/// <summary>Positions this element and all it's children relative to their parent.</summary>
public void PositionLocally()
{
// This is the first pass of layout requests.
// It locates elements locally whilst also finding their width and height.
ComputedStyle computed = Style.Computed;
if (computed.Display == DisplayType.None)
{
// Don't draw this element or it's kids.
return;
}
if (!IsRebuildingChildren)
{
// Update child nodes (thread safety):
KidsToRender = ChildNodes;
}
float depth = Document.Renderer.Depth;
float maxDepth = Document.Renderer.MaxDepth;
bool elementPositioned = false;
if (!computed.FixedDepth)
{
elementPositioned = (computed.IsOffset() || computed.Position != PositionType.Relative);
if (elementPositioned)
{
// This element has been positioned - make sure it's ontop of the current highest element:
Document.Renderer.Depth = Document.Renderer.MaxDepth;
if (Document.Renderer.DepthUsed)
{
Document.Renderer.IncreaseDepth();
}
else
{
Document.Renderer.DepthUsed = true;
}
computed.ZIndex = Document.Renderer.Depth;
}
else
{
computed.ZIndex = depth;
}
}
else
{
computed.ZIndex = computed.FixedZIndex;
}
if (KidsToRender != null || HScrollbar || VScrollbar)
{
if (computed.FixedDepth)
{
// Set the depth buffer to this element so it's kids are at the right height; restore it after.
// Offset by the document's depth if we're in a document in a document (e.g. iframe):
Element documentParent = Document.html.parentNode;
if (documentParent != null && documentParent != this)
{
computed.ZIndex += documentParent.Style.Computed.ZIndex;
}
Document.Renderer.Depth = computed.ZIndex;
if (computed.ZIndex > Document.Renderer.MaxDepth)
{
Document.Renderer.MaxDepth = Document.Renderer.Depth;
}
}
else if (computed.BGImage != null || computed.BGColour != null)
{
// Only increase the depth if the element has a background image/colour to get it's kids away from.
Document.Renderer.IncreaseDepth();
}
}
if (KidsToRender != null)
{
for (int i = 0; i < KidsToRender.Count; i++)
{
KidsToRender[i].PositionLocally();
}
}
if (HScrollbar)
{
HorizontalScrollbar.Element.PositionLocally();
}
if (VScrollbar)
{
VerticalScrollbar.Element.PositionLocally();
}
// Restore the depth:
if (elementPositioned)
{
// This element has been positioned - everything after it must be ontop of it and all it's kids.
Document.Renderer.Depth = Document.Renderer.MaxDepth;
Document.Renderer.IncreaseDepth();
}
else if (computed.FixedDepth)
{
Document.Renderer.Depth = depth;
Document.Renderer.MaxDepth = maxDepth;
}
if (computed.Display == Css.DisplayType.Inline && computed.Position == Css.PositionType.Relative)
{
// Relative Inline - The kids will be packed onto the next element up's lines (this is done internally by the PackOnLine function).
// Fixed or absolute pack their own lines.
if (computed.BGImage == null && computed.BGColour == null && computed.Border == null)
{
// Only occurs though if the element has no background or border - if it does, it should act like an inline-block element.
return;
}
}
Document.Renderer.BeginLinePack(this);
if (KidsToRender != null || HScrollbar || VScrollbar)
{
if (KidsToRender != null)
{
for (int i = 0; i < KidsToRender.Count; i++)
{
Document.Renderer.PackOnLine(KidsToRender[i]);
}
}
if (HScrollbar)
{
Document.Renderer.PackOnLine(HorizontalScrollbar.Element);
}
if (VScrollbar)
{
Document.Renderer.PackOnLine(VerticalScrollbar.Element);
}
}
Document.Renderer.EndLinePack(this);
}