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

   1 /*
   2  * Copyright (C) 2012, Google Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1.  Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  * 2.  Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  14  *     its contributors may be used to endorse or promote products derived
  15  *     from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef AXNodeObject_h
  30 #define AXNodeObject_h
  31
  32 #include "modules/ModulesExport.h"
  33 #include "modules/accessibility/AXObject.h"
  34 #include "wtf/Forward.h"
  35
  36 namespace blink {
  37
  38 class AXObjectCacheImpl;
  39 class Element;
  40 class HTMLLabelElement;
  41 class LayoutRect;
  42 class Node;
  43
  44 class MODULES_EXPORT AXNodeObject : public AXObject {
  45 protected:
  46     AXNodeObject(Node*, AXObjectCacheImpl&);
  47
  48 public:
  49     static AXNodeObject* create(Node*, AXObjectCacheImpl&);
  50     ~AXNodeObject() override;
  51     DECLARE_VIRTUAL_TRACE();
  52
  53 protected:
  54     // Protected data.
  55     AccessibilityRole m_ariaRole;
  56     bool m_childrenDirty;
  57 #if ENABLE(ASSERT)
  58     bool m_initialized;
  59 #endif
  60
  61     bool computeAccessibilityIsIgnored(IgnoredReasons* = nullptr) const override;
  62     const AXObject* inheritsPresentationalRoleFrom() const override;
  63     virtual AccessibilityRole determineAccessibilityRole();
  64     AccessibilityRole determineAccessibilityRoleUtil();
  65     String accessibilityDescriptionForElements(WillBeHeapVector<RawPtrWillBeMember<Element>> &elements) const;
  66     void alterSliderValue(bool increase);
  67     String ariaAccessibilityDescription() const;
  68     String ariaAutoComplete() const;
  69     void ariaLabelledbyElements(WillBeHeapVector<RawPtrWillBeMember<Element>>& elements) const;
  70     AccessibilityRole determineAriaRoleAttribute() const;
  71     void tokenVectorFromAttribute(Vector<String>&, const QualifiedName&) const;
  72     void elementsFromAttribute(WillBeHeapVector<RawPtrWillBeMember<Element>>& elements, const QualifiedName&) const;
  73     void accessibilityChildrenFromAttribute(QualifiedName attr, AccessibilityChildrenVector&) const;
  74
  75     bool hasContentEditableAttributeSet() const;
  76     bool isTextControl() const override;
  77     bool allowsTextRanges() const { return isTextControl(); }
  78     // This returns true if it's focusable but it's not content editable and it's not a control or ARIA control.
  79     bool isGenericFocusableElement() const;
  80     HTMLLabelElement* labelForElement(const Element*) const;
  81     AXObject* menuButtonForMenu() const;
  82     Element* menuItemElementForMenu() const;
  83     Element* mouseButtonListener() const;
  84     String deprecatedPlaceholder() const;
  85     AccessibilityRole remapAriaRoleDueToParent(AccessibilityRole) const;
  86     bool isNativeCheckboxOrRadio() const;
  87     void setNode(Node*);
  88     AXObject* correspondingControlForLabelElement() const;
  89     HTMLLabelElement* labelElementContainer() const;
  90
  91     //
  92     // Overridden from AXObject.
  93     //
  94
  95     void init() override;
  96     void detach() override;
  97     bool isDetached() const override { return !m_node; }
  98     bool isAXNodeObject() const final { return true; }
  99
 100     // Check object role or purpose.
 101     bool isAnchor() const final;
 102     bool isControl() const override;
 103     bool isControllingVideoElement() const;
 104     bool isEditable() const override { return isTextControl(); }
 105     bool isEmbeddedObject() const final;
 106     bool isFieldset() const final;
 107     bool isHeading() const final;
 108     bool isHovered() const final;
 109     bool isImage() const final;
 110     bool isImageButton() const;
 111     bool isInputImage() const final;
 112     bool isLink() const final;
 113     bool isMenu() const final;
 114     bool isMenuButton() const final;
 115     bool isMeter() const final;
 116     bool isMultiSelectable() const override;
 117     bool isNativeImage() const;
 118     bool isNativeTextControl() const final;
 119     bool isNonNativeTextControl() const final;
 120     bool isPasswordField() const final;
 121     bool isProgressIndicator() const override;
 122     bool isRichlyEditable() const override { return hasContentEditableAttributeSet(); }
 123     bool isSlider() const override;
 124     bool isNativeSlider() const override;
 125
 126     // Check object state.
