зеркало из https://github.com/mozilla/gecko-dev.git
119 строки
4.3 KiB
C++
119 строки
4.3 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef mozilla_a11y_Pivot_h_
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#define mozilla_a11y_Pivot_h_
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#include <stdint.h>
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#include "Role.h"
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#include "mozilla/dom/ChildIterator.h"
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#include "AccessibleOrProxy.h"
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namespace mozilla {
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namespace a11y {
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class LocalAccessible;
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class HyperTextAccessible;
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class DocAccessible;
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class PivotRule {
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public:
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// A filtering function that returns a bitmask from
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// nsIAccessibleTraversalRule: FILTER_IGNORE (0x0): Don't match this
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// accessible. FILTER_MATCH (0x1): Match this accessible FILTER_IGNORE_SUBTREE
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// (0x2): Ignore accessible's subtree.
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virtual uint16_t Match(const AccessibleOrProxy& aAccOrProxy) = 0;
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};
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// The Pivot class is used for searching for accessible nodes in a given subtree
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// with a given criteria. Since it only holds a weak reference to the root,
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// this class is meant to be used primarily on the stack.
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class Pivot final {
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public:
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explicit Pivot(const AccessibleOrProxy& aRoot);
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Pivot() = delete;
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Pivot(const Pivot&) = delete;
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Pivot& operator=(const Pivot&) = delete;
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~Pivot();
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// Return the next accessible after aAnchor in pre-order that matches the
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// given rule. If aIncludeStart, return aAnchor if it matches the rule.
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AccessibleOrProxy Next(AccessibleOrProxy& aAnchor, PivotRule& aRule,
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bool aIncludeStart = false);
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// Return the previous accessible before aAnchor in pre-order that matches the
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// given rule. If aIncludeStart, return aAnchor if it matches the rule.
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AccessibleOrProxy Prev(AccessibleOrProxy& aAnchor, PivotRule& aRule,
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bool aIncludeStart = false);
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// Return the first accessible within the root that matches the pivot rule.
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AccessibleOrProxy First(PivotRule& aRule);
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// Return the last accessible within the root that matches the pivot rule.
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AccessibleOrProxy Last(PivotRule& aRule);
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// Return the next range of text according to the boundary type.
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LocalAccessible* NextText(LocalAccessible* aAnchor, int32_t* aStartOffset,
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int32_t* aEndOffset, int32_t aBoundaryType);
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// Return the previous range of text according to the boundary type.
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LocalAccessible* PrevText(LocalAccessible* aAnchor, int32_t* aStartOffset,
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int32_t* aEndOffset, int32_t aBoundaryType);
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// Return the accessible at the given screen coordinate if it matches the
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// pivot rule.
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AccessibleOrProxy AtPoint(int32_t aX, int32_t aY, PivotRule& aRule);
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private:
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AccessibleOrProxy AdjustStartPosition(AccessibleOrProxy& aAnchor,
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PivotRule& aRule,
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uint16_t* aFilterResult);
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// Search in preorder for the first accessible to match the rule.
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AccessibleOrProxy SearchForward(AccessibleOrProxy& aAnchor, PivotRule& aRule,
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bool aSearchCurrent);
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// Reverse search in preorder for the first accessible to match the rule.
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AccessibleOrProxy SearchBackward(AccessibleOrProxy& aAnchor, PivotRule& aRule,
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bool aSearchCurrent);
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// Search in preorder for the first text accessible.
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HyperTextAccessible* SearchForText(LocalAccessible* aAnchor, bool aBackward);
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AccessibleOrProxy mRoot;
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};
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/**
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* This rule matches accessibles on a given role, filtering out non-direct
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* descendants if necessary.
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*/
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class PivotRoleRule : public PivotRule {
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public:
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explicit PivotRoleRule(role aRole);
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explicit PivotRoleRule(role aRole, AccessibleOrProxy& aDirectDescendantsFrom);
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virtual uint16_t Match(const AccessibleOrProxy& aAccOrProxy) override;
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protected:
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role mRole;
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AccessibleOrProxy mDirectDescendantsFrom;
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};
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/**
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* This rule matches any local LocalAccessible (i.e. not RemoteAccessible) in
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* the same document as the anchor. That is, it includes any descendant
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* OuterDocAccessible, but not its descendants.
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*/
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class LocalAccInSameDocRule : public PivotRule {
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public:
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virtual uint16_t Match(const AccessibleOrProxy& aAccOrProxy) override;
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};
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} // namespace a11y
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} // namespace mozilla
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#endif // mozilla_a11y_Pivot_h_
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