private void LayoutChild(
NativeView child,
LayoutParams layoutParams,
Rectangle arrangeRect)
{
if (null == child)
{
throw new ArgumentNullException(nameof(child));
}
if (null == layoutParams)
{
throw new ArgumentNullException(nameof(layoutParams));
}
var childLayoutProperties = child.LayoutProperties();
// Handle gravity flags
LayoutAxis axis = GetLayoutAxis(layoutParams.DockRegion);
float childLeft = arrangeRect.Left + layoutParams.Margin.Left;
float childLayoutWidth = childLayoutProperties.MeasuredSize.Width;
var horizontalAlignment = layoutParams.HorizontalAlignment;
if (horizontalAlignment == LayoutAlignment.Center)
{
childLeft = arrangeRect.Left + layoutParams.Margin.Left + ((arrangeRect.Width - (layoutParams.Margin.Left + childLayoutProperties.MeasuredSize.Width + layoutParams.Margin.Right)) / 2);
}
else if (horizontalAlignment == LayoutAlignment.End)
{
childLeft = arrangeRect.Right - (childLayoutProperties.MeasuredSize.Width + layoutParams.Margin.Right);
}
else if ((horizontalAlignment == LayoutAlignment.Fill) && (axis != LayoutAxis.Horizontal))
{
// Use the entire available width (minus the margins) to layout the child
childLayoutWidth = arrangeRect.Width - layoutParams.Margin.Left - layoutParams.Margin.Right;
}
float childTop = arrangeRect.Top + layoutParams.Margin.Top;
float childLayoutHeight = childLayoutProperties.MeasuredSize.Height;
var verticalAlignment = layoutParams.VerticalAlignment;
if (verticalAlignment == LayoutAlignment.Center)
{
childTop = arrangeRect.Top + layoutParams.Margin.Top + ((arrangeRect.Height - (layoutParams.Margin.Top + childLayoutProperties.MeasuredSize.Height + layoutParams.Margin.Bottom)) / 2);
}
else if (verticalAlignment == LayoutAlignment.End)
{
childTop = arrangeRect.Bottom - (childLayoutProperties.MeasuredSize.Height + layoutParams.Margin.Bottom);
}
else if ((verticalAlignment == LayoutAlignment.Fill) && (axis != LayoutAxis.Vertical))
{
// Use the entire available height (minus the margins) to layout the child
childLayoutHeight = arrangeRect.Height - layoutParams.Margin.Top - layoutParams.Margin.Bottom;
}
// Layout the child with gravity taken into account
child.Layout(
childLeft,
childTop,
Math.Max(0, childLeft + childLayoutWidth),
Math.Max(0, childTop + childLayoutHeight));
}
