summaryrefslogtreecommitdiffstats
path: root/accessible/base/Pivot.h
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--accessible/base/Pivot.h141
1 files changed, 141 insertions, 0 deletions
diff --git a/accessible/base/Pivot.h b/accessible/base/Pivot.h
new file mode 100644
index 0000000000..bd2814f48e
--- /dev/null
+++ b/accessible/base/Pivot.h
@@ -0,0 +1,141 @@
+/* -*- 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_Pivot_h_
+#define mozilla_a11y_Pivot_h_
+
+#include <stdint.h>
+#include "mozilla/a11y/Role.h"
+#include "mozilla/dom/ChildIterator.h"
+
+namespace mozilla {
+namespace a11y {
+
+class DocAccessible;
+class Accessible;
+
+class PivotRule {
+ public:
+ // A filtering function that returns a bitmask from
+ // nsIAccessibleTraversalRule: FILTER_IGNORE (0x0): Don't match this
+ // accessible. FILTER_MATCH (0x1): Match this accessible FILTER_IGNORE_SUBTREE
+ // (0x2): Ignore accessible's subtree.
+ virtual uint16_t Match(Accessible* aAcc) = 0;
+};
+
+// The Pivot class is used for searching for accessible nodes in a given subtree
+// with a given criteria. Since it only holds a weak reference to the root,
+// this class is meant to be used primarily on the stack.
+class Pivot final {
+ public:
+ explicit Pivot(Accessible* aRoot);
+ Pivot() = delete;
+ Pivot(const Pivot&) = delete;
+ Pivot& operator=(const Pivot&) = delete;
+
+ ~Pivot();
+
+ // Return the next accessible after aAnchor in pre-order that matches the
+ // given rule. If aIncludeStart, return aAnchor if it matches the rule.
+ Accessible* Next(Accessible* aAnchor, PivotRule& aRule,
+ bool aIncludeStart = false);
+
+ // Return the previous accessible before aAnchor in pre-order that matches the
+ // given rule. If aIncludeStart, return aAnchor if it matches the rule.
+ Accessible* Prev(Accessible* aAnchor, PivotRule& aRule,
+ bool aIncludeStart = false);
+
+ // Return the first accessible within the root that matches the pivot rule.
+ Accessible* First(PivotRule& aRule);
+
+ // Return the last accessible within the root that matches the pivot rule.
+ Accessible* Last(PivotRule& aRule);
+
+ // Return the accessible at the given screen coordinate if it matches the
+ // pivot rule.
+ Accessible* AtPoint(int32_t aX, int32_t aY, PivotRule& aRule);
+
+ private:
+ Accessible* AdjustStartPosition(Accessible* aAnchor, PivotRule& aRule,
+ uint16_t* aFilterResult);
+
+ // Search in preorder for the first accessible to match the rule.
+ Accessible* SearchForward(Accessible* aAnchor, PivotRule& aRule,
+ bool aSearchCurrent);
+
+ // Reverse search in preorder for the first accessible to match the rule.
+ Accessible* SearchBackward(Accessible* aAnchor, PivotRule& aRule,
+ bool aSearchCurrent);
+
+ Accessible* mRoot;
+};
+
+/**
+ * This rule matches accessibles on a given role, filtering out non-direct
+ * descendants if necessary.
+ */
+class PivotRoleRule : public PivotRule {
+ public:
+ explicit PivotRoleRule(role aRole);
+ explicit PivotRoleRule(role aRole, Accessible* aDirectDescendantsFrom);
+
+ virtual uint16_t Match(Accessible* aAcc) override;
+
+ protected:
+ role mRole;
+ Accessible* mDirectDescendantsFrom;
+};
+
+/**
+ * This rule matches accessibles with a given state.
+ */
+class PivotStateRule : public PivotRule {
+ public:
+ explicit PivotStateRule(uint64_t aState);
+
+ virtual uint16_t Match(Accessible* aAcc) override;
+
+ protected:
+ uint64_t mState;
+};
+
+/**
+ * This rule matches any local LocalAccessible (i.e. not RemoteAccessible) in
+ * the same document as the anchor. That is, it includes any descendant
+ * OuterDocAccessible, but not its descendants.
+ */
+class LocalAccInSameDocRule : public PivotRule {
+ public:
+ virtual uint16_t Match(Accessible* aAcc) override;
+};
+
+/**
+ * This rule matches remote radio button accessibles with the given name
+ * attribute. It assumes the cache is enabled.
+ */
+class PivotRadioNameRule : public PivotRule {
+ public:
+ explicit PivotRadioNameRule(const nsString& aName);
+
+ virtual uint16_t Match(Accessible* aAcc) override;
+
+ protected:
+ const nsString& mName;
+};
+
+/**
+ * This rule doesn't search iframes. Subtrees that should be
+ * pruned by way of nsAccUtils::MustPrune are also not searched.
+ */
+
+class MustPruneSameDocRule : public PivotRule {
+ public:
+ virtual uint16_t Match(Accessible* aAcc) override;
+};
+
+} // namespace a11y
+} // namespace mozilla
+
+#endif // mozilla_a11y_Pivot_h_