Source/modules/accessibility/AXNodeObject.h

/*
 * Copyright (C) 2012, Google Inc. All rights reserved.
 *
 * 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
 *     documentation and/or other materials provided with the distribution.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     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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 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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 */

#ifndef AXNodeObject_h
#define AXNodeObject_h

#include "modules/ModulesExport.h"
#include "modules/accessibility/AXObject.h"
#include "wtf/Forward.h"

namespace blink {

class AXObjectCacheImpl;
class Element;
class HTMLLabelElement;
class LayoutRect;
class Node;

class MODULES_EXPORT AXNodeObject : public AXObject {
protected:
    AXNodeObject(Node*, AXObjectCacheImpl&);

public:
    static AXNodeObject* create(Node*, AXObjectCacheImpl&);
    ~AXNodeObject() override;
    DECLARE_VIRTUAL_TRACE();

protected:
    // Protected data.
    AccessibilityRole m_ariaRole;
    bool m_childrenDirty;
#if ENABLE(ASSERT)
    bool m_initialized;
#endif

    bool computeAccessibilityIsIgnored(IgnoredReasons* = nullptr) const override;
    const AXObject* inheritsPresentationalRoleFrom() const override;
    virtual AccessibilityRole determineAccessibilityRole();
    AccessibilityRole determineAccessibilityRoleUtil();
    String accessibilityDescriptionForElements(WillBeHeapVector<RawPtrWillBeMember<Element>> &elements) const;
    void alterSliderValue(bool increase);
    String ariaAccessibilityDescription() const;
    String ariaAutoComplete() const;
    void ariaLabelledbyElements(WillBeHeapVector<RawPtrWillBeMember<Element>>& elements) const;
    AccessibilityRole determineAriaRoleAttribute() const;
    void tokenVectorFromAttribute(Vector<String>&, const QualifiedName&) const;
    void elementsFromAttribute(WillBeHeapVector<RawPtrWillBeMember<Element>>& elements, const QualifiedName&) const;
    void accessibilityChildrenFromAttribute(QualifiedName attr, AccessibilityChildrenVector&) const;

    bool hasContentEditableAttributeSet() const;
    bool isTextControl() const override;
    bool allowsTextRanges() const { return isTextControl(); }
    // This returns true if it's focusable but it's not content editable and it's not a control or ARIA control.
    bool isGenericFocusableElement() const;
    HTMLLabelElement* labelForElement(const Element*) const;
    AXObject* menuButtonForMenu() const;
    Element* menuItemElementForMenu() const;
    Element* mouseButtonListener() const;
    String deprecatedPlaceholder() const;
    AccessibilityRole remapAriaRoleDueToParent(AccessibilityRole) const;
    bool isNativeCheckboxOrRadio() const;
    void setNode(Node*);
    AXObject* correspondingControlForLabelElement() const;
    HTMLLabelElement* labelElementContainer() const;

    //
    // Overridden from AXObject.
    //

    void init() override;
    void detach() override;
    bool isDetached() const override { return !m_node; }
    bool isAXNodeObject() const final { return true; }

    // Check object role or purpose.
    bool isAnchor() const final;
    bool isControl() const override;
    bool isControllingVideoElement() const;
    bool isEditable() const override { return isTextControl(); }
    bool isEmbeddedObject() const final;
    bool isFieldset() const final;
    bool isHeading() const final;
    bool isHovered() const final;
    bool isImage() const final;
    bool isImageButton() const;
    bool isInputImage() const final;
    bool isLink() const final;
    bool isMenu() const final;
    bool isMenuButton() const final;
    bool isMeter() const final;
    bool isMultiSelectable() const override;
    bool isNativeImage() const;
    bool isNativeTextControl() const final;
    bool isNonNativeTextControl() const final;
    bool isPasswordField() const final;
    bool isProgressIndicator() const override;
    bool isRichlyEditable() const override { return hasContentEditableAttributeSet(); }
    bool isSlider() const override;
    bool isNativeSlider() const override;

