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Diffstat (limited to 'layout/generic/nsPageFrame.cpp')
| -rw-r--r-- | layout/generic/nsPageFrame.cpp | 958 |
1 files changed, 958 insertions, 0 deletions
diff --git a/layout/generic/nsPageFrame.cpp b/layout/generic/nsPageFrame.cpp new file mode 100644 index 0000000000..af0e2f4f72 --- /dev/null +++ b/layout/generic/nsPageFrame.cpp @@ -0,0 +1,958 @@ +/* -*- 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 http://mozilla.org/MPL/2.0/. */ + +#include "nsPageFrame.h" + +#include "mozilla/AppUnits.h" +#include "mozilla/PresShell.h" +#include "mozilla/StaticPrefs_layout.h" +#include "mozilla/gfx/2D.h" +#include "mozilla/intl/Segmenter.h" +#include "gfxContext.h" +#include "nsDeviceContext.h" +#include "nsFontMetrics.h" +#include "nsIFrame.h" +#include "nsLayoutUtils.h" +#include "nsPresContext.h" +#include "nsGkAtoms.h" +#include "nsFieldSetFrame.h" +#include "nsPageContentFrame.h" +#include "nsDisplayList.h" +#include "nsPageSequenceFrame.h" // for nsSharedPageData +#include "nsTextFormatter.h" // for page number localization formatting +#include "nsBidiUtils.h" +#include "nsIPrintSettings.h" +#include "PrintedSheetFrame.h" + +#include "mozilla/Logging.h" +extern mozilla::LazyLogModule gLayoutPrintingLog; +#define PR_PL(_p1) MOZ_LOG(gLayoutPrintingLog, mozilla::LogLevel::Debug, _p1) + +using namespace mozilla; +using namespace mozilla::gfx; + +nsPageFrame* NS_NewPageFrame(PresShell* aPresShell, ComputedStyle* aStyle) { + return new (aPresShell) nsPageFrame(aStyle, aPresShell->GetPresContext()); +} + +NS_IMPL_FRAMEARENA_HELPERS(nsPageFrame) + +NS_QUERYFRAME_HEAD(nsPageFrame) + NS_QUERYFRAME_ENTRY(nsPageFrame) +NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame) + +nsPageFrame::nsPageFrame(ComputedStyle* aStyle, nsPresContext* aPresContext) + : nsContainerFrame(aStyle, aPresContext, kClassID) {} + +nsPageFrame::~nsPageFrame() = default; + +nsReflowStatus nsPageFrame::ReflowPageContent( + nsPresContext* aPresContext, const ReflowInput& aPageReflowInput) { + nsPageContentFrame* const frame = PageContentFrame(); + // If this is the first page, it won't have its page name and computed style + // set yet. Before reflow, make sure that page name and computed style have + // been applied. + frame->EnsurePageName(); + // XXX Pay attention to the page's border and padding... + // + // Reflow our ::-moz-page-content frame, allowing it only to be as big as we + // are (minus margins). + const nsSize pageSize = ComputePageSize(); + // Scaling applied to the page in the single page-per-sheet case (used for + // down-scaling when the page is too large to fit on the sheet we are printing + // on). In the single page-per-sheet case, we need this here to preemptively + // increase the margins by the same amount that the scaling will reduce them + // in order to make sure that their physical size is unchanged (particularly + // important for the unwriteable margins). + const auto* ppsInfo = GetSharedPageData()->PagesPerSheetInfo(); + const float pageSizeScale = + ppsInfo->mNumPages == 1 ? ComputeSinglePPSPageSizeScale(pageSize) : 1.0f; + // Scaling applied to content, as given by the print UI. + // This is an additional scale factor that is applied to the content in the + // nsPageContentFrame. + const float extraContentScale = aPresContext->GetPageScale(); + // Size for the page content. This will be scaled by extraContentScale, and + // is used to calculate the computed size of the nsPageContentFrame content + // by subtracting margins. + nsSize availableSpace = pageSize; + + // When the reflow size is NS_UNCONSTRAINEDSIZE it means we are reflowing + // a single page to print selection. So this means we want to use + // NS_UNCONSTRAINEDSIZE without altering it. + // + // FIXME(emilio): Is this still true? + availableSpace.width = + NSToCoordCeil(availableSpace.width / extraContentScale); + if (availableSpace.height != NS_UNCONSTRAINEDSIZE) { + availableSpace.height = + NSToCoordCeil(availableSpace.height / extraContentScale); + } + + // Get the number of Twips per pixel from the PresContext + const nscoord onePixel = AppUnitsPerCSSPixel(); + + // insurance against infinite reflow, when reflowing less than a pixel + // XXX Shouldn't we do something more friendly when invalid margins + // are set? + if (availableSpace.width < onePixel || availableSpace.height < onePixel) { + NS_WARNING("Reflow aborted; no space for content"); + return {}; + } + + ReflowInput kidReflowInput( + aPresContext, aPageReflowInput, frame, + LogicalSize(frame->GetWritingMode(), availableSpace)); + kidReflowInput.mFlags.mIsTopOfPage = true; + kidReflowInput.mFlags.mTableIsSplittable = true; + + nsMargin