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gecko-dev/accessible/base/nsAccessiblePivot.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=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 "nsAccessiblePivot.h"
#include "HyperTextAccessible.h"
#include "nsAccUtils.h"
#include "States.h"
#include "xpcAccessibleDocument.h"
using namespace mozilla::a11y;
/**
* An object that stores a given traversal rule during the pivot movement.
*/
class RuleCache
{
public:
explicit RuleCache(nsIAccessibleTraversalRule* aRule) :
mRule(aRule), mAcceptRoles(nullptr),
mAcceptRolesLength{0}, mPreFilter{0} { }
~RuleCache () {
if (mAcceptRoles)
free(mAcceptRoles);
}
nsresult ApplyFilter(Accessible* aAccessible, uint16_t* aResult);
private:
nsCOMPtr<nsIAccessibleTraversalRule> mRule;
uint32_t* mAcceptRoles;
uint32_t mAcceptRolesLength;
uint32_t mPreFilter;
};
////////////////////////////////////////////////////////////////////////////////
// nsAccessiblePivot
nsAccessiblePivot::nsAccessiblePivot(Accessible* aRoot) :
mRoot(aRoot), mModalRoot(nullptr), mPosition(nullptr),
mStartOffset(-1), mEndOffset(-1)
{
NS_ASSERTION(aRoot, "A root accessible is required");
}
nsAccessiblePivot::~nsAccessiblePivot()
{
}
////////////////////////////////////////////////////////////////////////////////
// nsISupports
NS_IMPL_CYCLE_COLLECTION(nsAccessiblePivot, mRoot, mPosition, mObservers)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsAccessiblePivot)
NS_INTERFACE_MAP_ENTRY(nsIAccessiblePivot)
NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIAccessiblePivot)
NS_INTERFACE_MAP_END
NS_IMPL_CYCLE_COLLECTING_ADDREF(nsAccessiblePivot)
NS_IMPL_CYCLE_COLLECTING_RELEASE(nsAccessiblePivot)
////////////////////////////////////////////////////////////////////////////////
// nsIAccessiblePivot
NS_IMETHODIMP
nsAccessiblePivot::GetRoot(nsIAccessible** aRoot)
{
NS_ENSURE_ARG_POINTER(aRoot);
NS_IF_ADDREF(*aRoot = ToXPC(mRoot));
return NS_OK;
}
NS_IMETHODIMP
nsAccessiblePivot::GetPosition(nsIAccessible** aPosition)
{
NS_ENSURE_ARG_POINTER(aPosition);
NS_IF_ADDREF(*aPosition = ToXPC(mPosition));
return NS_OK;
}
NS_IMETHODIMP
nsAccessiblePivot::SetPosition(nsIAccessible* aPosition)
{
RefPtr<Accessible> position = nullptr;
if (aPosition) {
position = aPosition->ToInternalAccessible();
if (!position || !IsDescendantOf(position, GetActiveRoot()))
return NS_ERROR_INVALID_ARG;
}
// Swap old position with new position, saves us an AddRef/Release.