    // Check object state.
    bool isChecked() const final;
    bool isClickable() const final;
    bool isEnabled() const override;
    AccessibilityExpanded isExpanded() const override;
    bool isIndeterminate() const final;
    bool isPressed() const final;
    bool isReadOnly() const override;
    bool isRequired() const final;

    // Check whether certain properties can be modified.
    bool canSetFocusAttribute() const override;
    bool canSetValueAttribute() const override;

    // Properties of static elements.
    RGBA32 colorValue() const final;
    bool canvasHasFallbackContent() const final;
    bool deprecatedExposesTitleUIElement() const override;
    int headingLevel() const final;
    unsigned hierarchicalLevel() const final;
    AccessibilityOrientation orientation() const override;
    String text() const override;
    AXObject* deprecatedTitleUIElement() const override;

    // Properties of interactive elements.
    AccessibilityButtonState checkboxOrRadioValue() const final;
    InvalidState invalidState() const final;
    // Only used when invalidState() returns InvalidStateOther.
    String ariaInvalidValue() const final;
    String valueDescription() const override;
    float valueForRange() const override;
    float maxValueForRange() const override;
    float minValueForRange() const override;
    String stringValue() const override;

    // ARIA attributes.
    String ariaDescribedByAttribute() const final;
    String ariaLabelledbyAttribute() const final;
    AccessibilityRole ariaRoleAttribute() const final;

    // Accessibility Text.
    String deprecatedTextUnderElement(TextUnderElementMode) const override;
    String deprecatedAccessibilityDescription() const override;
    String deprecatedTitle(TextUnderElementMode) const override;
    String deprecatedHelpText() const override;
    String computedName() const override;

    // New AX name calculation.
    String textAlternative(bool recursive, bool inAriaLabelledByTraversal, AXObjectSet& visited, AXNameFrom&, AXObjectVector* nameObjects, NameSources*) const override;

    // Location and click point in frame-relative coordinates.
    LayoutRect elementRect() const override;

    // High-level accessibility tree access.
    AXObject* computeParent() const override;
    AXObject* computeParentIfExists() const override;

    // Low-level accessibility tree exploration.
    AXObject* firstChild() const override;
    AXObject* nextSibling() const override;
    void addChildren() override;
    bool canHaveChildren() const override;
    void addChild(AXObject*);
    void insertChild(AXObject*, unsigned index);

    // DOM and Render tree access.
    Element* actionElement() const final;
    Element* anchorElement() const override;
    Document* document() const override;
    Node* node() const override { return m_node; }

    // Modify or take an action on an object.
    void setFocused(bool) final;
    void increment() final;
    void decrement() final;

    // Notifications that this object may have changed.
    void childrenChanged() override;
    void selectionChanged() final;
    void textChanged() override;
    void updateAccessibilityRole() final;

    // Position in set and Size of set
    int posInSet() const override;
    int setSize() const override;

    // Aria-owns.
    void computeAriaOwnsChildren(HeapVector<Member<AXObject>>& ownedChildren);

private:
    RawPtrWillBeMember<Node> m_node;

    String deprecatedAlternativeTextForWebArea() const;
    void deprecatedAlternativeText(HeapVector<Member<AccessibilityText>>&) const;
    void deprecatedAriaLabelledbyText(HeapVector<Member<AccessibilityText>>&) const;

    String textFromDescendants(AXObjectSet& visited) const;
    String textFromElements(bool inAriaLabelledByTraversal, AXObjectSet& visited, WillBeHeapVector<RawPtrWillBeMember<Element>>& elements, AXObjectVector* nameObjects) const;
    String textFromAriaLabelledby(AXObjectSet& visited, AXObjectVector* nameObjects) const;
    String nativeTextAlternative(AXObjectSet& visited, AXNameFrom&, AXObjectVector* nameObjects, NameSources*, bool* foundTextAlternative) const;
    float stepValueForRange() const;
    AXObject* findChildWithTagName(const HTMLQualifiedName&) const;
    bool isDescendantOfElementType(const HTMLQualifiedName& tagName) const;
};

DEFINE_AX_OBJECT_TYPE_CASTS(AXNodeObject, isAXNodeObject());

} // namespace blink

#endif // AXNodeObject_h