| // Copyright 2013 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef UI_ACCESSIBILITY_AX_NODE_H_ |
| #define UI_ACCESSIBILITY_AX_NODE_H_ |
| |
| #include <stdint.h> |
| |
| #include <memory> |
| #include <ostream> |
| #include <string> |
| #include <vector> |
| |
| #include "base/optional.h" |
| #include "build/build_config.h" |
| #include "ui/accessibility/ax_export.h" |
| #include "ui/accessibility/ax_node_data.h" |
| #include "ui/accessibility/ax_tree_id.h" |
| |
| namespace ui { |
| |
| class AXTableInfo; |
| struct AXLanguageInfo; |
| struct AXTreeData; |
| |
| // One node in an AXTree. |
| class AX_EXPORT AXNode final { |
| public: |
| // Defines the type used for AXNode IDs. |
| using AXID = int32_t; |
| |
| // If a node is not yet or no longer valid, its ID should have a value of |
| // kInvalidAXID. |
| static constexpr AXID kInvalidAXID = 0; |
| |
| // Interface to the tree class that owns an AXNode. We use this instead |
| // of letting AXNode have a pointer to its AXTree directly so that we're |
| // forced to think twice before calling an AXTree interface that might not |
| // be necessary. |
| class OwnerTree { |
| public: |
| struct Selection { |
| bool is_backward; |
| AXID anchor_object_id; |
| int anchor_offset; |
| ax::mojom::TextAffinity anchor_affinity; |
| AXID focus_object_id; |
| int focus_offset; |
| ax::mojom::TextAffinity focus_affinity; |
| }; |
| |
| // See AXTree::GetAXTreeID. |
| virtual AXTreeID GetAXTreeID() const = 0; |
| // See AXTree::GetTableInfo. |
| virtual AXTableInfo* GetTableInfo(const AXNode* table_node) const = 0; |
| // See AXTree::GetFromId. |
| virtual AXNode* GetFromId(int32_t id) const = 0; |
| // See AXTree::data. |
| virtual const AXTreeData& data() const = 0; |
| |
| virtual base::Optional<int> GetPosInSet(const AXNode& node) = 0; |
| virtual base::Optional<int> GetSetSize(const AXNode& node) = 0; |
| |
| virtual Selection GetUnignoredSelection() const = 0; |
| virtual bool GetTreeUpdateInProgressState() const = 0; |
| virtual bool HasPaginationSupport() const = 0; |
| }; |
| |
| template <typename NodeType, |
| NodeType* (NodeType::*NextSibling)() const, |
| NodeType* (NodeType::*PreviousSibling)() const, |
| NodeType* (NodeType::*FirstChild)() const, |
| NodeType* (NodeType::*LastChild)() const> |
| class ChildIteratorBase { |
| public: |
| ChildIteratorBase(const NodeType* parent, NodeType* child); |
| ChildIteratorBase(const ChildIteratorBase& it); |
| ~ChildIteratorBase() {} |
| bool operator==(const ChildIteratorBase& rhs) const; |
| bool operator!=(const ChildIteratorBase& rhs) const; |
| ChildIteratorBase& operator++(); |
| ChildIteratorBase& operator--(); |
| NodeType* get() const; |
| NodeType& operator*() const; |
| NodeType* operator->() const; |
| |
| protected: |
| const NodeType* parent_; |
| NodeType* child_; |
| }; |
| |
| // The constructor requires a parent, id, and index in parent, but |
| // the data is not required. After initialization, only index_in_parent |
| // and unignored_index_in_parent is allowed to change, the others are |
| // guaranteed to never change. |
| AXNode(OwnerTree* tree, |
| AXNode* parent, |
| int32_t id, |
| size_t index_in_parent, |
| size_t unignored_index_in_parent = 0); |
| virtual ~AXNode(); |
| |
| // Accessors. |
| OwnerTree* tree() const { return tree_; } |
| AXID id() const { return data_.id; } |
| AXNode* parent() const { return parent_; } |
| const AXNodeData& data() const { return data_; } |
| const std::vector<AXNode*>& children() const { return children_; } |
| size_t index_in_parent() const { return index_in_parent_; } |
| |
| // Returns ownership of |data_| to the caller; effectively clearing |data_|. |
| AXNodeData&& TakeData(); |
| |
