/// <summary>
/// Push a new box onto the layout stack, thus getting deeper into layout hierarchy.
/// Automatically allocates a Bondary object from pool.
/// </summary>
public LayoutLevel PushLayoutLevel([NotNull] BoxTree.Node node)
{
if (m_pooledBoundaries.Count == 0)
{
m_pooledBoundaries.Push(new Boundary());
}
var boundary = m_pooledBoundaries.Pop();
switch (CurrentOperation)
{
case Operation.VerticalLayout:
boundary.Prepare(node);
break;
case Operation.HorizontalLayout:
boundary.PrepareForHorizontalLayout(node);
break;
default:
throw new InvalidOperationException("This operation can only be invoked when performing vertical or horizontal layouts");
}
var result = new LayoutLevel(node, boundary);
m_layoutStack.Push(result);
BoundaryChanged?.Invoke(this, new BoundaryChangedEventArgs(boundary, result, this));
return(result);
}
/// <summary>
/// Pops a box from current layout stack, thus getting higher out from layout hierarchy.
/// Automatically merges popped <see cref="Boundary"/> into the current level.
/// </summary>
public void PopLayoutLevel()
{
var innerLevel = m_layoutStack.Pop();
BoundaryChanged?.Invoke(this, new BoundaryChangedEventArgs(innerLevel.Boundary, innerLevel, this));
// if this was not the root, merge boundaries into current level
if (m_layoutStack.Count > 0)
{
var higherLevel = m_layoutStack.Peek();
switch (CurrentOperation)
{
case Operation.VerticalLayout:
higherLevel.Boundary.VerticalMergeFrom(innerLevel.Boundary);
higherLevel.BranchRoot.State.BranchExterior = higherLevel.Boundary.BoundingRect;
break;
case Operation.HorizontalLayout:
{
// do not apply overlap adjustment for assistant branch, they are always above regular children
if (higherLevel.BranchRoot.AssistantsRoot != innerLevel.BranchRoot)
{
var strategy = higherLevel.BranchRoot.State.RequireLayoutStrategy();
var overlap = higherLevel.Boundary.ComputeOverlap(
innerLevel.Boundary, strategy.SiblingSpacing, Diagram.LayoutSettings.BranchSpacing);
if (overlap > 0)
{
LayoutAlgorithm.MoveBranch(this, innerLevel, overlap);
BoundaryChanged?.Invoke(this, new BoundaryChangedEventArgs(innerLevel.Boundary, innerLevel, this));
}
}
higherLevel.Boundary.MergeFrom(innerLevel.Boundary);
// Do not update branch vertical measurements from the boundary, because boundary adds children one-by-one.
// If we take it from boundary, then branch vertical measurement will be incorrect until all children are laid out horizontally,
// and this temporarily incorrect state will break those algorithms that need to know combined branch height.
higherLevel.BranchRoot.State.BranchExterior = new Rect(
higherLevel.Boundary.BoundingRect.Left,
higherLevel.BranchRoot.State.BranchExterior.Top,
higherLevel.Boundary.BoundingRect.Size.Width,
higherLevel.BranchRoot.State.BranchExterior.Size.Height);
}
break;
default:
throw new InvalidOperationException(
"This operation can only be invoked when performing vertical or horizontal layouts");
}
BoundaryChanged?.Invoke(this, new BoundaryChangedEventArgs(higherLevel.Boundary, higherLevel, this));
}
// return boundary to the pool
m_pooledBoundaries.Push(innerLevel.Boundary);
}
/// <summary>
/// Merges a provided spacer box into the current branch boundary.
/// </summary>
public void MergeSpacer([NotNull] BoxTree.Node spacer)
{
if (CurrentOperation != Operation.HorizontalLayout)
{
throw new InvalidOperationException("Spacers can only be merged during horizontal layout");
}
if (m_layoutStack.Count == 0)
{
throw new InvalidOperationException("Cannot merge spacers at top nesting level");
}
var level = m_layoutStack.Peek();
level.Boundary.MergeFrom(spacer);
BoundaryChanged?.Invoke(this, new BoundaryChangedEventArgs(level.Boundary, level, this));
}