mPosition.swap(position);
int32_t oldStart = mStartOffset, oldEnd = mEndOffset;
mStartOffset = mEndOffset = -1;
NotifyOfPivotChange(position, oldStart, oldEnd,
nsIAccessiblePivot::REASON_NONE, false);
return NS_OK;
}
NS_IMETHODIMP
nsAccessiblePivot::GetModalRoot(nsIAccessible** aModalRoot)
{
NS_ENSURE_ARG_POINTER(aModalRoot);
NS_IF_ADDREF(*aModalRoot = ToXPC(mModalRoot));
return NS_OK;
}
NS_IMETHODIMP
nsAccessiblePivot::SetModalRoot(nsIAccessible* aModalRoot)
{
Accessible* modalRoot = nullptr;
if (aModalRoot) {
modalRoot = aModalRoot->ToInternalAccessible();
if (!modalRoot || !IsDescendantOf(modalRoot, mRoot))
return NS_ERROR_INVALID_ARG;
}
mModalRoot = modalRoot;
return NS_OK;
}
NS_IMETHODIMP
nsAccessiblePivot::GetStartOffset(int32_t* aStartOffset)
{
NS_ENSURE_ARG_POINTER(aStartOffset);
*aStartOffset = mStartOffset;
return NS_OK;
}
NS_IMETHODIMP
nsAccessiblePivot::GetEndOffset(int32_t* aEndOffset)
{
NS_ENSURE_ARG_POINTER(aEndOffset);
*aEndOffset = mEndOffset;
return NS_OK;
}
NS_IMETHODIMP
nsAccessiblePivot::SetTextRange(nsIAccessibleText* aTextAccessible,
int32_t aStartOffset, int32_t aEndOffset,
bool aIsFromUserInput, uint8_t aArgc)
{
NS_ENSURE_ARG(aTextAccessible);
// Check that start offset is smaller than end offset, and that if a value is
// smaller than 0, both should be -1.
NS_ENSURE_TRUE(aStartOffset <= aEndOffset &&
(aStartOffset >= 0 || (aStartOffset != -1 && aEndOffset != -1)),
NS_ERROR_INVALID_ARG);
nsCOMPtr<nsIAccessible> xpcAcc = do_QueryInterface(aTextAccessible);
NS_ENSURE_ARG(xpcAcc);
RefPtr<Accessible> acc = xpcAcc->ToInternalAccessible();
NS_ENSURE_ARG(acc);
HyperTextAccessible* position = acc->AsHyperText();
if (!position || !IsDescendantOf(position, GetActiveRoot()))
return NS_ERROR_INVALID_ARG;
// Make sure the given offsets don't exceed the character count.
if (aEndOffset > static_cast<int32_t>(position->CharacterCount()))
return NS_ERROR_FAILURE;
int32_t oldStart = mStartOffset, oldEnd = mEndOffset;
mStartOffset = aStartOffset;
mEndOffset = aEndOffset;
mPosition.swap(acc);
NotifyOfPivotChange(acc, oldStart, oldEnd,
nsIAccessiblePivot::REASON_TEXT,
(aArgc > 0) ? aIsFromUserInput : true);
return NS_OK;
}
// Traversal functions
NS_IMETHODIMP
nsAccessiblePivot::MoveNext(nsIAccessibleTraversalRule* aRule,
nsIAccessible* aAnchor, bool aIncludeStart,
bool aIsFromUserInput, uint8_t aArgc, bool* aResult)
{
NS_ENSURE_ARG(aResult);
NS_ENSURE_ARG(aRule);
*aResult = false;
Accessible* anchor = mPosition;
if (aArgc > 0 && aAnchor)
anchor = aAnchor->ToInternalAccessible();
if (anchor && (anchor->IsDefunct() || !IsDescendantOf(anchor, GetActiveRoot())))
return NS_ERROR_NOT_IN_TREE;
nsresult rv = NS_OK;
Accessible* accessible =
SearchForward(anchor, aRule, (aArgc > 1) ? aIncludeStart : false, &rv);
NS_ENSURE_SUCCESS(rv, rv);
if (accessible)
*aResult = MovePivotInternal(accessible, nsIAccessiblePivot::REASON_NEXT,
(aArgc > 2) ? aIsFromUserInput : true);
return NS_OK;
}
NS_IMETHODIMP
nsAccessiblePivot::MovePrevious(nsIAccessibleTraversalRule* aRule,
nsIAccessible* aAnchor,
bool aIncludeStart, bool aIsFromUserInput,
uint8_t aArgc, bool* aResult)
{
NS_ENSURE_ARG(aResult);
NS_ENSURE_ARG(aRule);
*aResult = false;
Accessible* anchor = mPosition;
if (aArgc > 0 && aAnchor)
anchor = aAnchor->ToInternalAccessible();