| // Walking the tree skipping ignored nodes. |
| size_t GetUnignoredChildCount() const; |
| AXNode* GetUnignoredChildAtIndex(size_t index) const; |
| AXNode* GetUnignoredParent() const; |
| size_t GetUnignoredIndexInParent() const; |
| size_t GetIndexInParent() const; |
| AXNode* GetFirstUnignoredChild() const; |
| AXNode* GetLastUnignoredChild() const; |
| AXNode* GetDeepestFirstUnignoredChild() const; |
| AXNode* GetDeepestLastUnignoredChild() const; |
| AXNode* GetNextUnignoredSibling() const; |
| AXNode* GetPreviousUnignoredSibling() const; |
| AXNode* GetNextUnignoredInTreeOrder() const; |
| AXNode* GetPreviousUnignoredInTreeOrder() const; |
| |
| using UnignoredChildIterator = |
| ChildIteratorBase<AXNode, |
| &AXNode::GetNextUnignoredSibling, |
| &AXNode::GetPreviousUnignoredSibling, |
| &AXNode::GetFirstUnignoredChild, |
| &AXNode::GetLastUnignoredChild>; |
| UnignoredChildIterator UnignoredChildrenBegin() const; |
| UnignoredChildIterator UnignoredChildrenEnd() const; |
| |
| // Walking the tree including both ignored and unignored nodes. |
| // These methods consider only the direct children or siblings of a node. |
| AXNode* GetFirstChild() const; |
| AXNode* GetLastChild() const; |
| AXNode* GetPreviousSibling() const; |
| AXNode* GetNextSibling() const; |
| |
| // Returns true if the node has any of the text related roles, including |
| // kStaticText, kInlineTextBox and kListMarker (for Legacy Layout). Does not |
| // include any text field roles. |
| bool IsText() const; |
| |
| // Returns true if the node has any line break related roles or is the child |
| // of a node with line break related roles. |
| bool IsLineBreak() const; |
| |
| // Set the node's accessibility data. This may be done during initialization |
| // or later when the node data changes. |
| void SetData(const AXNodeData& src); |
| |
| // Update this node's location. This is separate from |SetData| just because |
| // changing only the location is common and should be more efficient than |
| // re-copying all of the data. |
| // |
| // The node's location is stored as a relative bounding box, the ID of |
| // the element it's relative to, and an optional transformation matrix. |
| // See ax_node_data.h for details. |
| void SetLocation(int32_t offset_container_id, |
| const gfx::RectF& location, |
| gfx::Transform* transform); |
| |
| // Set the index in parent, for example if siblings were inserted or deleted. |
| void SetIndexInParent(size_t index_in_parent); |
| |
| // Update the unignored index in parent for unignored children. |
| void UpdateUnignoredCachedValues(); |
| |
| // Swap the internal children vector with |children|. This instance |
| // now owns all of the passed children. |
| void SwapChildren(std::vector<AXNode*>* children); |
| |
| // This is called when the AXTree no longer includes this node in the |
| // tree. Reference counting is used on some platforms because the |
| // operating system may hold onto a reference to an AXNode |
| // object even after we're through with it, so this may decrement the |
| // reference count and clear out the object's data. |
| void Destroy(); |
| |
| // Returns true if this node is equal to or a descendant of |ancestor|. |
| bool IsDescendantOf(const AXNode* ancestor) const; |
| |
| // Gets the text offsets where new lines start either from the node's data or |
| // by computing them and caching the result. |
| std::vector<int> GetOrComputeLineStartOffsets(); |
| |
| // Accessing accessibility attributes. |
| // See |AXNodeData| for more information. |
| |
| bool HasBoolAttribute(ax::mojom::BoolAttribute attribute) const { |
| return data().HasBoolAttribute(attribute); |
| } |
| bool GetBoolAttribute(ax::mojom::BoolAttribute attribute) const { |
