third_party/WebKit/Source/modules/accessibility/AXLayoutObject.h

/*
 * Copyright (C) 2008 Apple Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
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 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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 */

#ifndef AXLayoutObject_h
#define AXLayoutObject_h

#include "modules/ModulesExport.h"
#include "modules/accessibility/AXNodeObject.h"
#include "platform/geometry/LayoutRect.h"
#include "wtf/Forward.h"

namespace blink {

class AXObjectCacheImpl;
class AXSVGRoot;
class Element;
class FrameView;
class HTMLAreaElement;
class IntPoint;
class Node;
class Widget;

class MODULES_EXPORT AXLayoutObject : public AXNodeObject {
  WTF_MAKE_NONCOPYABLE(AXLayoutObject);

 protected:
  AXLayoutObject(LayoutObject*, AXObjectCacheImpl&);

 public:
  static AXLayoutObject* create(LayoutObject*, AXObjectCacheImpl&);
  ~AXLayoutObject() override;

  // Public, overridden from AXObject.
  LayoutObject* getLayoutObject() const final { return m_layoutObject; }
  LayoutBoxModelObject* getLayoutBoxModelObject() const;
  ScrollableArea* getScrollableAreaIfScrollable() const final;
  AccessibilityRole determineAccessibilityRole() override;
  AccessibilityRole nativeAccessibilityRoleIgnoringAria() const override;

 protected:
  LayoutObject* m_layoutObject;

  LayoutObject* layoutObjectForRelativeBounds() const override {
    return m_layoutObject;
  }

  //
  // Overridden from AXObject.
  //

  void init() override;
  void detach() override;
  bool isDetached() const override { return !m_layoutObject; }
  bool isAXLayoutObject() const override { return true; }

  // Check object role or purpose.
  bool isEditable() const override;
  bool isRichlyEditable() const override;
  bool isLinked() const override;
  bool isLoaded() const override;
  bool isOffScreen() const override;
  bool isReadOnly() const override;
  bool isVisited() const override;

  // Check object state.
  bool isFocused() const override;
  bool isSelected() const override;

  // Whether objects are ignored, i.e. not included in the tree.
  AXObjectInclusion defaultObjectInclusion(
      IgnoredReasons* = nullptr) const override;
  bool computeAccessibilityIsIgnored(IgnoredReasons* = nullptr) const override;

  // Properties of static elements.
  const AtomicString& accessKey() const override;
  RGBA32 computeBackgroundColor() const final;
  RGBA32 color() const final;
  String fontFamily() const final;
  // Font size is in pixels.
  float fontSize() const final;
  String text() const override;
  AccessibilityTextDirection textDirection() const final;
  int textLength() const override;
  TextStyle getTextStyle() const final;
  KURL url() const override;

  // Inline text boxes.
  void loadInlineTextBoxes() override;
  AXObject* nextOnLine() const override;
  AXObject* previousOnLine() const override;

  // Properties of interactive elements.
  String stringValue() const override;

  // ARIA attributes.
  void ariaFlowToElements(AXObjectVector&) const override;
  void ariaControlsElements(AXObjectVector&) const override;
  void ariaDescribedbyElements(AXObjectVector&) const override;
  void ariaLabelledbyElements(AXObjectVector&) const override;
  void ariaOwnsElements(AXObjectVector&) const override;

  bool ariaHasPopup() const override;
  bool ariaRoleHasPresentationalChildren() const override;
  AXObject* ancestorForWhichThisIsAPresentationalChild() const override;
  bool supportsARIADragging() const override;
  bool supportsARIADropping() const override;
  bool supportsARIAFlowTo() const override;
  bool supportsARIAOwns() const override;

  // ARIA live-region features.
  const AtomicString& liveRegionStatus() const override;
  const AtomicString& liveRegionRelevant() const override;
  bool liveRegionAtomic() const override;
  bool liveRegionBusy() const override;

  // AX name calc.
  String textAlternative(bool recursive,
                         bool inAriaLabelledByTraversal,
                         AXObjectSet& visited,
                         AXNameFrom&,
                         AXRelatedObjectVector*,
                         NameSources*) const override;

  // Methods that retrieve or manipulate the current selection.

  AXRange selection() const override;
  AXRange selectionUnderObject() const override;
  void setSelection(const AXRange&) override;

  // Hit testing.
  AXObject* accessibilityHitTest(const IntPoint&) const override;
  AXObject* elementAccessibilityHitTest(const IntPoint&) const override;

  // High-level accessibility tree access. Other modules should only use these
  // functions.
  AXObject* computeParent() const override;
  AXObject* computeParentIfExists() const override;

  // Low-level accessibility tree exploration, only for use within the
  // accessibility module.
  AXObject* rawFirstChild() const override;
  AXObject* rawNextSibling() const override;
  void addChildren() override;
  bool canHaveChildren() const override;
  void updateChildrenIfNecessary() override;
  bool needsToUpdateChildren() const override { return m_childrenDirty; }
  void setNeedsToUpdateChildren() override { m_childrenDirty = true; }
  void clearChildren() override;

  // Properties of the object's owning document or page.
  double estimatedLoadingProgress() const override;

  // DOM and layout tree access.
  Node* getNode() const override;
  Document* getDocument() const override;
  FrameView* documentFrameView() const override;
  Element* anchorElement() const override;

  void setValue(const String&) override;

  // Notifications that this object may have changed.
  void handleActiveDescendantChanged() override;
  void handleAriaExpandedChanged() override;
  void textChanged() override;

  // Text metrics. Most of these should be deprecated, needs major cleanup.
  int index(const VisiblePosition&) const override;
  VisiblePosition visiblePositionForIndex(int) const override;
  void lineBreaks(Vector<int>&) const final;

 private:
  AXObject* treeAncestorDisallowingChild() const;
  bool isTabItemSelected() const;
  bool isValidSelectionBound(const AXObject*) const;
  AXObject* accessibilityImageMapHitTest(HTMLAreaElement*,
                                         const IntPoint&) const;
  LayoutObject* layoutParentObject() const;
  bool isSVGImage() const;
  void detachRemoteSVGRoot();
  AXSVGRoot* remoteSVGRootElement() const;
  AXObject* remoteSVGElementHitTest(const IntPoint&) const;
  void offsetBoundingBoxForRemoteSVGElement(LayoutRect&) const;
  void addHiddenChildren();
  void addTextFieldChildren();
  void addImageMapChildren();
  void addCanvasChildren();
  void addPopupChildren();
  void addRemoteSVGChildren();
  void addInlineTextBoxChildren(bool force);

  bool elementAttributeValue(const QualifiedName&) const;
  LayoutRect computeElementRect() const;
  AXRange textControlSelection() const;
  int indexForVisiblePosition(const VisiblePosition&) const;
  AXLayoutObject* getUnignoredObjectFromNode(Node&) const;
};

DEFINE_AX_OBJECT_TYPE_CASTS(AXLayoutObject, isAXLayoutObject());

}  // namespace blink

#endif  // AXLayoutObject_h