protected virtual void OnLayout(LayoutEventArgs e)
{
if (Initialized && !_state[s_stateInLayout])
{
_state[s_stateInLayout] = true;
try
{
Margin = DefaultMargin;
CachedBoundsMode = true;
try
{
// dont layout in the constructor that's just tacky.
bool parentNeedsLayout = LayoutEngine.Layout(this, e);
}
finally
{
CachedBoundsMode = false;
}
ToolStripPanelCell cell = RowManager.GetNextVisibleCell(Cells.Count - 1, /*forward*/ false);
if (cell is null)
{
ApplyCachedBounds();
}
else if (Orientation == Orientation.Horizontal)
{
OnLayoutHorizontalPostFix();
}
else
{
OnLayoutVerticalPostFix();
}
}
finally
{
_state[s_stateInLayout] = false;
}
}
}
private void OnLayoutVerticalPostFix()
{
ToolStripPanelCell cell = RowManager.GetNextVisibleCell(Cells.Count - 1, /*forward*/ false);
// figure out how much space we actually need to free.
int spaceToFree = cell.CachedBounds.Bottom - RowManager.DisplayRectangle.Bottom;
if (spaceToFree <= 0)
{
// we're all good. Just apply the cached bounds.
ApplyCachedBounds();
return;
}
// STEP 1 remove empty space in the row.
// since layout sisuspended, we'll need to watch changes to the margin
// as a result of calling FreeSpaceFromRow.
int[] margins = new int[Cells.Count];
for (int i = 0; i < Cells.Count; i++)
{
ToolStripPanelCell c = Cells[i] as ToolStripPanelCell;
margins[i] = c.Margin.Top;
}
spaceToFree -= RowManager.FreeSpaceFromRow(spaceToFree);
// now apply those changes to the cached bounds.
for (int i = 0; i < Cells.Count; i++)
{
ToolStripPanelCell c = Cells[i] as ToolStripPanelCell;
Rectangle cachedBounds = c.CachedBounds;
cachedBounds.X = Math.Max(0, cachedBounds.X - margins[i] - c.Margin.Top);
c.CachedBounds = cachedBounds;
}
if (spaceToFree <= 0)
{
ApplyCachedBounds();
return;
}
// STEP 2 change the size of the remaing ToolStrips from Bottom to Top.
int[] cellOffsets = null;
for (int i = Cells.Count - 1; i >= 0; i--)
{
ToolStripPanelCell currentCell = Cells[i] as ToolStripPanelCell;
if (currentCell.Visible)
{
Size minSize = GetMinimumSize(currentCell.Control as ToolStrip);
Rectangle cachedBounds = currentCell.CachedBounds;
// found some space to free.
if (cachedBounds.Height > minSize.Height)
{
spaceToFree -= (cachedBounds.Height - minSize.Height);
// make sure we dont take more space than we need - if spaceToFree is less than 0, add back in.
cachedBounds.Height = (spaceToFree < 0) ? minSize.Height + -spaceToFree : minSize.Height;
// we're not reperforming a layout, so we need to adjust the next cell
for (int j = i + 1; j < Cells.Count; j++)
{
if (cellOffsets is null)
{
cellOffsets = new int[Cells.Count];
}
cellOffsets[j] += Math.Max(0, currentCell.CachedBounds.Height - cachedBounds.Height);
}
currentCell.CachedBounds = cachedBounds;
}
}
if (spaceToFree <= 0)
{
break;
}
}
// fixup for items before it shrinking.
if (cellOffsets != null)
{
for (int i = 0; i < Cells.Count; i++)
{
ToolStripPanelCell c = Cells[i] as ToolStripPanelCell;
Rectangle cachedBounds = c.CachedBounds;
cachedBounds.Y -= cellOffsets[i];
c.CachedBounds = cachedBounds;
}
}
ApplyCachedBounds();
}