| return data().GetBoolAttribute(attribute); |
| } |
| bool GetBoolAttribute(ax::mojom::BoolAttribute attribute, bool* value) const { |
| return data().GetBoolAttribute(attribute, value); |
| } |
| |
| bool HasFloatAttribute(ax::mojom::FloatAttribute attribute) const { |
| return data().HasFloatAttribute(attribute); |
| } |
| float GetFloatAttribute(ax::mojom::FloatAttribute attribute) const { |
| return data().GetFloatAttribute(attribute); |
| } |
| bool GetFloatAttribute(ax::mojom::FloatAttribute attribute, |
| float* value) const { |
| return data().GetFloatAttribute(attribute, value); |
| } |
| |
| bool HasIntAttribute(ax::mojom::IntAttribute attribute) const { |
| return data().HasIntAttribute(attribute); |
| } |
| int GetIntAttribute(ax::mojom::IntAttribute attribute) const { |
| return data().GetIntAttribute(attribute); |
| } |
| bool GetIntAttribute(ax::mojom::IntAttribute attribute, int* value) const { |
| return data().GetIntAttribute(attribute, value); |
| } |
| |
| bool HasStringAttribute(ax::mojom::StringAttribute attribute) const { |
| return data().HasStringAttribute(attribute); |
| } |
| const std::string& GetStringAttribute( |
| ax::mojom::StringAttribute attribute) const { |
| return data().GetStringAttribute(attribute); |
| } |
| bool GetStringAttribute(ax::mojom::StringAttribute attribute, |
| std::string* value) const { |
| return data().GetStringAttribute(attribute, value); |
| } |
| |
| bool GetString16Attribute(ax::mojom::StringAttribute attribute, |
| base::string16* value) const { |
| return data().GetString16Attribute(attribute, value); |
| } |
| base::string16 GetString16Attribute( |
| ax::mojom::StringAttribute attribute) const { |
| return data().GetString16Attribute(attribute); |
| } |
| |
| bool HasIntListAttribute(ax::mojom::IntListAttribute attribute) const { |
| return data().HasIntListAttribute(attribute); |
| } |
| const std::vector<int32_t>& GetIntListAttribute( |
| ax::mojom::IntListAttribute attribute) const { |
| return data().GetIntListAttribute(attribute); |
| } |
| bool GetIntListAttribute(ax::mojom::IntListAttribute attribute, |
| std::vector<int32_t>* value) const { |
| return data().GetIntListAttribute(attribute, value); |
| } |
| |
| bool HasStringListAttribute(ax::mojom::StringListAttribute attribute) const { |
| return data().HasStringListAttribute(attribute); |
| } |
| const std::vector<std::string>& GetStringListAttribute( |
| ax::mojom::StringListAttribute attribute) const { |
| return data().GetStringListAttribute(attribute); |
| } |
| bool GetStringListAttribute(ax::mojom::StringListAttribute attribute, |
| std::vector<std::string>* value) const { |
| return data().GetStringListAttribute(attribute, value); |
| } |
| |
| bool GetHtmlAttribute(const char* attribute, base::string16* value) const { |
| return data().GetHtmlAttribute(attribute, value); |
| } |
| bool GetHtmlAttribute(const char* attribute, std::string* value) const { |
| return data().GetHtmlAttribute(attribute, value); |
| } |
| |
| // Return the hierarchical level if supported. |
| base::Optional<int> GetHierarchicalLevel() const; |
| |
| // PosInSet and SetSize public methods. |
| bool IsOrderedSetItem() const; |
| bool IsOrderedSet() const; |
| base::Optional<int> GetPosInSet(); |
| base::Optional<int> GetSetSize(); |
| |
| // Helpers for GetPosInSet and GetSetSize. |
| // Returns true if the role of ordered set matches the role of item. |
| // Returns false otherwise. |
| bool SetRoleMatchesItemRole(const AXNode* ordered_set) const; |
| |
| // Container objects that should be ignored for computing PosInSet and SetSize |
| // for ordered sets. |
| bool IsIgnoredContainerForOrderedSet() const; |
| |
