gecko-dev/layout/generic/nsPageFrame.cpp

711 lines
25 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "nsDeviceContext.h"
#include "nsLayoutUtils.h"
#include "nsPresContext.h"
#include "nsRenderingContext.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 "prlog.h"
#ifdef PR_LOGGING
extern PRLogModuleInfo *GetLayoutPrintingLog();
#define PR_PL(_p1) PR_LOG(GetLayoutPrintingLog(), PR_LOG_DEBUG, _p1)
#else
#define PR_PL(_p1)
#endif
using namespace mozilla;
using namespace mozilla::gfx;
nsPageFrame*
NS_NewPageFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) nsPageFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(nsPageFrame)
nsPageFrame::nsPageFrame(nsStyleContext* aContext)
: nsContainerFrame(aContext)
{
}
nsPageFrame::~nsPageFrame()
{
}
void
nsPageFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
DO_GLOBAL_REFLOW_COUNT("nsPageFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
aStatus = NS_FRAME_COMPLETE; // initialize out parameter
NS_ASSERTION(mFrames.FirstChild() &&
nsGkAtoms::pageContentFrame == mFrames.FirstChild()->GetType(),
"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;
}
nsHTMLReflowState kidReflowState(aPresContext, aReflowState, frame,
LogicalSize(frame->GetWritingMode(),
maxSize));
kidReflowState.mFlags.mIsTopOfPage = true;
kidReflowState.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.
nsMargin pageContentMargin;
const nsStyleSides& marginStyle = kidReflowState.mStyleMargin->mMargin;
NS_FOR_CSS_SIDES(side) {
if (marginStyle.GetUnit(side) == eStyleUnit_Auto) {
pageContentMargin.Side(side) = mPD->mReflowMargin.Side(side);
} else {
pageContentMargin.Side(side) = kidReflowState.ComputedPhysicalMargin().Side(side);
}
}
nscoord maxWidth = maxSize.width - pageContentMargin.LeftRight() / scale;
nscoord maxHeight;
if (maxSize.height == NS_UNCONSTRAINEDSIZE) {
maxHeight = NS_UNCONSTRAINEDSIZE;
} else {
maxHeight = maxSize.height - pageContentMargin.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) {
pageContentMargin.Side(side) = mPD->mReflowMargin.Side(side);
}
maxWidth = maxSize.width - pageContentMargin.LeftRight() / scale;
if (maxHeight != NS_UNCONSTRAINEDSIZE) {
maxHeight = maxSize.height - pageContentMargin.TopBottom() / scale;
}
}
kidReflowState.SetComputedWidth(maxWidth);
kidReflowState.SetComputedHeight(maxHeight);
// calc location of frame
nscoord xc = pageContentMargin.left;
nscoord yc = pageContentMargin.top;
// Get the child's desired size
ReflowChild(frame, aPresContext, aDesiredSize, kidReflowState, xc, yc, 0, aStatus);
// Place and size the child
FinishReflowChild(frame, aPresContext, aDesiredSize, &kidReflowState, xc, yc, 0);
NS_ASSERTION(!NS_FRAME_IS_FULLY_COMPLETE(aStatus) ||
!frame->GetNextInFlow(), "bad child flow list");
}
PR_PL(("PageFrame::Reflow %p ", this));
PR_PL(("[%d,%d][%d,%d]\n", aDesiredSize.Width(), aDesiredSize.Height(),
aReflowState.AvailableWidth(), aReflowState.AvailableHeight()));
// Return our desired size
WritingMode wm = aReflowState.GetWritingMode();
aDesiredSize.ISize(wm) = aReflowState.AvailableISize();
if (aReflowState.AvailableBSize() != NS_UNCONSTRAINEDSIZE) {
aDesiredSize.BSize(wm) = aReflowState.AvailableBSize();
}
aDesiredSize.SetOverflowAreasToDesiredBounds();
FinishAndStoreOverflow(&aDesiredSize);
PR_PL(("PageFrame::Reflow %p ", this));
PR_PL(("[%d,%d]\n", aReflowState.AvailableWidth(), aReflowState.AvailableHeight()));
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
}
nsIAtom*
nsPageFrame::GetType() const
{
return nsGkAtoms::pageFrame;
}
#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.get(), mPD->mDateTimeStr.get());
}
// 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) {
char16_t * uStr = nsTextFormatter::smprintf(mPD->mPageNumAndTotalsFormat.get(), mPageNum, mTotNumPages);
aNewStr.ReplaceSubstring(kPageAndTotal.get(), uStr);
nsMemory::Free(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) {
char16_t * uStr = nsTextFormatter::smprintf(mPD->mPageNumFormat.get(), mPageNum);
aNewStr.ReplaceSubstring(kPage.get(), uStr);
nsMemory::Free(uStr);
}
NS_NAMED_LITERAL_STRING(kTitle, "&T");
if (aStr.Find(kTitle) != kNotFound) {
aNewStr.ReplaceSubstring(kTitle.get(), mPD->mDocTitle.get());
}
NS_NAMED_LITERAL_STRING(kDocURL, "&U");
if (aStr.Find(kDocURL) != kNotFound) {
