gecko/layout/generic/nsFrameList.cpp

610 lines
17 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Pierre Phaneuf <pp@ludusdesign.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/* class for maintaining a linked list of child frames */
#include "nsFrameList.h"
#include "nsIFrame.h"
#include "nsLayoutUtils.h"
#ifdef IBMBIDI
#include "nsCOMPtr.h"
#include "nsGkAtoms.h"
#include "nsILineIterator.h"
#include "nsBidiPresUtils.h"
#endif // IBMBIDI
const nsFrameList* nsFrameList::sEmptyList;
/* static */
nsresult
nsFrameList::Init()
{
NS_PRECONDITION(!sEmptyList, "Shouldn't be allocated");
sEmptyList = new nsFrameList();
if (!sEmptyList)
return NS_ERROR_OUT_OF_MEMORY;
return NS_OK;
}
void
nsFrameList::Destroy()
{
DestroyFrames();
delete this;
}
void
nsFrameList::DestroyFrames()
{
nsIFrame* next;
for (nsIFrame* frame = mFirstChild; frame; frame = next) {
next = frame->GetNextSibling();
frame->Destroy();
mFirstChild = next;
}
}
PRBool
nsFrameList::RemoveFrame(nsIFrame* aFrame, nsIFrame* aPrevSiblingHint)
{
NS_PRECONDITION(nsnull != aFrame, "null ptr");
if (aFrame) {
nsIFrame* nextFrame = aFrame->GetNextSibling();
if (aFrame == mFirstChild) {
mFirstChild = nextFrame;
aFrame->SetNextSibling(nsnull);
return PR_TRUE;
}
else {
nsIFrame* prevSibling = aPrevSiblingHint;
if (!prevSibling || prevSibling->GetNextSibling() != aFrame) {
prevSibling = GetPrevSiblingFor(aFrame);
}
if (prevSibling) {
prevSibling->SetNextSibling(nextFrame);
aFrame->SetNextSibling(nsnull);
return PR_TRUE;
}
}
}
// aFrame was not in the list.
return PR_FALSE;
}
PRBool
nsFrameList::RemoveFirstChild()
{
if (mFirstChild) {
RemoveFrame(mFirstChild);
return PR_TRUE;
}
return PR_FALSE;
}
PRBool
nsFrameList::DestroyFrame(nsIFrame* aFrame, nsIFrame* aPrevSiblingHint)
{
NS_PRECONDITION(nsnull != aFrame, "null ptr");
if (RemoveFrame(aFrame, aPrevSiblingHint)) {
aFrame->Destroy();
return PR_TRUE;
}
return PR_FALSE;
}
void
nsFrameList::InsertFrames(nsIFrame* aParent,
nsIFrame* aPrevSibling,
nsIFrame* aFrameList)
{
// XXXbz once we have fast access to last frames (and have an nsFrameList
// here, not an nsIFrame*), we should clean up this method significantly.
NS_PRECONDITION(nsnull != aFrameList, "null ptr");
if (nsnull != aFrameList) {
nsIFrame* lastNewFrame = nsnull;
if (aParent) {
for (nsIFrame* frame = aFrameList; frame;
frame = frame->GetNextSibling()) {
frame->SetParent(aParent);
lastNewFrame = frame;
}
}
// Get the last new frame if necessary
if (!lastNewFrame &&
((aPrevSibling && aPrevSibling->GetNextSibling()) ||
mFirstChild)) {
nsFrameList tmp(aFrameList);
lastNewFrame = tmp.LastChild();
}
// Link the new frames into the child list
if (!aPrevSibling) {
NS_ASSERTION(lastNewFrame || !mFirstChild,
"Should have lastNewFrame here");
if (lastNewFrame) {
lastNewFrame->SetNextSibling(mFirstChild);
}
mFirstChild = aFrameList;
}
else {
NS_ASSERTION(aFrameList->GetParent() == aPrevSibling->GetParent(),
"prev sibling has different parent");
nsIFrame* nextFrame = aPrevSibling->GetNextSibling();
NS_ASSERTION(!nextFrame ||
aFrameList->GetParent() == nextFrame->GetParent(),
"next sibling has different parent");
aPrevSibling->SetNextSibling(aFrameList);
NS_ASSERTION(lastNewFrame || !nextFrame, "Should have lastNewFrame here");
if (lastNewFrame) {
lastNewFrame->SetNextSibling(nextFrame);
}
}
}
#ifdef DEBUG
CheckForLoops();
#endif
}
nsFrameList
nsFrameList::ExtractHead(FrameLinkEnumerator& aLink)
{
NS_PRECONDITION(&aLink.List() == this, "Unexpected list");
NS_PRECONDITION(!aLink.PrevFrame() ||
aLink.PrevFrame()->GetNextSibling() ==
aLink.NextFrame(),
"Unexpected PrevFrame()");
NS_PRECONDITION(aLink.PrevFrame() ||
aLink.NextFrame() == FirstChild(),
"Unexpected NextFrame()");
NS_PRECONDITION(!aLink.PrevFrame() ||
aLink.NextFrame() != FirstChild(),
"Unexpected NextFrame()");
NS_PRECONDITION(aLink.mEnd == nsnull,
"Unexpected mEnd for frame link enumerator");
nsIFrame* prev = aLink.PrevFrame();
nsIFrame* newFirstFrame = nsnull;
if (prev) {
// Truncate the list after |prev| and hand the first part to our new list.