| const std::string& GetInheritedStringAttribute( |
| ax::mojom::StringAttribute attribute) const; |
| base::string16 GetInheritedString16Attribute( |
| ax::mojom::StringAttribute attribute) const; |
| |
| // If this node is a leaf, returns the inner text of this node. This is |
| // equivalent to its visible accessible name. Otherwise, if this node is not a |
| // leaf, represents every non-textual child node with a special "embedded |
| // object character", and every textual child node with its inner text. |
| // Textual nodes include e.g. static text and white space. |
| // |
| // This is how displayed text and embedded objects are represented in |
| // ATK and IAccessible2 APIs. |
| std::string GetHypertext() const; |
| |
| // Returns the text of this node and all descendant nodes; including text |
| // found in embedded objects. |
| // |
| // Only text displayed on screen is included. Text from ARIA and HTML |
| // attributes that is either not displayed on screen, or outside this node, is |
| // not returned. |
| std::string GetInnerText() const; |
| |
| // Returns a string representing the language code. |
| // |
| // This will consider the language declared in the DOM, and may eventually |
| // attempt to automatically detect the language from the text. |
| // |
| // This language code will be BCP 47. |
| // |
| // Returns empty string if no appropriate language was found. |
| std::string GetLanguage() const; |
| |
| // Returns the value of a control such as a text field, a slider, a <select> |
| // element, a date picker or an ARIA combo box. In order to minimize |
| // cross-process communication between the renderer and the browser, this |
| // method may compute the value from the control's inner text in the case of a |
| // text field. |
| std::string GetValueForControl() const; |
| |
| // |
| // Helper functions for tables, table rows, and table cells. |
| // Most of these functions construct and cache an AXTableInfo behind |
| // the scenes to infer many properties of tables. |
| // |
| // These interfaces use attributes provided by the source of the |
| // AX tree where possible, but fills in missing details and ignores |
| // specified attributes when they're bad or inconsistent. That way |
| // you're guaranteed to get a valid, consistent table when using these |
| // interfaces. |
| // |
| |
| // Table-like nodes (including grids). All indices are 0-based except |
| // ARIA indices are all 1-based. In other words, the top-left corner |
| // of the table is row 0, column 0, cell index 0 - but that same cell |
| // has a minimum ARIA row index of 1 and column index of 1. |
| // |
| // The below methods return base::nullopt if the AXNode they are called on is |
| // not inside a table. |
| bool IsTable() const; |
| base::Optional<int> GetTableColCount() const; |
| base::Optional<int> GetTableRowCount() const; |
| base::Optional<int> GetTableAriaColCount() const; |
| base::Optional<int> GetTableAriaRowCount() const; |
| base::Optional<int> GetTableCellCount() const; |
| base::Optional<bool> GetTableHasColumnOrRowHeaderNode() const; |
| AXNode* GetTableCaption() const; |
| AXNode* GetTableCellFromIndex(int index) const; |
| AXNode* GetTableCellFromCoords(int row_index, int col_index) const; |
| // Get all the column header node ids of the table. |
| std::vector<AXNode::AXID> GetTableColHeaderNodeIds() const; |
| // Get the column header node ids associated with |col_index|. |
| std::vector<AXNode::AXID> GetTableColHeaderNodeIds(int col_index) const; |
| // Get the row header node ids associated with |row_index|. |
| std::vector<AXNode::AXID> GetTableRowHeaderNodeIds(int row_index) const; |
| std::vector<AXNode::AXID> GetTableUniqueCellIds() const; |
