/* -*- 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/gfx/2D.h" #include "gfxContext.h" #include "nsDeviceContext.h" #include "nsFontMetrics.h" #include "nsLayoutUtils.h" #include "nsPresContext.h" #include "nsGkAtoms.h" #include "nsIPresShell.h" #include "nsPageContentFrame.h" #include "nsDisplayList.h" #include "nsLayoutUtils.h" // for function BinarySearchForPosition #include "nsSimplePageSequenceFrame.h" // for nsSharedPageData #include "nsTextFormatter.h" // for page number localization formatting #include "nsBidiUtils.h" #include "nsIPrintSettings.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(nsIPresShell* aPresShell, nsStyleContext* aContext) { return new (aPresShell) nsPageFrame(aContext); } NS_IMPL_FRAMEARENA_HELPERS(nsPageFrame) NS_QUERYFRAME_HEAD(nsPageFrame) NS_QUERYFRAME_ENTRY(nsPageFrame) NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame) nsPageFrame::nsPageFrame(nsStyleContext* aContext) : nsContainerFrame(aContext, kClassID) { } nsPageFrame::~nsPageFrame() { } void nsPageFrame::Reflow(nsPresContext* aPresContext, ReflowOutput& aDesiredSize, const ReflowInput& aReflowInput, nsReflowStatus& aStatus) { MarkInReflow(); DO_GLOBAL_REFLOW_COUNT("nsPageFrame"); DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, aStatus); MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!"); NS_ASSERTION(mFrames.FirstChild() && mFrames.FirstChild()->IsPageContentFrame(), "pageFrame must have a pageContentFrame child"); // Resize our frame allowing it only to be as big as we are // XXX Pay attention to the page's border and padding... if (mFrames.NotEmpty()) { nsIFrame* frame = mFrames.FirstChild(); // 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 nscoord avHeight; if (mPD->mReflowSize.height == NS_UNCONSTRAINEDSIZE) { avHeight = NS_UNCONSTRAINEDSIZE; } else { avHeight = mPD->mReflowSize.height; } nsSize maxSize(mPD->mReflowSize.width, avHeight); float scale = aPresContext->GetPageScale(); maxSize.width = NSToCoordCeil(maxSize.width / scale); if (maxSize.height != NS_UNCONSTRAINEDSIZE) { maxSize.height = NSToCoordCeil(maxSize.height / scale); } // Get the number of Twips per pixel from the PresContext nscoord onePixelInTwips = nsPresContext::CSSPixelsToAppUnits(1); // insurance against infinite reflow, when reflowing less than a pixel // XXX Shouldn't we do something more friendly when invalid margins // are set? if (maxSize.width < onePixelInTwips || maxSize.height < onePixelInTwips) { aDesiredSize.ClearSize(); NS_WARNING("Reflow aborted; no space for content"); return; } ReflowInput kidReflowInput(aPresContext, aReflowInput, frame, LogicalSize(frame->GetWritingMode(), maxSize)); kidReflowInput.mFlags.mIsTopOfPage = true; kidReflowInput.mFlags.mTableIsSplittable = true; // Use the margins given in the @page rule. // If a margin is 'auto', use the margin from the print settings for that side. const nsStyleSides& marginStyle = kidReflowInput.mStyleMargin->mMargin; NS_FOR_CSS_SIDES(side) { if (marginStyle.GetUnit(side) == eStyleUnit_Auto) { mPageContentMargin.Side(side) = mPD->mReflowMargin.Side(side); } else { mPageContentMargin.Side(side) = kidReflowInput.ComputedPhysicalMargin().Side(side); } } nscoord maxWidth = maxSize.width - mPageContentMargin.LeftRight() / scale; nscoord maxHeight; if (maxSize.height == NS_UNCONSTRAINEDSIZE) { maxHeight = NS_UNCONSTRAINEDSIZE; } else { maxHeight = maxSize.height - mPageContentMargin.TopBottom() / scale; } // Check the width and height, if they're too small we reset the