gecko-dev/layout/base/nsFrameTraversal.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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* 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
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*
* Software distributed under the License is distributed on an "AS IS" basis,
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* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org 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):
*
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* 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
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#include "nsCOMPtr.h"
#include "nsGkAtoms.h"
#include "nsFrameTraversal.h"
#include "nsFrameList.h"
#include "nsPlaceholderFrame.h"
class nsFrameIterator : public nsIFrameEnumerator
{
public:
typedef nsIFrame::ChildListID ChildListID;
NS_DECL_ISUPPORTS
virtual void First();
virtual void Next();
virtual nsIFrame* CurrentItem();
virtual bool IsDone();
virtual void Last();
virtual void Prev();
nsFrameIterator(nsPresContext* aPresContext, nsIFrame *aStart,
nsIteratorType aType, bool aLockScroll, bool aFollowOOFs);
protected:
void setCurrent(nsIFrame *aFrame){mCurrent = aFrame;}
nsIFrame *getCurrent(){return mCurrent;}
void setStart(nsIFrame *aFrame){mStart = aFrame;}
nsIFrame *getStart(){return mStart;}
nsIFrame *getLast(){return mLast;}
void setLast(nsIFrame *aFrame){mLast = aFrame;}
PRInt8 getOffEdge(){return mOffEdge;}
void setOffEdge(PRInt8 aOffEdge){mOffEdge = aOffEdge;}
void SetLockInScrollView(bool aLockScroll){mLockScroll = aLockScroll;}
/*
Our own versions of the standard frame tree navigation
methods, which, if the iterator is following out-of-flows,
apply the following rules for placeholder frames:
- If a frame HAS a placeholder frame, getting its parent
gets the placeholder's parent.
- If a frame's first child or next/prev sibling IS a
placeholder frame, then we instead return the real frame.
- If a frame HAS a placeholder frame, getting its next/prev
sibling gets the placeholder frame's next/prev sibling.
These are all applied recursively to support multiple levels of
placeholders.
*/
nsIFrame* GetParentFrame(nsIFrame* aFrame);
// like GetParentFrame but returns null once a popup frame is reached
nsIFrame* GetParentFrameNotPopup(nsIFrame* aFrame);
nsIFrame* GetFirstChild(nsIFrame* aFrame);
nsIFrame* GetLastChild(nsIFrame* aFrame);
nsIFrame* GetNextSibling(nsIFrame* aFrame);
nsIFrame* GetPrevSibling(nsIFrame* aFrame);
/*
These methods are overridden by the bidi visual iterator to have the
semantics of "get first child in visual order", "get last child in visual
order", "get next sibling in visual order" and "get previous sibling in visual
order".
*/
virtual nsIFrame* GetFirstChildInner(nsIFrame* aFrame);
virtual nsIFrame* GetLastChildInner(nsIFrame* aFrame);
virtual nsIFrame* GetNextSiblingInner(nsIFrame* aFrame);
virtual nsIFrame* GetPrevSiblingInner(nsIFrame* aFrame);
nsIFrame* GetPlaceholderFrame(nsIFrame* aFrame);
bool IsPopupFrame(nsIFrame* aFrame);
nsPresContext* mPresContext;
bool mLockScroll;
bool mFollowOOFs;
nsIteratorType mType;
private:
nsIFrame *mStart;
nsIFrame *mCurrent;
nsIFrame *mLast; //the last one that was in current;
PRInt8 mOffEdge; //0= no -1 to far prev, 1 to far next;
};
// Bidi visual iterator
class nsVisualIterator: public nsFrameIterator
{
public:
nsVisualIterator(nsPresContext* aPresContext, nsIFrame *aStart,
nsIteratorType aType, bool aLockScroll, bool aFollowOOFs) :
nsFrameIterator(aPresContext, aStart, aType, aLockScroll, aFollowOOFs) {}
protected:
nsIFrame* GetFirstChildInner(nsIFrame* aFrame);
nsIFrame* GetLastChildInner(nsIFrame* aFrame);
nsIFrame* GetNextSiblingInner(nsIFrame* aFrame);
nsIFrame* GetPrevSiblingInner(nsIFrame* aFrame);
};
/************IMPLEMENTATIONS**************/
nsresult NS_CreateFrameTraversal(nsIFrameTraversal** aResult)
{