| // Extra computed nodes for the accessibility tree for macOS: |
| // one column node for each table column, followed by one |
| // table header container node, or nullptr if not applicable. |
| const std::vector<AXNode*>* GetExtraMacNodes() const; |
| |
| // Table row-like nodes. |
| bool IsTableRow() const; |
| base::Optional<int> GetTableRowRowIndex() const; |
| // Get the node ids that represent rows in a table. |
| std::vector<AXNode::AXID> GetTableRowNodeIds() const; |
| |
| #if defined(OS_APPLE) |
| // Table column-like nodes. These nodes are only present on macOS. |
| bool IsTableColumn() const; |
| base::Optional<int> GetTableColColIndex() const; |
| #endif // defined(OS_APPLE) |
| |
| // Table cell-like nodes. |
| bool IsTableCellOrHeader() const; |
| base::Optional<int> GetTableCellIndex() const; |
| base::Optional<int> GetTableCellColIndex() const; |
| base::Optional<int> GetTableCellRowIndex() const; |
| base::Optional<int> GetTableCellColSpan() const; |
| base::Optional<int> GetTableCellRowSpan() const; |
| base::Optional<int> GetTableCellAriaColIndex() const; |
| base::Optional<int> GetTableCellAriaRowIndex() const; |
| std::vector<AXNode::AXID> GetTableCellColHeaderNodeIds() const; |
| std::vector<AXNode::AXID> GetTableCellRowHeaderNodeIds() const; |
| void GetTableCellColHeaders(std::vector<AXNode*>* col_headers) const; |
| void GetTableCellRowHeaders(std::vector<AXNode*>* row_headers) const; |
| |
| // Helper methods to check if a cell is an ARIA-1.1+ 'cell' or 'gridcell' |
| bool IsCellOrHeaderOfARIATable() const; |
| bool IsCellOrHeaderOfARIAGrid() const; |
| |
| // Return an object containing information about the languages detected on |
| // this node. |
| // Callers should not retain this pointer, instead they should request it |
| // every time it is needed. |
| // |
| // Returns nullptr if the node has no language info. |
| AXLanguageInfo* GetLanguageInfo() const; |
| |
| // This should only be called by LabelLanguageForSubtree and is used as part |
| // of the language detection feature. |
| void SetLanguageInfo(std::unique_ptr<AXLanguageInfo> lang_info); |
| |
| // Destroy the language info for this node. |
| void ClearLanguageInfo(); |
| |
| // Returns true if node is a group and is a direct descendant of a set-like |
| // element. |
| bool IsEmbeddedGroup() const; |
| |
| // Returns true if node has ignored state or ignored role. |
| bool IsIgnored() const; |
| |
| // Returns true if node is invisible or ignored. |
| bool IsInvisibleOrIgnored() const; |
| |
| // Returns true if node is focused within this tree. |
| bool IsFocusedWithinThisTree() const; |
| |
| // Returns true if an ancestor of this node (not including itself) is a |
| // leaf node, meaning that this node is not actually exposed to any |
| // platform's accessibility layer. |
| bool IsChildOfLeaf() const; |
| |
| // Returns true if this is a leaf node, meaning all its |
| // children should not be exposed to any platform's native accessibility |
| // layer. |
| // |
| // The definition of a leaf includes nodes with children that are exclusively |
| // an internal renderer implementation, such as the children of an HTML native |
| // text field, as well as nodes with presentational children according to the |
| // ARIA and HTML5 Specs. Also returns true if all of the node's descendants |
| // are ignored. |
| // |
| // A leaf node should never have children that are focusable or |
| // that might send notifications. |
| bool IsLeaf() const; |
| |
| // Returns true if this node is a list marker or if it's a descendant |
| // of a list marker node. Returns false otherwise. |
| bool IsInListMarker() const; |
| |
| // Returns true if this node is a collapsed popup button that is parent to a |