if (anchor && (anchor->IsDefunct() || !IsDescendantOf(anchor, GetActiveRoot())))
return NS_ERROR_NOT_IN_TREE;
nsresult rv = NS_OK;
Accessible* accessible =
SearchBackward(anchor, aRule, (aArgc > 1) ? aIncludeStart : false, &rv);
NS_ENSURE_SUCCESS(rv, rv);
if (accessible)
*aResult = MovePivotInternal(accessible, nsIAccessiblePivot::REASON_PREV,
(aArgc > 2) ? aIsFromUserInput : true);
return NS_OK;
}
NS_IMETHODIMP
nsAccessiblePivot::MoveFirst(nsIAccessibleTraversalRule* aRule,
bool aIsFromUserInput,
uint8_t aArgc, bool* aResult)
{
NS_ENSURE_ARG(aResult);
NS_ENSURE_ARG(aRule);
Accessible* root = GetActiveRoot();
NS_ENSURE_TRUE(root && !root->IsDefunct(), NS_ERROR_NOT_IN_TREE);
nsresult rv = NS_OK;
Accessible* accessible = SearchForward(root, aRule, true, &rv);
NS_ENSURE_SUCCESS(rv, rv);
if (accessible)
*aResult = MovePivotInternal(accessible, nsIAccessiblePivot::REASON_FIRST,
(aArgc > 0) ? aIsFromUserInput : true);
return NS_OK;
}
NS_IMETHODIMP
nsAccessiblePivot::MoveLast(nsIAccessibleTraversalRule* aRule,
bool aIsFromUserInput,
uint8_t aArgc, bool* aResult)
{
NS_ENSURE_ARG(aResult);
NS_ENSURE_ARG(aRule);
Accessible* root = GetActiveRoot();
NS_ENSURE_TRUE(root && !root->IsDefunct(), NS_ERROR_NOT_IN_TREE);
*aResult = false;
nsresult rv = NS_OK;
Accessible* lastAccessible = root;
Accessible* accessible = nullptr;
// First go to the last accessible in pre-order
while (lastAccessible->HasChildren())
lastAccessible = lastAccessible->LastChild();
// Search backwards from last accessible and find the last occurrence in the doc
accessible = SearchBackward(lastAccessible, aRule, true, &rv);
NS_ENSURE_SUCCESS(rv, rv);
if (accessible)
*aResult = MovePivotInternal(accessible, nsAccessiblePivot::REASON_LAST,
(aArgc > 0) ? aIsFromUserInput : true);
return NS_OK;
}
NS_IMETHODIMP
nsAccessiblePivot::MoveNextByText(TextBoundaryType aBoundary,
bool aIsFromUserInput, uint8_t aArgc,
bool* aResult)
{
NS_ENSURE_ARG(aResult);
*aResult = false;
int32_t tempStart = mStartOffset, tempEnd = mEndOffset;
Accessible* tempPosition = mPosition;
Accessible* root = GetActiveRoot();
while (true) {
NS_ENSURE_TRUE(tempPosition, NS_ERROR_UNEXPECTED);
Accessible* curPosition = tempPosition;
HyperTextAccessible* text = nullptr;
// Find the nearest text node using a preorder traversal starting from
// the current node.
if (!(text = tempPosition->AsHyperText())) {
text = SearchForText(tempPosition, false);
if (!text)
return NS_OK;
if (text != curPosition)
tempStart = tempEnd = -1;
tempPosition = text;
}
// If the search led to the parent of the node we started on (e.g. when
// starting on a text leaf), start the text movement from the end of that
// node, otherwise we just default to 0.
if (tempEnd == -1)
tempEnd = text == curPosition->Parent() ?
text->GetChildOffset(curPosition) : 0;
// If there's no more text on the current node, try to find the next text
// node; if there isn't one, bail out.
if (tempEnd == static_cast<int32_t>(text->CharacterCount())) {
if (tempPosition == root)
return NS_OK;
// If we're currently sitting on a link, try move to either the next
// sibling or the parent, whichever is closer to the current end
// offset. Otherwise, do a forward search for the next node to land on
// (we don't do this in the first case because we don't want to go to the
// subtree).