NS_ENSURE_ARG_POINTER(aResult);
*aResult = nsnull;
nsCOMPtr<nsIFrameTraversal> t(new nsFrameTraversal());
*aResult = t;
NS_ADDREF(*aResult);
return NS_OK;
}
nsresult
NS_NewFrameTraversal(nsIFrameEnumerator **aEnumerator,
nsPresContext* aPresContext,
nsIFrame *aStart,
nsIteratorType aType,
bool aVisual,
bool aLockInScrollView,
bool aFollowOOFs)
{
if (!aEnumerator || !aStart)
return NS_ERROR_NULL_POINTER;
nsCOMPtr<nsIFrameEnumerator> trav;
if (aVisual) {
trav = new nsVisualIterator(aPresContext, aStart, aType,
aLockInScrollView, aFollowOOFs);
} else {
trav = new nsFrameIterator(aPresContext, aStart, aType,
aLockInScrollView, aFollowOOFs);
}
trav.forget(aEnumerator);
return NS_OK;
}
nsFrameTraversal::nsFrameTraversal()
{
}
nsFrameTraversal::~nsFrameTraversal()
{
}
NS_IMPL_ISUPPORTS1(nsFrameTraversal,nsIFrameTraversal)
NS_IMETHODIMP
nsFrameTraversal::NewFrameTraversal(nsIFrameEnumerator **aEnumerator,
nsPresContext* aPresContext,
nsIFrame *aStart,
PRInt32 aType,
bool aVisual,
bool aLockInScrollView,
bool aFollowOOFs)
{
return NS_NewFrameTraversal(aEnumerator, aPresContext, aStart,
static_cast<nsIteratorType>(aType),
aVisual, aLockInScrollView, aFollowOOFs);
}
// nsFrameIterator implementation
NS_IMPL_ISUPPORTS1(nsFrameIterator, nsIFrameEnumerator)
nsFrameIterator::nsFrameIterator(nsPresContext* aPresContext, nsIFrame *aStart,
nsIteratorType aType, bool aLockInScrollView,
bool aFollowOOFs)
{
mOffEdge = 0;
mPresContext = aPresContext;
if (aFollowOOFs && aStart)
aStart = nsPlaceholderFrame::GetRealFrameFor(aStart);
setStart(aStart);
setCurrent(aStart);
setLast(aStart);
mType = aType;
SetLockInScrollView(aLockInScrollView);
mFollowOOFs = aFollowOOFs;
}
nsIFrame*
nsFrameIterator::CurrentItem()
{
if (mOffEdge)
return nsnull;
return mCurrent;
}
bool
nsFrameIterator::IsDone()
{
return mOffEdge != 0;
}
void
nsFrameIterator::First()
{
mCurrent = mStart;
}
static bool
IsRootFrame(nsIFrame* aFrame)
{
nsIAtom* atom = aFrame->GetType();
return (atom == nsGkAtoms::canvasFrame) ||
(atom == nsGkAtoms::rootFrame);
}
void
nsFrameIterator::Last()
{
nsIFrame* result;
nsIFrame* parent = getCurrent();
// If the current frame is a popup, don't move farther up the tree.
// Otherwise, get the nearest root frame or popup.
if (parent->GetType() != nsGkAtoms::menuPopupFrame) {
while (!IsRootFrame(parent) && (result = GetParentFrameNotPopup(parent)))
parent = result;
}
while ((result = GetLastChild(parent))) {
parent = result;
}
setCurrent(parent);
if (!parent)
setOffEdge(1);
}
void
nsFrameIterator::Next()
{
// recursive-oid method to get next frame
nsIFrame *result = nsnull;
nsIFrame *parent = getCurrent();
if (!parent)
parent = getLast();
if (mType == eLeaf) {
// Drill down to first leaf
while ((result = GetFirstChild(parent))) {
parent = result;
}
} else if (mType == ePreOrder) {
result = GetFirstChild(parent);
if (result)
parent = result;
}
if (parent != getCurrent()) {
result = parent;
} else {
while (parent) {
result = GetNextSibling(parent);
if (result) {
if (mType != ePreOrder) {
parent = result;
while ((result = GetFirstChild(parent))) {
parent = result;
}
result = parent;
}
break;
}
else {
result = GetParentFrameNotPopup(parent);
if (!result || IsRootFrame(result) ||
(mLockScroll && result->GetType() == nsGkAtoms::scrollFrame)) {
result = nsnull;
break;
}
if (mType == ePostOrder)
break;
parent = result;
}
}
}
setCurrent(result);
if (!result) {
setOffEdge(1);
setLast(parent);
}
}
void
nsFrameIterator::Prev()
{
// recursive-oid method to get prev frame
nsIFrame *result = nsnull;
nsIFrame *parent = getCurrent();
if (!parent)
parent = getLast();
if (mType == eLeaf) {
// Drill down to last leaf
while ((result = GetLastChild(parent))) {
parent = result;
}
} else if (mType == ePostOrder) {
result = GetLastChild(parent);
if (result)
parent = result;
}
if (parent != getCurrent()) {
result = parent;
} else {
while (parent) {
result = GetPrevSibling(parent);
if (result) {