| // menu list popup. |
| bool IsCollapsedMenuListPopUpButton() const; |
| |
| // Returns the popup button ancestor of this current node if any. The popup |
| // button needs to be the parent of a menu list popup and needs to be |
| // collapsed. |
| AXNode* GetCollapsedMenuListPopUpButtonAncestor() const; |
| |
| // If this node is within an editable region, returns the node that is at the |
| // root of that editable region, otherwise returns nullptr. In accessibility, |
| // an editable region is synonymous to a text field. |
| AXNode* GetTextFieldAncestor() const; |
| |
| // Returns true if this node is either a plain text field , or one of its |
| // ancestors is. |
| bool IsDescendantOfPlainTextField() const; |
| |
| // Finds and returns a pointer to ordered set containing node. |
| AXNode* GetOrderedSet() const; |
| |
| private: |
| // Computes the text offset where each line starts by traversing all child |
| // leaf nodes. |
| void ComputeLineStartOffsets(std::vector<int>* line_offsets, |
| int* start_offset) const; |
| AXTableInfo* GetAncestorTableInfo() const; |
| void IdVectorToNodeVector(const std::vector<int32_t>& ids, |
| std::vector<AXNode*>* nodes) const; |
| |
| int UpdateUnignoredCachedValuesRecursive(int startIndex); |
| AXNode* ComputeLastUnignoredChildRecursive() const; |
| AXNode* ComputeFirstUnignoredChildRecursive() const; |
| |
| // Returns the value of a range control such as a slider or a scroll bar in |
| // text format. |
| std::string GetTextForRangeValue() const; |
| |
| // Returns the value of a color well (a color chooser control) in a human |
| // readable format. For example: "50% red 40% green 90% blue". |
| std::string GetValueForColorWell() const; |
| |
| // Returns the value of a text field. If necessary, computes the value from |
| // the field's internal representation in the accessibility tree, in order to |
| // minimize cross-process communication between the renderer and the browser |
| // processes. |
| std::string GetValueForTextField() const; |
| |
| OwnerTree* const tree_; // Owns this. |
| size_t index_in_parent_; |
| size_t unignored_index_in_parent_; |
| size_t unignored_child_count_ = 0; |
| AXNode* const parent_; |
| std::vector<AXNode*> children_; |
| AXNodeData data_; |
| |
| // Stores the detected language computed from the node's text. |
| std::unique_ptr<AXLanguageInfo> language_info_; |
| }; |
| |
| AX_EXPORT std::ostream& operator<<(std::ostream& stream, const AXNode& node); |
| |
| template <typename NodeType, |
| NodeType* (NodeType::*NextSibling)() const, |
| NodeType* (NodeType::*PreviousSibling)() const, |
| NodeType* (NodeType::*FirstChild)() const, |
| NodeType* (NodeType::*LastChild)() const> |
| AXNode::ChildIteratorBase<NodeType, |
| NextSibling, |
| PreviousSibling, |
| FirstChild, |
| LastChild>::ChildIteratorBase(const NodeType* parent, |
| NodeType* child) |
| : parent_(parent), child_(child) {} |
| |
| template <typename NodeType, |
| NodeType* (NodeType::*NextSibling)() const, |
| NodeType* (NodeType::*PreviousSibling)() const, |
| NodeType* (NodeType::*FirstChild)() const, |
| NodeType* (NodeType::*LastChild)() const> |
| AXNode::ChildIteratorBase<NodeType, |
| NextSibling, |
| PreviousSibling, |
| FirstChild, |
| LastChild>::ChildIteratorBase(const ChildIteratorBase& |
| it) |
| : parent_(it.parent_), child_(it.child_) {} |
| |
| template <typename NodeType, |
| NodeType* (NodeType::*NextSibling)() const, |
| NodeType* (NodeType::*PreviousSibling)() const, |
| NodeType* (NodeType::*FirstChild)() const, |
| NodeType* (NodeType::*LastChild)() const> |
| bool AXNode::ChildIteratorBase<NodeType, |
| NextSibling, |
| PreviousSibling, |