Accessible* sibling = tempPosition->NextSibling();
if (tempPosition->IsLink()) {
if (sibling && sibling->IsLink()) {
tempStart = tempEnd = -1;
tempPosition = sibling;
} else {
tempStart = tempPosition->StartOffset();
tempEnd = tempPosition->EndOffset();
tempPosition = tempPosition->Parent();
}
} else {
tempPosition = SearchForText(tempPosition, false);
if (!tempPosition)
return NS_OK;
tempStart = tempEnd = -1;
}
continue;
}
AccessibleTextBoundary startBoundary, endBoundary;
switch (aBoundary) {
case CHAR_BOUNDARY:
startBoundary = nsIAccessibleText::BOUNDARY_CHAR;
endBoundary = nsIAccessibleText::BOUNDARY_CHAR;
break;
case WORD_BOUNDARY:
startBoundary = nsIAccessibleText::BOUNDARY_WORD_START;
endBoundary = nsIAccessibleText::BOUNDARY_WORD_END;
break;
default:
return NS_ERROR_INVALID_ARG;
}
nsAutoString unusedText;
int32_t newStart = 0, newEnd = 0, currentEnd = tempEnd;
text->TextAtOffset(tempEnd, endBoundary, &newStart, &tempEnd, unusedText);
text->TextBeforeOffset(tempEnd, startBoundary, &newStart, &newEnd, unusedText);
int32_t potentialStart = newEnd == tempEnd ? newStart : newEnd;
tempStart = potentialStart > tempStart ? potentialStart : currentEnd;
// The offset range we've obtained might have embedded characters in it,
// limit the range to the start of the first occurrence of an embedded
// character.
Accessible* childAtOffset = nullptr;
for (int32_t i = tempStart; i < tempEnd; i++) {
childAtOffset = text->GetChildAtOffset(i);
if (childAtOffset && !childAtOffset->IsText()) {
tempEnd = i;
break;
}
}
// If there's an embedded character at the very start of the range, we
// instead want to traverse into it. So restart the movement with
// the child as the starting point.
if (childAtOffset && !childAtOffset->IsText() &&
tempStart == static_cast<int32_t>(childAtOffset->StartOffset())) {
tempPosition = childAtOffset;
tempStart = tempEnd = -1;
continue;
}
*aResult = true;
Accessible* startPosition = mPosition;
int32_t oldStart = mStartOffset, oldEnd = mEndOffset;
mPosition = tempPosition;
mStartOffset = tempStart;
mEndOffset = tempEnd;
NotifyOfPivotChange(startPosition, oldStart, oldEnd,
nsIAccessiblePivot::REASON_TEXT,
(aArgc > 0) ? aIsFromUserInput : true);
return NS_OK;
}
}
NS_IMETHODIMP
nsAccessiblePivot::MovePreviousByText(TextBoundaryType aBoundary,
bool aIsFromUserInput, uint8_t aArgc,
bool* aResult)
{
NS_ENSURE_ARG(aResult);
*aResult = false;
int32_t tempStart = mStartOffset, tempEnd = mEndOffset;
Accessible* tempPosition = mPosition;
Accessible* root = GetActiveRoot();
while (true) {
NS_ENSURE_TRUE(tempPosition, NS_ERROR_UNEXPECTED);
Accessible* curPosition = tempPosition;
HyperTextAccessible* text;
// Find the nearest text node using a reverse preorder traversal starting
// from the current node.
if (!(text = tempPosition->AsHyperText())) {
text = SearchForText(tempPosition, true);
if (!text)
return NS_OK;
if (text != curPosition)
tempStart = tempEnd = -1;
tempPosition = text;
}
// If the search led to the parent of the node we started on (e.g. when
// starting on a text leaf), start the text movement from the end of that
// node, otherwise we just default to 0.
