internal void ScrollColumnIntoViewCore(ScrollIntoViewOperation <int> scrollOperation)
{
var update = new DelegateUpdate <UpdateFlags>(() =>
{
if (scrollOperation.ScrollAttempts < ScrollIntoViewOperation <int> .MaxScrollAttempts)
{
this.ScrollColumnIndexIntoView(scrollOperation);
scrollOperation.ScrollAttempts++;
if (this.IsColumnIndexInView(scrollOperation))
{
if (scrollOperation.CompletedAction != null)
{
scrollOperation.CompletedAction();
}
}
else
{
this.ScrollColumnIntoViewCore(scrollOperation);
}
}
});
this.GridView.UpdateService.RegisterUpdate(update);
}
internal void ScrollIndexIntoView(ScrollIntoViewOperation <ItemInfo?> operation)
{
var index = operation.RequestedItem.Value.Slot;
var frozenContainersLength = 0;
var itemLength = this.layoutController.strategy.Layout.PhysicalLengthForSlot(index);
var offsetToScroll = this.layoutController.strategy.Layout.PhysicalOffsetFromSlot(index) - itemLength;
if (DoubleArithmetics.IsLessThan(operation.InitialScrollOffset + frozenContainersLength, offsetToScroll))
{
if (index > 0)
{
offsetToScroll -= this.View.Orientation == Orientation.Vertical ? this.View.ViewportHeight : this.View.ViewportWidth;
offsetToScroll += itemLength;
}
}
else if (DoubleArithmetics.IsLessThanOrEqual(offsetToScroll, operation.InitialScrollOffset + frozenContainersLength))
{
offsetToScroll -= frozenContainersLength;
}
var scrollPosition = this.View.Orientation == Orientation.Vertical ? new RadPoint(this.View.ScrollOffset, Math.Max(0, offsetToScroll)) : new RadPoint(Math.Max(0, offsetToScroll), this.View.ScrollOffset);
this.View.SetScrollPosition(scrollPosition, true, true);
}
internal void ScrollIndexIntoViewCore(ScrollIntoViewOperation <int> scrollOperation)
{
var update = new DelegateUpdate <UpdateFlags>(() =>
{
if (scrollOperation.ScrollAttempts < ScrollIntoViewOperation <int> .MaxScrollAttempts)
{
if (this.IsIndexInView(scrollOperation))
{
if (scrollOperation.CompletedAction != null)
{
this.GridView.UpdateService.RegisterUpdate(new DelegateUpdate <UpdateFlags>(scrollOperation.CompletedAction));
}
}
else
{
this.ScrollIndexIntoView(scrollOperation);
scrollOperation.ScrollAttempts++;
this.ScrollIndexIntoViewCore(scrollOperation);
}
}
})
{
RequiresValidMeasure = true
};
this.GridView.UpdateService.RegisterUpdate(update);
}
internal void ScrollIndexIntoView(ScrollIntoViewOperation <int> operation)
{
var index = operation.RequestedItem;
var frozenContainersLength = Math.Max(0, this.RowPool.FrozenContainersLength);
var itemLength = this.rowLayout.RenderInfo.ValueForIndex(index);
var offsetToScroll = this.rowLayout.RenderInfo.OffsetFromIndex(index) - itemLength;
if (DoubleArithmetics.IsLessThan(operation.InitialScrollOffset + frozenContainersLength, offsetToScroll))
{
if (index > 0)
{
offsetToScroll -= this.View.ViewportHeight;
offsetToScroll += itemLength;
}
}
else if (DoubleArithmetics.IsLessThanOrEqual(offsetToScroll, operation.InitialScrollOffset + frozenContainersLength))
{
offsetToScroll -= frozenContainersLength;
}
var scrollPosition = new RadPoint(this.PhysicalHorizontalOffset, Math.Max(0, offsetToScroll));
this.GridView.SetScrollPosition(scrollPosition, true, true);
}
internal bool IsIndexInView(ScrollIntoViewOperation <ItemInfo?> operation)
{
var element = this.layoutController.strategy.GetDisplayedElement(operation.RequestedItem.Value.Slot, operation.RequestedItem.Value.Id);
if (element == null)
{
return(false);
}
var frozenContainersLength = 0;
bool isIndexIntoView;
if (this.View.Orientation == Orientation.Vertical)
{
isIndexIntoView = DoubleArithmetics.IsGreaterThanOrEqual(element.LayoutSlot.Y, this.View.ScrollOffset + frozenContainersLength) &&
DoubleArithmetics.IsLessThanOrEqual(element.LayoutSlot.Y + element.LayoutSlot.Height, this.View.ScrollOffset + this.View.ViewportHeight);
}
else
{
isIndexIntoView = DoubleArithmetics.IsGreaterThanOrEqual(element.LayoutSlot.X, this.View.ScrollOffset + frozenContainersLength) &&
DoubleArithmetics.IsLessThanOrEqual(element.LayoutSlot.X + element.LayoutSlot.Width, this.View.ScrollOffset + this.View.ViewportWidth);
}
return(isIndexIntoView);
}
internal bool IsColumnIndexInView(ScrollIntoViewOperation <int> operation)
{
var column = this.ColumnPool.GetDisplayedElement(operation.RequestedItem);
if (column == null)
{
return(false);
}
// Since the headers are not part of the scrollviewer we need to compare their position to the viewport window and omit the scroll offset.