defaultMargins = aPresContext->GetDefaultPageMargin(); + // The default margins are in the coordinate space of the physical paper. + // Scale them by the pageSizeScale to convert them to the content coordinate + // space. + for (const auto side : mozilla::AllPhysicalSides()) { + defaultMargins.Side(side) = + NSToCoordRound((float)defaultMargins.Side(side) / pageSizeScale); + } + mPageContentMargin = defaultMargins; + + // Use the margins given in the @page rule if told to do so. + // We clamp to the paper's unwriteable margins to avoid clipping, *except* + // that we will respect a margin of zero if specified, assuming this means + // the document is intended to fit the paper size exactly, and the client is + // taking full responsibility for what happens around the edges. + if (mPD->mPrintSettings->GetHonorPageRuleMargins()) { + const auto& margin = kidReflowInput.mStyleMargin->mMargin; + for (const auto side : mozilla::AllPhysicalSides()) { + if (!margin.Get(side).IsAuto()) { + // Computed margins are already in the coordinate space of the content, + // do not scale. + const nscoord computed = + kidReflowInput.ComputedPhysicalMargin().Side(side); + // Respecting a zero margin is particularly important when the client + // is PDF.js where the PDF already contains the margins. + // User could also be asking to ignore unwriteable margins (Though + // currently, it is impossible through the print UI to set both + // `HonorPageRuleMargins` and `IgnoreUnwriteableMargins`). + if (computed == 0 || + mPD->mPrintSettings->GetIgnoreUnwriteableMargins()) { + mPageContentMargin.Side(side) = computed; + } else { + // Unwriteable margins are in the coordinate space of the physical + // paper. Scale them by the pageSizeScale to convert them to the + // content coordinate space. + const int32_t unwriteableTwips = + mPD->mPrintSettings->GetUnwriteableMarginInTwips().Side(side); + const nscoord unwriteable = nsPresContext::CSSTwipsToAppUnits( + (float)unwriteableTwips / pageSizeScale); + mPageContentMargin.Side(side) = std::max( + kidReflowInput.ComputedPhysicalMargin().Side(side), unwriteable); + } + } + } + } + + // TODO: This seems odd that we need to scale the margins by the extra + // scale factor, but this is needed for correct margins. + // Why are the margins already scaled? Shouldn't they be stored so that this + // scaling factor would be redundant? + nscoord computedWidth = + availableSpace.width - mPageContentMargin.LeftRight() / extraContentScale; + nscoord computedHeight; + if (availableSpace.height == NS_UNCONSTRAINEDSIZE) { + computedHeight = NS_UNCONSTRAINEDSIZE; + } else { + computedHeight = availableSpace.height - + mPageContentMargin.TopBottom() / extraContentScale; + } + + // Check the width and height, if they're too small we reset the margins + // back to the default. + if (computedWidth < onePixel || computedHeight < onePixel) { + mPageContentMargin = defaultMargins; + computedWidth = availableSpace.width - + mPageContentMargin.LeftRight() / extraContentScale; + if (computedHeight != NS_UNCONSTRAINEDSIZE) { + computedHeight = availableSpace.height - + mPageContentMargin.TopBottom() / extraContentScale; + } + // And if they're still too small, we give up. + if (computedWidth < onePixel || computedHeight < onePixel) { + NS_WARNING("Reflow aborted; no space for content"); + return {}; + } + } + + kidReflowInput.SetComputedWidth(computedWidth); + kidReflowInput.SetComputedHeight(computedHeight); + + // calc location of frame + const nscoord xc = mPageContentMargin.left; + const nscoord yc = mPageContentMargin.top; + + // Get the child's desired size + ReflowOutput kidOutput(kidReflowInput); + nsReflowStatus kidStatus; + ReflowChild(frame, aPresContext, kidOutput, kidReflowInput, xc, yc, + ReflowChildFlags::Default, kidStatus); + + // Place and size the child + FinishReflowChild(frame, aPresContext, kidOutput, &kidReflowInput, xc, yc, + ReflowChildFlags::Default); + + NS_ASSERTION(!kidStatus.IsFullyComplete() || !frame->GetNextInFlow(), + "bad child flow list"); + return kidStatus; +} + +void nsPageFrame::Reflow(nsPresContext* aPresContext, + ReflowOutput& aReflowOutput, + const ReflowInput& aReflowInput, + nsReflowStatus& aStatus) { + MarkInReflow(); + DO_GLOBAL_REFLOW_COUNT("nsPageFrame"); + DISPLAY_REFLOW(aPresContext, this, aReflowInput, aReflowOutput, aStatus); + MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!"); + MOZ_ASSERT(mPD, "Need a pointer to nsSharedPageData before reflow starts"); + + // Our status is the same as our child's. + aStatus = ReflowPageContent(aPresContext, aReflowInput); + + PR_PL(("PageFrame::Reflow %p ", this)); + PR_PL(("[%d,%d][%d,%d]\n", aReflowOutput.Width(), aReflowOutput.Height(), + aReflowInput.AvailableWidth(), aReflowInput.AvailableHeight())); + + // Return