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      1 
      2 /*
      3  * Copyright (C) 2008 Apple Inc. All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  *
      9  * 1.  Redistributions of source code must retain the above copyright
     10  *     notice, this list of conditions and the following disclaimer.
     11  * 2.  Redistributions in binary form must reproduce the above copyright
     12  *     notice, this list of conditions and the following disclaimer in the
     13  *     documentation and/or other materials provided with the distribution.
     14  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
     15  *     its contributors may be used to endorse or promote products derived
     16  *     from this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
     19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     21  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 #ifndef AccessibilityRenderObject_h
     31 #define AccessibilityRenderObject_h
     32 
     33 #include "AccessibilityObject.h"
     34 #include <wtf/Forward.h>
     35 
     36 namespace WebCore {
     37 
     38 class AXObjectCache;
     39 class Element;
     40 class Frame;
     41 class FrameView;
     42 class HitTestResult;
     43 class HTMLAnchorElement;
     44 class HTMLAreaElement;
     45 class HTMLElement;
     46 class HTMLLabelElement;
     47 class HTMLMapElement;
     48 class HTMLSelectElement;
     49 class IntPoint;
     50 class IntSize;
     51 class Node;
     52 class RenderListBox;
     53 class RenderTextControl;
     54 class RenderView;
     55 class VisibleSelection;
     56 class Widget;
     57 
     58 class AccessibilityRenderObject : public AccessibilityObject {
     59 protected:
     60     AccessibilityRenderObject(RenderObject*);
     61 public:
     62     static PassRefPtr<AccessibilityRenderObject> create(RenderObject*);
     63     virtual ~AccessibilityRenderObject();
     64 
     65     bool isAccessibilityRenderObject() const { return true; }
     66 
     67     virtual bool isAnchor() const;
     68     virtual bool isAttachment() const;
     69     virtual bool isHeading() const;
     70     virtual bool isLink() const;
     71     virtual bool isImageButton() const;
     72     virtual bool isImage() const;
     73     virtual bool isNativeImage() const;
     74     virtual bool isPasswordField() const;
     75     virtual bool isNativeTextControl() const;
     76     virtual bool isWebArea() const;
     77     virtual bool isFileUploadButton() const;
     78     virtual bool isInputImage() const;
     79     virtual bool isProgressIndicator() const;
     80     virtual bool isSlider() const;
     81     virtual bool isMenuRelated() const;
     82     virtual bool isMenu() const;
     83     virtual bool isMenuBar() const;
     84     virtual bool isMenuButton() const;
     85     virtual bool isMenuItem() const;
     86     virtual bool isControl() const;
     87     virtual bool isFieldset() const;
     88     virtual bool isGroup() const;
     89 
     90     virtual bool isEnabled() const;
     91     virtual bool isSelected() const;
     92     virtual bool isFocused() const;
     93     virtual bool isChecked() const;
     94     virtual bool isHovered() const;
     95     virtual bool isIndeterminate() const;
     96     virtual bool isLoaded() const;
     97     virtual bool isMultiSelectable() const;
     98     virtual bool isOffScreen() const;
     99     virtual bool isPressed() const;
    100     virtual bool isReadOnly() const;
    101     virtual bool isVisited() const;
    102     virtual bool isRequired() const;
    103     virtual bool isLinked() const;
    104     virtual void setIsExpanded(bool);
    105 
    106     virtual bool canSetFocusAttribute() const;
    107     virtual bool canSetTextRangeAttributes() const;
    108     virtual bool canSetValueAttribute() const;
    109     virtual bool canSetExpandedAttribute() const;
    110 
    111     virtual void setAccessibleName(String&);
    112 
    113     // Provides common logic used by all elements when determining isIgnored.
    114     AccessibilityObjectInclusion accessibilityIsIgnoredBase() const;
    115     virtual bool accessibilityIsIgnored() const;
    116 
    117     virtual int headingLevel() const;
    118     virtual AccessibilityButtonState checkboxOrRadioValue() const;
    119     virtual String valueDescription() const;
    120     virtual float valueForRange() const;
    121     virtual float maxValueForRange() const;
    122     virtual float minValueForRange() const;
    123     virtual AccessibilityObject* selectedRadioButton();
    124     virtual AccessibilityObject* selectedTabItem();
    125     virtual int layoutCount() const;
    126     virtual double estimatedLoadingProgress() const;
    127 
    128     virtual AccessibilityObject* firstChild() const;
    129     virtual AccessibilityObject* lastChild() const;
    130     virtual AccessibilityObject* previousSibling() const;
    131     virtual AccessibilityObject* nextSibling() const;
    132     virtual AccessibilityObject* parentObject() const;
    133     virtual AccessibilityObject* parentObjectIfExists() const;
    134     virtual AccessibilityObject* observableObject() const;
    135     virtual void linkedUIElements(AccessibilityChildrenVector&) const;
    136     virtual bool exposesTitleUIElement() const;
    137     virtual AccessibilityObject* titleUIElement() const;
    138     virtual AccessibilityObject* correspondingControlForLabelElement() const;
    139     virtual AccessibilityObject* correspondingLabelForControlElement() const;
    140 
    141     virtual void ariaOwnsElements(AccessibilityChildrenVector&) const;
    142     virtual bool supportsARIAOwns() const;
    143     virtual AccessibilityRole ariaRoleAttribute() const;
    144     virtual bool isPresentationalChildOfAriaRole() const;
    145     virtual bool ariaRoleHasPresentationalChildren() const;
    146     void updateAccessibilityRole();
    147 
    148     // Should be called on the root accessibility object to kick off a hit test.
