// 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));
}
// Helper to get the total measured width of all subviews, including all padding and margins
private nfloat getTotalMeasuredWidth()
{
return((nfloat)(Padding.TotalWidth() + getTotalSpacing() + SubViews.Where(x => !x.Gone).Sum(x => x.GetMeasuredSize().Width + x.LayoutParameters.Margins.TotalWidth())));
}
// Helper to get the total measured height of all subviews, including all padding and margins
private nfloat getTotalMeasuredHeight()
{
return(Padding.TotalHeight() + getTotalSpacing() + (nfloat)SubViews.Where(x => !x.Gone).Sum(x => x.GetMeasuredSize().Height + x.LayoutParameters.Margins.TotalHeight()));
}
protected override void onMeasure(float parentWidth, float parentHeight)
{
var unresolved = new List <View>();
var width = LayoutParameters.TryResolveWidth(this, parentWidth);
var height = LayoutParameters.TryResolveHeight(this, parentHeight);
// Remove padding
if (width != float.MaxValue)
{
width -= Padding.TotalWidth();
}
if (height != float.MaxValue)
{
height -= Padding.TotalHeight();
}
// Measure all subviews where both dimensions can be resolved
bool haveResolvedSize = false;
float maxWidth = 0, maxHeight = 0;
foreach (var v in SubViews.Where(x => !x.Gone))
{
// Try to resolve subview width
var subViewWidth = float.MaxValue;
if (v.LayoutParameters.WidthUnits == Units.ParentRatio)
{
if (width == float.MaxValue)
{
unresolved.Add(v);
continue;
}
else
{
subViewWidth = width - v.LayoutParameters.Margins.TotalWidth();
}
}
// Try to resolve subview height
var subViewHeight = float.MaxValue;
if (v.LayoutParameters.HeightUnits == Units.ParentRatio)
{
if (height == float.MaxValue)
{
unresolved.Add(v);
continue;
}
else
{
subViewHeight = height - v.LayoutParameters.Margins.TotalHeight();
}
}
// Measure it
v.Measure(subViewWidth, subViewHeight);
if (!haveResolvedSize)
{
maxWidth = v.GetMeasuredSize().Width + v.LayoutParameters.Margins.TotalWidth();
maxHeight = v.GetMeasuredSize().Height + v.LayoutParameters.Margins.TotalHeight();
haveResolvedSize = true;
}
else
{
maxWidth = Math.Max(maxWidth, v.GetMeasuredSize().Width + v.LayoutParameters.Margins.TotalWidth());
maxHeight = Math.Max(maxHeight, v.GetMeasuredSize().Height + v.LayoutParameters.Margins.TotalHeight());
}
}
// Now resolve the unresolved subviews by either using the dimensions of the view
// that were resolved, or none were, use their natural size
foreach (var v in unresolved)
{
var subViewWidth = float.MaxValue;
if (v.LayoutParameters.WidthUnits == Units.ParentRatio && haveResolvedSize)
{
subViewWidth = maxWidth - v.LayoutParameters.Margins.TotalWidth();
}
var subViewHeight = float.MaxValue;
if (v.LayoutParameters.HeightUnits == Units.ParentRatio && haveResolvedSize)
{
subViewHeight = maxHeight - v.LayoutParameters.Margins.TotalHeight();
}
// Measure it
v.Measure(subViewWidth, subViewHeight);
}
SizeF sizeMeasured = SizeF.Empty;
if (width == float.MaxValue)
{
sizeMeasured.Width = SubViews.Max(x => x.GetMeasuredSize().Width + x.LayoutParameters.Margins.TotalWidth()) + Padding.TotalWidth();
}
if (height == float.MaxValue)
{
sizeMeasured.Height = SubViews.Max(x => x.GetMeasuredSize().Height + x.LayoutParameters.Margins.TotalHeight()) + Padding.TotalHeight();
}
// Done!