our desired size + WritingMode wm = aReflowInput.GetWritingMode(); + aReflowOutput.ISize(wm) = aReflowInput.AvailableISize(); + if (aReflowInput.AvailableBSize() != NS_UNCONSTRAINEDSIZE) { + aReflowOutput.BSize(wm) = aReflowInput.AvailableBSize(); + } + + aReflowOutput.SetOverflowAreasToDesiredBounds(); + FinishAndStoreOverflow(&aReflowOutput); + + PR_PL(("PageFrame::Reflow %p ", this)); + PR_PL(("[%d,%d]\n", aReflowInput.AvailableWidth(), + aReflowInput.AvailableHeight())); +} + +#ifdef DEBUG_FRAME_DUMP +nsresult nsPageFrame::GetFrameName(nsAString& aResult) const { + return MakeFrameName(u"Page"_ns, aResult); +} +#endif + +void nsPageFrame::ProcessSpecialCodes(const nsString& aStr, nsString& aNewStr) { + aNewStr = aStr; + + // Search to see if the &D code is in the string + // then subst in the current date/time + constexpr auto kDate = u"&D"_ns; + if (aStr.Find(kDate) != kNotFound) { + aNewStr.ReplaceSubstring(kDate, mPD->mDateTimeStr); + } + + // NOTE: Must search for &PT before searching for &P + // + // Search to see if the "page number and page" total code are in the string + // and replace the page number and page total code with the actual + // values + constexpr auto kPageAndTotal = u"&PT"_ns; + if (aStr.Find(kPageAndTotal) != kNotFound) { + nsAutoString uStr; + nsTextFormatter::ssprintf(uStr, mPD->mPageNumAndTotalsFormat.get(), + mPageNum, mPD->mRawNumPages); + aNewStr.ReplaceSubstring(kPageAndTotal, uStr); + } + + // Search to see if the page number code is in the string + // and replace the page number code with the actual value + constexpr auto kPage = u"&P"_ns; + if (aStr.Find(kPage) != kNotFound) { + nsAutoString uStr; + nsTextFormatter::ssprintf(uStr, mPD->mPageNumFormat.get(), mPageNum); + aNewStr.ReplaceSubstring(kPage, uStr); + } + + constexpr auto kTitle = u"&T"_ns; + if (aStr.Find(kTitle) != kNotFound) { + aNewStr.ReplaceSubstring(kTitle, mPD->mDocTitle); + } + + constexpr auto kDocURL = u"&U"_ns; + if (aStr.Find(kDocURL) != kNotFound) { + aNewStr.ReplaceSubstring(kDocURL, mPD->mDocURL); + } + + constexpr auto kPageTotal = u"&L"_ns; + if (aStr.Find(kPageTotal) != kNotFound) { + nsAutoString uStr; + nsTextFormatter::ssprintf(uStr, mPD->mPageNumFormat.get(), + mPD->mRawNumPages); + aNewStr.ReplaceSubstring(kPageTotal, uStr); + } +} + +//------------------------------------------------------------------------------ +nscoord nsPageFrame::GetXPosition(gfxContext& aRenderingContext, + nsFontMetrics& aFontMetrics, + const nsRect& aRect, int32_t aJust, + const nsString& aStr) { + nscoord width = nsLayoutUtils::AppUnitWidthOfStringBidi( + aStr, this, aFontMetrics, aRenderingContext); + nscoord x = aRect.x; + switch (aJust) { + case nsIPrintSettings::kJustLeft: + x += mPD->mEdgePaperMargin.left; + break; + + case nsIPrintSettings::kJustCenter: + x += (aRect.width - width) / 2; + break; + + case nsIPrintSettings::kJustRight: + x += aRect.width - width - mPD->mEdgePaperMargin.right; + break; + } // switch + + return x; +} + +// Draw a header or footer +// @param aRenderingContext - rendering content to draw into +// @param aHeaderFooter - indicates whether it is a header or footer +// @param aStrLeft - string for the left header or footer; can be empty +// @param aStrCenter - string for the center header or footer; can be empty +// @param aStrRight - string for the right header or footer; can be empty +// @param aRect - the rect of the page +// @param aAscent - the ascent of the font +// @param aHeight - the height of the font +void nsPageFrame::DrawHeaderFooter( + gfxContext& aRenderingContext, nsFontMetrics& aFontMetrics, + nsHeaderFooterEnum aHeaderFooter, const nsString& aStrLeft, + const nsString& aStrCenter, const nsString& aStrRight, const nsRect& aRect, + nscoord aAscent, nscoord aHeight) { + int32_t numStrs = 0; + if (!aStrLeft.IsEmpty()) numStrs++; + if (!aStrCenter.IsEmpty()) numStrs++; + if (!aStrRight.IsEmpty()) numStrs++; + + if (numStrs == 0) return; + const nscoord contentWidth = + aRect.width - (mPD->mEdgePaperMargin.left + mPD->mEdgePaperMargin.right); + const nscoord strSpace = contentWidth / numStrs; + + if (!aStrLeft.IsEmpty()) { + DrawHeaderFooter(aRenderingContext, aFontMetrics, aHeaderFooter, + nsIPrintSettings::kJustLeft, aStrLeft, aRect, aAscent, + aHeight, strSpace); + } + if (!aStrCenter.IsEmpty()) { + DrawHeaderFooter(aRenderingContext, aFontMetrics, aHeaderFooter, + nsIPrintSettings::kJustCenter, aStrCenter, aRect, aAscent, + aHeight, strSpace); + } + if (!aStrRight.IsEmpty()) { + DrawHeaderFooter(aRenderingContext, aFontMetrics, aHeaderFooter, + nsIPrintSettings::kJustRight, aStrRight, aRect, aAscent, + aHeight, strSpace); + } +} + +// Draw