/// <summary>
/// Begins a storyboard and waits for it to complete.
/// </summary>
public static async Task BeginAsync(this Storyboard storyboard)
{
await EventAsync.FromEvent <object>(
eh => storyboard.Completed += eh,
eh => storyboard.Completed -= eh,
storyboard.Begin);
}
/// <summary>
/// Scrolls to horizontal offset asynchronously.
/// </summary>
/// <param name="scrollViewer">The scroll viewer.</param>
/// <param name="offset">The offset.</param>
/// <returns>The task that completes when scrolling is complete.</returns>
public static async Task ScrollToHorizontalOffsetAsync(this ScrollViewer scrollViewer, double offset)
{
if (offset < 0)
{
offset = 0;
}
if (offset > scrollViewer.ScrollableWidth)
{
offset = scrollViewer.ScrollableWidth;
}
var currentOffset = scrollViewer.HorizontalOffset;
// ReSharper disable CompareOfFloatsByEqualityOperator
if (offset == currentOffset)
{
return;
}
scrollViewer.ScrollToHorizontalOffset(offset);
if (scrollViewer.HorizontalOffset == offset)
{
return;
}
if (scrollViewer.HorizontalOffset != currentOffset)
{
return;
}
// ReSharper restore CompareOfFloatsByEqualityOperator
await EventAsync.FromEvent <ScrollViewerViewChangedEventArgs>(
eh => scrollViewer.ViewChanged += eh,
eh => scrollViewer.ViewChanged -= eh);
}
/// <summary>
/// Scrolls to vertical offset with animation asynchronously.
/// </summary>
/// <param name="scrollViewer">The scroll viewer.</param>
/// <param name="offset">The offset.</param>
/// <returns>The task that completes when scrolling is complete.</returns>
public static async Task ScrollToVerticalOffsetWithAnimationAsync(this ScrollViewer scrollViewer, double offset)
{
if (offset < 0)
{
offset = 0;
}
if (offset > scrollViewer.ScrollableHeight)
{
offset = scrollViewer.ScrollableHeight;
}
var currentOffset = scrollViewer.VerticalOffset;
// ReSharper disable CompareOfFloatsByEqualityOperator
if (offset == currentOffset)
{
return;
}
await scrollViewer.ScrollToVerticalOffsetWithAnimation(offset);
if (scrollViewer.VerticalOffset == offset)
{
return;
}
if (scrollViewer.VerticalOffset != currentOffset)
{
return;
}
// ReSharper restore CompareOfFloatsByEqualityOperator
await EventAsync.FromEvent <ScrollViewerViewChangedEventArgs>(
eh => scrollViewer.ViewChanged += eh,
eh => scrollViewer.ViewChanged -= eh);
}