public static Size ComputeDesiredSize(this IFrameworkElement frameworkElement, double widthConstraint, double heightConstraint)
{
_ = frameworkElement ?? throw new ArgumentNullException(nameof(frameworkElement));
if (frameworkElement.Handler == null)
{
return(Size.Zero);
}
var margin = frameworkElement.GetMargin();
// Adjust the constraints to account for the margins
widthConstraint -= margin.HorizontalThickness;
heightConstraint -= margin.VerticalThickness;
// Determine whether the external constraints or the requested size values will determine the measurements
widthConstraint = LayoutManager.ResolveConstraints(widthConstraint, frameworkElement.Width);
heightConstraint = LayoutManager.ResolveConstraints(heightConstraint, frameworkElement.Height);
// Ask the handler to do the actual measuring
var measureWithMargins = frameworkElement.Handler.GetDesiredSize(widthConstraint, heightConstraint);
// Account for the margins when reporting the desired size value
return(new Size(measureWithMargins.Width + margin.HorizontalThickness,
measureWithMargins.Height + margin.VerticalThickness));
}
public Size Measure(double widthConstraint, double heightConstraint)
{
double width = 0;
double height = 0;
if (!double.IsInfinity(widthConstraint))
{
width = widthConstraint;
}
if (!double.IsInfinity(heightConstraint))
{
height = heightConstraint;
}
height = LayoutManager.ResolveConstraints(height, FlexLayout.Height, height, FlexLayout.MinimumHeight, FlexLayout.MaximumHeight);
width = LayoutManager.ResolveConstraints(width, FlexLayout.Width, width, FlexLayout.MinimumWidth, FlexLayout.MaximumWidth);
return(new Size(width, height));
}
public Size Measure(double widthConstraint, double heightConstraint)
{
double measuredHeight = 0;
double measuredWidth = 0;
FlexLayout.Layout(widthConstraint, heightConstraint);
foreach (var child in FlexLayout)
{
if (child.Visibility == Visibility.Collapsed)
{
continue;
}
var frame = FlexLayout.GetFlexFrame(child);
measuredHeight = Math.Max(measuredHeight, frame.Bottom);
measuredWidth = Math.Max(measuredWidth, frame.Right);
}
var finalHeight = LayoutManager.ResolveConstraints(heightConstraint, FlexLayout.Height, measuredHeight, FlexLayout.MinimumHeight, FlexLayout.MaximumHeight);
var finalWidth = LayoutManager.ResolveConstraints(widthConstraint, FlexLayout.Width, measuredWidth, FlexLayout.MinimumWidth, FlexLayout.MaximumWidth);
return(new Size(finalWidth, finalHeight));
}