From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- accessible/base/TreeWalker.h | 142 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 accessible/base/TreeWalker.h (limited to 'accessible/base/TreeWalker.h') diff --git a/accessible/base/TreeWalker.h b/accessible/base/TreeWalker.h new file mode 100644 index 0000000000..9093d8187f --- /dev/null +++ b/accessible/base/TreeWalker.h @@ -0,0 +1,142 @@ +/* -*- 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/. */ + +#ifndef mozilla_a11y_TreeWalker_h_ +#define mozilla_a11y_TreeWalker_h_ + +#include "mozilla/Attributes.h" +#include +#include "mozilla/dom/ChildIterator.h" +#include "nsCOMPtr.h" + +class nsIContent; + +namespace mozilla { +namespace a11y { + +class LocalAccessible; +class DocAccessible; + +/** + * This class is used to walk the DOM tree to create accessible tree. + */ +class TreeWalker final { + public: + enum { + // used to walk the existing tree of the given node + eWalkCache = 1, + // used to walk the context tree starting from given node + eWalkContextTree = 2 | eWalkCache, + eScoped = 4 + }; + + /** + * Used to navigate and create if needed the accessible children. + */ + explicit TreeWalker(LocalAccessible* aContext); + + /** + * Used to navigate the accessible children relative to the anchor. + * + * @param aContext [in] container accessible for the given node, used to + * define accessible context + * @param aAnchorNode [in] the node the search will be prepared relative to + * @param aFlags [in] flags (see enum above) + */ + TreeWalker(LocalAccessible* aContext, nsIContent* aAnchorNode, + uint32_t aFlags = eWalkCache); + + /** + * Navigates the accessible children within the anchor node subtree. + */ + TreeWalker(DocAccessible* aDocument, nsIContent* aAnchorNode); + + ~TreeWalker(); + + /** + * Resets the walker state, and sets the given node as an anchor. Returns a + * first accessible element within the node including the node itself. + */ + LocalAccessible* Scope(nsIContent* aAnchorNode); + + /** + * Resets the walker state. + */ + void Reset() { + mPhase = eAtStart; + mStateStack.Clear(); + mARIAOwnsIdx = 0; + } + + /** + * Sets the walker state to the given child node if it's within the anchor. + */ + bool Seek(nsIContent* aChildNode); + + /** + * Return the next/prev accessible. + * + * @note Returned accessible is bound to the document, if the accessible is + * rejected during tree creation then the caller should be unbind it + * from the document. + */ + LocalAccessible* Next(); + LocalAccessible* Prev(); + + LocalAccessible* Context() const { return mContext; } + DocAccessible* Document() const { return mDoc; } + + private: + TreeWalker(); + TreeWalker(const TreeWalker&); + TreeWalker& operator=(const TreeWalker&); + + /** + * Return an accessible for the given node if any. + */ + LocalAccessible* AccessibleFor(nsIContent* aNode, uint32_t aFlags, + bool* aSkipSubtree); + + /** + * Create new state for the given node and push it on top of stack / at bottom + * of stack. + * + * @note State stack is used to navigate up/down the DOM subtree during + * accessible children search. + */ + dom::AllChildrenIterator* PushState(nsIContent* aContent, + bool aStartAtBeginning) { + return mStateStack.AppendElement( + dom::AllChildrenIterator(aContent, mChildFilter, aStartAtBeginning)); + } + dom::AllChildrenIterator* PrependState(nsIContent* aContent, + bool aStartAtBeginning) { + return mStateStack.InsertElementAt( + 0, dom::AllChildrenIterator(aContent, mChildFilter, aStartAtBeginning)); + } + + /** + * Pop state from stack. + */ + dom::AllChildrenIterator* PopState(); + + DocAccessible* mDoc; + LocalAccessible* mContext; + nsIContent* mAnchorNode; + + AutoTArray mStateStack; + uint32_t mARIAOwnsIdx; + + int32_t mChildFilter; + uint32_t mFlags; + + enum Phase { eAtStart, eAtDOM, eAtARIAOwns, eAtEnd }; + Phase mPhase; +}; + +} // namespace a11y +} // namespace mozilla + +#endif // mozilla_a11y_TreeWalker_h_ -- cgit v1.2.3