aNewStr.ReplaceSubstring(kDocURL.get(), mPD->mDocURL.get());
}
NS_NAMED_LITERAL_STRING(kPageTotal, "&L");
if (aStr.Find(kPageTotal) != kNotFound) {
char16_t * uStr = nsTextFormatter::smprintf(mPD->mPageNumFormat.get(), mTotNumPages);
aNewStr.ReplaceSubstring(kPageTotal.get(), uStr);
nsMemory::Free(uStr);
}
}
//------------------------------------------------------------------------------
nscoord nsPageFrame::GetXPosition(nsRenderingContext& aRenderingContext,
const nsRect& aRect,
int32_t aJust,
const nsString& aStr)
{
nscoord width = nsLayoutUtils::GetStringWidth(this, &aRenderingContext,
aStr.get(), aStr.Length());
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(nsRenderingContext& aRenderingContext,
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, aHeaderFooter,
nsIPrintSettings::kJustLeft, aStrLeft, aRect, aAscent,
aHeight, strSpace);
}
if (!aStrCenter.IsEmpty()) {
DrawHeaderFooter(aRenderingContext, aHeaderFooter,
nsIPrintSettings::kJustCenter, aStrCenter, aRect, aAscent,
aHeight, strSpace);
}
if (!aStrRight.IsEmpty()) {
DrawHeaderFooter(aRenderingContext, 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(nsRenderingContext& aRenderingContext,
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);
if ((aHeaderFooter == eHeader && aHeight < mPD->mReflowMargin.top) ||
(aHeaderFooter == eFooter && aHeight < mPD->mReflowMargin.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(&aRenderingContext, 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, aRect, aJust, str);
nscoord y;
if (aHeaderFooter == eHeader) {
y = aRect.y + mPD->mEdgePaperMargin.top;
} else {
y = aRect.YMost() - aHeight - mPD->mEdgePaperMargin.bottom;
}
DrawTarget* drawTarget = aRenderingContext.GetDrawTarget();
gfxContext* gfx = aRenderingContext.ThebesContext();
// set up new clip and draw the text
gfx->Save();
gfx->Clip(NSRectToSnappedRect(aRect, PresContext()->AppUnitsPerDevPixel(),
*drawTarget));
aRenderingContext.ThebesContext()->SetColor(NS_RGB(0,0,0));
nsLayoutUtils::DrawString(this, &aRenderingContext, str.get(), str.Length(), nsPoint(x, y + aAscent));
gfx->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->~nsDisplayItem();
continue;
}
}
newList.AppendToTop(i);
}
aList->AppendToTop(&newList);
}
static void
BuildDisplayListForExtraPage(nsDisplayListBuilder* aBuilder,
nsPageFrame* aPage, nsIFrame* aExtraPage,
const nsRect& aDirtyRect, 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, aDirtyRect, &list);
PruneDisplayListForExtraPage(aBuilder, aPage, aExtraPage, &list);
aList->AppendToTop(&list);
}
static nsIFrame*
GetNextPage(nsIFrame* aPageContentFrame)
{
// XXX ugh
nsIFrame* pageFrame = aPageContentFrame->GetParent();
NS_ASSERTION(pageFrame->GetType() == nsGkAtoms::pageFrame,
"pageContentFrame has unexpected parent");
nsIFrame* nextPageFrame = pageFrame->GetNextSibling();
if (!nextPageFrame)
return nullptr;
NS_ASSERTION(nextPageFrame->GetType() == nsGkAtoms::pageFrame,
"pageFrame's sibling is not a page frame...");
nsIFrame* f = nextPageFrame->GetFirstPrincipalChild();
NS_ASSERTION(f, "pageFrame has no page content frame!");
NS_ASSERTION(f->GetType() == nsGkAtoms::pageContentFrame,
"pageFrame's child is not page content!");
return f;
}
static void PaintHeaderFooter(nsIFrame* aFrame, nsRenderingContext* aCtx,
const nsRect& aDirtyRect, nsPoint aPt)
{
static_cast<nsPageFrame*>(aFrame)->PaintHeaderFooter(*aCtx, aPt);
}
static gfx::Matrix4x4 ComputePageTransform(nsIFrame* aFrame, float aAppUnitsPerPixel)
{
float scale = aFrame->PresContext()->GetPageScale();
return gfx::Matrix4x4::Scaling(scale, scale, 1);
}
//------------------------------------------------------------------------------
void
nsPageFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists)
{
nsDisplayListCollection set;
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 dirtyRect = child->GetVisualOverflowRectRelativeToSelf();
child->BuildDisplayListForStackingContext(aBuilder, dirtyRect, &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) {
BuildDisplayListForExtraPage(aBuilder, this, page,
dirtyRect + child->GetOffsetTo(page), &content);
}
// Invoke AutoBuildingDisplayList to ensure that the correct dirtyRect
// is used to compute the visible rect if AddCanvasBackgroundColorItem
// creates a display item.