    149     virtual AccessibilityObject* accessibilityHitTest(const IntPoint&) const;
    150 
    151     virtual Element* actionElement() const;
    152     Element* mouseButtonListener() const;
    153     FrameView* frameViewIfRenderView() const;
    154     virtual Element* anchorElement() const;
    155     AccessibilityObject* menuForMenuButton() const;
    156     AccessibilityObject* menuButtonForMenu() const;
    157 
    158     virtual IntRect boundingBoxRect() const;
    159     virtual IntRect elementRect() const;
    160     virtual IntSize size() const;
    161     virtual IntPoint clickPoint() const;
    162 
    163     void setRenderer(RenderObject* renderer) { m_renderer = renderer; }
    164     virtual RenderObject* renderer() const { return m_renderer; }
    165     RenderBoxModelObject* renderBoxModelObject() const;
    166     virtual Node* node() const;
    167 
    168     RenderView* topRenderer() const;
    169     RenderTextControl* textControl() const;
    170     Document* document() const;
    171     FrameView* topDocumentFrameView() const;
    172     HTMLLabelElement* labelElementContainer() const;
    173 
    174     virtual KURL url() const;
    175     virtual PlainTextRange selectedTextRange() const;
    176     virtual VisibleSelection selection() const;
    177     virtual String stringValue() const;
    178     virtual String ariaLabeledByAttribute() const;
    179     virtual String title() const;
    180     virtual String ariaDescribedByAttribute() const;
    181     virtual String accessibilityDescription() const;
    182     virtual String helpText() const;
    183     virtual String textUnderElement() const;
    184     virtual String text() const;
    185     virtual int textLength() const;
    186     virtual String selectedText() const;
    187     virtual const AtomicString& accessKey() const;
    188     virtual const String& actionVerb() const;
    189     virtual Widget* widget() const;
    190     virtual Widget* widgetForAttachmentView() const;
    191     virtual void getDocumentLinks(AccessibilityChildrenVector&);
    192     virtual FrameView* documentFrameView() const;
    193     virtual unsigned hierarchicalLevel() const;
    194 
    195     virtual const AccessibilityChildrenVector& children();
    196     virtual void clearChildren();
    197     virtual void updateChildrenIfNecessary();
    198 
    199     virtual void setFocused(bool);
    200     virtual void setSelectedTextRange(const PlainTextRange&);
    201     virtual void setValue(const String&);
    202     virtual void setSelected(bool);
    203     virtual void setSelectedRows(AccessibilityChildrenVector&);
    204     virtual void changeValueByPercent(float percentChange);
    205     virtual AccessibilityOrientation orientation() const;
    206     virtual void increment();
    207     virtual void decrement();
    208 
    209     virtual void detach();
    210     virtual void childrenChanged();
    211     virtual void contentChanged();
    212     virtual void addChildren();
    213     virtual bool canHaveChildren() const;
    214     virtual void selectedChildren(AccessibilityChildrenVector&);
    215     virtual void visibleChildren(AccessibilityChildrenVector&);
    216     virtual void tabChildren(AccessibilityChildrenVector&);
    217     virtual bool shouldFocusActiveDescendant() const;
    218     virtual AccessibilityObject* activeDescendant() const;
    219     virtual void handleActiveDescendantChanged();
    220     virtual void handleAriaExpandedChanged();
    221 
    222     virtual VisiblePositionRange visiblePositionRange() const;
    223     virtual VisiblePositionRange visiblePositionRangeForLine(unsigned) const;
    224     virtual IntRect boundsForVisiblePositionRange(const VisiblePositionRange&) const;
    225     virtual void setSelectedVisiblePositionRange(const VisiblePositionRange&) const;
    226     virtual bool supportsARIAFlowTo() const;
    227     virtual void ariaFlowToElements(AccessibilityChildrenVector&) const;
    228     virtual bool ariaHasPopup() const;
    229 
    230     virtual bool supportsARIADropping() const;
    231     virtual bool supportsARIADragging() const;
    232     virtual bool isARIAGrabbed();
    233     virtual void setARIAGrabbed(bool);
    234     virtual void determineARIADropEffects(Vector<String>&);
    235 
    236     virtual VisiblePosition visiblePositionForPoint(const IntPoint&) const;
    237     virtual VisiblePosition visiblePositionForIndex(unsigned indexValue, bool lastIndexOK) const;
