private IUIAutomationElement GetNearbyElement(GetElementDelegate getNextElement)
{
var currentElement = GetCurrentElement();
if (currentElement == null)
{
return(null);
}
var treeWalker = A11yAutomation.GetTreeWalker(this.TreeViewMode);
var retVal = getNextElement?.Invoke(treeWalker, currentElement);
// make sure that we skip an element from current process while walking tree.
// this code should be hit only at App level. but for sure.
if (DesktopElement.IsFromCurrentProcess(retVal))
{
var tmp = retVal;
retVal = getNextElement?.Invoke(treeWalker, retVal);
// since element is not in use, release.
Marshal.ReleaseComObject(tmp);
}
Marshal.ReleaseComObject(treeWalker);
return(retVal);
}
/// <summary>
/// Call this function to find a nearby element and update SelectAction if successful.
/// This function is the starting point for the navigation logic of this class.
/// </summary>
/// <param name="getElementMethod">
/// a delegate used to find the next nearby element.
/// </param>
private void MoveTo(GetElementDelegate getElementMethod)
{
lock (this)
{
_MoveTo(getElementMethod);
}
}
/// <summary>
/// Call this function to find a nearby element and update SelectAction if successful.
/// This function is the starting point for the navigation logic of this class.
/// </summary>
/// <param name="getElementMethod">
/// a delegate used to find the next nearby element.
/// </param>
private void MoveTo(GetElementDelegate getElementMethod)
{
lock (_movementLock)
{
_MoveTo(getElementMethod);
}
}
/// <summary>
/// Do not call this function directly. Instead, call MoveTo().
/// </summary>
/// <param name="getElementMethod"></param>
private void _MoveTo(GetElementDelegate getElementMethod)
{
var element = GetNearbyElement(getElementMethod);
if (element == null)
{
throw new TreeNavigationFailedException();
}
#pragma warning disable CA2000 // Call IDisposable.Dispose()
var desktopElement = new DesktopElement(element, true, false);
#pragma warning restore CA2000
desktopElement.PopulateMinimumPropertiesForSelection();
if (desktopElement.IsRootElement() == false)
{
this.SelectAction?.SetCandidateElement(desktopElement);
this.SelectAction?.Select();
}
else
{
// if it is desktop, release it.
desktopElement.Dispose();
throw new TreeNavigationFailedException();
}
}
static JSCompileOptions()
{
GetElement = getElement;
GetElementAttributeName = getElementAttributeName;
GetIntroductionScript = getIntroductionScript;
DefaultVTable = new VTable {
element = Marshal.GetFunctionPointerForDelegate(GetElement),
elementAttributeName = Marshal.GetFunctionPointerForDelegate(GetElementAttributeName),
introductionScript = Marshal.GetFunctionPointerForDelegate(GetIntroductionScript),
};
pDefaultVTable = Marshal.AllocHGlobal(Marshal.SizeOf(DefaultVTable));
Marshal.StructureToPtr(DefaultVTable, pDefaultVTable, false);
Default = new JSCompileOptions();
}
