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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.
#ifndef UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_DELEGATE_H_
#define UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_DELEGATE_H_
#include "ui/accessibility/ax_enums.h"
#include "ui/accessibility/ax_export.h"
#include "ui/gfx/geometry/vector2d.h"
#include "ui/gfx/native_widget_types.h"
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 {
public:
// 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 ui::AXTreeData& GetTreeData() const = 0;
// Get the window the node is contained in.
virtual gfx::NativeWindow GetTopLevelWidget() = 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 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.
virtual gfx::Rect GetScreenBoundsRect() 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;
virtual ui::AXPlatformNode* GetFromNodeID(int32_t id) = 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 ui::AXAction
// provided in |data|.
virtual bool AccessibilityPerformAction(const ui::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;
};
} // namespace ui
#endif // UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_DELEGATE_H_