a header or footer string +// @param aRenderingContext - rendering context to draw into +// @param aHeaderFooter - indicates whether it is a header or footer +// @param aJust - indicates where the string is located within the header/footer +// @param aStr - the string to be drawn +// @param aRect - the rect of the page +// @param aHeight - the height of the font +// @param aAscent - the ascent of the font +// @param aWidth - available width for the string +void nsPageFrame::DrawHeaderFooter(gfxContext& aRenderingContext, + nsFontMetrics& aFontMetrics, + nsHeaderFooterEnum aHeaderFooter, + int32_t aJust, const nsString& aStr, + const nsRect& aRect, nscoord aAscent, + nscoord aHeight, nscoord aWidth) { + DrawTarget* drawTarget = aRenderingContext.GetDrawTarget(); + + if ((aHeaderFooter == eHeader && aHeight < mPageContentMargin.top) || + (aHeaderFooter == eFooter && aHeight < mPageContentMargin.bottom)) { + nsAutoString str; + ProcessSpecialCodes(aStr, str); + + int32_t len = (int32_t)str.Length(); + if (len == 0) { + return; // bail is empty string + } + + int32_t index; + int32_t textWidth = 0; + const char16_t* text = str.get(); + // find how much text fits, the "position" is the size of the available area + if (nsLayoutUtils::BinarySearchForPosition(drawTarget, aFontMetrics, text, + 0, 0, 0, len, int32_t(aWidth), + index, textWidth)) { + if (index < len - 1) { + // we can't fit in all the text, try to remove 3 glyphs and append + // three "." charactrers. + + // TODO: This might not actually remove three glyphs in cases where + // ZWJ sequences, regional indicators, etc are used. + // We also have guarantee that removing three glyphs will make enough + // space for the ellipse, if they are zero-width or even just narrower + // than the "." character. + // See https://bugzilla.mozilla.org/1765008 + mozilla::intl::GraphemeClusterBreakReverseIteratorUtf16 revIter(str); + + // Start iteration at the point where the text does properly fit. + revIter.Seek(index); + + // Step backwards 3 times, checking if we have any string left by the + // end. + revIter.Next(); + revIter.Next(); + if (const Maybe<uint32_t> maybeIndex = revIter.Next()) { + // TODO: We should consider checking for the ellipse character, or + // possibly for another continuation indicator based on + // localization. + // See https://bugzilla.mozilla.org/1765007 + str.Truncate(*maybeIndex); + str.AppendLiteral("..."); + } else { + // We can only fit 3 or fewer chars. Just show nothing + str.Truncate(); + } + } + } else { + return; // bail if couldn't find the correct length + } + + if (HasRTLChars(str)) { + PresContext()->SetBidiEnabled(); + } + + // calc the x and y positions of the text + nscoord x = + GetXPosition(aRenderingContext, aFontMetrics, aRect, aJust, str); + nscoord y; + if (aHeaderFooter == eHeader) { + y = aRect.y + mPD->mEdgePaperMargin.top; + } else { + y = aRect.YMost() - aHeight - mPD->mEdgePaperMargin.bottom; + } + + // set up new clip and draw the text + aRenderingContext.Save(); + aRenderingContext.Clip(NSRectToSnappedRect( + aRect, PresContext()->AppUnitsPerDevPixel(), *drawTarget)); + aRenderingContext.SetColor(sRGBColor::OpaqueBlack()); + nsLayoutUtils::DrawString(this, aFontMetrics, &aRenderingContext, str.get(), + str.Length(), nsPoint(x, y + aAscent), nullptr, + DrawStringFlags::ForceHorizontal); + aRenderingContext.Restore(); + } +} + +class nsDisplayHeaderFooter final : public nsPaintedDisplayItem { + public: + nsDisplayHeaderFooter(nsDisplayListBuilder* aBuilder, nsPageFrame* aFrame) + : nsPaintedDisplayItem(aBuilder, aFrame) { + MOZ_COUNT_CTOR(nsDisplayHeaderFooter); + } + MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayHeaderFooter) + + virtual void Paint(nsDisplayListBuilder* aBuilder, + gfxContext* aCtx) override { +#ifdef DEBUG + nsPageFrame* pageFrame = do_QueryFrame(mFrame); + MOZ_ASSERT(pageFrame, "We should have an nsPageFrame"); +#endif + static_cast<nsPageFrame*>(mFrame)->PaintHeaderFooter( + *aCtx, ToReferenceFrame(), false); + } + NS_DISPLAY_DECL_NAME("HeaderFooter", TYPE_HEADER_FOOTER) + + virtual nsRect GetComponentAlphaBounds( + nsDisplayListBuilder* aBuilder) const override { + bool snap; + return GetBounds(aBuilder, &snap); + } +}; + +static void PaintMarginGuides(nsIFrame* aFrame, DrawTarget* aDrawTarget, + const nsRect& aDirtyRect, nsPoint aPt) { + // Set up parameters needed to draw the guides: we draw them in blue, + // using 2px-long dashes with 2px separation and a line width of 0.5px. + // Drawing is antialiased, so on a non-hidpi screen where the line width is + // less than one device pixel, it doesn't disappear but renders fainter + // than a solid 1px-wide line