margins // back to the default. if (maxWidth < onePixelInTwips || (maxHeight != NS_UNCONSTRAINEDSIZE && maxHeight < onePixelInTwips)) { NS_FOR_CSS_SIDES(side) { mPageContentMargin.Side(side) = mPD->mReflowMargin.Side(side); } maxWidth = maxSize.width - mPageContentMargin.LeftRight() / scale; if (maxHeight != NS_UNCONSTRAINEDSIZE) { maxHeight = maxSize.height - mPageContentMargin.TopBottom() / scale; } } kidReflowInput.SetComputedWidth(maxWidth); kidReflowInput.SetComputedHeight(maxHeight); // calc location of frame nscoord xc = mPageContentMargin.left; nscoord yc = mPageContentMargin.top; // Get the child's desired size ReflowChild(frame, aPresContext, aDesiredSize, kidReflowInput, xc, yc, 0, aStatus); // Place and size the child FinishReflowChild(frame, aPresContext, aDesiredSize, &kidReflowInput, xc, yc, 0); NS_ASSERTION(!aStatus.IsFullyComplete() || !frame->GetNextInFlow(), "bad child flow list"); } PR_PL(("PageFrame::Reflow %p ", this)); PR_PL(("[%d,%d][%d,%d]\n", aDesiredSize.Width(), aDesiredSize.Height(), aReflowInput.AvailableWidth(), aReflowInput.AvailableHeight())); // Return our desired size WritingMode wm = aReflowInput.GetWritingMode(); aDesiredSize.ISize(wm) = aReflowInput.AvailableISize(); if (aReflowInput.AvailableBSize() != NS_UNCONSTRAINEDSIZE) { aDesiredSize.BSize(wm) = aReflowInput.AvailableBSize(); } aDesiredSize.SetOverflowAreasToDesiredBounds(); FinishAndStoreOverflow(&aDesiredSize); PR_PL(("PageFrame::Reflow %p ", this)); PR_PL(("[%d,%d]\n", aReflowInput.AvailableWidth(), aReflowInput.AvailableHeight())); NS_FRAME_SET_TRUNCATION(aStatus, aReflowInput, aDesiredSize); } #ifdef DEBUG_FRAME_DUMP nsresult nsPageFrame::GetFrameName(nsAString& aResult) const { return MakeFrameName(NS_LITERAL_STRING("Page"), 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 NS_NAMED_LITERAL_STRING(kDate, "&D"); 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 NS_NAMED_LITERAL_STRING(kPageAndTotal, "&PT"); if (aStr.Find(kPageAndTotal) != kNotFound) { nsAutoString uStr; nsTextFormatter::ssprintf(uStr, mPD->mPageNumAndTotalsFormat.get(), mPageNum, mTotNumPages); 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 NS_NAMED_LITERAL_STRING(kPage, "&P"); if (aStr.Find(kPage) != kNotFound) { nsAutoString uStr; nsTextFormatter::ssprintf(uStr, mPD->mPageNumFormat.get(), mPageNum); aNewStr.ReplaceSubstring(kPage, uStr); } NS_NAMED_LITERAL_STRING(kTitle, "&T"); if (aStr.Find(kTitle) != kNotFound) { aNewStr.ReplaceSubstring(kTitle, mPD->mDocTitle); } NS_NAMED_LITERAL_STRING(kDocURL, "&U"); if (aStr.Find(kDocURL) != kNotFound) { aNewStr.ReplaceSubstring(kDocURL, mPD->mDocURL); } NS_NAMED_LITERAL_STRING(kPageTotal, "&L"); if (aStr.Find(kPageTotal) != kNotFound) { nsAutoString uStr; nsTextFormatter::ssprintf(uStr, mPD->mPageNumFormat.get(), mTotNumPages); 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 ot 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; nscoord strSpace = aRect.width / 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) { nscoord contentWidth = aWidth - (mPD->mEdgePaperMargin.left + mPD->mEdgePaperMargin.right); DrawTarget* drawTarget = aRenderingContext.GetDrawTarget(); if ((aHeaderFooter == eHeader && aHeight < mPageContentMargin.top) || (aHeaderFooter == eFooter && aHeight < mPageContentMargin.bottom)) { nsAutoString str; ProcessSpecialCodes(aStr, str); int32_t indx; int32_t textWidth = 0; const char16_t* text = str.get(); int32_t len = (int32_t)str.Length(); if (len == 0) { return; // bail is empty string } // 