protected virtual void ArrangeCore(Rect finalRect)
{
if (IsVisible)
{
var useLayoutRounding = UseLayoutRounding;
var scale = LayoutHelper.GetLayoutScale(this);
var margin = Margin;
var originX = finalRect.X + margin.Left;
var originY = finalRect.Y + margin.Top;
// Margin has to be treated separately because the layout rounding function is not linear
// f(a + b) != f(a) + f(b)
// If the margin isn't pre-rounded some sizes will be offset by 1 pixel in certain scales.
if (useLayoutRounding)
{
margin = LayoutHelper.RoundLayoutThickness(margin, scale, scale);
}
var availableSizeMinusMargins = new Size(
Math.Max(0, finalRect.Width - margin.Left - margin.Right),
Math.Max(0, finalRect.Height - margin.Top - margin.Bottom));
var horizontalAlignment = HorizontalAlignment;
var verticalAlignment = VerticalAlignment;
var size = availableSizeMinusMargins;
if (horizontalAlignment != HorizontalAlignment.Stretch)
{
size = size.WithWidth(Math.Min(size.Width, DesiredSize.Width - margin.Left - margin.Right));
}
if (verticalAlignment != VerticalAlignment.Stretch)
{
size = size.WithHeight(Math.Min(size.Height, DesiredSize.Height - margin.Top - margin.Bottom));
}
size = LayoutHelper.ApplyLayoutConstraints(this, size);
if (useLayoutRounding)
{
size = LayoutHelper.RoundLayoutSizeUp(size, scale, scale);
availableSizeMinusMargins = LayoutHelper.RoundLayoutSizeUp(availableSizeMinusMargins, scale, scale);
}
size = ArrangeOverride(size).Constrain(size);
switch (horizontalAlignment)
{
case HorizontalAlignment.Center:
case HorizontalAlignment.Stretch:
originX += (availableSizeMinusMargins.Width - size.Width) / 2;
break;
case HorizontalAlignment.Right:
originX += availableSizeMinusMargins.Width - size.Width;
break;
}
switch (verticalAlignment)
{
case VerticalAlignment.Center:
case VerticalAlignment.Stretch:
originY += (availableSizeMinusMargins.Height - size.Height) / 2;
break;
case VerticalAlignment.Bottom:
originY += availableSizeMinusMargins.Height - size.Height;
break;
}
if (useLayoutRounding)
{
originX = LayoutHelper.RoundLayoutValue(originX, scale);
originY = LayoutHelper.RoundLayoutValue(originY, scale);
}
Bounds = new Rect(originX, originY, size.Width, size.Height);
}
}
protected virtual Size MeasureCore(Size availableSize)
{
if (IsVisible)
{
var margin = Margin;
var useLayoutRounding = UseLayoutRounding;
var scale = 1.0;
if (useLayoutRounding)
{
scale = LayoutHelper.GetLayoutScale(this);
margin = LayoutHelper.RoundLayoutThickness(margin, scale, scale);
}
ApplyStyling();
ApplyTemplate();
var constrained = LayoutHelper.ApplyLayoutConstraints(
this,
availableSize.Deflate(margin));
var measured = MeasureOverride(constrained);
var width = measured.Width;
var height = measured.Height;
{
double widthCache = Width;
if (!double.IsNaN(widthCache))
{
width = widthCache;
}
}
width = Math.Min(width, MaxWidth);
width = Math.Max(width, MinWidth);
{
double heightCache = Height;
if (!double.IsNaN(heightCache))
{
height = heightCache;
}
}
height = Math.Min(height, MaxHeight);
height = Math.Max(height, MinHeight);
if (useLayoutRounding)
{
(width, height) = LayoutHelper.RoundLayoutSizeUp(new Size(width, height), scale, scale);
}
width = Math.Min(width, availableSize.Width);
height = Math.Min(height, availableSize.Height);
return(NonNegative(new Size(width, height).Inflate(margin)));
}
else
{
return(new Size());
}
}
