//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
// primary ctor used to create all providers for IAccessible objects.
// hwnd is the window this object belongs to.
// root is a provider for the OBJID_CLIENT of the window. may be null if it is not yet known.
// don't call this constructor directly -- call a Create or Wrap function below.
protected MsaaNativeProvider(Accessible acc, IntPtr hwnd, MsaaNativeProvider parent, MsaaNativeProvider knownRoot, RootStatus isRoot)
{
Debug.Assert(acc != null, "acc");
Debug.Assert(hwnd != IntPtr.Zero);
_acc = acc;
_hwnd = hwnd;
_parent = parent; // can be null if not known.
_knownRoot = knownRoot; // can be null if not known.
_isRoot = isRoot; // can be RootStatus.Unknown
// _controlType defaults to null. computed on demand.
}
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
// the creation of any msaa-based provider funnels through this function.
// it creates an object of the base or correct derived class for the specified IAccessible object.
private static MsaaNativeProvider Wrap(Accessible acc, IntPtr hwnd, MsaaNativeProvider parent, MsaaNativeProvider knownRoot, RootStatus isRoot)
{
// if acc is null then return null.
if (acc == null)
return null;
// check that parent is actually our parent - sometimes hit-test and navigation skip layers, so we
// may need to reconstruct the parent chain to account for skipped-over ancestors: keep climbing
// upwards till we reach the 'parent' that was passed in...
MsaaNativeProvider parentChain = parent;
if (parent != null)
{
ArrayList actualParentChain = null;
Accessible scan = acc.Parent;
while (scan != null)
{
if (Accessible.Compare(scan, parent._acc))
break; // found actual parent
// found intermediate ancestor - add to list...
if (actualParentChain == null)
actualParentChain = new ArrayList();
actualParentChain.Add(scan);
scan = scan.Parent;
}
if (actualParentChain != null)
{
// if we found intermediate ancestors, process them top-down, creating
// MsaaNativeProviders for each in turn, using the bottom-most one as
// our own actual parent...
for (int i = actualParentChain.Count - 1; i >= 0; i--)
{
Accessible ancestor = (Accessible)actualParentChain[i];
parentChain = new MsaaNativeProvider(ancestor, hwnd, parentChain, knownRoot, isRoot);
}
}
}
return new MsaaNativeProvider(acc, hwnd, parentChain, knownRoot, isRoot);
}