public void InvalidateScrollInfo ()
{
if (ScrollInfo != null) {
ExtentHeight = ScrollInfo.ExtentHeight;
ExtentWidth = ScrollInfo.ExtentWidth;
ViewportHeight = ScrollInfo.ViewportHeight;
ViewportWidth = ScrollInfo.ViewportWidth;
UpdateScrollBar (Orientation.Horizontal, ScrollInfo.HorizontalOffset);
UpdateScrollBar (Orientation.Vertical, ScrollInfo.VerticalOffset);
UpdateScrollbarVisibility ();
}
// UIA Event
RaiseViewportChangedEvent (ViewportWidth, ViewportHeight);
if (Math.Max(0, ExtentHeight - ViewportHeight) != ScrollableHeight) {
SetValueImpl (ScrollableHeightProperty, Math.Max(0, ExtentHeight - ViewportHeight));
InvalidateMeasure ();
}
if (Math.Max(0, ExtentWidth - ViewportWidth) != ScrollableWidth) {
SetValueImpl (ScrollableWidthProperty, Math.Max(0, ExtentWidth - ViewportWidth));
InvalidateMeasure ();
}
}
public void SetHorizontalOffset(double offset)
{
if (offset < 0 || this.viewport.Width >= this.extent.Width)
{
offset = 0;
}
else if (offset + this.viewport.Width >= this.extent.Width)
{
offset = this.extent.Width - this.viewport.Width;
}
this.contentOffset.X = offset;
if (usingCustomScrolling)
{
this.horizontalBackend.SetOffset(offset);
}
else
{
this.transform.X = -offset;
}
if (ScrollOwner != null)
{
ScrollOwner.InvalidateScrollInfo();
}
}