if (tempStart == -1) {
if (tempPosition != curPosition)
tempStart = text == curPosition->Parent() ?
text->GetChildOffset(curPosition) : text->CharacterCount();
else
tempStart = 0;
}
// If there's no more text on the current node, try to find the previous
// text node; if there isn't one, bail out.
if (tempStart == 0) {
if (tempPosition == root)
return NS_OK;
// If we're currently sitting on a link, try move to either the previous
// sibling or the parent, whichever is closer to the current end
// offset. Otherwise, do a forward search for the next node to land on
// (we don't do this in the first case because we don't want to go to the
// subtree).
Accessible* sibling = tempPosition->PrevSibling();
if (tempPosition->IsLink()) {
if (sibling && sibling->IsLink()) {
HyperTextAccessible* siblingText = sibling->AsHyperText();
tempStart = tempEnd = siblingText ?
siblingText->CharacterCount() : -1;
tempPosition = sibling;
} else {
tempStart = tempPosition->StartOffset();
tempEnd = tempPosition->EndOffset();
tempPosition = tempPosition->Parent();
}
} else {
HyperTextAccessible* tempText = SearchForText(tempPosition, true);
if (!tempText)
return NS_OK;
tempPosition = tempText;
tempStart = tempEnd = tempText->CharacterCount();
}
continue;
}
AccessibleTextBoundary startBoundary, endBoundary;
switch (aBoundary) {
case CHAR_BOUNDARY:
startBoundary = nsIAccessibleText::BOUNDARY_CHAR;
endBoundary = nsIAccessibleText::BOUNDARY_CHAR;
break;
case WORD_BOUNDARY:
startBoundary = nsIAccessibleText::BOUNDARY_WORD_START;
endBoundary = nsIAccessibleText::BOUNDARY_WORD_END;
break;
default:
return NS_ERROR_INVALID_ARG;
}
nsAutoString unusedText;
int32_t newStart = 0, newEnd = 0, currentStart = tempStart, potentialEnd = 0;
text->TextBeforeOffset(tempStart, startBoundary, &newStart, &newEnd, unusedText);
if (newStart < tempStart)
tempStart = newEnd >= currentStart ? newStart : newEnd;
else // XXX: In certain odd cases newStart is equal to tempStart
text->TextBeforeOffset(tempStart - 1, startBoundary, &newStart,
&tempStart, unusedText);
text->TextAtOffset(tempStart, endBoundary, &newStart, &potentialEnd,
unusedText);
tempEnd = potentialEnd < tempEnd ? potentialEnd : currentStart;
// The offset range we've obtained might have embedded characters in it,
// limit the range to the start of the last occurrence of an embedded
// character.
Accessible* childAtOffset = nullptr;
for (int32_t i = tempEnd - 1; i >= tempStart; i--) {
childAtOffset = text->GetChildAtOffset(i);
if (childAtOffset && !childAtOffset->IsText()) {
tempStart = childAtOffset->EndOffset();
break;
}
}
// If there's an embedded character at the very end of the range, we
// instead want to traverse into it. So restart the movement with
// the child as the starting point.