nsDisplayListBuilder::AutoBuildingDisplayList
building(aBuilder, child, dirtyRect, 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.AppendNewToTop(new (aBuilder) nsDisplayTransform(aBuilder, child,
&content, content.GetVisibleRect(), ::ComputePageTransform));
set.Content()->AppendToTop(&content);
if (PresContext()->IsRootPaginatedDocument()) {
set.Content()->AppendNewToTop(new (aBuilder)
nsDisplayGeneric(aBuilder, this, ::PaintHeaderFooter,
"HeaderFooter",
nsDisplayItem::TYPE_HEADER_FOOTER));
}
set.MoveTo(aLists);
}
//------------------------------------------------------------------------------
void
nsPageFrame::SetPageNumInfo(int32_t aPageNumber, int32_t aTotalPages)
{
mPageNum = aPageNumber;
mTotNumPages = aTotalPages;
}
void
nsPageFrame::PaintHeaderFooter(nsRenderingContext& aRenderingContext,
nsPoint aPt)
{
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.ThebesContext()->SetColor(NS_RGB(0,0,0));
// Get the FontMetrics to determine width.height of strings
nsRefPtr<nsFontMetrics> fontMet;
pc->DeviceContext()->GetMetricsFor(mPD->mHeadFootFont, nullptr,
gfxFont::eHorizontal,
pc->GetUserFontSet(),
pc->GetTextPerfMetrics(),
*getter_AddRefs(fontMet));
aRenderingContext.SetFont(fontMet);
nscoord ascent = 0;
nscoord visibleHeight = 0;
if (fontMet) {
visibleHeight = fontMet->MaxHeight();
ascent = fontMet->MaxAscent();
}
// print document headers and footers
nsXPIDLString headerLeft, headerCenter, headerRight;
mPD->mPrintSettings->GetHeaderStrLeft(getter_Copies(headerLeft));
mPD->mPrintSettings->GetHeaderStrCenter(getter_Copies(headerCenter));
mPD->mPrintSettings->GetHeaderStrRight(getter_Copies(headerRight));
DrawHeaderFooter(aRenderingContext, eHeader,
headerLeft, headerCenter, headerRight,
rect, ascent, visibleHeight);
nsXPIDLString footerLeft, footerCenter, footerRight;
mPD->mPrintSettings->GetFooterStrLeft(getter_Copies(footerLeft));
mPD->mPrintSettings->GetFooterStrCenter(getter_Copies(footerCenter));
mPD->mPrintSettings->GetFooterStrRight(getter_Copies(footerRight));
DrawHeaderFooter(aRenderingContext, 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<nsPageContentFrame*>(mFrames.FirstChild());
if (pcf) {
pcf->SetSharedPageData(mPD);
}
}
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), mHaveReflowed(false)
{
}
nsPageBreakFrame::~nsPageBreakFrame()
{
}
nscoord
nsPageBreakFrame::GetIntrinsicISize()
{
return nsPresContext::CSSPixelsToAppUnits(1);
}
nscoord
nsPageBreakFrame::GetIntrinsicBSize()
{
return 0;
}
void
nsPageBreakFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
DO_GLOBAL_REFLOW_COUNT("nsPageBreakFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
// Override reflow, since we don't want to deal with what our
// computed values are.
WritingMode wm = aReflowState.GetWritingMode();
LogicalSize finalSize(wm, GetIntrinsicISize(),
aReflowState.AvailableBSize() == NS_UNCONSTRAINEDSIZE ?
0 : aReflowState.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;
aStatus = NS_FRAME_COMPLETE;
}
nsIAtom*
nsPageBreakFrame::GetType() const
{
return nsGkAtoms::pageBreakFrame;
}
#ifdef DEBUG_FRAME_DUMP
nsresult
nsPageBreakFrame::GetFrameName(nsAString& aResult) const
{
return MakeFrameName(NS_LITERAL_STRING("PageBreak"), aResult);
}
#endif