gecko-dev/accessible/src/base/nsOuterDocAccessible.cpp

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 *   Original Author: Aaron Leventhal (aaronl@netscape.com)
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#include "nsOuterDocAccessible.h"

#include "nsAccUtils.h"
#include "nsDocAccessible.h"

////////////////////////////////////////////////////////////////////////////////
// nsOuterDocAccessible
////////////////////////////////////////////////////////////////////////////////

nsOuterDocAccessible::
  nsOuterDocAccessible(nsIContent *aContent, nsIWeakReference *aShell) :
  nsAccessibleWrap(aContent, aShell)
{
}

////////////////////////////////////////////////////////////////////////////////
// nsISupports

NS_IMPL_ISUPPORTS_INHERITED0(nsOuterDocAccessible,
                             nsAccessible)

////////////////////////////////////////////////////////////////////////////////
// nsAccessible public (DON'T add methods here)

PRUint32
nsOuterDocAccessible::NativeRole()
{
  return nsIAccessibleRole::ROLE_INTERNAL_FRAME;
}

nsresult
nsOuterDocAccessible::GetStateInternal(PRUint32 *aState, PRUint32 *aExtraState)
{
  nsresult rv = nsAccessible::GetStateInternal(aState, aExtraState);
  NS_ENSURE_A11Y_SUCCESS(rv, rv);

  *aState &= ~nsIAccessibleStates::STATE_FOCUSABLE;
  return NS_OK;
}

nsresult
nsOuterDocAccessible::GetChildAtPoint(PRInt32 aX, PRInt32 aY,
                                      PRBool aDeepestChild,
                                      nsIAccessible **aChild)
{
  PRInt32 docX = 0, docY = 0, docWidth = 0, docHeight = 0;
  nsresult rv = GetBounds(&docX, &docY, &docWidth, &docHeight);
  NS_ENSURE_SUCCESS(rv, rv);

  if (aX < docX || aX >= docX + docWidth || aY < docY || aY >= docY + docHeight)
    return NS_OK;

  // Always return the inner doc as direct child accessible unless bounds
  // outside of it.
  nsCOMPtr<nsIAccessible> childAcc;
  rv = GetFirstChild(getter_AddRefs(childAcc));
  NS_ENSURE_SUCCESS(rv, rv);

  if (!childAcc)
    return NS_OK;

  if (aDeepestChild)
    return childAcc->GetDeepestChildAtPoint(aX, aY, aChild);

  NS_ADDREF(*aChild = childAcc);
  return NS_OK;
}

nsresult
nsOuterDocAccessible::GetAttributesInternal(nsIPersistentProperties *aAttributes)
{
  nsAutoString tag;
  aAttributes->GetStringProperty(NS_LITERAL_CSTRING("tag"), tag);
  if (!tag.IsEmpty()) {
    // We're overriding the ARIA attributes on an sub document, but we don't want to
    // override the other attributes
    return NS_OK;
  }
  return nsAccessible::GetAttributesInternal(aAttributes);
}

////////////////////////////////////////////////////////////////////////////////
// nsIAccessible

NS_IMETHODIMP
nsOuterDocAccessible::GetNumActions(PRUint8 *aNumActions)
{
  NS_ENSURE_ARG_POINTER(aNumActions);
  *aNumActions = 0;

  // Internal frame, which is the doc's parent, should not have a click action.
  return NS_OK;
}

NS_IMETHODIMP
nsOuterDocAccessible::GetActionName(PRUint8 aIndex, nsAString& aName)
{
  aName.Truncate();

  return NS_ERROR_INVALID_ARG;
}

NS_IMETHODIMP
nsOuterDocAccessible::GetActionDescription(PRUint8 aIndex, nsAString& aDescription)
{
  aDescription.Truncate();

  return NS_ERROR_INVALID_ARG;
}

NS_IMETHODIMP
nsOuterDocAccessible::DoAction(PRUint8 aIndex)
{
  return NS_ERROR_INVALID_ARG;
}

