public Size CalcIdealSize(IUserInterfaceRenderContext renderContext, Size maxSize, IList <IRenderElement> children)
{
int idealCrossSize = 0;
int idealAxisSize = 0;
foreach (var item in children)
{
if (!item.Display.IsVisible)
{
continue;
}
var itemBox = item.Display.Region.MarginToContentOffset;
var itemMaxSize = LayoutMath.ItemContentMaxSize(itemBox, maxSize);
item.Display.Region.IdealContentSize
= item.CalcIdealContentSize(renderContext, maxSize);
var itemIdealContentSize = item.Display.Region.CalcConstrainedContentSize(maxSize);
var itemIdealMarginSize = itemBox.Expand(itemIdealContentSize);
idealCrossSize = Math.Max(idealCrossSize, CrossAxis(itemIdealMarginSize));
idealAxisSize += MainAxis(itemIdealMarginSize);
}
return(SetSize(idealAxisSize, idealCrossSize));
}
/// <summary>
/// Updates the ideal size property for each child.
/// Returns the total ideal margin size along the main axis.
/// </summary>
/// <param name="renderContext"></param>
/// <param name="mySize"></param>
/// <param name="children"></param>
/// <returns></returns>
private int CalcChildrenIdealSizes(IUserInterfaceRenderContext renderContext,
Size mySize,
IList <IRenderElement> children)
{
foreach (var item in children)
{
LayoutMath.CalcIdealSize(item, renderContext, mySize);
item.Display.Region.SetContentSize(item.Display.Region.IdealContentSize);
}
return(children.Sum(x => MainAxis(x.Display.Region.IdealMarginSize)));
}
public override Size CalcIdealContentSize(IUserInterfaceRenderContext renderContext, Size maxSize)
{
Array.Clear(columnWidths, 0, columnWidths.Length);
Array.Clear(rowHeights, 0, rowHeights.Length);
for (int y = 0; y < Rows; y++)
{
for (int x = 0; x < Columns; x++)
{
var item = ChildAt(x, y);
SetSizeAt(x, y, Size.Empty);
if (item == null)
{
continue;
}
var itemBox = item.Display.Region.MarginToContentOffset;
var itemMaxSize = LayoutMath.ItemContentMaxSize(itemBox, maxSize);
item.Display.Region.IdealContentSize
= item.CalcIdealContentSize(renderContext, maxSize);
var itemIdealSize = item.Display.Region.CalcConstrainedContentSize(maxSize);
SetSizeAt(x, y, itemIdealSize);
columnWidths[x] = Math.Max(columnWidths[x], itemIdealSize.Width + itemBox.Width);
rowHeights[y] = Math.Max(rowHeights[y], itemIdealSize.Height + itemBox.Height);
}
}
for (int i = 0; i < Columns; i++)
{
columnWidths[i] = Math.Min(maxSize.Width, columnWidths[i]);
}
for (int i = 0; i < Rows; i++)
{
rowHeights[i] = Math.Min(maxSize.Height, rowHeights[i]);
}
var idealWidth = columnWidths.Sum();
var idealHeight = rowHeights.Sum();
return(new Size(idealWidth, idealHeight));
}
public override Size CalcIdealContentSize(IUserInterfaceRenderContext renderContext, Size maxSize)
{
UpdateChildLists();
maxSize = LayoutMath.ConstrainMaxSize(maxSize, Style.Size);
switch (Direction)
{
case FlexDirection.Column:
case FlexDirection.ColumnReverse:
return(vertical.CalcIdealSize(renderContext, maxSize, layoutChildren));
case FlexDirection.Row:
case FlexDirection.RowReverse:
return(horizontal.CalcIdealSize(renderContext, maxSize, layoutChildren));
default:
throw new InvalidOperationException();
}
}
public void ConstrainMaxSizeWithFixedSizeConstraintTest(
int initialWidth,
int initialHeight,
int maxWidth,
int maxHeight,
int expectedMaxWidth,
int expectedMaxHeight)
{
Size initial = new Size(initialWidth, initialHeight);
SizeConstraints constraints = new SizeConstraints
{
MaxWidth = maxWidth,
MaxHeight = maxHeight,
};
Size result = LayoutMath.ConstrainMaxSize(initial, constraints);
result.Width.Should().Be(expectedMaxWidth);
result.Height.Should().Be(expectedMaxHeight);
}
private void ContractItems(IList <IRenderElement> children,
Size mySize,
ref int extraSpace)
{
if (extraSpace >= 0)
{
return;
}
float fExtraSpace = extraSpace;
int iter = 0;
while (Math.Abs(fExtraSpace) > 1e-6 && iter < 5)
{
float shrinkAmount = fExtraSpace / children.Count(
x => MainAxis(x.Display.Region.ContentSize)
- MainAxis(x.Style.Size?.ToMinSize() ?? Size.Empty)
> 0);
foreach (var item in children)
{
Size currentSize = item.Display.Region.ContentRect.Size;
Size newSize = SetSize(MainAxis(currentSize) + (int)shrinkAmount,
CrossAxis(currentSize));
newSize = LayoutMath.ConstrainSize(newSize, item.Style.Size);
item.Display.Region.SetContentSize(newSize);
int diff = MainAxis(new Size(newSize.Width - currentSize.Width,
newSize.Height - currentSize.Height));
fExtraSpace -= diff;
}
iter++;
}
extraSpace = (int)fExtraSpace;
}