 127     bool isChecked() const final;
 128     bool isClickable() const final;
 129     bool isEnabled() const override;
 130     AccessibilityExpanded isExpanded() const override;
 131     bool isIndeterminate() const final;
 132     bool isPressed() const final;
 133     bool isReadOnly() const override;
 134     bool isRequired() const final;
 135
 136     // Check whether certain properties can be modified.
 137     bool canSetFocusAttribute() const override;
 138     bool canSetValueAttribute() const override;
 139
 140     // Properties of static elements.
 141     RGBA32 colorValue() const final;
 142     bool canvasHasFallbackContent() const final;
 143     bool deprecatedExposesTitleUIElement() const override;
 144     int headingLevel() const final;
 145     unsigned hierarchicalLevel() const final;
 146     AccessibilityOrientation orientation() const override;
 147     String text() const override;
 148     AXObject* deprecatedTitleUIElement() const override;
 149
 150     // Properties of interactive elements.
 151     AccessibilityButtonState checkboxOrRadioValue() const final;
 152     InvalidState invalidState() const final;
 153     // Only used when invalidState() returns InvalidStateOther.
 154     String ariaInvalidValue() const final;
 155     String valueDescription() const override;
 156     float valueForRange() const override;
 157     float maxValueForRange() const override;
 158     float minValueForRange() const override;
 159     String stringValue() const override;
 160
 161     // ARIA attributes.
 162     String ariaDescribedByAttribute() const final;
 163     String ariaLabelledbyAttribute() const final;
 164     AccessibilityRole ariaRoleAttribute() const final;
 165
 166     // Accessibility Text.
 167     String deprecatedTextUnderElement(TextUnderElementMode) const override;
 168     String deprecatedAccessibilityDescription() const override;
 169     String deprecatedTitle(TextUnderElementMode) const override;
 170     String deprecatedHelpText() const override;
 171     String computedName() const override;
 172
 173     // New AX name calculation.
 174     String textAlternative(bool recursive, bool inAriaLabelledByTraversal, AXObjectSet& visited, AXNameFrom&, AXObjectVector* nameObjects, NameSources*) const override;
 175
 176     // Location and click point in frame-relative coordinates.
 177     LayoutRect elementRect() const override;
 178
 179     // High-level accessibility tree access.
 180     AXObject* computeParent() const override;
 181     AXObject* computeParentIfExists() const override;
 182
 183     // Low-level accessibility tree exploration.
 184     AXObject* firstChild() const override;
 185     AXObject* nextSibling() const override;
 186     void addChildren() override;
 187     bool canHaveChildren() const override;
 188     void addChild(AXObject*);
 189     void insertChild(AXObject*, unsigned index);
 190
 191     // DOM and Render tree access.
 192     Element* actionElement() const final;
 193     Element* anchorElement() const override;
 194     Document* document() const override;
 195     Node* node() const override { return m_node; }
 196
 197     // Modify or take an action on an object.
 198     void setFocused(bool) final;
 199     void increment() final;
 200     void decrement() final;
 201
 202     // Notifications that this object may have changed.
 203     void childrenChanged() override;
 204     void selectionChanged() final;
 205     void textChanged() override;
 206     void updateAccessibilityRole() final;
 207
 208     // Position in set and Size of set
 209     int posInSet() const override;
 210     int setSize() const override;
 211
 212     // Aria-owns.
 213     void computeAriaOwnsChildren(HeapVector<Member<AXObject>>& ownedChildren);
 214
 215 private:
 216     RawPtrWillBeMember<Node> m_node;
 217
 218     String deprecatedAlternativeTextForWebArea() const;
 219     void deprecatedAlternativeText(HeapVector<Member<AccessibilityText>>&) const;
 220     void deprecatedAriaLabelledbyText(HeapVector<Member<AccessibilityText>>&) const;
 221
 222     String textFromDescendants(AXObjectSet& visited) const;
 223     String textFromElements(bool inAriaLabelledByTraversal, AXObjectSet& visited, WillBeHeapVector<RawPtrWillBeMember<Element>>& elements, AXObjectVector* nameObjects) const;
 224     String textFromAriaLabelledby(AXObjectSet& visited, AXObjectVector* nameObjects) const;
 225     String nativeTextAlternative(AXObjectSet& visited, AXNameFrom&, AXObjectVector* nameObjects, NameSources*, bool* foundTextAlternative) const;
 226     float stepValueForRange() const;
 227     AXObject* findChildWithTagName(const HTMLQualifiedName&) const;
 228     bool isDescendantOfElementType(const HTMLQualifiedName& tagName) const;
 229 };
 230
 231 DEFINE_AX_OBJECT_TYPE_CASTS(AXNodeObject, isAXNodeObject());
 232
 233 } // namespace blink
 234
 235 #endif // AXNodeObject_h