// Provides the next spot in the boolean array with a 'false' value.
#pragma warning disable SA1009 // Closing parenthesis must be followed by a space.
internal static IEnumerable <(int row, int column)> GetFreeSpot(TakenSpotsReferenceHolder arrayref, int firstcolumn, bool topdown)
#pragma warning restore SA1009 // Closing parenthesis must be followed by a space.
{
if (topdown)
{
var rows = arrayref.SpotsTaken.GetLength(0);
// Layout spots from Top-Bottom, Left-Right (right-left handled automatically by Grid with Flow-Direction).
// Effectively transpose the Grid Layout.
for (int c = 0; c < arrayref.SpotsTaken.GetLength(1); c++)
{
int start = (c == 0 && firstcolumn > 0 && firstcolumn < rows) ? firstcolumn : 0;
for (int r = start; r < rows; r++)
{
if (!arrayref.SpotsTaken[r, c])
{
yield return(r, c);
}
}
}
}
else
{
var columns = arrayref.SpotsTaken.GetLength(1);
// Layout spots as normal from Left-Right.
// (right-left handled automatically by Grid with Flow-Direction
// during its layout, internal model is always left-right).
for (int r = 0; r < arrayref.SpotsTaken.GetLength(0); r++)
{
int start = (r == 0 && firstcolumn > 0 && firstcolumn < columns) ? firstcolumn : 0;
for (int c = start; c < columns; c++)
{
if (!arrayref.SpotsTaken[r, c])
{
yield return(r, c);
}
}
}
}
}
/// <inheritdoc/>
protected override Size MeasureOverride(Size availableSize)
{
// Get all Visible FrameworkElement Children
var visible = Children.Where(item => item.Visibility != Visibility.Collapsed && item is FrameworkElement).Select(item => item as FrameworkElement).ToArray();
#pragma warning disable SA1008 // Opening parenthesis must be spaced correctly
var(rows, columns) = GetDimensions(visible, Rows, Columns, FirstColumn);
#pragma warning restore SA1008 // Opening parenthesis must be spaced correctly
// Now that we know size, setup automatic rows/columns
// to utilize Grid for UniformGrid behavior.
// We also interleave any specified rows/columns with fixed sizes.
SetupRowDefinitions(rows);
SetupColumnDefinitions(columns);
var spotref = new TakenSpotsReferenceHolder(rows, columns);
// Figure out which children we should automatically layout and where available openings are.
foreach (var child in visible)
{
var row = GetRow(child);
var col = GetColumn(child);
var rowspan = GetRowSpan(child);
var colspan = GetColumnSpan(child);
// If an element needs to be forced in the 0, 0 position,
// they should manually set UniformGrid.AutoLayout to False for that element.
if ((row == 0 && col == 0 && Microsoft.Toolkit.Uwp.UI.Controls.UniformGrid.GetAutoLayout(child) == null) ||
Microsoft.Toolkit.Uwp.UI.Controls.UniformGrid.GetAutoLayout(child) == true)
{
Microsoft.Toolkit.Uwp.UI.Controls.UniformGrid.SetAutoLayout(child, true);
}
else
{
Microsoft.Toolkit.Uwp.UI.Controls.UniformGrid.SetAutoLayout(child, false);
spotref.SpotsTaken.Fill(true, row, col, colspan, rowspan); // row, col, width, height
}
}
// Setup available size with our known dimensions now.
// UniformGrid expands size based on largest singular item.
double columnSpacingSize = 0;
double rowSpacingSize = 0;
// Guard for 15063 as Grid Spacing only works on 16299+.
if (_hasGridSpacing)
{
columnSpacingSize = ColumnSpacing * (columns - 1);
rowSpacingSize = RowSpacing * (rows - 1);
}
Size childSize = new Size(
(availableSize.Width - columnSpacingSize) / columns,
(availableSize.Height - rowSpacingSize) / rows);
double maxWidth = 0.0;
double maxHeight = 0.0;
// Set Grid Row/Col for every child with autolayout = true
// Backwards with FlowDirection
var freespots = GetFreeSpot(spotref, FirstColumn, Orientation == Orientation.Vertical).GetEnumerator();
foreach (var child in visible)
{
// Set location if we're in charge
if (Microsoft.Toolkit.Uwp.UI.Controls.UniformGrid.GetAutoLayout(child) == true)
{
if (freespots.MoveNext())
{
#pragma warning disable SA1009 // Closing parenthesis must be followed by a space.
#pragma warning disable SA1008 // Opening parenthesis must be spaced correctly
var(row, column) = freespots.Current;
#pragma warning restore SA1008 // Opening parenthesis must be spaced correctly
#pragma warning restore SA1009 // Closing parenthesis must be followed by a space.
SetRow(child, row);
SetColumn(child, column);
var rowspan = GetRowSpan(child);
var colspan = GetColumnSpan(child);
if (rowspan > 1 || colspan > 1)
{
// TODO: Need to tie this into iterator
spotref.SpotsTaken.Fill(true, row, column, GetColumnSpan(child), GetRowSpan(child)); // row, col, width, height
}
}
else
{
// We've run out of spots as the developer has
// most likely given us a fixed size and too many elements
// Therefore, tell this element it has no size and move on.
child.Measure(Size.Empty);
_overflow.Add(child);
continue;
}
}
else if (GetRow(child) < 0 || GetRow(child) >= rows ||
GetColumn(child) < 0 || GetColumn(child) >= columns)
{
// A child is specifying a location, but that location is outside
// of our grid space, so we should hide it instead.
child.Measure(Size.Empty);
_overflow.Add(child);
continue;
}
// Get measurement for max child
child.Measure(childSize);
maxWidth = Math.Max(child.DesiredSize.Width, maxWidth);
maxHeight = Math.Max(child.DesiredSize.Height, maxHeight);
}
// Return our desired size based on the largest child we found, our dimensions, and spacing.
var desiredSize = new Size((maxWidth * (double)columns) + columnSpacingSize, (maxHeight * (double)rows) + rowSpacingSize);
// Required to perform regular grid measurement, but ignore result.
base.MeasureOverride(desiredSize);
return(desiredSize);
}