// Do measurement when in vertical orientation
private void MeasureVertical(nfloat parentWidth, nfloat parentHeight)
{
// Work out our width
var width = LayoutParameters.TryResolveWidth(this, parentWidth, parentHeight);
var height = LayoutParameters.TryResolveHeight(this, parentWidth, parentHeight);
// Allow room for padding
if (width != nfloat.MaxValue)
{
width -= Padding.TotalWidth();
}
// Work out the total fixed size
nfloat totalFixedSize = 0;
double totalWeight = 0;
int visibleViewCount = 0;
foreach (var v in SubViews.Where(x => !x.Gone))
{
if (v.LayoutParameters.HeightUnits == Units.ParentRatio)
{
// We'll deal with this later
// For now, lets just total up the specified weights
totalWeight += v.LayoutParameters.Weight;
}
else
{
// Lay it out
v.Measure(adjustLayoutWidth(width, v), nfloat.MaxValue);
totalFixedSize += v.GetMeasuredSize().Height;
}
// Include margins
totalFixedSize += v.LayoutParameters.Margins.TotalHeight();
visibleViewCount++;
}
// Also need to include our own padding
totalFixedSize += Padding.TotalHeight();
// And spacing between controls
if (visibleViewCount > 1)
{
totalFixedSize += (visibleViewCount - 1) * Spacing;
}
nfloat totalVariableSize = 0;
if (LayoutParameters.HeightUnits == Units.ContentRatio || height == nfloat.MaxValue)
{
// This is a weird case: we have a height of wrap content, but child items that want to fill parent too.
// Temporarily switch those items to wrap content and use their natural size
foreach (var v in SubViews.Where(x => !x.Gone && x.LayoutParameters.HeightUnits == Units.ParentRatio))
{
v.Measure(adjustLayoutWidth(width, v), nfloat.MaxValue);
totalVariableSize += v.GetMeasuredSize().Height;
}
}
else
{
// If we've had an explicit weight passed to us, ignore the calculated total weight and use it instead
if (_totalWeight != 0)
{
totalWeight = _totalWeight;
}
// Work out how much room we've got to share around
nfloat room = height - totalFixedSize;
// Layout the fill parent items
foreach (var v in SubViews.Where(x => !x.Gone && x.LayoutParameters.HeightUnits == Units.ParentRatio))
{
// Work out size
if (room < 0)
{
room = 0;
}
nfloat size = (nfloat)(totalWeight == 0 ? room : room * v.LayoutParameters.Weight / totalWeight);
// Measure it
v.Measure(adjustLayoutWidth(width, v), size);
// Update total size
totalVariableSize += v.GetMeasuredSize().Height;
// Adjust the weighting calculation in case the view didn't accept our measurement
room -= v.GetMeasuredSize().Height;
totalWeight -= v.LayoutParameters.Weight;
}
}
CGSize sizeMeasured = CGSize.Empty;
if (width == nfloat.MaxValue)
{
// Work out the maximum width of all children that aren't fill parent
sizeMeasured.Width = 0;
foreach (var v in SubViews.Where(x => !x.Gone && x.LayoutParameters.WidthUnits != Units.ParentRatio))
{
nfloat totalChildWidth = v.GetMeasuredSize().Width + v.LayoutParameters.Margins.TotalWidth();
if (totalChildWidth > sizeMeasured.Width)
{
sizeMeasured.Width = totalChildWidth;
}
}
// Set the width of all children that are fill parent
foreach (var v in SubViews.Where(x => !x.Gone && x.LayoutParameters.WidthUnits == Units.ParentRatio))
{
v.Measure(sizeMeasured.Width, v.GetMeasuredSize().Height);
}
sizeMeasured.Width += Padding.TotalWidth();
}
else
{
width += Padding.TotalWidth();
}
if (height == nfloat.MaxValue)
{
height = totalFixedSize + totalVariableSize;
}
if (LayoutParameters.ParentIsScorllView(this))
{
height = totalFixedSize + totalVariableSize;
if (LayoutParameters.HeightUnits == Units.ParentRatio)
{
height = height < parentHeight ? parentHeight : height;
}
}
// And finally, set our measure dimensions
SetMeasuredSize(LayoutParameters.ResolveSize(new CGSize(width, height), sizeMeasured));
}