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(contentWidth), indx, textWidth)) { if (indx < len-1 ) { // we can't fit in all the text if (indx > 3) { // But we can fit in at least 4 chars. Show all but 3 of them, then // an ellipsis. // XXXbz for non-plane0 text, this may be cutting things in the // middle of a codepoint! Also, we have no guarantees that the three // dots will fit in the space the three chars we removed took up with // these font metrics! str.Truncate(indx-3); 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(); } // cacl 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(Color(0.f, 0.f, 0.f)); nsLayoutUtils::DrawString(this, aFontMetrics, &aRenderingContext, str.get(), str.Length(), nsPoint(x, y + aAscent), nullptr, DrawStringFlags::eForceHorizontal); aRenderingContext.Restore(); } } /** * Remove all leaf display items that are not for descendants of * aBuilder->GetReferenceFrame() from aList. * @param aPage the page we're constructing the display list for * @param aExtraPage the page we constructed aList for * @param aList the list that is modified in-place */ static void PruneDisplayListForExtraPage(nsDisplayListBuilder* aBuilder, nsPageFrame* aPage, nsIFrame* aExtraPage, nsDisplayList* aList) { nsDisplayList newList; while (true) { nsDisplayItem* i = aList->RemoveBottom(); if (!i) break; nsDisplayList* subList = i->GetSameCoordinateSystemChildren(); if (subList) { PruneDisplayListForExtraPage(aBuilder, aPage, aExtraPage, subList); i->UpdateBounds(aBuilder); } else { nsIFrame* f = i->Frame(); if (!nsLayoutUtils::IsProperAncestorFrameCrossDoc(aPage, f)) { // We're throwing this away so call its destructor now. The memory // is owned by aBuilder which destroys all items at once. i->Destroy(aBuilder); continue; } } newList.AppendToTop(i); } aList->AppendToTop(&newList); } static void BuildDisplayListForExtraPage(nsDisplayListBuilder* aBuilder, nsPageFrame* aPage, nsIFrame* aExtraPage, nsDisplayList* aList) { // The only content in aExtraPage we care about is out-of-flow content whose // placeholders have occurred in aPage. If // NS_FRAME_FORCE_DISPLAY_LIST_DESCEND_INTO is not set, then aExtraPage has // no such content. if (!aExtraPage->HasAnyStateBits(NS_FRAME_FORCE_DISPLAY_LIST_DESCEND_INTO)) { return; } nsDisplayList list; aExtraPage->BuildDisplayListForStackingContext(aBuilder, &list); PruneDisplayListForExtraPage(aBuilder, aPage, aExtraPage, &list); aList->AppendToTop(&list); } static nsIFrame* GetNextPage(nsIFrame* aPageContentFrame) { // XXX ugh nsIFrame* pageFrame = aPageContentFrame->GetParent(); NS_ASSERTION(pageFrame->IsPageFrame(), "pageContentFrame has unexpected parent"); nsIFrame* nextPageFrame = pageFrame->GetNextSibling(); if (!nextPageFrame) return nullptr; NS_ASSERTION(nextPageFrame->IsPageFrame(), "pageFrame's sibling is not a page frame..."); nsIFrame* f = nextPageFrame->PrincipalChildList().FirstChild(); NS_ASSERTION(f, "pageFrame has no page content frame!"); NS_ASSERTION(f->IsPageContentFrame(), "pageFrame's child is not page content!"); return f; } static gfx::Matrix4x4 ComputePageTransform(nsIFrame* aFrame, float aAppUnitsPerPixel) { float scale = aFrame->PresContext()->GetPageScale(); return gfx::Matrix4x4::Scaling(scale, scale, 1); } class nsDisplayHeaderFooter : public nsDisplayItem { public: nsDisplayHeaderFooter(nsDisplayListBuilder* aBuilder, nsPageFrame *aFrame) : nsDisplayItem(aBuilder, aFrame) { MOZ_COUNT_CTOR(nsDisplayHeaderFooter); } #ifdef NS_BUILD_REFCNT_LOGGING virtual ~nsDisplayHeaderFooter() { MOZ_COUNT_DTOR(nsDisplayHeaderFooter); } #endif 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(mFrame)-> PaintHeaderFooter(*aCtx, ToReferenceFrame(), mDisableSubpixelAA); } NS_DISPLAY_DECL_NAME("HeaderFooter", TYPE_HEADER_FOOTER) virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) const override { bool snap; return GetBounds(aBuilder, &snap); } }; //------------------------------------------------------------------------------ void nsPageFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder, const nsDisplayListSet& aLists) { nsDisplayListCollection set(aBuilder); if (PresContext()->IsScreen()) { DisplayBorderBackgroundOutline(aBuilder, aLists); } nsIFrame *child = mFrames.FirstChild(); float scale = PresContext()->GetPageScale(); nsRect clipRect(nsPoint(0, 0), child->GetSize()); // Note: this computation matches how we compute maxSize.height // in nsPageFrame::Reflow nscoord expectedPageContentHeight = NSToCoordCeil(GetSize().height / scale); if (clipRect.height > expectedPageContentHeight) { // We're doing print-selection, with one long page-content frame. // Clip to the appropriate page-content slice for the current page. NS_ASSERTION(mPageNum > 0, "page num should be positive"); // Note: The pageContentFrame's y-position has been set such that a zero // y-value matches the top edge of the current page. So, to clip to the // current page's content (in coordinates *relative* to the page content // frame), we just negate its y-position and add the top margin. clipRect.y = NSToCoordCeil((-child->GetRect().y + mPD->mReflowMargin.top) / scale); clipRect.height = expectedPageContentHeight; NS_ASSERTION(clipRect.y < child->GetSize().height, "Should be clipping to region inside the page content bounds"); } clipRect += aBuilder->ToReferenceFrame(child); nsDisplayList content; { DisplayListClipState::AutoSaveRestore clipState(aBuilder); // Overwrite current clip, since we're going to wrap in a transform // and the current clip is no longer meaningful. clipState.Clear(); clipState.ClipContainingBlockDescendants(clipRect, nullptr); nsRect visibleRect = child->GetVisualOverflowRectRelativeToSelf(); nsDisplayListBuilder::AutoBuildingDisplayList buildingForChild(aBuilder, child, visibleRect, visibleRect, aBuilder->IsAtRootOfPseudoStackingContext()); child->BuildDisplayListForStackingContext(aBuilder, &content); // We may need to paint out-of-flow frames whose placeholders are // on other pages. Add those pages to our display list. Note that // out-of-flow frames can't be placed after their placeholders so // we don't have to process earlier pages. The display lists for // these extra pages are pruned so that only display items for the // page we currently care about (which we would have reached by // following placeholders to their out-of-flows) end up on the list. nsIFrame* page = child; while ((page = GetNextPage(page)) != nullptr) { nsRect childVisible = visibleRect + child->GetOffsetTo(page); nsDisplayListBuilder::AutoBuildingDisplayList buildingForChild(aBuilder, page, childVisible, childVisible, aBuilder->IsAtRootOfPseudoStackingContext()); BuildDisplayListForExtraPage(aBuilder, this, page, &content); } // Invoke AutoBuildingDisplayList to ensure that the correct visibleRect // is used to compute the visible rect if AddCanvasBackgroundColorItem // creates a display item. nsDisplayListBuilder::AutoBuildingDisplayList building(aBuilder, child, visibleRect, visibleRect, true); // Add the canvas background color