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Diffstat (limited to 'accessible/base/nsAccessiblePivot.cpp')
| -rw-r--r-- | accessible/base/nsAccessiblePivot.cpp | 523 |
1 files changed, 523 insertions, 0 deletions
diff --git a/accessible/base/nsAccessiblePivot.cpp b/accessible/base/nsAccessiblePivot.cpp new file mode 100644 index 0000000000..ad25885507 --- /dev/null +++ b/accessible/base/nsAccessiblePivot.cpp @@ -0,0 +1,523 @@ +/* -*- 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 "Pivot.h" +#include "xpcAccessibleDocument.h" +#include "nsTArray.h" +#include "mozilla/Maybe.h" + +using namespace mozilla::a11y; +using mozilla::DebugOnly; +using mozilla::Maybe; + +/** + * An object that stores a given traversal rule during the pivot movement. + */ +class RuleCache : public PivotRule { + public: + explicit RuleCache(nsIAccessibleTraversalRule* aRule) + : mRule(aRule), mPreFilter{0} {} + ~RuleCache() {} + + virtual uint16_t Match(Accessible* aAcc) override; + + private: + nsCOMPtr<nsIAccessibleTraversalRule> mRule; + Maybe<nsTArray<uint32_t>> mAcceptRoles; + uint32_t mPreFilter; +}; + +//////////////////////////////////////////////////////////////////////////////// +// nsAccessiblePivot + +nsAccessiblePivot::nsAccessiblePivot(LocalAccessible* 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<LocalAccessible> 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, + nsIAccessiblePivot::NO_BOUNDARY, 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) { + LocalAccessible* 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<LocalAccessible> 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_NONE, + nsIAccessiblePivot::NO_BOUNDARY, + (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; + + LocalAccessible* anchor = mPosition; + if (aArgc > 0 && aAnchor) anchor = aAnchor->ToInternalAccessible(); + + if (anchor && + (anchor->IsDefunct() || !IsDescendantOf(anchor, GetActiveRoot()))) { + return NS_ERROR_NOT_IN_TREE; + } + + Pivot pivot(GetActiveRoot()); + RuleCache rule(aRule); + Accessible* newPos = + pivot.Next(anchor, rule, (aArgc > 1) ? aIncludeStart : false); + if (newPos && newPos->IsLocal()) { + *aResult = + MovePivotInternal(newPos->AsLocal(), nsIAccessiblePivot::REASON_NEXT, + (aArgc > 2) ? aIsFromUserInput : true); + } else if (newPos && newPos->IsRemote()) { + // we shouldn't ever end up with a proxy here, but if we do for some + // reason something is wrong. we should still return OK if we're null + return NS_ERROR_FAILURE; + } + + 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; + + LocalAccessible* anchor = mPosition; + if (aArgc > 0 && aAnchor) anchor = aAnchor->ToInternalAccessible(); + + if (anchor && + (anchor->IsDefunct() || !IsDescendantOf(anchor, GetActiveRoot()))) { + return NS_ERROR_NOT_IN_TREE; + } + + Pivot pivot(GetActiveRoot()); + RuleCache rule(aRule); + Accessible* newPos = + pivot.Prev(anchor, rule, (aArgc > 1) ? aIncludeStart : false); + if (newPos && newPos->IsLocal()) { + *aResult = + MovePivotInternal(newPos->AsLocal(), nsIAccessiblePivot::REASON_PREV, + (aArgc > 2) ? aIsFromUserInput : true); + } else if (newPos && newPos->IsRemote()) { + // we shouldn't ever end up with a proxy here, but if we do for some + // reason something is wrong. we should still return OK if we're null + return NS_ERROR_FAILURE; + } + + return NS_OK; +} + +NS_IMETHODIMP +nsAccessiblePivot::MoveFirst(nsIAccessibleTraversalRule* aRule, + bool aIsFromUserInput, uint8_t aArgc, + bool* aResult) { + NS_ENSURE_ARG(aResult); + NS_ENSURE_ARG(aRule); + + LocalAccessible* root = GetActiveRoot(); + NS_ENSURE_TRUE(root && !root->IsDefunct(), NS_ERROR_NOT_IN_TREE); + + Pivot pivot(GetActiveRoot()); + RuleCache rule(aRule); + Accessible* newPos = pivot.First(rule); + if (newPos && newPos->IsLocal()) { + *aResult = + MovePivotInternal(newPos->AsLocal(), nsIAccessiblePivot::REASON_FIRST, + (aArgc > 0) ? aIsFromUserInput : true); + } else if (newPos && newPos->IsRemote()) { + // we shouldn't ever end up with a proxy here, but if we do for some + // reason something is wrong. we should still return OK if we're null + return NS_ERROR_FAILURE; + } + + return NS_OK; +} + +NS_IMETHODIMP +nsAccessiblePivot::MoveLast(nsIAccessibleTraversalRule* aRule, + bool aIsFromUserInput, uint8_t aArgc, + bool* aResult) { + NS_ENSURE_ARG(aResult); + NS_ENSURE_ARG(aRule); + + LocalAccessible* root = GetActiveRoot(); + NS_ENSURE_TRUE(root && !root->IsDefunct(), NS_ERROR_NOT_IN_TREE); + + Pivot pivot(root); + RuleCache rule(aRule); + Accessible* newPos = pivot.Last(rule); + if (newPos && newPos->IsLocal()) { + *aResult = + MovePivotInternal(newPos->AsLocal(), nsIAccessiblePivot::REASON_LAST, + (aArgc > 0) ? aIsFromUserInput : true); + } else if (newPos && newPos->IsRemote()) { + // we shouldn't ever end up with a proxy here, but if we do for some + // reason something is wrong. we should still return OK if we're null + return NS_ERROR_FAILURE; + } + + return NS_OK; +} + +NS_IMETHODIMP +nsAccessiblePivot::MoveNextByText(TextBoundaryType aBoundary, + bool aIsFromUserInput, uint8_t aArgc, + bool* aResult) { + NS_ENSURE_ARG(aResult); + + *aResult = false; + + Pivot pivot(GetActiveRoot()); + + int32_t newStart = mStartOffset, newEnd = mEndOffset; + Accessible* newPos = pivot.NextText(mPosition, &newStart, &newEnd, aBoundary); + if (LocalAccessible* localNewPos = newPos ? newPos->AsLocal() : nullptr) { + *aResult = true; + int32_t oldStart = mStartOffset, oldEnd = mEndOffset; + LocalAccessible* oldPos = mPosition; + mStartOffset = newStart; + mEndOffset = newEnd; + mPosition = localNewPos; + NotifyOfPivotChange(oldPos, oldStart, oldEnd, + nsIAccessiblePivot::REASON_NEXT, aBoundary, + (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; + + Pivot pivot(GetActiveRoot()); + + int32_t newStart = mStartOffset, newEnd = mEndOffset; + Accessible* newPos = pivot.PrevText(mPosition, &newStart, &newEnd, aBoundary); + if (LocalAccessible* localNewPos = newPos ? newPos->AsLocal() : nullptr) { + *aResult = true; + int32_t oldStart = mStartOffset, oldEnd = mEndOffset; + LocalAccessible* oldPos = mPosition; + mStartOffset = newStart; + mEndOffset = newEnd; + mPosition = localNewPos; + NotifyOfPivotChange(oldPos, oldStart, oldEnd, + nsIAccessiblePivot::REASON_PREV, aBoundary, + (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; + + LocalAccessible* root = GetActiveRoot(); + NS_ENSURE_TRUE(root && !root->IsDefunct(), NS_ERROR_NOT_IN_TREE); + + RuleCache rule(aRule); + Pivot pivot(root); + + Accessible* newPos = pivot.AtPoint(aX, aY, rule); + if ((newPos && newPos->IsLocal()) || + !aIgnoreNoMatch) { // TODO does this need a proxy check? + *aResult = MovePivotInternal(newPos ? newPos->AsLocal() : nullptr, + nsIAccessiblePivot::REASON_POINT, + (aArgc > 0) ? aIsFromUserInput : true); + } else if (newPos && newPos->IsRemote()) { + // we shouldn't ever end up with a proxy here, but if we do for some + // reason something is wrong. we should still return OK if we're null + return NS_ERROR_FAILURE; + } + + 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(LocalAccessible* aAccessible, + LocalAccessible* aAncestor) { + if (!aAncestor || aAncestor->IsDefunct()) return false; + + // XXX Optimize with IsInDocument() when appropriate. Blocked by bug 759875. + LocalAccessible* accessible = aAccessible; + do { + if (accessible == aAncestor) return true; + } while ((accessible = accessible->LocalParent())); + + return false; +} + +bool nsAccessiblePivot::MovePivotInternal(LocalAccessible* aPosition, + PivotMoveReason aReason, + bool aIsFromUserInput) { + RefPtr<LocalAccessible> oldPosition = std::move(mPosition); + mPosition = aPosition; + int32_t oldStart = mStartOffset, oldEnd = mEndOffset; + mStartOffset = mEndOffset = -1; + + return NotifyOfPivotChange(oldPosition, oldStart, oldEnd, aReason, + nsIAccessiblePivot::NO_BOUNDARY, aIsFromUserInput); +} + +bool nsAccessiblePivot::NotifyOfPivotChange(LocalAccessible* aOldPosition, + int32_t aOldStart, int32_t aOldEnd, + int16_t aReason, + int16_t aBoundaryType, + bool aIsFromUserInput) { + if (aOldPosition == mPosition && aOldStart == mStartOffset && + aOldEnd == mEndOffset) { + return false; + } + + nsCOMPtr<nsIAccessible> xpcOldPos = ToXPC(aOldPosition); // death grip + for (nsIAccessiblePivotObserver* obs : mObservers.ForwardRange()) { + obs->OnPivotChanged(this, xpcOldPos, aOldStart, aOldEnd, ToXPC(mPosition), + mStartOffset, mEndOffset, aReason, aBoundaryType, + aIsFromUserInput); + } + + return true; +} + +uint16_t RuleCache::Match(Accessible* aAcc) { + uint16_t result = nsIAccessibleTraversalRule::FILTER_IGNORE; + + if (!mAcceptRoles) { + mAcceptRoles.emplace(); + DebugOnly<nsresult> rv = mRule->GetMatchRoles(*mAcceptRoles); + MOZ_ASSERT(NS_SUCCEEDED(rv)); + rv = mRule->GetPreFilter(&mPreFilter); + MOZ_ASSERT(NS_SUCCEEDED(rv)); + } + + if (mPreFilter) { + uint64_t state = aAcc->State(); + + if ((nsIAccessibleTraversalRule::PREFILTER_PLATFORM_PRUNED & mPreFilter) && + nsAccUtils::MustPrune(aAcc)) { + result |= nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE; + } + + if ((nsIAccessibleTraversalRule::PREFILTER_INVISIBLE & mPreFilter) && + (state & states::INVISIBLE)) { + return result; + } + + if ((nsIAccessibleTraversalRule::PREFILTER_OFFSCREEN & mPreFilter) && + (state & states::OFFSCREEN)) { + return result; + } + + if ((nsIAccessibleTraversalRule::PREFILTER_NOT_FOCUSABLE & mPreFilter) && + !(state & states::FOCUSABLE)) { + return result; + } + + if (nsIAccessibleTraversalRule::PREFILTER_TRANSPARENT & mPreFilter) { + if (aAcc->Opacity() == 0.0f) { + return result | nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE; + } + } + } + + if (mAcceptRoles->Length() > 0) { + uint32_t accessibleRole = aAcc->Role(); + bool matchesRole = false; + for (uint32_t idx = 0; idx < mAcceptRoles->Length(); idx++) { + matchesRole = mAcceptRoles->ElementAt(idx) == accessibleRole; + if (matchesRole) break; + } + + if (!matchesRole) { + return result; + } + } + + uint16_t matchResult = nsIAccessibleTraversalRule::FILTER_IGNORE; + + DebugOnly<nsresult> rv = mRule->Match(ToXPC(aAcc), &matchResult); + MOZ_ASSERT(NS_SUCCEEDED(rv)); + + return result | matchResult; +} |