prev->SetNextSibling(nsnull);
newFirstFrame = mFirstChild;
mFirstChild = aLink.NextFrame();
// Now make sure aLink doesn't point to a frame we no longer have.
aLink.mPrev = nsnull;
}
// else aLink is pointing to before our first frame. Nothing to do.
return nsFrameList(newFirstFrame);
}
nsFrameList
nsFrameList::ExtractTail(FrameLinkEnumerator& aLink)
{
NS_PRECONDITION(&aLink.List() == this, "Unexpected list");
NS_PRECONDITION(!aLink.PrevFrame() ||
aLink.PrevFrame()->GetNextSibling() ==
aLink.NextFrame(),
"Unexpected PrevFrame()");
NS_PRECONDITION(aLink.PrevFrame() ||
aLink.NextFrame() == FirstChild(),
"Unexpected NextFrame()");
NS_PRECONDITION(!aLink.PrevFrame() ||
aLink.NextFrame() != FirstChild(),
"Unexpected NextFrame()");
NS_PRECONDITION(aLink.mEnd == nsnull,
"Unexpected mEnd for frame link enumerator");
nsIFrame* prev = aLink.PrevFrame();
nsIFrame* newFirstFrame;
if (prev) {
// Truncate the list after |prev| and hand the second part to our new list
prev->SetNextSibling(nsnull);
newFirstFrame = aLink.NextFrame();
} else {
// Hand the whole list over to our new list
newFirstFrame = mFirstChild;
mFirstChild = nsnull;
}
// Now make sure aLink doesn't point to a frame we no longer have.
aLink.mFrame = nsnull;
NS_POSTCONDITION(aLink.AtEnd(), "What's going on here?");
return nsFrameList(newFirstFrame);
}
nsIFrame*
nsFrameList::LastChild() const
{
nsIFrame* frame = mFirstChild;
if (!frame) {
return nsnull;
}
nsIFrame* next = frame->GetNextSibling();
while (next) {
frame = next;
next = frame->GetNextSibling();
}
return frame;
}
nsIFrame*
nsFrameList::FrameAt(PRInt32 aIndex) const
{
NS_PRECONDITION(aIndex >= 0, "invalid arg");
if (aIndex < 0) return nsnull;
nsIFrame* frame = mFirstChild;
while ((aIndex-- > 0) && frame) {
frame = frame->GetNextSibling();
}
return frame;
}
PRInt32
nsFrameList::IndexOf(nsIFrame* aFrame) const
{
PRInt32 count = 0;
for (nsIFrame* f = mFirstChild; f; f = f->GetNextSibling()) {
if (f == aFrame)
return count;
++count;
}
return -1;
}
PRBool
nsFrameList::ContainsFrame(const nsIFrame* aFrame) const
{
NS_PRECONDITION(nsnull != aFrame, "null ptr");
nsIFrame* frame = mFirstChild;
while (frame) {
if (frame == aFrame) {
return PR_TRUE;
}
frame = frame->GetNextSibling();
}
return PR_FALSE;
}
PRBool
nsFrameList::ContainsFrameBefore(const nsIFrame* aFrame, const nsIFrame* aEnd) const
{
NS_PRECONDITION(nsnull != aFrame, "null ptr");
nsIFrame* frame = mFirstChild;
while (frame) {
if (frame == aEnd) {
return PR_FALSE;
}
if (frame == aFrame) {
return PR_TRUE;
}
frame = frame->GetNextSibling();
}
return PR_FALSE;
}
PRInt32
nsFrameList::GetLength() const
{
PRInt32 count = 0;
nsIFrame* frame = mFirstChild;
while (frame) {
count++;
frame = frame->GetNextSibling();
}
return count;
}
static int CompareByContentOrder(const nsIFrame* aF1, const nsIFrame* aF2)
{
if (aF1->GetContent() != aF2->GetContent()) {