return(DoubleArithmetics.Ceiling(column.LayoutSlot.X) >= 0 &&
DoubleArithmetics.IsLessThanOrEqual(column.LayoutSlot.X + column.layoutSlot.Width, this.View.ViewportWidth));
}
internal bool IsIndexInView(ScrollIntoViewOperation <int> operation)
{
var layoutSlot = this.RowPool.GetPreviousDisplayedLayoutSlot(operation.RequestedItem);
if (layoutSlot == RadRect.Invalid)
{
return(false);
}
var frozenContainersLength = Math.Max(0, this.RowPool.FrozenContainersLength);
return(DoubleArithmetics.IsGreaterThanOrEqual(layoutSlot.Y, this.PhysicalVerticalOffset + frozenContainersLength) &&
DoubleArithmetics.IsLessThanOrEqual(layoutSlot.Y + layoutSlot.Height, this.PhysicalVerticalOffset + this.View.ViewportHeight));
}
/// <summary>
/// Attempts to bring the data item at the specified zero-based index into view asynchronously.
/// </summary>
/// <param name="index">The zero-based index of the item to scroll.</param>
/// <param name="scrollCompletedAction">Arbitrary action that may be executed after the asynchronous update is executed.</param>
public void ScrollIndexIntoView(int index, Action scrollCompletedAction)
{
if (!this.IsTemplateApplied)
{
this.updateService.RegisterUpdate(new DelegateUpdate <UpdateFlags>(() => this.ScrollIndexIntoView(index, scrollCompletedAction)));
return;
}
var scrollOperation = new ScrollIntoViewOperation <int>(index, this.ScrollViewer.VerticalOffset)
{
CompletedAction = scrollCompletedAction
};
this.Model.ScrollIndexIntoViewCore(scrollOperation);
}
/// <summary>
/// Attempts to bring the specified data item into view asynchronously.
/// </summary>
/// <param name="item">The data item to scroll to.</param>
/// <param name="scrollCompletedAction">Arbitrary action that may be executed after the asynchronous update is executed.</param>
public void ScrollItemIntoView(object item, Action scrollCompletedAction)
{
if (!this.IsTemplateApplied)
{
this.updateService.RegisterUpdate(new DelegateUpdate <UpdateFlags>(() => this.ScrollItemIntoView(item, scrollCompletedAction)));
return;
}
var info = this.model.FindItemInfo(item);
if (info != null)
{
var scrollOperation = new ScrollIntoViewOperation <int>(info.Value.LayoutInfo.Line, this.ScrollViewer.VerticalOffset)
{
CompletedAction = scrollCompletedAction
};
this.Model.ScrollIndexIntoViewCore(scrollOperation);
}
}
internal void ScrollColumnIndexIntoView(ScrollIntoViewOperation <int> operation)
{
var columnIndex = operation.RequestedItem;
if (columnIndex < 0)
{
return;
}
var itemLength = this.columnLayout.RenderInfo.ValueForIndex(columnIndex);
var offsetToScroll = this.columnLayout.RenderInfo.OffsetFromIndex(columnIndex) - itemLength;
if (this.PhysicalHorizontalOffset < offsetToScroll)
{
offsetToScroll -= this.View.ViewportWidth - itemLength;
}
var scrollPosition = new RadPoint(offsetToScroll, this.PhysicalVerticalOffset);
this.GridView.SetScrollPosition(scrollPosition, true, true);
}
/// <summary>
/// Attempts to bring the specified <see cref="DataGridColumn" /> into view asynchronously.
/// </summary>
/// <param name="column">The column.</param>
/// <param name="scrollCompletedAction">Arbitrary action that may be executed after the asynchronous update is executed.</param>
public void ScrollColumnIntoView(DataGridColumn column, Action scrollCompletedAction)
{
if (!this.IsTemplateApplied)
{
this.updateService.RegisterUpdate(new DelegateUpdate <UpdateFlags>(() => this.ScrollColumnIntoView(column, scrollCompletedAction)));
return;
}
// TODO: consider adding displayindex to the columns to improve this when this operation become a performance issue.
var columnIndex = this.Columns.IndexOf(column);
if (columnIndex < 0)
{
return;
}
var scrollOperation = new ScrollIntoViewOperation <int>(columnIndex, this.ScrollViewer.VerticalOffset)
{
CompletedAction = scrollCompletedAction
};
this.Model.ScrollColumnIntoViewCore(scrollOperation);
}
