use that to compute its "cell"
+      // when painting.
+      pageFrame->SetIndexOnSheet(numPagesOnThisSheet);
+      numPagesOnThisSheet++;
+    }
+
+    // This is the app-unit size of the page (in physical & logical units).
+    // Note: The page sizes come from CSS or else from the user selected size;
+    // pages are never reflowed to fit their sheet - if/when necessary they are
+    // scaled to fit their sheet. Hence why we get the page's own dimensions to
+    // use as its "available space"/"container size" here.
+    const nsSize physPageSize = pageFrame->ComputePageSize();
+    const LogicalSize pageSize(wm, physPageSize);
+
+    ReflowInput pageReflowInput(aPresContext, aReflowInput, pageFrame,
+                                pageSize);
+
+    // For layout purposes, we position *all* our nsPageFrame children at our
+    // origin. Then, if we have multiple pages-per-sheet, we'll shrink & shift
+    // each one into the right position as a paint-time effect, in
+    // BuildDisplayList.
+    LogicalPoint pagePos(wm);
+
+    // Outparams for reflow:
+    ReflowOutput pageReflowOutput(pageReflowInput);
+    nsReflowStatus status;
+
+    ReflowChild(pageFrame, aPresContext, pageReflowOutput, pageReflowInput, wm,
+                pagePos, physPageSize, ReflowChildFlags::Default, status);
+
+    FinishReflowChild(pageFrame, aPresContext, pageReflowOutput,
+                      &pageReflowInput, wm, pagePos, physPageSize,
+                      ReflowChildFlags::Default);
+
+    // Since we don't support incremental reflow in printed documents (see the
+    // early-return in nsPageSequenceFrame::Reflow), we can assume that this
+    // was the first time that pageFrame has been reflowed, and so there's no
+    // way that it could already have a next-in-flow. If it *did* have a
+    // next-in-flow, we would need to handle it in the 'status' logic below.
+    NS_ASSERTION(!pageFrame->GetNextInFlow(), "bad child flow list");
+
+    // Did this page complete the document, or do we need to generate
+    // another page frame?
+    if (status.IsFullyComplete()) {
+      // The page we just reflowed is the final page! Record its page number
+      // as the number of pages:
+      mPD->mRawNumPages = pageFrame->GetPageNum();
+    } else {
+      // Create a continuation for our page frame. We add the continuation to
+      // our child list, and then potentially push it to our overflow list, if
+      // it really belongs on the next sheet.
+      nsIFrame* continuingPage =
+          PresShell()->FrameConstructor()->CreateContinuingFrame(pageFrame,
+                                                                 this);
+      mFrames.InsertFrame(nullptr, pageFrame, continuingPage);
+      const bool isContinuingPageSkipped =
+          TagIfSkippedByCustomRange(static_cast<nsPageFrame*>(continuingPage),
+                                    pageFrame->GetPageNum() + 1, mPD);
+
+      // If we've already reached the target number of pages for this sheet,
+      // and this continuation page that we just created is meant to be
+      // displayed (i.e. it's in the chosen page range), then we need to push it
+      // to our overflow list so that it'll go onto a subsequent sheet.
+      // Otherwise we leave it on this sheet. This ensures we *only* generate
+      // another sheet IFF there's a displayable page that will end up on it.
+      if (numPagesOnThisSheet >= desiredPagesPerSheet &&
+          !isContinuingPageSkipped) {
+        PushChildrenToOverflow(continuingPage, pageFrame);
+        aStatus.SetIncomplete();
+      }
+    }
+  }
+
+  // This should hold for the first sheet, because our UI should prevent the
+  // user from creating a 0-length page range; and it should hold for
+  // subsequent sheets because we should only create an additional sheet when
+  // we discover a displayable (i.e. non-skipped) page that we need to push
+  // to that new sheet.
+
+  // XXXdholbert In certain edge cases (e.g. after a page-orientation-flip that
+  // reduces the page count), it's possible for us to be given a page range
+  // that is *entirely out-of-bounds* (with "from" & "to" both being larger
+  // than our actual page-number count).  This scenario produces a single
+  // PrintedSheetFrame with zero displayable pages on it, which is a weird
+  // state to be in. This is hopefully a scenario that the frontend code can
+  // detect and recover from (e.g. by clamping the range to our reported
+  // `rawNumPages`), but it can't do that until *after* we've completed this
+  // problematic reflow and can reported an up-to-date `rawNumPages` to the
+  // frontend.  So: to give the frontend a chance to intervene and apply some
+  // correction/clamping to its print-range parameters, we soften this
+  // assertion *specifically for the first printed sheet*.
+  if (!GetPrevContinuation()) {
+    NS_WARNING_ASSERTION(numPagesOnThisSheet > 0,
+                         "Shouldn't create a sheet with no displayable pages "
+                         "on it");
+  } else {
+    MOZ_ASSERT(numPagesOnThisSheet > 0,
+               "Shouldn't create a sheet with no displayable pages on it");
+  }
+
+  MOZ_ASSERT(numPagesOnThisSheet <= desiredPagesPerSheet,
+             "Shouldn't have more than desired number of displayable pages "
+             "on this sheet");
+  mNumPages = numPagesOnThisSheet;
+
+  // Populate our ReflowOutput outparam -- just use up all the
+  // available space, for both our desired size & overflow areas.