| FirstChild, |
| LastChild>::operator==(const ChildIteratorBase& |
| rhs) const { |
| return parent_ == rhs.parent_ && child_ == rhs.child_; |
| } |
| |
| template <typename NodeType, |
| NodeType* (NodeType::*NextSibling)() const, |
| NodeType* (NodeType::*PreviousSibling)() const, |
| NodeType* (NodeType::*FirstChild)() const, |
| NodeType* (NodeType::*LastChild)() const> |
| bool AXNode::ChildIteratorBase<NodeType, |
| NextSibling, |
| PreviousSibling, |
| FirstChild, |
| LastChild>::operator!=(const ChildIteratorBase& |
| rhs) const { |
| return parent_ != rhs.parent_ || child_ != rhs.child_; |
| } |
| |
| template <typename NodeType, |
| NodeType* (NodeType::*NextSibling)() const, |
| NodeType* (NodeType::*PreviousSibling)() const, |
| NodeType* (NodeType::*FirstChild)() const, |
| NodeType* (NodeType::*LastChild)() const> |
| AXNode::ChildIteratorBase<NodeType, |
| NextSibling, |
| PreviousSibling, |
| FirstChild, |
| LastChild>& |
| AXNode::ChildIteratorBase<NodeType, |
| NextSibling, |
| PreviousSibling, |
| FirstChild, |
| LastChild>::operator++() { |
| // |child_ = nullptr| denotes the iterator's past-the-end condition. When we |
| // increment the iterator past the end, we remain at the past-the-end iterator |
| // condition. |
| if (child_ && parent_) { |
| if (child_ == (parent_->*LastChild)()) |
| child_ = nullptr; |
| else |
| child_ = (child_->*NextSibling)(); |
| } |
| |
| return *this; |
| } |
| |
| template <typename NodeType, |
| NodeType* (NodeType::*NextSibling)() const, |
| NodeType* (NodeType::*PreviousSibling)() const, |
| NodeType* (NodeType::*FirstChild)() const, |
| NodeType* (NodeType::*LastChild)() const> |
| AXNode::ChildIteratorBase<NodeType, |
| NextSibling, |
| PreviousSibling, |
| FirstChild, |
| LastChild>& |
| AXNode::ChildIteratorBase<NodeType, |
| NextSibling, |
| PreviousSibling, |
| FirstChild, |
| LastChild>::operator--() { |
| if (parent_) { |
| // If the iterator is past the end, |child_=nullptr|, decrement the iterator |
| // gives us the last iterator element. |
| if (!child_) |
| child_ = (parent_->*LastChild)(); |
| // Decrement the iterator gives us the previous element, except when the |
| // iterator is at the beginning; in which case, decrementing the iterator |
| // remains at the beginning. |
| else if (child_ != (parent_->*FirstChild)()) |
| child_ = (child_->*PreviousSibling)(); |
| } |
| |
| return *this; |
| } |
| |
| template <typename NodeType, |
| NodeType* (NodeType::*NextSibling)() const, |
| NodeType* (NodeType::*PreviousSibling)() const, |
| NodeType* (NodeType::*FirstChild)() const, |
| NodeType* (NodeType::*LastChild)() const> |
| NodeType* AXNode::ChildIteratorBase<NodeType, |
| NextSibling, |
| PreviousSibling, |
| FirstChild, |
| LastChild>::get() const { |
| DCHECK(child_); |
| return child_; |
| } |
| |
| template <typename NodeType, |
| NodeType* (NodeType::*NextSibling)() const, |
| NodeType* (NodeType::*PreviousSibling)() const, |
| NodeType* (NodeType::*FirstChild)() const, |
| NodeType* (NodeType::*LastChild)() const> |
| NodeType& AXNode::ChildIteratorBase<NodeType, |
| NextSibling, |
| PreviousSibling, |
| FirstChild, |
| LastChild>::operator*() const { |
| DCHECK(child_); |
| return *child_; |
| } |
| |
| template <typename NodeType, |
| NodeType* (NodeType::*NextSibling)() const, |
| NodeType* (NodeType::*PreviousSibling)() const, |
| NodeType* (NodeType::*FirstChild)() const, |
| NodeType* (NodeType::*LastChild)() const> |
| NodeType* AXNode::ChildIteratorBase<NodeType, |
| NextSibling, |
| PreviousSibling, |
| FirstChild, |
| LastChild>::operator->() const { |
| DCHECK(child_); |
| return child_; |
| } |
| |
| } // namespace ui |
| |
| #endif // UI_ACCESSIBILITY_AX_NODE_H_ |