would be. + // (In many cases, the entire preview is scaled down so that the guides + // will be nominally less than 1 dev px even on a hidpi screen, resulting + // in lighter antialiased rendering so they don't dominate the page.) + ColorPattern pattern(ToDeviceColor(sRGBColor(0.0f, 0.0f, 1.0f))); + Float dashes[] = {2.0f, 2.0f}; + StrokeOptions stroke(/* line width (in CSS px) */ 0.5f, + JoinStyle::MITER_OR_BEVEL, CapStyle::BUTT, + /* mitre limit (default, not used) */ 10.0f, + /* set dash pattern of 2px stroke, 2px gap */ + ArrayLength(dashes), dashes, + /* dash offset */ 0.0f); + DrawOptions options; + + MOZ_RELEASE_ASSERT(aFrame->IsPageFrame()); + const nsMargin& margin = + static_cast<nsPageFrame*>(aFrame)->GetUsedPageContentMargin(); + int32_t appUnitsPerDevPx = aFrame->PresContext()->AppUnitsPerDevPixel(); + + // Get the frame's rect and inset by the margins to get the edges of the + // content area, where we want to draw the guides. + // We draw in two stages, first applying the top/bottom margins and drawing + // the horizontal guides across the full width of the page. + nsRect rect(aPt, aFrame->GetSize()); + rect.Deflate(nsMargin(margin.top, 0, margin.bottom, 0)); + Rect r = NSRectToRect(rect, appUnitsPerDevPx); + aDrawTarget->StrokeLine(r.TopLeft(), r.TopRight(), pattern, stroke, options); + aDrawTarget->StrokeLine(r.BottomLeft(), r.BottomRight(), pattern, stroke, + options); + + // Then reset rect, apply the left/right margins, and draw vertical guides + // extending the full height of the page. + rect = nsRect(aPt, aFrame->GetSize()); + rect.Deflate(nsMargin(0, margin.right, 0, margin.left)); + r = NSRectToRect(rect, appUnitsPerDevPx); + aDrawTarget->StrokeLine(r.TopLeft(), r.BottomLeft(), pattern, stroke, + options); + aDrawTarget->StrokeLine(r.TopRight(), r.BottomRight(), pattern, stroke, + options); +} + +static std::tuple<uint32_t, uint32_t> GetRowAndColFromIdx(uint32_t aIdxOnSheet, + uint32_t aNumCols) { + // Compute the row index by *dividing* the item's ordinal position by how + // many items fit in each row (i.e. the number of columns), and flooring. + // Compute the column index by getting the remainder of that division: + // Notably, mNumRows is irrelevant to this computation; that's because + // we're adding new items column-by-column rather than row-by-row. + return {aIdxOnSheet / aNumCols, aIdxOnSheet % aNumCols}; +} + +// Helper for BuildDisplayList: +static gfx::Matrix4x4 ComputePagesPerSheetAndPageSizeTransform( + const nsIFrame* aFrame, float aAppUnitsPerPixel) { + MOZ_ASSERT(aFrame->IsPageFrame()); + auto* pageFrame = static_cast<const nsPageFrame*>(aFrame); + const nsSize contentPageSize = pageFrame->ComputePageSize(); + MOZ_ASSERT(contentPageSize.width > 0 && contentPageSize.height > 0); + nsSharedPageData* pd = pageFrame->GetSharedPageData(); + const auto* ppsInfo = pd->PagesPerSheetInfo(); + + gfx::Matrix4x4 transform; + + if (ppsInfo->mNumPages == 1) { + float scale = pageFrame->ComputeSinglePPSPageSizeScale(contentPageSize); + transform = gfx::Matrix4x4::Scaling(scale, scale, 1); + return transform; + } + + // The multiple pages-per-sheet case. + + const nsContainerFrame* const parentFrame = pageFrame->GetParent(); + MOZ_ASSERT(parentFrame->IsPrintedSheetFrame(), + "Parent of nsPageFrame should be PrintedSheetFrame"); + auto* sheetFrame = static_cast<const PrintedSheetFrame*>(parentFrame); + + // Begin with the translation of the page to its pages-per-sheet grid "cell" + // (the grid origin accounts for the sheet's unwriteable margins): + const nsPoint gridOrigin = sheetFrame->GetGridOrigin(); + const nscoord cellWidth = sheetFrame->GetGridCellWidth(); + const nscoord cellHeight = sheetFrame->GetGridCellHeight(); + uint32_t rowIdx, colIdx; + std::tie(rowIdx, colIdx) = GetRowAndColFromIdx(pageFrame->IndexOnSheet(), + sheetFrame->GetGridNumCols()); + transform = gfx::Matrix4x4::Translation( + NSAppUnitsToFloatPixels(gridOrigin.x + nscoord(colIdx) * cellWidth, + aAppUnitsPerPixel), + NSAppUnitsToFloatPixels(gridOrigin.y + nscoord(rowIdx) * cellHeight, + aAppUnitsPerPixel), + 0.0f); + + // Scale the page to fit, centered, in the grid cell: + float scaleX = float(cellWidth) / float(contentPageSize.width); + float scaleY = float(cellHeight) / float(contentPageSize.height); + MOZ_ASSERT(scaleX > 0.0f && scaleX <= 1.0f && scaleY > 0.0f && + scaleY <= 1.0f); + float scale; + float dx = 0.0f, dy = 0.0f; + if (scaleX < scaleY) { + scale = scaleX; + // We need to scale down more for the width than the height, so we'll have + // some spare space in the page's vertical direction. We offset the page + // to share that space equally above and below the page to center it. + nscoord extraSpace = + cellHeight - NSToCoordRound(float(contentPageSize.height) * scale); + dy = NSAppUnitsToFloatPixels(extraSpace / 2, aAppUnitsPerPixel); + } else { + scale = scaleY; + nscoord extraSpace = + cellWidth - NSToCoordRound(float(contentPageSize.width) * scale); + dx = NSAppUnitsToFloatPixels(extraSpace / 2, aAppUnitsPerPixel); + } + transform.PreTranslate(dx, dy, 0.0f); + transform.PreScale(scale, scale, 1.0f); + + // Apply 'page-orientation' to any applicable pages: + if (StaticPrefs::layout_css_page_orientation_enabled()) { + const StylePageOrientation& orientation = + pageFrame->PageContentFrame()->StylePage()->mPageOrientation; + + double angle = 0.0; + if (orientation == StylePageOrientation::RotateLeft) { + angle = -M_PI / 2.0; + } else if (orientation == StylePageOrientation::RotateRight) { + angle = M_PI / 2.0; + } + + if (angle != 0.0) { + float cellRatio = float(sheetFrame->GetGridCellWidth()) / + float(sheetFrame->GetGridCellHeight()); + float pageRatio = + float(contentPageSize.width) / float(contentPageSize.height); + // To fit into the available space on a sheet, a page typically needs to + // be scaled. If rotated 90 degrees, the scale will be different (assuming + // the page size is rectangular, not square). This variable flags whether + // the scale at the default rotation is the smaller of the two scales. + bool isSmallerOfRotatedScales = floor(cellRatio) != floor(pageRatio); + float fitScale = cellRatio; + if (isSmallerOfRotatedScales != bool(floor(fitScale))) { + fitScale = 1.0f / cellRatio; + } + + transform.PreTranslate( + NSAppUnitsToFloatPixels(contentPageSize.width / 2, aAppUnitsPerPixel), + NSAppUnitsToFloatPixels(contentPageSize.height / 2, + aAppUnitsPerPixel), + 0); + transform.PreScale(fitScale, fitScale, 1.0f); + transform.RotateZ(angle); + transform.PreTranslate( + NSAppUnitsToFloatPixels(-contentPageSize.width / 2, + aAppUnitsPerPixel), + NSAppUnitsToFloatPixels(-contentPageSize.height / 2, + aAppUnitsPerPixel), + 0); + } + } + + return transform; +} + +nsIFrame::ComputeTransformFunction nsPageFrame::GetTransformGetter() const { + return ComputePagesPerSheetAndPageSizeTransform; +} + +nsPageContentFrame* nsPageFrame::PageContentFrame() const { + nsIFrame* const frame = mFrames.FirstChild(); + MOZ_ASSERT(frame, "pageFrame must have one child"); + MOZ_ASSERT(frame->IsPageContentFrame(), + "pageFrame must have pageContentFrame as the first child"); + return static_cast<nsPageContentFrame*>(frame); +} + +nsSize nsPageFrame::ComputePageSize() const { + // Compute the expected page-size. + const nsPageFrame* const frame = + StaticPrefs::layout_css_allow_mixed_page_sizes() + ? this + : static_cast<nsPageFrame*>(FirstContinuation()); + const StylePageSize& pageSize = frame->PageContentFrame()->StylePage()->mSize; + nsSize size = PresContext()->GetPageSize(); + if (pageSize.IsSize()) { + // Use the specified size, + // ignoring sizes that include a zero width or height. + // These are also ignored in ServoStyleSet::GetPageSizeForPageName() + // when getting the paper size. + nscoord cssPageWidth = pageSize.AsSize().width.ToAppUnits(); + nscoord cssPageHeight = pageSize.AsSize().height.ToAppUnits(); + if (cssPageWidth > 0 && cssPageHeight > 0) { + return nsSize{cssPageWidth, cssPageHeight}; + } + // Invalid size; just return the default + return size; + } + + if (pageSize.IsOrientation()) { + // Ensure the correct orientation is applied. + if (pageSize.AsOrientation() == StylePageSizeOrientation::Portrait) { + if (size.width > size.height) { + std::swap(size.width, size.height); + } + } else { + MOZ_ASSERT(pageSize.AsOrientation() == + StylePageSizeOrientation::Landscape); + if (size.width < size.height) { + std::swap(size.width, size.height); + } + } + } else { + MOZ_ASSERT(pageSize.IsAuto(), "Impossible page-size value?"); + } + return size; +} + +float nsPageFrame::ComputeSinglePPSPageSizeScale( + const nsSize aContentPageSize) const { + MOZ_ASSERT(GetSharedPageData()->PagesPerSheetInfo()->mNumPages == 1, + "Only intended for the pps==1 case"); + MOZ_ASSERT(aContentPageSize == ComputePageSize(), + "Incorrect content page size"); + + // Check for the simplest case first, an auto page-size which requires no + // scaling at all. + { + const nsPageFrame* const frame = + StaticPrefs::layout_css_allow_mixed_page_sizes() + ? this + : static_cast<nsPageFrame*>(FirstContinuation()); + const StylePageSize& pageSize = + frame->PageContentFrame()->StylePage()->mSize; + if (pageSize.IsAuto()) { + return 1.0f; + } + } + + const nsContainerFrame* const parent = GetParent(); + MOZ_ASSERT(parent && parent->IsPrintedSheetFrame(), + "Parent of nsPageFrame should be PrintedSheetFrame"); + const auto* sheet = static_cast<const PrintedSheetFrame*>(parent); + + // Compute scaling due to a possible mismatch in the paper size we are + // printing to (from the pres context) and the specified page size when the + // content uses "@page {size: ...