/// <summary>
/// Create an accessible object from an IAccessible instance and a child ID.
/// </summary>
public SystemAccessibleObject(IAccessible iacc, int childID)
{
if (iacc == null)
{
throw new ArgumentNullException();
}
//if (childID < 0) throw new ArgumentException();
if (childID != 0)
{
try
{
object realChild = iacc.get_accChild(childID);
if (realChild != null)
{
iacc = (IAccessible)realChild;
childID = 0;
}
}
//catch (ArgumentException) { }
//catch (InvalidCastException) { }
catch (Exception) { } // general error handling, e.g. IBM/Lotus Notes otherwise crashes with COMException here
}
this.iacc = iacc;
this.childID = childID;
}
public override AccessibleObject GetChild(int index)
{
try {
object o = acc.get_accChild(index);
if (o == null && this.GetChildCount() > 0)
{
return(new SystemAccessible(this, this.acc, index));
}
return(Wrap(o));
} catch {
return(null);
}
}
/// <summary>
/// Create an accessible object from an IAccessible instance and a child ID.
/// </summary>
public SystemAccessibleObject(IAccessible iacc, int childID)
{
if (iacc == null)
{
throw new ArgumentNullException();
}
//if (childID < 0) throw new ArgumentException();
if (childID != 0)
{
try {
object realChild = iacc.get_accChild(childID);
if (realChild != null)
{
iacc = (IAccessible)realChild;
childID = 0;
}
} catch (ArgumentException) { }
}
IAccessible = iacc;
ChildID = childID;
}
object?IAccessibleInternal.get_accChild(object childID) => AsNativeAccessible(publicIAccessible.get_accChild(childID));
/// <summary>
/// Create an accessible object from an IAccessible instance and a child ID.
/// </summary>
public SystemAccessibleObject(IAccessible iacc, int childID)
{
if (iacc == null) throw new ArgumentNullException();
//if (childID < 0) throw new ArgumentException();
if (childID != 0)
{
try
{
object realChild = iacc.get_accChild(childID);
if (realChild != null)
{
iacc = (IAccessible)realChild;
childID = 0;
}
}
//catch (ArgumentException) { }
//catch (InvalidCastException) { }
catch (Exception) { } // general error handling, e.g. IBM/Lotus Notes otherwise crashes with COMException here
}
this.iacc = iacc;
this.childID = childID;
}
/// <summary>
/// Create an accessible object from an IAccessible instance and a child ID.
/// </summary>
public SystemAccessibleObject(IAccessible iacc, int childID)
{
if (iacc == null) throw new ArgumentNullException();
//if (childID < 0) throw new ArgumentException();
if (childID != 0)
{
try
{
object realChild = iacc.get_accChild(childID);
if (realChild != null)
{
iacc = (IAccessible)realChild;
childID = 0;
}
}
catch (ArgumentException) { }
}
this.iacc = iacc;
this.childID = childID;
}
// CreateObjRef not overridden; not sure of relevance.
// DoDefaultAction not yet delegated.
// Equals not delegated.
/// <summary>
/// The nth child. Apparently they don't have to be indexed sequentially...
/// perhaps MS expects you to use Navigate(next)? The Views impl indexes
/// children sequentially starting from 1.
/// </summary>
/// <param name="index"></param>
/// <returns></returns>
public override AccessibleObject GetChild(int index)
{
return(new AccessibleObjectFromIAccessible((IAccessible)(m_acc.get_accChild(index))));
}
// Gets an IAccessible and idChild for an object that may be a full IAccessible or a ChildID of 'parent'
private static void IAccessibleFromObject(object obj, IAccessible parent, out IAccessible acc, out int idChild)
{
idChild = 0;
acc = obj as IAccessible;
// first see if o is a full IAccessible object
if (acc != null)
{
idChild = NativeMethods.CHILD_SELF;
}
else if (obj is int)
{
// call get_accChild to check if the object has its own IAccessible...
object test = null;
try
{
try
{
test = parent.get_accChild((int)obj);
}
catch (System.Security.SecurityException)
{
// Workaround for Partial Trust [....] issue - they sometimes return
// a security error - use workaround to get a new IAccessible for the same
// object, and retry...
IAccessible accNew = WashPartialTrustWinformsAccessible(parent);
if (accNew != null)
test = accNew.get_accChild((int)obj);
}
}
catch (Exception e)
{
// Some impls of get_accChild return inappropriate error codes (eg. Trident
// used to return E_INVALIDCAST; others returned E_FAIL). To be more robust,
// do what the MSAA tools (eg. inspect etc) do and ignore the error, using
// the VT_I4 to access the child instead. If there really is an error, we'll
// hit it when we try to access the child itself.
// Some impls (MediaPlayer) return E_POINTER, which translates
// to NullReferenceException; ignore that also.
if (Misc.IsCriticalException(e) && ! (e is NullReferenceException))
{
throw;
}
}
if (test is IAccessible)
{
acc = (IAccessible)test;
idChild = NativeMethods.CHILD_SELF;
}
else
{
// it is a ChildID and parent is handling
acc = parent;
idChild = (int)obj;
}
}
}
object UnsafeNativeMethods.IAccessibleInternal.get_accChild(object childID)
{
IntSecurity.UnmanagedCode.Assert();
return(AsNativeAccessible(publicIAccessible.get_accChild(childID)));
}