SetMeasuredSize(LayoutParameters.ResolveSize(new SizeF(width, height), sizeMeasured));
}
// Do measurement when in horizontal orientation
private void MeasureHorizontal(nfloat parentWidth, nfloat parentHeight)
{
// Work out our height
nfloat layoutWidth = LayoutParameters.TryResolveWidth(this, parentWidth, parentHeight);
nfloat layoutHeight = LayoutParameters.TryResolveHeight(this, parentWidth, parentHeight);
// Work out the total fixed size
var paddings = Padding.TotalWidth();
_goneViews = new List <View>();
_arrangedViews = new View[RowDefinitions.Count, ColumnDefinitions.Count];
var columnWidthFillParentSubviews = new List <View>();
//calculating columns
var minWidth = (nfloat)ColumnDefinitions.Sum(x => x.MinWidth);
foreach (var v in SubViews.Where(x => !x.Gone))
{
_arrangedViews[v.Row, v.Column] = v;
var columnDefinition = ColumnDefinitions[v.Column];
var rowDefinition = RowDefinitions[v.Column];
nfloat width;
if (columnDefinition.Width > 0)
{
width = columnDefinition.Width;
}
else if (columnDefinition.MaxWidth > 0)
{
width = columnDefinition.MaxWidth;
}
else
{
width = parentWidth - paddings;
}
nfloat height;
if (rowDefinition.Height > 0)
{
height = rowDefinition.Height;
}
else
{
height = adjustLayoutHeight(layoutHeight, v);
}
if (v.LayoutParameters.WidthUnits != Units.ParentRatio)
{
v.Measure(width - v.LayoutParameters.Margins.TotalWidth(), height);
}
else
{
v._measuredSize = new CGSize(0, 0);
v._measuredSizeValid = true;
columnWidthFillParentSubviews.Add(v);
}
}
{
nfloat totalWeight = 0;
nfloat totalWidth = 0;
var columnId = -1;
foreach (var column in ColumnDefinitions)
{
columnId++;
column.CalculatedWidth = 0;
if (column.Width > 0)
{
column.CalculatedWidth = column.Width;
}
else if (column.Width == AutoSize.WrapContent)
{
for (int rowId = 0; rowId < RowDefinitions.Count; rowId++)
{
var v = _arrangedViews[rowId, columnId];
if (v != null)
{
column.CalculatedWidth = NMath.Max(column.CalculatedWidth, v.GetMeasuredSize().Width + v.LayoutParameters.Margins.TotalWidth());
}
}
}
else if (column.Width == AutoSize.FillParent)
{
totalWeight += column.Weight;
}
totalWidth += column.CalculatedWidth;
}
var room = layoutWidth - totalWidth;
foreach (var column in ColumnDefinitions.Where(x => x.Width == AutoSize.FillParent))
{
columnId++;
column.CalculatedWidth = room * column.Weight / totalWeight;
}
}
{
var totalWeight = 0;
var totalHeight = 0;
var rowId = -1;
foreach (var row in RowDefinitions)
{
rowId++;
if (row.Height > 0)
{
row.CalculatedHeight = row.Height;
continue;
}
if (row.Height == AutoSize.WrapContent)
{
row.CalculatedHeight = 0;
for (int columnId = 0; columnId < ColumnDefinitions.Count; columnId++)
{
var v = _arrangedViews[rowId, columnId];
if (v != null)
{
row.CalculatedHeight = NMath.Max(row.CalculatedHeight, v.GetMeasuredSize().Height);
}
}
}
}
var room = layoutHeight - totalHeight;
foreach (var row in RowDefinitions.Where(x => x.Height == AutoSize.FillParent))
{
row.CalculatedHeight = room * row.Weight / totalWeight;
}
}
CGSize sizeMeasured = CGSize.Empty;
foreach (var item in ColumnDefinitions)
{
sizeMeasured.Width += item.CalculatedWidth;
}
sizeMeasured.Width += ColSpacing * (ColumnDefinitions.Count - 1);
foreach (var item in RowDefinitions)
{
sizeMeasured.Height += item.CalculatedHeight;
}
sizeMeasured.Height += RowSpacing * (RowDefinitions.Count - 1);
foreach (var v in columnWidthFillParentSubviews)
{
v.Measure(ColumnDefinitions[v.Column].CalculatedWidth, RowDefinitions[v.Row].CalculatedHeight);
}
// And finally, set our measure dimensions
SetMeasuredSize(LayoutParameters.ResolveSize(new CGSize(layoutWidth, layoutHeight), sizeMeasured));
}