public override void LayoutSubviews()
{
var oldSize = Frame.Size;
#if ENABLE_DEBUG_LOG
string debugIndent = String.Concat(Enumerable.Repeat(" ", numSuperviews(this)));
LogLine($"{debugIndent}LayoutSubviews {GetHashCode()} {this.GetType()}");
#else
const string debugIndent = "";
#endif
base.LayoutSubviews();
this.UpdateLayout();
if (CurrentLayout == null)
{
return;
}
// Allow streched cells that are in an auto sized column or row only if there is at
// least one non-stretched cell that starts that same column/row
foreach (var cell in this.CurrentLayout.Cells)
{
if (cell.Position.Horizontal == Layout.Alignment.Stretched &&
this.CurrentLayout.ColumnDefinitions[cell.Position.Column].SizeType == Layout.SizeType.Auto &&
!this.CurrentLayout.Cells.Any(c => c.Position.Column == cell.Position.Column && c.Position.Horizontal != Layout.Alignment.Stretched))
{
throw new Exception($"Grid {ID}: Stretched horizontal cell alignment on row {cell.Position.Row}, col {cell.Position.Column} cannot be used in an auto sized column when there is no other cell in that column that is not stretched");
}
if (cell.Position.Vertical == Layout.Alignment.Stretched &&
this.CurrentLayout.RowDefinitions[cell.Position.Row].SizeType == Layout.SizeType.Auto &&
!this.CurrentLayout.Cells.Any(c => c.Position.Row == cell.Position.Row && c.Position.Vertical != Layout.Alignment.Stretched))
{
throw new Exception($"Grid {ID}: Stretched vertical cell alignment on row {cell.Position.Row}, col {cell.Position.Column} cannot be used in an auto sized row when there is no other cell in that column that is not stretched");
}
}
#if ENABLE_DEBUG_LOG
LogLine($"{debugIndent}Cells at start of layout:");
foreach (var cell in this.CurrentLayout.Cells)
{
LogLine($"{debugIndent} {cell}");
}
#endif
var horizontallyStretchedCells = this.CurrentLayout.Cells.Where(c => c.IncludeInAutoWidthSizeCalcs &&
c.View != null && c.Position.Horizontal == Layout.Alignment.Stretched);
if (horizontallyStretchedCells.Any())
{
LogLine($"{debugIndent} Setting width of horizontally stretched cells");
var widths1 = this.CurrentLayout.CalculateAbsoluteColumnWidth(this).Item2;
foreach (var cell in horizontallyStretchedCells)
{
nfloat w = CalcSpanWidth(cell, widths1);
LogLine($"{debugIndent} Setting cell.View Width to {w}");
nfloat width = w - cell.Position.Margin.Width();
if (RoundLayout)
{
width = width.RoundToScale();
}
cell.View.SetWidth(width);
LogLine($"{debugIndent} Before LayoutSubviews {cell.DebugLabel}");
cell.View.LayoutSubviews();
LogLine($"{debugIndent} After LayoutSubviews cell.View Size={cell.View.Frame.Size} {cell.DebugLabel}");
}
}
var verticallyStretchedCells = this.CurrentLayout.Cells.Where(c => c.IncludeInAutoWidthSizeCalcs &&
c.View != null && c.Position.Vertical == Layout.Alignment.Stretched);
if (verticallyStretchedCells.Any())
{
LogLine($"{debugIndent} Setting height of vertically stretched cells");
var heights1 = this.CurrentLayout.CalculateAbsoluteRowHeight(this).Item2;
foreach (var cell in verticallyStretchedCells)
{
nfloat h = CalcSpanHeight(cell, heights1);
LogLine($"{debugIndent} Setting cell.View Height to {h}");
nfloat height = h - cell.Position.Margin.Height();
if (RoundLayout)
{
height = height.RoundToScale();
}
cell.View.SetHeight(height);
LogLine($"{debugIndent} Before LayoutSubviews {cell.DebugLabel}");
cell.View.LayoutSubviews();
LogLine($"{debugIndent} After LayoutSubviews cell.View Size={cell.View.Frame.Size} {cell.DebugLabel}");
}
}
// Calculate row sizes
var heights = this.CurrentLayout.CalculateAbsoluteRowHeight(this);
nfloat gridHeight = heights.Item1;
nfloat[] absoluteRowHeight = heights.Item2;
LogLine($"{debugIndent} AutoHeight={AutoHeight}, gridHeight={gridHeight}, Frame.Height={Frame.Height}");
// Calculate column sizes
var widths = this.CurrentLayout.CalculateAbsoluteColumnWidth(this);
nfloat gridWidth = widths.Item1;
nfloat[] absoluteColumnWidth = widths.Item2;
LogLine($"{debugIndent} AutoWidth={AutoWidth} gridWidth={gridWidth}, Frame.Width={Frame.Width}");
var newGridFrame = new CGRect(Frame.Location, new CGSize(gridWidth, gridHeight));
LogLine($"{debugIndent} newGridFrame={newGridFrame}, old Frame={Frame}");