if (childAtOffset && !childAtOffset->IsText() &&
tempEnd == static_cast<int32_t>(childAtOffset->EndOffset())) {
tempPosition = childAtOffset;
tempStart = tempEnd = childAtOffset->AsHyperText()->CharacterCount();
continue;
}
*aResult = true;
Accessible* startPosition = mPosition;
int32_t oldStart = mStartOffset, oldEnd = mEndOffset;
mPosition = tempPosition;
mStartOffset = tempStart;
mEndOffset = tempEnd;
NotifyOfPivotChange(startPosition, oldStart, oldEnd,
nsIAccessiblePivot::REASON_TEXT,
(aArgc > 0) ? aIsFromUserInput : true);
return NS_OK;
}
}
NS_IMETHODIMP
nsAccessiblePivot::MoveToPoint(nsIAccessibleTraversalRule* aRule,
int32_t aX, int32_t aY, bool aIgnoreNoMatch,
bool aIsFromUserInput, uint8_t aArgc,
bool* aResult)
{
NS_ENSURE_ARG_POINTER(aResult);
NS_ENSURE_ARG_POINTER(aRule);
*aResult = false;
Accessible* root = GetActiveRoot();
NS_ENSURE_TRUE(root && !root->IsDefunct(), NS_ERROR_NOT_IN_TREE);
RuleCache cache(aRule);
Accessible* match = nullptr;
Accessible* child = root->ChildAtPoint(aX, aY, Accessible::eDeepestChild);
while (child && root != child) {
uint16_t filtered = nsIAccessibleTraversalRule::FILTER_IGNORE;
nsresult rv = cache.ApplyFilter(child, &filtered);
NS_ENSURE_SUCCESS(rv, rv);
// Ignore any matching nodes that were below this one
if (filtered & nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE)
match = nullptr;
// Match if no node below this is a match
if ((filtered & nsIAccessibleTraversalRule::FILTER_MATCH) && !match) {
nsIntRect childRect = child->Bounds();
// Double-check child's bounds since the deepest child may have been out
// of bounds. This assures we don't return a false positive.
if (childRect.Contains(aX, aY))
match = child;
}
child = child->Parent();
}
if (match || !aIgnoreNoMatch)
*aResult = MovePivotInternal(match, nsIAccessiblePivot::REASON_POINT,
(aArgc > 0) ? aIsFromUserInput : true);
return NS_OK;
}
// Observer functions
NS_IMETHODIMP
nsAccessiblePivot::AddObserver(nsIAccessiblePivotObserver* aObserver)
{
NS_ENSURE_ARG(aObserver);
mObservers.AppendElement(aObserver);
return NS_OK;
}
NS_IMETHODIMP
nsAccessiblePivot::RemoveObserver(nsIAccessiblePivotObserver* aObserver)
{
NS_ENSURE_ARG(aObserver);
return mObservers.RemoveElement(aObserver) ? NS_OK : NS_ERROR_FAILURE;
}
// Private utility methods
bool
nsAccessiblePivot::IsDescendantOf(Accessible* aAccessible, Accessible* aAncestor)
{
if (!aAncestor || aAncestor->IsDefunct())
return false;
// XXX Optimize with IsInDocument() when appropriate. Blocked by bug 759875.
Accessible* accessible = aAccessible;
do {
if (accessible == aAncestor)
return true;
} while ((accessible = accessible->Parent()));
return false;
}
bool
nsAccessiblePivot::MovePivotInternal(Accessible* aPosition,
PivotMoveReason aReason,
bool aIsFromUserInput)
{
RefPtr<Accessible> oldPosition = mPosition.forget();
mPosition = aPosition;
int32_t oldStart = mStartOffset, oldEnd = mEndOffset;
mStartOffset = mEndOffset = -1;
return NotifyOfPivotChange(oldPosition, oldStart, oldEnd, aReason,
aIsFromUserInput);
}
Accessible*
nsAccessiblePivot::AdjustStartPosition(Accessible* aAccessible,
RuleCache& aCache,
uint16_t* aFilterResult,
nsresult* aResult)
{
Accessible* matched = aAccessible;
*aResult = aCache.ApplyFilter(aAccessible, aFilterResult);
if (aAccessible != mRoot && aAccessible != mModalRoot) {
for (Accessible* temp = aAccessible->Parent();
temp && temp != mRoot && temp != mModalRoot; temp = temp->Parent()) {
uint16_t filtered = nsIAccessibleTraversalRule::FILTER_IGNORE;
*aResult = aCache.ApplyFilter(temp, &filtered);
NS_ENSURE_SUCCESS(*aResult, nullptr);
if (filtered & nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE) {
*aFilterResult = filtered;
matched = temp;
}
}
}
if (aAccessible == mPosition && mStartOffset != -1 && mEndOffset != -1) {
HyperTextAccessible* text = aAccessible->AsHyperText();
if (text) {
matched = text->GetChildAtOffset(mStartOffset);
}
}
return matched;
}
Accessible*
nsAccessiblePivot::SearchBackward(Accessible* aAccessible,
nsIAccessibleTraversalRule* aRule,
bool aSearchCurrent,
nsresult* aResult)
{
*aResult = NS_OK;
// Initial position could be unset, in that case return null.
