/// <summary>
/// <see cref="ITextView.BringPointIntoViewAsync"/>
/// </summary>
internal override void BringPointIntoViewAsync(Point point, object userState)
{
DocumentPageTextView pageTextView;
ITextPointer position;
BringPointIntoViewRequest pendingRequest;
bool bringIntoViewPending;
// Verify that layout information is valid. Cannot continue if not valid.
if (!IsValid)
{
throw new InvalidOperationException(SR.Get(SRID.TextViewInvalidLayout));
}
if (_pendingRequest != null)
{
// Ignore new request if the previous is not completed yet.
OnBringPointIntoViewCompleted(new BringPointIntoViewCompletedEventArgs(
point, null, false, null, false, userState));
}
else
{
pendingRequest = new BringPointIntoViewRequest(point, userState);
_pendingRequest = pendingRequest;
pageTextView = GetTextViewFromPoint(point, false);
// If the point is currently in the view, use existing TextView to retrieve the position.
// Otherwise, let the viewer handle the request.
if (pageTextView != null)
{
// Transform to DocumentPageView coordinates and query inner TextView
point = TransformToDescendant(pageTextView.RenderScope, point);
position = pageTextView.GetTextPositionFromPoint(point, true);
pendingRequest.Position = position;
OnBringPointIntoViewCompleted(pendingRequest);
}
else
{
// Request to bring point into view in the Viewer.
// This code is specific to known viewers. Since text selection is not
// exposed in a public way, it should not cause any "extensibility" problems.
GeneralTransform transform = _renderScope.TransformToAncestor(_viewer);
//
transform.TryTransform(point, out point);
bringIntoViewPending = false;
if (_viewer is FlowDocumentPageViewer)
{
// Special handling for FlowDocumentPageViewer
bringIntoViewPending = ((FlowDocumentPageViewer)_viewer).BringPointIntoView(point);
}
else if (_viewer is DocumentViewer)
{
// Special handling for DocumentViewer
bringIntoViewPending = ((DocumentViewer)_viewer).BringPointIntoView(point);
}
else
{
if (DoubleUtil.LessThan(point.X, 0))
{
if (_viewer.CanGoToPreviousPage)
{
_viewer.PreviousPage();
bringIntoViewPending = true;
}
}
else if (DoubleUtil.GreaterThan(point.X, _viewer.RenderSize.Width))
{
if (_viewer.CanGoToNextPage)
{
_viewer.NextPage();
bringIntoViewPending = true;
}
}
else if (DoubleUtil.LessThan(point.Y, 0))
{
if (_viewer.CanGoToPreviousPage)
{
_viewer.PreviousPage();
bringIntoViewPending = true;
}
}
else if (DoubleUtil.GreaterThan(point.Y, _viewer.RenderSize.Height))
{
if (_viewer.CanGoToNextPage)
{
_viewer.NextPage();
bringIntoViewPending = true;
}
}
}
if (!bringIntoViewPending)
{
OnBringPointIntoViewCompleted(pendingRequest);
}
}
}
}
/// <summary>
/// Fires BringPointIntoViewCompleted event.
/// </summary>
private void OnBringPointIntoViewCompleted(BringPointIntoViewRequest request)
{
_pendingRequest = null;
OnBringPointIntoViewCompleted(new BringPointIntoViewCompletedEventArgs(
request.Point, request.Position,
request.Position != null, null, false, request.UserState));
}