to the bottom of the list. This // happens after we've built the list so that AddCanvasBackgroundColorItem // can monkey with the contents if necessary. nsRect backgroundRect = nsRect(aBuilder->ToReferenceFrame(child), child->GetSize()); PresContext()->GetPresShell()->AddCanvasBackgroundColorItem( *aBuilder, content, child, backgroundRect, NS_RGBA(0,0,0,0)); } content.AppendToTop(new (aBuilder) nsDisplayTransform(aBuilder, child, &content, content.GetVisibleRect(), ::ComputePageTransform)); set.Content()->AppendToTop(&content); if (PresContext()->IsRootPaginatedDocument()) { set.Content()->AppendToTop(new (aBuilder) nsDisplayHeaderFooter(aBuilder, this)); } set.MoveTo(aLists); } //------------------------------------------------------------------------------ void nsPageFrame::SetPageNumInfo(int32_t aPageNumber, int32_t aTotalPages) { mPageNum = aPageNumber; mTotNumPages = aTotalPages; } void nsPageFrame::PaintHeaderFooter(gfxContext& aRenderingContext, nsPoint aPt, bool aDisableSubpixelAA) { nsPresContext* pc = PresContext(); if (!mPD->mPrintSettings) { if (pc->Type() == nsPresContext::eContext_PrintPreview || pc->IsDynamic()) mPD->mPrintSettings = pc->GetPrintSettings(); if (!mPD->mPrintSettings) return; } nsRect rect(aPt, mRect.Size()); aRenderingContext.SetColor(Color(0.f, 0.f, 0.f)); 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(); RefPtr fontMet = pc->DeviceContext()->GetMetricsFor(mPD->mHeadFootFont, params); nscoord ascent = 0; nscoord visibleHeight = 0; if (fontMet) { visibleHeight = fontMet->MaxHeight(); ascent = fontMet->MaxAscent(); } // 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 nsPageContentFrame * pcf = static_cast(mFrames.FirstChild()); if (pcf) { pcf->SetSharedPageData(mPD); } } void nsPageFrame::AppendDirectlyOwnedAnonBoxes(nsTArray& aResult) { MOZ_ASSERT(mFrames.FirstChild() && mFrames.FirstChild()->IsPageContentFrame(), "pageFrame must have a pageContentFrame child"); aResult.AppendElement(mFrames.FirstChild()); } nsIFrame* NS_NewPageBreakFrame(nsIPresShell* aPresShell, nsStyleContext* aContext) { NS_PRECONDITION(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(aContext); } NS_IMPL_FRAMEARENA_HELPERS(nsPageBreakFrame) nsPageBreakFrame::nsPageBreakFrame(nsStyleContext* aContext) : nsLeafFrame(aContext, kClassID) , mHaveReflowed(false) { } nsPageBreakFrame::~nsPageBreakFrame() { } nscoord nsPageBreakFrame::GetIntrinsicISize() { return nsPresContext::CSSPixelsToAppUnits(1); } nscoord nsPageBreakFrame::GetIntrinsicBSize() { return 0; } void nsPageBreakFrame::Reflow(nsPresContext* aPresContext, ReflowOutput& aDesiredSize, const ReflowInput& aReflowInput, nsReflowStatus& aStatus) { DO_GLOBAL_REFLOW_COUNT("nsPageBreakFrame"); DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, 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. WritingMode wm = aReflowInput.GetWritingMode(); LogicalSize finalSize(wm, GetIntrinsicISize(), aReflowInput.AvailableBSize() == NS_UNCONSTRAINEDSIZE ? 0 : aReflowInput.AvailableBSize()); // round the height down to the nearest pixel finalSize.BSize(wm) -= finalSize.BSize(wm) % nsPresContext::CSSPixelsToAppUnits(1); aDesiredSize.SetSize(wm, finalSize); // Note: not using NS_FRAME_FIRST_REFLOW here, since it's not clear whether // DidReflow will always get called before the next Reflow() call. mHaveReflowed = true; } #ifdef DEBUG_FRAME_DUMP nsresult nsPageBreakFrame::GetFrameName(nsAString& aResult) const { return MakeFrameName(NS_LITERAL_STRING("PageBreak"), aResult); } #endif