return nsLayoutUtils::CompareTreePosition(aF1->GetContent(), aF2->GetContent());
}
if (aF1 == aF2) {
return 0;
}
const nsIFrame* f;
for (f = aF2; f; f = f->GetPrevInFlow()) {
if (f == aF1) {
// f1 comes before f2 in the flow
return -1;
}
}
for (f = aF1; f; f = f->GetPrevInFlow()) {
if (f == aF2) {
// f1 comes after f2 in the flow
return 1;
}
}
NS_ASSERTION(PR_FALSE, "Frames for same content but not in relative flow order");
return 0;
}
class CompareByContentOrderComparator
{
public:
PRBool Equals(const nsIFrame* aA, const nsIFrame* aB) const {
return aA == aB;
}
PRBool LessThan(const nsIFrame* aA, const nsIFrame* aB) const {
return CompareByContentOrder(aA, aB) < 0;
}
};
void
nsFrameList::SortByContentOrder()
{
if (!mFirstChild)
return;
nsAutoTArray<nsIFrame*, 8> array;
nsIFrame* f;
for (f = mFirstChild; f; f = f->GetNextSibling()) {
array.AppendElement(f);
}
array.Sort(CompareByContentOrderComparator());
f = mFirstChild = array.ElementAt(0);
for (PRUint32 i = 1; i < array.Length(); ++i) {
nsIFrame* ff = array.ElementAt(i);
f->SetNextSibling(ff);
f = ff;
}
f->SetNextSibling(nsnull);
}
nsIFrame*
nsFrameList::GetPrevSiblingFor(nsIFrame* aFrame) const
{
NS_PRECONDITION(nsnull != aFrame, "null ptr");
if (aFrame == mFirstChild) {
return nsnull;
}
nsIFrame* frame = mFirstChild;
while (frame) {
nsIFrame* next = frame->GetNextSibling();
if (next == aFrame) {
break;
}
frame = next;
}
return frame;
}
#ifdef DEBUG
void
nsFrameList::List(FILE* out) const
{
fputs("<\n", out);
for (nsIFrame* frame = mFirstChild; frame;
frame = frame->GetNextSibling()) {
frame->List(out, 1);
}
fputs(">\n", out);
}
#endif
#ifdef IBMBIDI
nsIFrame*
nsFrameList::GetPrevVisualFor(nsIFrame* aFrame) const
{
if (!mFirstChild)
return nsnull;
nsIFrame* parent = mFirstChild->GetParent();
if (!parent)
return aFrame ? GetPrevSiblingFor(aFrame) : LastChild();
nsBidiLevel baseLevel = nsBidiPresUtils::GetFrameBaseLevel(mFirstChild);
nsBidiPresUtils* bidiUtils = mFirstChild->PresContext()->GetBidiUtils();
nsAutoLineIterator iter = parent->GetLineIterator();
if (!iter) {
// Parent is not a block Frame
if (parent->GetType() == nsGkAtoms::lineFrame) {
// Line frames are not bidi-splittable, so need to consider bidi reordering
if (baseLevel == NSBIDI_LTR) {
return bidiUtils->GetFrameToLeftOf(aFrame, mFirstChild, -1);
} else { // RTL
return bidiUtils->GetFrameToRightOf(aFrame, mFirstChild, -1);
}
} else {
// Just get the next or prev sibling, depending on block and frame direction.
nsBidiLevel frameEmbeddingLevel = nsBidiPresUtils::GetFrameEmbeddingLevel(mFirstChild);
if ((frameEmbeddingLevel & 1) == (baseLevel & 1)) {
return aFrame ? GetPrevSiblingFor(aFrame) : LastChild();
} else {
return aFrame ? aFrame->GetNextSibling() : mFirstChild;
}
}
}
// Parent is a block frame, so use the LineIterator to find the previous visual
// sibling on this line, or the last one on the previous line.