if (!aAccessible)
return nullptr;
RuleCache cache(aRule);
uint16_t filtered = nsIAccessibleTraversalRule::FILTER_IGNORE;
Accessible* accessible = AdjustStartPosition(aAccessible, cache,
&filtered, aResult);
NS_ENSURE_SUCCESS(*aResult, nullptr);
if (aSearchCurrent && (filtered & nsIAccessibleTraversalRule::FILTER_MATCH)) {
return accessible;
}
Accessible* root = GetActiveRoot();
while (accessible != root) {
Accessible* parent = accessible->Parent();
int32_t idxInParent = accessible->IndexInParent();
while (idxInParent > 0) {
if (!(accessible = parent->GetChildAt(--idxInParent)))
continue;
*aResult = cache.ApplyFilter(accessible, &filtered);
NS_ENSURE_SUCCESS(*aResult, nullptr);
Accessible* lastChild = nullptr;
while (!(filtered & nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE) &&
(lastChild = accessible->LastChild())) {
parent = accessible;
accessible = lastChild;
idxInParent = accessible->IndexInParent();
*aResult = cache.ApplyFilter(accessible, &filtered);
NS_ENSURE_SUCCESS(*aResult, nullptr);
}
if (filtered & nsIAccessibleTraversalRule::FILTER_MATCH)
return accessible;
}
if (!(accessible = parent))
break;
*aResult = cache.ApplyFilter(accessible, &filtered);
NS_ENSURE_SUCCESS(*aResult, nullptr);
if (filtered & nsIAccessibleTraversalRule::FILTER_MATCH)
return accessible;
}
return nullptr;
}
Accessible*
nsAccessiblePivot::SearchForward(Accessible* aAccessible,
nsIAccessibleTraversalRule* aRule,
bool aSearchCurrent,
nsresult* aResult)
{
*aResult = NS_OK;
// Initial position could be not set, in that case begin search from root.
Accessible* root = GetActiveRoot();
Accessible* accessible = (!aAccessible) ? root : aAccessible;
RuleCache cache(aRule);
uint16_t filtered = nsIAccessibleTraversalRule::FILTER_IGNORE;
accessible = AdjustStartPosition(accessible, cache, &filtered, aResult);
NS_ENSURE_SUCCESS(*aResult, nullptr);
if (aSearchCurrent && (filtered & nsIAccessibleTraversalRule::FILTER_MATCH))
return accessible;
while (true) {
Accessible* firstChild = nullptr;
while (!(filtered & nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE) &&
(firstChild = accessible->FirstChild())) {
accessible = firstChild;
*aResult = cache.ApplyFilter(accessible, &filtered);
NS_ENSURE_SUCCESS(*aResult, nullptr);
if (filtered & nsIAccessibleTraversalRule::FILTER_MATCH)
return accessible;
}
Accessible* sibling = nullptr;
Accessible* temp = accessible;
do {
if (temp == root)
break;
sibling = temp->NextSibling();
if (sibling)
break;
} while ((temp = temp->Parent()));
if (!sibling)
break;
accessible = sibling;
*aResult = cache.ApplyFilter(accessible, &filtered);
NS_ENSURE_SUCCESS(*aResult, nullptr);
if (filtered & nsIAccessibleTraversalRule::FILTER_MATCH)
return accessible;
}
return nullptr;
}
HyperTextAccessible*
nsAccessiblePivot::SearchForText(Accessible* aAccessible, bool aBackward)
{