Frame = newGridFrame;
LogLine($"{debugIndent} RowDefinitions = [{string.Join(",", this.CurrentLayout.RowDefinitions.Select(r => r.Size))}]");
LogLine($"{debugIndent} absoluteRowHeight = [{string.Join(",", absoluteRowHeight)}]");
LogLine($"{debugIndent} ColumnDefinitions = [{string.Join(",", this.CurrentLayout.ColumnDefinitions.Select(r => r.Size))}]");
LogLine($"{debugIndent} absoluteColumnWidth = [{string.Join(",", absoluteColumnWidth)}]");
// Calculate cell positions
var positions = CalcCellAbsolutePositions(absoluteColumnWidth, absoluteRowHeight);
// Layout subviews
foreach (var cell in this.CurrentLayout.Cells)
{
LogLine();
LogLine($"{debugIndent} Laying out col {cell.Position.Column}, row {cell.Position.Row}, {cell.DebugLabel}");
if (!cell.IncludeInAutoWidthSizeCalcs && !cell.IncludeInAutoHeightSizeCalcs)
{
LogLine($"{debugIndent} skipping: View.Hidden=true and IncludeInAutoWidthSizeCalcs,IncludeInAutoHeightSizeCalcs false");
continue;
}
if (cell.Position.Row >= this.CurrentLayout.RowDefinitions.Count())
{
throw new Exception($"Grid {ID}: a cell is defined at row {cell.Position.Row}, col {cell.Position.Column} but there are only {this.CurrentLayout.RowDefinitions.Count()} rows defined in the grid");
}
if (cell.Position.Column >= this.CurrentLayout.ColumnDefinitions.Count())
{
throw new Exception($"Grid {ID}: a cell is defined at row {cell.Position.Row}, col {cell.Position.Column} but there are only {this.CurrentLayout.ColumnDefinitions.Count()} columns defined in the grid");
}
cell.View?.LayoutSubviews();
var position = positions[cell.Position.Column, cell.Position.Row];
var cellSize = GetCellAbsoluteSize(absoluteColumnWidth, absoluteRowHeight, cell.Position);
var viewSize = cell.AutoSizeSize;
LogLine($"{debugIndent} position = {position}");
LogLine($"{debugIndent} cellSize = {cellSize}");
LogLine($"{debugIndent} viewSize = {viewSize}");
if (viewSize.Width == 0 && viewSize.Height == 0)
{
viewSize = cell.InitialSize;
LogLine($"{debugIndent} viewSize changed to cell.InitialSize = {viewSize}");
}
LogLine($"{debugIndent} Alignment: Vertical={cell.Position.Vertical}, Horizontal={cell.Position.Horizontal}");
switch (cell.Position.Vertical)
{
case Layout.Alignment.Stretched:
// Honor Margin.Top and Bottom
position.Y += cell.Position.Margin.Top;
cellSize.Height -= cell.Position.Margin.Height();
break;
case Layout.Alignment.Center:
// Honor Margin.Left and Right
position.Y += (cellSize.Height / 2f) - (viewSize.Height / 2f) + cell.Position.Margin.Top / 2f - cell.Position.Margin.Bottom / 2f;
cellSize.Height = viewSize.Height;
break;
case Layout.Alignment.Start:
// Honor Margin.Top
position.Y += cell.Position.Margin.Top;
cellSize.Height = viewSize.Height;
break;
case Layout.Alignment.End:
// Honor Margin.Bottom
position.Y += cellSize.Height - viewSize.Height - cell.Position.Margin.Bottom;
cellSize.Height = viewSize.Height;
break;
default:
break;
}
switch (cell.Position.Horizontal)
{
case Layout.Alignment.Stretched:
// Honor Margin.Left and Right
position.X += cell.Position.Margin.Left;
cellSize.Width -= cell.Position.Margin.Width();
break;
case Layout.Alignment.Center:
// Honor Margin.Left and Right
position.X += (cellSize.Width / 2f) - (viewSize.Width / 2f) + cell.Position.Margin.Left / 2f - cell.Position.Margin.Right / 2f;
cellSize.Width = viewSize.Width;
break;
case Layout.Alignment.Start:
// Honor Margin.Left
cellSize.Width = viewSize.Width;
position.X += cell.Position.Margin.Left;
break;
case Layout.Alignment.End:
// Honor Margin.Right
position.X += cellSize.Width - viewSize.Width - cell.Position.Margin.Right;
cellSize.Width = viewSize.Width;
break;
default:
break;
}
if (cell.Position.NoResize || cell.Position.NoPosition)
{
cellSize = cell.AutoSizeSize;
}
if (cell.Position.NoPosition)
{
position = cell.View.Frame.Location;
}
var newFrame = new CGRect(position, cellSize);
Log($"{debugIndent} newFrame={newFrame}, cell.View.Frame={cell.View?.Frame}");
if (newFrame != cell.View?.Frame)
{
Log(": UPDATE");
SetCellFrame(cell, newFrame);
}
LogLine();
Log($"{debugIndent} Finished {cell.DebugLabel}");
}
LogLine();
OnLayoutCompleted(oldSize, Frame.Size);
}