/// <summary>
/// Handles the <see cref="VideoTimelineSegment.HorizontalResizeDragCompletedEvent"/> attached event
/// for a <see cref="VideoTimelineSegment"/> element.
/// </summary>
/// <inheritdoc cref="HorizontalResizeDragCompletedEventHandler"/>
private void OnTrackSegmentHorizontalResizeDragCompleted(object sender, HorizontalResizeDragCompletedEventArgs e)
{
if (_isResizingSegment)
{
VideoTimelineSegment segmentElement = e.OriginalSource as VideoTimelineSegment;
Debug.Assert(segmentElement != null);
VideoTimelineTrack trackElement = segmentElement.ParentTrackElement;
SegmentViewModelBase segmentViewModel = segmentElement.DataContext as SegmentViewModelBase;
Debug.Assert(segmentViewModel != null);
int frameDiff = (int)Math.Round(_segmentResizeAdorner.HorizontalOffset / trackElement.PixelsPerFrame);
if (frameDiff != 0)
{
if (e.HorizontalSide == HorizontalSide.Left)
{
int newStartFrame = segmentViewModel.StartFrame + frameDiff;
ViewModel.ChangeTrackSegmentStartFrame(segmentViewModel, newStartFrame);
}
else // e.HorizontalSide == HorizontalSide.Right
{
int newEndFrame = segmentViewModel.EndFrame + frameDiff;
ViewModel.ChangeTrackSegmentEndFrame(segmentViewModel, newEndFrame);
}
}
segmentElement.Clip = null;
_segmentResizeAdorner?.Detach();
_segmentResizeAdorner = null;
_isResizingSegment = false;
}
e.Handled = true;
}
/// <summary>
/// Handles the <see cref="VideoTimelineSegment.HorizontalResizeDraggingEvent"/> attached event
/// for a <see cref="VideoTimelineSegment"/> element.
/// </summary>
/// <inheritdoc cref="HorizontalResizeDraggingEventHandler"/>
private void OnTrackSegmentHorizontalResizeDragging(object sender, HorizontalResizeDragEventArgs e)
{
e.Handled = true;
VideoTimelineSegment segmentElement = e.OriginalSource as VideoTimelineSegment;
Debug.Assert(segmentElement != null);
VideoTimelineTrack trackElement = segmentElement.ParentTrackElement;
SegmentViewModelBase segmentViewModel = segmentElement.DataContext as SegmentViewModelBase;
Debug.Assert(segmentViewModel != null);
int frameDiff = (int)Math.Round(e.HorizontalChange / trackElement.PixelsPerFrame);
if (frameDiff == 0)
{
return;
}
int proposedStartFrame = segmentViewModel.StartFrame;
int proposedEndFrame = segmentViewModel.EndFrame;
double framePixelOffset = trackElement.PixelsPerFrame * frameDiff;
bool isContracting = false;
Rect segmentElementClipRect;
if (e.HorizontalSide == HorizontalSide.Left)
{
proposedStartFrame += frameDiff;
if (!ViewModel.CanChangeTrackSegmentStartFrame(segmentViewModel, proposedStartFrame))
{
return;
}
if (frameDiff > 0)
{
isContracting = true;
segmentElementClipRect = new Rect(framePixelOffset, 0d, segmentElement.ActualWidth - framePixelOffset, segmentElement.ActualHeight);
}
}
else // e.HorizontalSide == HorizontalSide.Right
{
proposedEndFrame += frameDiff;
if (!ViewModel.CanChangeTrackSegmentEndFrame(segmentViewModel, proposedEndFrame))
{
return;
}
if (frameDiff < 0)
{
isContracting = true;
segmentElementClipRect = new Rect(
new Size(segmentElement.ActualWidth + framePixelOffset, segmentElement.ActualHeight)
);
}
}
if (isContracting)
{
if (segmentElement.Clip is RectangleGeometry rectangleGeometry)
{
rectangleGeometry.Rect = segmentElementClipRect;
}
else
{
segmentElement.Clip = new RectangleGeometry(segmentElementClipRect);
}
}
else
{
segmentElement.Clip = null;
}
if (_segmentResizeAdorner == null)
{
UIElement segmentElementContainer = segmentElement.TemplatedParent as UIElement;
Debug.Assert(segmentElementContainer != null);
_segmentResizeAdorner = new TrackSegmentResizeAdorner(adornedElement: trackElement, segmentElement,
segmentElementLeftCoordinate: Canvas.GetLeft(segmentElementContainer),
attachPosition: e.HorizontalSide);
_segmentResizeAdorner.Attach();
_isResizingSegment = true;
}
_segmentResizeAdorner.HorizontalOffset = framePixelOffset;
_segmentResizeAdorner.ToolTipData.StartFrame = proposedStartFrame;
_segmentResizeAdorner.ToolTipData.EndFrame = proposedEndFrame;
}