PRInt32 thisLine;
if (aFrame) {
thisLine = iter->FindLineContaining(aFrame);
if (thisLine < 0)
return nsnull;
} else {
thisLine = iter->GetNumLines();
}
nsIFrame* frame = nsnull;
nsIFrame* firstFrameOnLine;
PRInt32 numFramesOnLine;
nsRect lineBounds;
PRUint32 lineFlags;
if (aFrame) {
iter->GetLine(thisLine, &firstFrameOnLine, &numFramesOnLine, lineBounds, &lineFlags);
if (baseLevel == NSBIDI_LTR) {
frame = bidiUtils->GetFrameToLeftOf(aFrame, firstFrameOnLine, numFramesOnLine);
} else { // RTL
frame = bidiUtils->GetFrameToRightOf(aFrame, firstFrameOnLine, numFramesOnLine);
}
}
if (!frame && thisLine > 0) {
// Get the last frame of the previous line
iter->GetLine(thisLine - 1, &firstFrameOnLine, &numFramesOnLine, lineBounds, &lineFlags);
if (baseLevel == NSBIDI_LTR) {
frame = bidiUtils->GetFrameToLeftOf(nsnull, firstFrameOnLine, numFramesOnLine);
} else { // RTL
frame = bidiUtils->GetFrameToRightOf(nsnull, firstFrameOnLine, numFramesOnLine);
}
}
return frame;
}
nsIFrame*
nsFrameList::GetNextVisualFor(nsIFrame* aFrame) const
{
if (!mFirstChild)
return nsnull;
nsIFrame* parent = mFirstChild->GetParent();
if (!parent)
return aFrame ? GetPrevSiblingFor(aFrame) : mFirstChild;
nsBidiLevel baseLevel = nsBidiPresUtils::GetFrameBaseLevel(mFirstChild);
nsBidiPresUtils* bidiUtils = mFirstChild->PresContext()->GetBidiUtils();
nsAutoLineIterator iter = parent->GetLineIterator();
if (!iter) {
// Parent is not a block Frame
if (parent->GetType() == nsGkAtoms::lineFrame) {
// Line frames are not bidi-splittable, so need to consider bidi reordering
if (baseLevel == NSBIDI_LTR) {
return bidiUtils->GetFrameToRightOf(aFrame, mFirstChild, -1);
} else { // RTL
return bidiUtils->GetFrameToLeftOf(aFrame, mFirstChild, -1);
}
} else {
// Just get the next or prev sibling, depending on block and frame direction.
nsBidiLevel frameEmbeddingLevel = nsBidiPresUtils::GetFrameEmbeddingLevel(mFirstChild);
if ((frameEmbeddingLevel & 1) == (baseLevel & 1)) {
return aFrame ? aFrame->GetNextSibling() : mFirstChild;
} else {
return aFrame ? GetPrevSiblingFor(aFrame) : LastChild();
}
}
}
// Parent is a block frame, so use the LineIterator to find the next visual
// sibling on this line, or the first one on the next line.
PRInt32 thisLine;
if (aFrame) {
thisLine = iter->FindLineContaining(aFrame);
if (thisLine < 0)
return nsnull;
} else {
thisLine = -1;
}
nsIFrame* frame = nsnull;
nsIFrame* firstFrameOnLine;
PRInt32 numFramesOnLine;
nsRect lineBounds;
PRUint32 lineFlags;
if (aFrame) {
iter->GetLine(thisLine, &firstFrameOnLine, &numFramesOnLine, lineBounds, &lineFlags);
if (baseLevel == NSBIDI_LTR) {
frame = bidiUtils->GetFrameToRightOf(aFrame, firstFrameOnLine, numFramesOnLine);
} else { // RTL
frame = bidiUtils->GetFrameToLeftOf(aFrame, firstFrameOnLine, numFramesOnLine);
}
}
PRInt32 numLines = iter->GetNumLines();
if (!frame && thisLine < numLines - 1) {
// Get the first frame of the next line
iter->GetLine(thisLine + 1, &firstFrameOnLine, &numFramesOnLine, lineBounds, &lineFlags);
if (baseLevel == NSBIDI_LTR) {
frame = bidiUtils->GetFrameToRightOf(nsnull, firstFrameOnLine, numFramesOnLine);
} else { // RTL
frame = bidiUtils->GetFrameToLeftOf(nsnull, firstFrameOnLine, numFramesOnLine);
}
}
return frame;
}
#endif
#ifdef DEBUG
void
nsFrameList::CheckForLoops()
{
if (!mFirstChild) {
return;
}
// Simple algorithm to find a loop in a linked list -- advance pointers
// through it at speeds of 1 and 2, and if they ever get to be equal bail
nsIFrame *first = mFirstChild, *second = mFirstChild;
do {
first = first->GetNextSibling();
second = second->GetNextSibling();
if (!second) {
break;
}
second = second->GetNextSibling();
if (first == second) {
// Loop detected! Since second advances faster, they can't both be null;
// we would have broken out of the loop long ago.
NS_ERROR("loop in frame list. This will probably hang soon.");
break;
}
} while (first && second);
}
#endif