}" to specify a page size for the content. + float scale = 1.0f; + + const nsSize sheetSize = sheet->GetPrecomputedSheetSize(); + nscoord contentPageHeight = aContentPageSize.height; + // Scale down if the target is too wide. + if (aContentPageSize.width > sheetSize.width) { + scale *= float(sheetSize.width) / float(aContentPageSize.width); + contentPageHeight = NSToCoordRound(contentPageHeight * scale); + } + // Scale down if the target is too tall. + if (contentPageHeight > sheetSize.height) { + scale *= float(sheetSize.height) / float(contentPageHeight); + } + MOZ_ASSERT( + scale <= 1.0f, + "Page-size mismatches should only have caused us to scale down, not up."); + return scale; +} + +nsIFrame* nsPageFrame::FirstContinuation() const { + // Walk up to our grandparent, and then to down the grandparent's first + // child, and then that frame's first child. + // At every step we assert the frames are the type we expect them to be. + const nsContainerFrame* const parent = GetParent(); + MOZ_ASSERT(parent && parent->IsPrintedSheetFrame(), + "Parent of nsPageFrame should be PrintedSheetFrame"); + const nsContainerFrame* const pageSequenceFrame = parent->GetParent(); + MOZ_ASSERT(pageSequenceFrame && pageSequenceFrame->IsPageSequenceFrame(), + "Parent of PrintedSheetFrame should be nsPageSequenceFrame"); + const nsIFrame* const firstPrintedSheetFrame = + pageSequenceFrame->PrincipalChildList().FirstChild(); + MOZ_ASSERT( + firstPrintedSheetFrame && firstPrintedSheetFrame->IsPrintedSheetFrame(), + "Should have at least one child in nsPageSequenceFrame, and all " + "children of nsPageSequenceFrame should be PrintedSheetFrames"); + nsIFrame* const firstPageFrame = + static_cast<const nsContainerFrame*>(firstPrintedSheetFrame) + ->PrincipalChildList() + .FirstChild(); + MOZ_ASSERT(firstPageFrame && firstPageFrame->IsPageFrame(), + "Should have at least one child in PrintedSheetFrame, and all " + "children of PrintedSheetFrame should be nsPageFrames"); + MOZ_ASSERT(!firstPageFrame->GetPrevContinuation(), + "First descendent of nsPageSequenceFrame should not have a " + "previous continuation"); + return firstPageFrame; +} + +void nsPageFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder, + const nsDisplayListSet& aLists) { + nsDisplayList content(aBuilder); + nsDisplayListSet set(&content, &content, &content, &content, &content, + &content); + { + DisplayListClipState::AutoSaveRestore clipState(aBuilder); + clipState.Clear(); + + nsPresContext* const pc = PresContext(); + { + // We need to extend the building rect to include the specified page size + // (scaled by the print scaling factor), in case it is larger than the + // physical page size. In that case the nsPageFrame will be the size of + // the physical page, but the child nsPageContentFrame will be the larger + // specified page size. The more correct way to do this would be to fully + // reverse the result of ComputePagesPerSheetAndPageSizeTransform to + // handle this scaling, but this should have the same result and is + // easier. + const float scale = pc->GetPageScale(); + const nsSize pageSize = ComputePageSize(); + const nsRect scaledPageRect{0, 0, NSToCoordCeil(pageSize.width / scale), + NSToCoordCeil(pageSize.height / scale)}; + nsDisplayListBuilder::AutoBuildingDisplayList buildingForPageContentFrame( + aBuilder, this, scaledPageRect, scaledPageRect); + + nsContainerFrame::BuildDisplayList(aBuilder, set); + } + + if (pc->IsRootPaginatedDocument()) { + content.AppendNewToTop<nsDisplayHeaderFooter>(aBuilder, this); + + // For print-preview, show margin guides if requested in the settings. + if (pc->Type() == nsPresContext::eContext_PrintPreview && + mPD->mPrintSettings->GetShowMarginGuides()) { + content.AppendNewToTop<nsDisplayGeneric>( + aBuilder, this, PaintMarginGuides, "MarginGuides", + DisplayItemType::TYPE_MARGIN_GUIDES); + } + } + } + + // We'll be drawing the page with a (usually-trivial) + // N-pages-per-sheet transform applied, so our passed-in visible rect + // isn't meaningful while we're drawing our children, because the + // transform could scale down content whose coordinates are off-screen + // such that it ends up on-screen. So: we temporarily update the visible + // rect to be the child nsPageFrame's whole frame-rect (represented in + // this PrintedSheetFrame's coordinate space. + content.AppendNewToTop<nsDisplayTransform>( + aBuilder, this, &content, content.GetBuildingRect(), + nsDisplayTransform::WithTransformGetter); + + set.MoveTo(aLists); +} + +//------------------------------------------------------------------------------ +void nsPageFrame::DeterminePageNum() { + // If we have no previous continuation, we're page 1. Otherwise, we're + // just one more than our previous continuation's page number. + auto* prevContinuation = static_cast<nsPageFrame*>(GetPrevContinuation()); + mPageNum = prevContinuation ? prevContinuation->GetPageNum() + 1 : 1; +} + +void nsPageFrame::PaintHeaderFooter(gfxContext& aRenderingContext, nsPoint aPt, + bool aDisableSubpixelAA) { + nsPresContext* pc = PresContext(); + + nsRect rect(aPt, ComputePageSize()); + aRenderingContext.SetColor(sRGBColor::OpaqueBlack()); + + DrawTargetAutoDisableSubpixelAntialiasing disable( + aRenderingContext.GetDrawTarget(), aDisableSubpixelAA); + + // Get the FontMetrics to determine width.height of strings + nsFontMetrics::Params params; + params.userFontSet = pc->GetUserFontSet(); + params.textPerf = pc->GetTextPerfMetrics(); + params.featureValueLookup = pc->GetFontFeatureValuesLookup(); + RefPtr<nsFontMetrics> fontMet = pc->GetMetricsFor(mPD->mHeadFootFont, params); + + nscoord ascent = fontMet->MaxAscent(); + nscoord visibleHeight = fontMet->MaxHeight(); + + // print document headers and footers + nsString headerLeft, headerCenter, headerRight; + mPD->mPrintSettings->GetHeaderStrLeft(headerLeft); + mPD->mPrintSettings->GetHeaderStrCenter(headerCenter); + mPD->mPrintSettings->GetHeaderStrRight(headerRight); + DrawHeaderFooter(aRenderingContext, *fontMet, eHeader, headerLeft, + headerCenter, headerRight, rect, ascent, visibleHeight); + + nsString footerLeft, footerCenter, footerRight; + mPD->mPrintSettings->GetFooterStrLeft(footerLeft); + mPD->mPrintSettings->GetFooterStrCenter(footerCenter); + mPD->mPrintSettings->GetFooterStrRight(footerRight); + DrawHeaderFooter(aRenderingContext, *fontMet, eFooter, footerLeft, + footerCenter, footerRight, rect, ascent, visibleHeight); +} + +void nsPageFrame::SetSharedPageData(nsSharedPageData* aPD) { + mPD = aPD; + // Set the shared data into the page frame before reflow + PageContentFrame()->SetSharedPageData(mPD); +} + +nsIFrame* NS_NewPageBreakFrame(PresShell* aPresShell, ComputedStyle* aStyle) { + MOZ_ASSERT(aPresShell, "null PresShell"); + // check that we are only creating page break frames when printing + NS_ASSERTION(aPresShell->GetPresContext()->IsPaginated(), + "created a page break frame while not printing"); + + return new (aPresShell) + nsPageBreakFrame(aStyle, aPresShell->GetPresContext()); +} + +NS_IMPL_FRAMEARENA_HELPERS(nsPageBreakFrame) + +nsPageBreakFrame::nsPageBreakFrame(ComputedStyle* aStyle, + nsPresContext* aPresContext) + : nsLeafFrame(aStyle, aPresContext, kClassID) {} + +nsPageBreakFrame::~nsPageBreakFrame() = default; + +nscoord nsPageBreakFrame::GetIntrinsicISize() { + return nsPresContext::CSSPixelsToAppUnits(1); +} + +nscoord nsPageBreakFrame::GetIntrinsicBSize() { return 0; } + +void nsPageBreakFrame::Reflow(nsPresContext* aPresContext, + ReflowOutput& aReflowOutput, + const ReflowInput& aReflowInput, + nsReflowStatus& aStatus) { + DO_GLOBAL_REFLOW_COUNT("nsPageBreakFrame"); + DISPLAY_REFLOW(aPresContext, this, aReflowInput, aReflowOutput, aStatus); + MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!"); + + // Override reflow, since we don't want to deal with what our + // computed values are. + const WritingMode wm = aReflowInput.GetWritingMode(); + nscoord bSize = aReflowInput.AvailableBSize(); + if (aReflowInput.AvailableBSize() == NS_UNCONSTRAINEDSIZE) { + bSize = nscoord(0); + } else if (GetContent()->IsHTMLElement(nsGkAtoms::legend)) { + // If this is a page break frame for a _rendered legend_ then it should be + // ignored since these frames are inserted inside the fieldset's inner + // frame and thus "misplaced". nsFieldSetFrame::Reflow deals with these + // forced breaks explicitly instead. + const nsContainerFrame* parent = GetParent(); + if (parent && + parent->Style()->GetPseudoType() == PseudoStyleType::fieldsetContent) { + while ((parent = parent->GetParent())) { + if (const nsFieldSetFrame* const fieldset = do_QueryFrame(parent)) { + const auto* const legend = fieldset->GetLegend(); + if (legend && legend->GetContent() == GetContent()) { + bSize = nscoord(0); + } + break; + } + } + } + } + LogicalSize finalSize(wm, GetIntrinsicISize(), bSize); + // round the height down to the nearest pixel + // XXX(mats) why??? + finalSize.BSize(wm) -= + finalSize.BSize(wm) % nsPresContext::CSSPixelsToAppUnits(1); + aReflowOutput.SetSize(wm, finalSize); +} + +#ifdef DEBUG_FRAME_DUMP +nsresult nsPageBreakFrame::GetFrameName(nsAString& aResult) const { + return MakeFrameName(u"PageBreak"_ns, aResult); +} +#endif |