Accessible* root = GetActiveRoot();
Accessible* accessible = aAccessible;
while (true) {
Accessible* child = nullptr;
while ((child = (aBackward ? accessible->LastChild() :
accessible->FirstChild()))) {
accessible = child;
if (child->IsHyperText())
return child->AsHyperText();
}
Accessible* sibling = nullptr;
Accessible* temp = accessible;
do {
if (temp == root)
break;
if (temp != aAccessible && temp->IsHyperText())
return temp->AsHyperText();
sibling = aBackward ? temp->PrevSibling() : temp->NextSibling();
if (sibling)
break;
} while ((temp = temp->Parent()));
if (!sibling)
break;
accessible = sibling;
if (accessible->IsHyperText())
return accessible->AsHyperText();
}
return nullptr;
}
bool
nsAccessiblePivot::NotifyOfPivotChange(Accessible* aOldPosition,
int32_t aOldStart, int32_t aOldEnd,
int16_t aReason, bool aIsFromUserInput)
{
if (aOldPosition == mPosition &&
aOldStart == mStartOffset && aOldEnd == mEndOffset)
return false;
nsCOMPtr<nsIAccessible> xpcOldPos = ToXPC(aOldPosition); // death grip
nsTObserverArray<nsCOMPtr<nsIAccessiblePivotObserver> >::ForwardIterator iter(mObservers);
while (iter.HasMore()) {
nsIAccessiblePivotObserver* obs = iter.GetNext();
obs->OnPivotChanged(this, xpcOldPos, aOldStart, aOldEnd, aReason,
aIsFromUserInput);
}
return true;
}
nsresult
RuleCache::ApplyFilter(Accessible* aAccessible, uint16_t* aResult)
{
*aResult = nsIAccessibleTraversalRule::FILTER_IGNORE;
if (!mAcceptRoles) {
nsresult rv = mRule->GetMatchRoles(&mAcceptRoles, &mAcceptRolesLength);
NS_ENSURE_SUCCESS(rv, rv);
rv = mRule->GetPreFilter(&mPreFilter);
NS_ENSURE_SUCCESS(rv, rv);
}
if (mPreFilter) {
uint64_t state = aAccessible->State();
if ((nsIAccessibleTraversalRule::PREFILTER_INVISIBLE & mPreFilter) &&
(state & states::INVISIBLE))
return NS_OK;
if ((nsIAccessibleTraversalRule::PREFILTER_OFFSCREEN & mPreFilter) &&
(state & states::OFFSCREEN))
return NS_OK;
if ((nsIAccessibleTraversalRule::PREFILTER_NOT_FOCUSABLE & mPreFilter) &&
!(state & states::FOCUSABLE))
return NS_OK;
if (nsIAccessibleTraversalRule::PREFILTER_ARIA_HIDDEN & mPreFilter) {
if (aAccessible->IsARIAHidden()) {
*aResult |= nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
return NS_OK;
}
}
if ((nsIAccessibleTraversalRule::PREFILTER_TRANSPARENT & mPreFilter) &&
!(state & states::OPAQUE1)) {
nsIFrame* frame = aAccessible->GetFrame();
if (frame->StyleEffects()->mOpacity == 0.0f) {
*aResult |= nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
return NS_OK;
}
}
}
if (mAcceptRolesLength > 0) {
uint32_t accessibleRole = aAccessible->Role();
bool matchesRole = false;
for (uint32_t idx = 0; idx < mAcceptRolesLength; idx++) {
matchesRole = mAcceptRoles[idx] == accessibleRole;
if (matchesRole)
break;
}
if (!matchesRole)
return NS_OK;
}
return mRule->Match(ToXPC(aAccessible), aResult);
}
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