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// Copyright 2014 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.
#include <set>
#include "ui/accessibility/ax_enums.mojom.h"
#include "ui/accessibility/ax_export.h"
#include "ui/accessibility/platform/ax_unique_id.h"
#include "ui/gfx/geometry/vector2d.h"
#include "ui/gfx/native_widget_types.h"
namespace gfx {
class Rect;
namespace ui {
struct AXActionData;
struct AXNodeData;
struct AXTreeData;
class AXPlatformNode;
// An object that wants to be accessible should derive from this class.
// AXPlatformNode subclasses use this interface to query all of the information
// about the object in order to implement native accessibility APIs.
// Note that AXPlatformNode has support for accessibility trees where some
// of the objects in the tree are not implemented using AXPlatformNode.
// For example, you may have a native window with platform-native widgets
// in it, but in that window you have custom controls that use AXPlatformNode
// to provide accessibility. That's why GetParent, ChildAtIndex, HitTestSync,
// and GetFocus all return a gfx::NativeViewAccessible - so you can return a
// native accessible if necessary, and AXPlatformNode::GetNativeViewAccessible
// otherwise.
class AX_EXPORT AXPlatformNodeDelegate {
virtual ~AXPlatformNodeDelegate() = default;
// Get the accessibility data that should be exposed for this node.
// Virtually all of the information is obtained from this structure
// (role, state, name, cursor position, etc.) - the rest of this interface
// is mostly to implement support for walking the accessibility tree.
virtual const AXNodeData& GetData() const = 0;
// Get the accessibility tree data for this node.
virtual const AXTreeData& GetTreeData() const = 0;
// Get the accessibility node for the NSWindow the node is contained in. This
// method is only meaningful on macOS.
virtual gfx::NativeViewAccessible GetNSWindow() = 0;
// Get the parent of the node, which may be an AXPlatformNode or it may
// be a native accessible object implemented by another class.
virtual gfx::NativeViewAccessible GetParent() = 0;
// Get the index in parent. Typically this is the AXNode's index_in_parent_.
virtual int GetIndexInParent() const = 0;
// Get the number of children of this node.
virtual int GetChildCount() = 0;
// Get the child of a node given a 0-based index.
virtual gfx::NativeViewAccessible ChildAtIndex(int index) = 0;
// Get the bounds of this node in screen coordinates, applying clipping
// to all bounding boxes so that the resulting rect is within the window.
virtual gfx::Rect GetClippedScreenBoundsRect() const = 0;
// Get the bounds of this node in screen coordinates without applying
// any clipping; it may be outside of the window or offscreen.
virtual gfx::Rect GetUnclippedScreenBoundsRect() const = 0;
// Do a *synchronous* hit test of the given location in global screen
// coordinates, and the node within this node's subtree (inclusive) that's
// hit, if any.
// If the result is anything other than this object or NULL, it will be
// hit tested again recursively - that allows hit testing to work across
// implementation classes. It's okay to take advantage of this and return
// only an immediate child and not the deepest descendant.
// This function is mainly used by accessibility debugging software.
// Platforms with touch accessibility use a different asynchronous interface.
virtual gfx::NativeViewAccessible HitTestSync(int x, int y) = 0;
// Return the node within this node's subtree (inclusive) that currently
// has focus.
virtual gfx::NativeViewAccessible GetFocus() = 0;
// Get whether this node is offscreen.
virtual bool IsOffscreen() const = 0;
virtual AXPlatformNode* GetFromNodeID(int32_t id) = 0;
// Given a node ID attribute (one where IsNodeIdIntAttribute is true),
// and a destination node ID, return a set of all source node IDs that
// have that relationship attribute between them and the destination.
virtual std::set<int32_t> GetReverseRelations(ax::mojom::IntAttribute attr,
int32_t dst_id) = 0;
// Given a node ID list attribute (one where
// IsNodeIdIntListAttribute is true), and a destination node ID,
// return a set of all source node IDs that have that relationship
// attribute between them and the destination.
virtual std::set<int32_t> GetReverseRelations(
ax::mojom::IntListAttribute attr,
int32_t dst_id) = 0;
virtual const AXUniqueId& GetUniqueId() const = 0;
// Tables. All of these should be called on a node that's a table-like
// role.
virtual bool IsTable() const = 0;
virtual int32_t GetTableColCount() const = 0;
virtual int32_t GetTableRowCount() const = 0;
virtual int32_t GetTableAriaColCount() const = 0;
virtual int32_t GetTableAriaRowCount() const = 0;
virtual int32_t GetTableCellCount() const = 0;
virtual const std::vector<int32_t> GetColHeaderNodeIds() const = 0;
virtual const std::vector<int32_t> GetColHeaderNodeIds(
int32_t col_index) const = 0;
virtual const std::vector<int32_t> GetRowHeaderNodeIds() const = 0;
virtual const std::vector<int32_t> GetRowHeaderNodeIds(
int32_t row_index) const = 0;
// Table row-like nodes.
virtual bool IsTableRow() const = 0;
virtual int32_t GetTableRowRowIndex() const = 0;
// Table cell-like nodes.
virtual bool IsTableCellOrHeader() const = 0;
virtual int32_t GetTableCellIndex() const = 0;
virtual int32_t GetTableCellColIndex() const = 0;
virtual int32_t GetTableCellRowIndex() const = 0;
virtual int32_t GetTableCellColSpan() const = 0;
virtual int32_t GetTableCellRowSpan() const = 0;
virtual int32_t GetTableCellAriaColIndex() const = 0;
virtual int32_t GetTableCellAriaRowIndex() const = 0;
virtual int32_t GetCellId(int32_t row_index, int32_t col_index) const = 0;
virtual int32_t CellIndexToId(int32_t cell_index) const = 0;
// Ordered-set-like and item-like nodes.
virtual bool IsOrderedSetItem() const = 0;
virtual bool IsOrderedSet() const = 0;
virtual int32_t GetPosInSet() const = 0;
virtual int32_t GetSetSize() const = 0;
// Events.
// Return the platform-native GUI object that should be used as a target
// for accessibility events.
virtual gfx::AcceleratedWidget GetTargetForNativeAccessibilityEvent() = 0;
// Actions.
// Perform an accessibility action, switching on the ax::mojom::Action
// provided in |data|.
virtual bool AccessibilityPerformAction(const AXActionData& data) = 0;
// Testing.
// Accessibility objects can have the "hot tracked" state set when
// the mouse is hovering over them, but this makes tests flaky because
// the test behaves differently when the mouse happens to be over an
// element. The default value should be falses if not in testing mode.
virtual bool ShouldIgnoreHoveredStateForTesting() = 0;
AXPlatformNodeDelegate() = default;
} // namespace ui