////////////////////////////////////////////////////////////////////////////////
// nsAccessNode public

void
nsOuterDocAccessible::Shutdown()
{
  // XXX: sometimes outerdoc accessible is shutdown because of layout style
  // change however the presshell of underlying document isn't destroyed and
  // the document doesn't get pagehide events. Shutdown underlying document if
  // any to avoid hanging document accessible.
  NS_LOG_ACCDOCDESTROY_MSG("A11y outerdoc shutdown")
  NS_LOG_ACCDOCDESTROY_ACCADDRESS("outerdoc", this)

  nsAccessible *childAcc = mChildren.SafeElementAt(0, nsnull);
  if (childAcc) {
    NS_LOG_ACCDOCDESTROY("outerdoc's child document shutdown",
                         childAcc->GetDocumentNode())
    childAcc->Shutdown();
  }

  nsAccessibleWrap::Shutdown();
}

////////////////////////////////////////////////////////////////////////////////
// nsAccessible public

void
nsOuterDocAccessible::InvalidateChildren()
{
  // Do not invalidate children because nsAccDocManager is responsible for
  // document accessible lifetime when DOM document is created or destroyed. If
  // DOM document isn't destroyed but its presshell is destroyed (for example,
  // when DOM node of outerdoc accessible is hidden), then outerdoc accessible
  // notifies nsAccDocManager about this. If presshell is created for existing
  // DOM document (for example when DOM node of outerdoc accessible is shown)
  // then allow nsAccDocManager to handle this case since the document
  // accessible is created and appended as a child when it's requested.

  mChildrenFlags = eChildrenUninitialized;
}

PRBool
nsOuterDocAccessible::AppendChild(nsAccessible *aAccessible)
{
  // We keep showing the old document for a bit after creating the new one,
  // and while building the new DOM and frame tree. That's done on purpose
  // to avoid weird flashes of default background color.
  // The old viewer will be destroyed after the new one is created.
  // For a11y, it should be safe to shut down the old document now.
  if (mChildren.Length())
    mChildren[0]->Shutdown();

  if (!nsAccessible::AppendChild(aAccessible))
    return PR_FALSE;

  NS_LOG_ACCDOCCREATE("append document to outerdoc",
                      aAccessible->GetDocumentNode())
  NS_LOG_ACCDOCCREATE_ACCADDRESS("outerdoc", this)

  return PR_TRUE;
}

PRBool
nsOuterDocAccessible::RemoveChild(nsAccessible *aAccessible)
{
  nsAccessible *child = mChildren.SafeElementAt(0, nsnull);
  if (child != aAccessible) {
    NS_ERROR("Wrong child to remove!");
    return PR_FALSE;
  }

  NS_LOG_ACCDOCDESTROY("remove document from outerdoc",
                       child->GetDocumentNode())
  NS_LOG_ACCDOCDESTROY_ACCADDRESS("outerdoc", this)

  PRBool wasRemoved = nsAccessible::RemoveChild(child);

  NS_ASSERTION(!mChildren.Length(),
               "This child document of outerdoc accessible wasn't removed!");

  return wasRemoved;
}


////////////////////////////////////////////////////////////////////////////////
// nsAccessible protected

void
nsOuterDocAccessible::CacheChildren()
{
  // Request document accessible for the content document to make sure it's
  // created because once it's created it appends itself as a child.
  nsIDocument *outerDoc = mContent->GetCurrentDoc();
  if (!outerDoc)
    return;

  nsIDocument *innerDoc = outerDoc->GetSubDocumentFor(mContent);
  if (!innerDoc)
    return;

  nsDocAccessible *docAcc = GetAccService()->GetDocAccessible(innerDoc);
  NS_ASSERTION(docAcc && docAcc->GetParent() == this,
               "Document accessible isn't a child of outerdoc accessible!");
}