protected override void OnSizeAllocated(Gdk.Rectangle allocation)
{
//shrink the allocation we pass to the base layout, to allow for our extra border
if (showBorderLine)
{
allocation.X += 1;
allocation.Y += 1;
allocation.Height -= HScrollbar.Visible? 1 : 2;
allocation.Width -= VScrollbar.Visible? 1 : 2;
}
base.OnSizeAllocated(allocation);
//expand the scrollbars so they render over the new border
if (showBorderLine)
{
bool hasHScroll = HScrollbar.Visible;
bool hasVScroll = VScrollbar.Visible;
if (hasHScroll)
{
var alloc = HScrollbar.Allocation;
alloc.X -= 1;
alloc.Width += hasVScroll? 1 :2;
HScrollbar.SizeAllocate(alloc);
}
if (hasVScroll)
{
var alloc = VScrollbar.Allocation;
alloc.Y -= 1;
alloc.Height += hasHScroll? 1 : 2;
VScrollbar.SizeAllocate(alloc);
}
}
}
protected override void OnSizeAllocated(Rectangle allocation)
{
base.OnSizeAllocated(allocation);
int margin = BorderVisible ? 1 : 0;
int vwidth = vScrollBar.Visible ? vScrollBar.Requisition.Width : 0;
int hheight = hScrollBar.Visible ? hScrollBar.Requisition.Height : 0;
var childRectangle = new Rectangle(allocation.X + margin, allocation.Y + margin, allocation.Width - vwidth - margin * 2, allocation.Height - hheight - margin * 2);
if (Child != null)
{
Child.SizeAllocate(childRectangle);
}
if (vScrollBar.Visible)
{
int vChildTopHeight = -1;
foreach (var child in children.Where(child => child.ChildPosition == ChildPosition.Top))
{
child.Child.SizeAllocate(new Rectangle(childRectangle.RightInside(), childRectangle.Y + vChildTopHeight, allocation.Width - vwidth, child.Child.Requisition.Height));
vChildTopHeight += child.Child.Requisition.Height;
}
int v = vScrollBar is Scrollbar && hScrollBar.Visible ? hScrollBar.Requisition.Height : 0;
vScrollBar.SizeAllocate(new Rectangle(childRectangle.X + childRectangle.Width + margin, childRectangle.Y + vChildTopHeight, vwidth, Allocation.Height - v - vChildTopHeight - margin));
vAdjustment.Value = System.Math.Max(System.Math.Min(vAdjustment.Upper - vAdjustment.PageSize, vAdjustment.Value), vAdjustment.Lower);
}
if (hScrollBar.Visible)
{
int v = vScrollBar.Visible ? vScrollBar.Requisition.Width : 0;
hScrollBar.SizeAllocate(new Rectangle(allocation.X, childRectangle.Y + childRectangle.Height + margin, allocation.Width - v, hheight));
hScrollBar.Value = System.Math.Max(System.Math.Min(hAdjustment.Upper - hAdjustment.PageSize, hScrollBar.Value), hAdjustment.Lower);
}
}
