gecko-dev/accessible/src/base/nsAccessible.h

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 * Contributor(s):
 *      John Gaunt (jgaunt@netscape.com)
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#ifndef _nsAccessible_H_
#define _nsAccessible_H_

#include "nsCOMPtr.h"
#include "nsGenericAccessible.h"
#include "nsIAccessible.h"
#include "nsIAccessibilityService.h"
#include "nsIDOMNode.h"
#include "nsIFocusController.h"
#include "nsIPresContext.h"
#include "nsIPresShell.h"
#include "nsPoint.h"
#include "nsRect.h"
#include "nsWeakReference.h"
#include "nsIDOMNodeList.h"
#include "nsIBindingManager.h"

#define ACCESSIBLE_BUNDLE_URL "chrome://global-platform/locale/accessible.properties"

class nsIContent;
class nsIDocShell;
class nsIFrame;
class nsIWebShell;

enum { eSiblingsUninitialized = -1, eSiblingsWalkNormalDOM = -2};  // Used in sibling index field as flags

class nsAccessible : public nsGenericAccessible
{
public:
  // to eliminate the confusion of "magic numbers" -- if ( 0 ){ foo; }
  enum { eAction_Switch=0, eAction_Jump=0, eAction_Click=0, eAction_Select=0 };
  // how many actions
  enum { eNo_Action=0, eSingle_Action=1 };

  nsAccessible(nsIDOMNode* aNode, nsIWeakReference* aShell);
  virtual ~nsAccessible();

  NS_IMETHOD GetAccName(nsAString& _retval);
  NS_IMETHOD GetAccParent(nsIAccessible **_retval); 
  NS_IMETHOD GetAccNextSibling(nsIAccessible **_retval); 
  NS_IMETHOD GetAccPreviousSibling(nsIAccessible **_retval); 
  NS_IMETHOD GetAccFirstChild(nsIAccessible **_retval); 
  NS_IMETHOD GetAccLastChild(nsIAccessible **_retval); 
  NS_IMETHOD GetAccChildCount(PRInt32 *_retval); 
  NS_IMETHOD GetAccState(PRUint32 *_retval); 
  NS_IMETHOD GetAccFocused(nsIAccessible **_retval); 
  NS_IMETHOD AccGetAt(PRInt32 x, PRInt32 y, nsIAccessible **_retval); 
  NS_IMETHOD AccGetBounds(PRInt32 *x, PRInt32 *y, PRInt32 *width, PRInt32 *height); 
  NS_IMETHOD AccRemoveSelection(void); 
  NS_IMETHOD AccTakeSelection(void); 
  NS_IMETHOD AccTakeFocus(void); 
  NS_IMETHOD AccGetDOMNode(nsIDOMNode **_retval); 

protected:
  virtual nsIFrame* GetFrame();
  virtual nsIFrame* GetBoundsFrame();
  virtual void GetBounds(nsRect& aRect, nsIFrame** aRelativeFrame);
  virtual void GetPresContext(nsCOMPtr<nsIPresContext>& aContext);
  PRBool IsPartiallyVisible(); 
  NS_IMETHOD AppendLabelText(nsIDOMNode *aLabelNode, nsAString& _retval);
  NS_IMETHOD AppendLabelFor(nsIContent *aLookNode, const nsAString *aId, nsAString *aLabel);
  NS_IMETHOD GetHTMLAccName(nsAString& _retval);
  NS_IMETHOD GetXULAccName(nsAString& _retval);
  NS_IMETHOD AppendFlatStringFromSubtree(nsIContent *aContent, nsAString *aFlatString);
  NS_IMETHOD AppendFlatStringFromContentNode(nsIContent *aContent, nsAString *aFlatString);
  NS_IMETHOD AppendStringWithSpaces(nsAString *aFlatString, const nsAString& textEquivalent);
  NS_IMETHOD GetFocusedElement(nsIDOMElement **aFocusedElement);
  NS_IMETHOD CacheOptimizations(nsIAccessible *aParent, PRInt32 aSiblingIndex, nsIDOMNodeList *aSiblingList);
  // helper method to verify frames
  static PRBool IsCorrectFrameType(nsIFrame* aFrame, nsIAtom* aAtom);
  static nsresult GetTranslatedString(const nsAString& aKey, nsAString& aStringOut);
  void GetScrollOffset(nsRect *aRect);
  void GetScreenOrigin(nsIPresContext *aPresContext, nsIFrame *aFrame, nsRect *aRect);

  // Data Members
  nsCOMPtr<nsIDOMNode> mDOMNode;
  nsCOMPtr<nsIWeakReference> mPresShell;
  nsCOMPtr<nsIAccessible> mParent;
  nsCOMPtr<nsIDOMNodeList> mSiblingList; // If some of our computed siblings are anonymous content nodes, cache node list
  PRInt32 mSiblingIndex; // Cache where we are in list of kids that we got from nsIBindingManager::GetContentList(parentContent)
};


/** This class is used to walk the DOM tree. It skips
  * everything but nodes that either implement nsIAccessible
  * or have primary frames that implement "GetAccessible"
  */

struct WalkState {
  nsCOMPtr<nsIAccessible> accessible;
  nsCOMPtr<nsIDOMNode> domNode;
  nsCOMPtr<nsIDOMNodeList> siblingList;
  PRInt32 siblingIndex;  // Holds a state flag or an index into the siblingList
  WalkState *prevState;
};

 
class nsAccessibleTreeWalker {
public:
  nsAccessibleTreeWalker(nsIWeakReference* aShell, nsIDOMNode* aContent, 
    PRInt32 aCachedSiblingIndex, nsIDOMNodeList *aCachedSiblingList, PRBool mWalkAnonymousContent);
  ~nsAccessibleTreeWalker();

  NS_IMETHOD GetNextSibling();
  NS_IMETHOD GetPreviousSibling();
  NS_IMETHOD GetParent();
  NS_IMETHOD GetFirstChild();
  NS_IMETHOD GetLastChild();
  PRInt32 GetChildCount();
  WalkState mState;

protected:
  NS_IMETHOD GetChildBefore(nsIDOMNode* aParent, nsIDOMNode* aChild);
  PRBool IsHidden();
  PRBool GetAccessible();
  NS_IMETHOD GetFullTreeParentNode(nsIDOMNode *aChildNode, nsIDOMNode **aParentNodeOut);
  void GetSiblings(nsIDOMNode *aOneOfTheSiblings);
  void GetKids(nsIDOMNode *aParent);

  void ClearState();
  NS_IMETHOD PushState();
  NS_IMETHOD PopState();

  nsCOMPtr<nsIWeakReference> mPresShell;
  nsCOMPtr<nsIAccessibilityService> mAccService;
  nsCOMPtr<nsIBindingManager> mBindingManager;
};

#endif