if (mType != ePostOrder) {
parent = result;
while ((result = GetLastChild(parent))) {
parent = result;
}
result = parent;
}
break;
} else {
result = GetParentFrameNotPopup(parent);
if (!result || IsRootFrame(result) ||
(mLockScroll && result->GetType() == nsGkAtoms::scrollFrame)) {
result = nsnull;
break;
}
if (mType == ePreOrder)
break;
parent = result;
}
}
}
setCurrent(result);
if (!result) {
setOffEdge(-1);
setLast(parent);
}
}
nsIFrame*
nsFrameIterator::GetParentFrame(nsIFrame* aFrame)
{
if (mFollowOOFs)
aFrame = GetPlaceholderFrame(aFrame);
if (aFrame)
return aFrame->GetParent();
return nsnull;
}
nsIFrame*
nsFrameIterator::GetParentFrameNotPopup(nsIFrame* aFrame)
{
if (mFollowOOFs)
aFrame = GetPlaceholderFrame(aFrame);
if (aFrame) {
nsIFrame* parent = aFrame->GetParent();
if (!IsPopupFrame(parent))
return parent;
}
return nsnull;
}
nsIFrame*
nsFrameIterator::GetFirstChild(nsIFrame* aFrame)
{
nsIFrame* result = GetFirstChildInner(aFrame);
if (mLockScroll && result && result->GetType() == nsGkAtoms::scrollFrame)
return nsnull;
if (result && mFollowOOFs) {
result = nsPlaceholderFrame::GetRealFrameFor(result);
if (IsPopupFrame(result))
result = GetNextSibling(result);
}
return result;
}
nsIFrame*
nsFrameIterator::GetLastChild(nsIFrame* aFrame)
{
nsIFrame* result = GetLastChildInner(aFrame);
if (mLockScroll && result && result->GetType() == nsGkAtoms::scrollFrame)
return nsnull;
if (result && mFollowOOFs) {
result = nsPlaceholderFrame::GetRealFrameFor(result);
if (IsPopupFrame(result))
result = GetPrevSibling(result);
}
return result;
}
nsIFrame*
nsFrameIterator::GetNextSibling(nsIFrame* aFrame)
{
nsIFrame* result = nsnull;
if (mFollowOOFs)
aFrame = GetPlaceholderFrame(aFrame);
if (aFrame) {
result = GetNextSiblingInner(aFrame);
if (result && mFollowOOFs)
result = nsPlaceholderFrame::GetRealFrameFor(result);
}
if (mFollowOOFs && IsPopupFrame(result))
result = GetNextSibling(result);
return result;
}
nsIFrame*
nsFrameIterator::GetPrevSibling(nsIFrame* aFrame)
{
nsIFrame* result = nsnull;
if (mFollowOOFs)
aFrame = GetPlaceholderFrame(aFrame);
if (aFrame) {
result = GetPrevSiblingInner(aFrame);
if (result && mFollowOOFs)
result = nsPlaceholderFrame::GetRealFrameFor(result);
}
if (mFollowOOFs && IsPopupFrame(result))
result = GetPrevSibling(result);
return result;
}
nsIFrame*
nsFrameIterator::GetFirstChildInner(nsIFrame* aFrame) {
return aFrame->GetFirstPrincipalChild();
}
nsIFrame*
nsFrameIterator::GetLastChildInner(nsIFrame* aFrame) {
return aFrame->PrincipalChildList().LastChild();
}
nsIFrame*
nsFrameIterator::GetNextSiblingInner(nsIFrame* aFrame) {
return aFrame->GetNextSibling();
}
nsIFrame*
nsFrameIterator::GetPrevSiblingInner(nsIFrame* aFrame) {
return aFrame->GetPrevSibling();
}
nsIFrame*
nsFrameIterator::GetPlaceholderFrame(nsIFrame* aFrame)
{
nsIFrame* result = aFrame;
nsIPresShell *presShell = mPresContext->GetPresShell();
if (presShell) {
nsIFrame* placeholder = presShell->GetPlaceholderFrameFor(aFrame);
if (placeholder)
result = placeholder;
}
if (result != aFrame)
result = GetPlaceholderFrame(result);
return result;
}
bool
nsFrameIterator::IsPopupFrame(nsIFrame* aFrame)
{
return (aFrame &&
aFrame->GetStyleDisplay()->mDisplay == NS_STYLE_DISPLAY_POPUP);
}
// nsVisualIterator implementation
nsIFrame*
nsVisualIterator::GetFirstChildInner(nsIFrame* aFrame) {
return aFrame->PrincipalChildList().GetNextVisualFor(nsnull);
}
nsIFrame*
nsVisualIterator::GetLastChildInner(nsIFrame* aFrame) {
return aFrame->PrincipalChildList().GetPrevVisualFor(nsnull);
}
nsIFrame*
nsVisualIterator::GetNextSiblingInner(nsIFrame* aFrame) {
nsIFrame* parent = GetParentFrame(aFrame);
if (!parent)
return nsnull;
return parent->PrincipalChildList().GetNextVisualFor(aFrame);
}
nsIFrame*
nsVisualIterator::GetPrevSiblingInner(nsIFrame* aFrame) {
nsIFrame* parent = GetParentFrame(aFrame);
if (!parent)
return nsnull;
return parent->PrincipalChildList().GetPrevVisualFor(aFrame);
}