    238     virtual int index(const VisiblePosition&) const;
    239 
    240     virtual VisiblePosition visiblePositionForIndex(int) const;
    241     virtual int indexForVisiblePosition(const VisiblePosition&) const;
    242 
    243     virtual PlainTextRange doAXRangeForLine(unsigned) const;
    244     virtual PlainTextRange doAXRangeForIndex(unsigned) const;
    245 
    246     virtual String doAXStringForRange(const PlainTextRange&) const;
    247     virtual IntRect doAXBoundsForRange(const PlainTextRange&) const;
    248 
    249     virtual void updateBackingStore();
    250 
    251     virtual String stringValueForMSAA() const;
    252     virtual String stringRoleForMSAA() const;
    253     virtual String nameForMSAA() const;
    254     virtual String descriptionForMSAA() const;
    255     virtual AccessibilityRole roleValueForMSAA() const;
    256 
    257 protected:
    258     RenderObject* m_renderer;
    259     AccessibilityRole m_ariaRole;
    260     mutable bool m_childrenDirty;
    261 
    262     void setRenderObject(RenderObject* renderer) { m_renderer = renderer; }
    263     void ariaLabeledByElements(Vector<Element*>& elements) const;
    264     bool needsToUpdateChildren() const { return m_childrenDirty; }
    265 
    266     virtual bool isDetached() const { return !m_renderer; }
    267 
    268 private:
    269     void ariaListboxSelectedChildren(AccessibilityChildrenVector&);
    270     void ariaListboxVisibleChildren(AccessibilityChildrenVector&);
    271     bool ariaIsHidden() const;
    272     bool isDescendantOfBarrenParent() const;
    273     bool isAllowedChildOfTree() const;
    274     bool hasTextAlternative() const;
    275     String positionalDescriptionForMSAA() const;
    276     PlainTextRange ariaSelectedTextRange() const;
    277 
    278     Element* menuElementForMenuButton() const;
    279     Element* menuItemElementForMenu() const;
    280     AccessibilityRole determineAccessibilityRole();
    281     AccessibilityRole determineAriaRoleAttribute() const;
    282 
    283     bool isTabItemSelected() const;
    284     bool isNativeCheckboxOrRadio() const;
    285     IntRect checkboxOrRadioRect() const;
    286     void addRadioButtonGroupMembers(AccessibilityChildrenVector& linkedUIElements) const;
    287     AccessibilityObject* internalLinkElement() const;
    288     AccessibilityObject* accessibilityImageMapHitTest(HTMLAreaElement*, const IntPoint&) const;
    289     AccessibilityObject* accessibilityParentForImageMap(HTMLMapElement*) const;
    290     bool renderObjectIsObservable(RenderObject*) const;
    291     RenderObject* renderParentObject() const;
    292 
    293     void ariaSelectedRows(AccessibilityChildrenVector&);
    294 
    295     bool elementAttributeValue(const QualifiedName&) const;
    296     void setElementAttributeValue(const QualifiedName&, bool);
    297 
    298     String accessibilityDescriptionForElements(Vector<Element*> &elements) const;
    299     void elementsFromAttribute(Vector<Element*>& elements, const QualifiedName&) const;
    300     String ariaAccessibilityDescription() const;
    301 
    302     virtual ESpeak speakProperty() const;
    303 
    304     virtual const AtomicString& ariaLiveRegionStatus() const;
    305     virtual const AtomicString& ariaLiveRegionRelevant() const;
    306     virtual bool ariaLiveRegionAtomic() const;
    307     virtual bool ariaLiveRegionBusy() const;
    308 
    309     bool inheritsPresentationalRole() const;
    310     void setNeedsToUpdateChildren() const { m_childrenDirty = true; }
    311 
    312     mutable AccessibilityRole m_roleForMSAA;
    313 };
    314 
    315 inline AccessibilityRenderObject* toAccessibilityRenderObject(AccessibilityObject* object)
    316 {
    317     ASSERT(!object || object->isAccessibilityRenderObject());
    318     return static_cast<AccessibilityRenderObject*>(object);
    319 }
    320 
    321 inline const AccessibilityRenderObject* toAccessibilityRenderObject(const AccessibilityObject* object)
    322 {
    323     ASSERT(!object || object->isAccessibilityRenderObject());
    324     return static_cast<const AccessibilityRenderObject*>(object);
    325 }
    326 
    327 // This will catch anyone doing an unnecessary cast.
    328 void toAccessibilityRenderObject(const AccessibilityRenderObject*);
    329 
    330 } // namespace WebCore
    331 
    332 #endif // AccessibilityRenderObject_h
    333