+  aReflowOutput.ISize(wm) = aReflowInput.AvailableISize();
+  if (aReflowInput.AvailableBSize() != NS_UNCONSTRAINEDSIZE) {
+    aReflowOutput.BSize(wm) = aReflowInput.AvailableBSize();
+  }
+  aReflowOutput.SetOverflowAreasToDesiredBounds();
+
+  FinishAndStoreOverflow(&aReflowOutput);
+}
+
+nsSize PrintedSheetFrame::PrecomputeSheetSize(
+    const nsPresContext* aPresContext) {
+  mPrecomputedSize = aPresContext->GetPageSize();
+  if (mPD->mPrintSettings->HasOrthogonalSheetsAndPages()) {
+    std::swap(mPrecomputedSize.width, mPrecomputedSize.height);
+  }
+  return mPrecomputedSize;
+}
+
+void PrintedSheetFrame::ComputePagesPerSheetGridMetrics(
+    const nsSize& aSheetSize) {
+  MOZ_ASSERT(mPD->PagesPerSheetInfo()->mNumPages > 1,
+             "Unnecessary to call this in a regular 1-page-per-sheet scenario; "
+             "the computed values won't ever be used in that case");
+
+  // Compute the space available for the pages-per-sheet "page grid" (just
+  // subtract the sheet's unwriteable margin area):
+  nsSize availSpaceOnSheet = aSheetSize;
+  nsMargin uwm = mPD->mPrintSettings->GetIgnoreUnwriteableMargins()
+                     ? nsMargin{}
+                     : nsPresContext::CSSTwipsToAppUnits(
+                           mPD->mPrintSettings->GetUnwriteableMarginInTwips());
+
+  // XXXjwatt Once we support heterogeneous sheet orientations, we'll also need
+  // to rotate uwm if this sheet is not the primary orientation.
+  if (mPD->mPrintSettings->HasOrthogonalSheetsAndPages()) {
+    // aSheetSize already takes account of the switch of *sheet* orientation
+    // that we do in this case (the orientation implied by the page size
+    // dimensions in the nsIPrintSettings applies to *pages*). That is not the
+    // case for the unwriteable margins since we got them from the
+    // nsIPrintSettings object ourself, so we need to adjust `uwm` here.
+    //
+    // Note: In practice, sheets with an orientation that is orthogonal to the
+    // physical orientation of sheets output by a printer must be rotated 90
+    // degrees for/by the printer. In that case the convention seems to be that
+    // the "left" edge of the orthogonally oriented sheet becomes the "top",
+    // and so forth. The rotation direction will matter in the case that the
+    // top and bottom unwriteable margins are different, or the left and right
+    // unwriteable margins are different. So we need to match this behavior,
+    // which means we must rotate the `uwm` 90 degrees *counter-clockwise*.
+    nsMargin rotated(uwm.right, uwm.bottom, uwm.left, uwm.top);
+    uwm = rotated;
+  }
+
+  availSpaceOnSheet.width -= uwm.LeftRight();
+  availSpaceOnSheet.height -= uwm.TopBottom();
+
+  if (MOZ_UNLIKELY(availSpaceOnSheet.IsEmpty())) {
+    // This sort of thing should be rare, but it can happen if there are
+    // bizarre page sizes, and/or if there's an unexpectedly large unwriteable
+    // margin area.
+    NS_WARNING("Zero area for pages-per-sheet grid, or zero-sized grid");
+    mGridOrigin = nsPoint(0, 0);
+    mGridNumCols = 1;
+    return;
+  }
+
+  // If there are a different number of rows vs. cols, we'll aim to put
+  // the larger number of items in the longer axis.
+  const auto* ppsInfo = mPD->PagesPerSheetInfo();
+  uint32_t smallerNumTracks = ppsInfo->mNumPages / ppsInfo->mLargerNumTracks;
+  bool sheetIsPortraitLike = aSheetSize.width < aSheetSize.height;
+  auto numCols =
+      sheetIsPortraitLike ? smallerNumTracks : ppsInfo->mLargerNumTracks;
+  auto numRows =
+      sheetIsPortraitLike ? ppsInfo->mLargerNumTracks : smallerNumTracks;
+
+  mGridOrigin = nsPoint(uwm.left, uwm.top);
+  mGridNumCols = numCols;
+  mGridCellWidth = availSpaceOnSheet.width / nscoord(numCols);
+  mGridCellHeight = availSpaceOnSheet.height / nscoord(numRows);
+}
+
+#ifdef DEBUG_FRAME_DUMP
+nsresult PrintedSheetFrame::GetFrameName(nsAString& aResult) const {
+  return MakeFrameName(u"PrintedSheet"_ns, aResult);
+}
+#endif
+
+}  // namespace mozilla