/// <summary>
/// Discover the preferred size of the element.
/// </summary>
/// <param name="context">Layout context.</param>
public override Size GetPreferredSize(ViewLayoutContext context)
{
// Sync child elements to the current group items
SyncChildrenToRibbonGroupItems();
// Clear down the cache of item sizes
_sizeList.Clear();
_viewList.Clear();
_viewToGap.Clear();
int totalWidth = 0;
ViewBase previousChild = null;
// Find the size of each individual visible child item
for (int i = 0; i < this.Count; i++)
{
ViewBase child = this[i];
// Only interested in visible items
if (child.Visible)
{
// Are we positioning a cluster?
if (child is ViewLayoutRibbonGroupCluster)
{
// Inform cluster if it is immediatley after another cluster (and so potentially needs a separator)
ViewLayoutRibbonGroupCluster clusterChild = (ViewLayoutRibbonGroupCluster)child;
clusterChild.StartSeparator = (previousChild != null) && !(previousChild is ViewLayoutRibbonGroupCluster);
clusterChild.EndSeparator = true;
}
// Can we calculate the spacing gap between the previous and this item
if (previousChild != null)
{
if (_viewToItem.ContainsKey(child) &&
_viewToItem.ContainsKey(previousChild))
{
// Cast to correct type
IRibbonGroupItem childItem = _viewToItem[child] as IRibbonGroupItem;
IRibbonGroupItem previousItem = _viewToItem[previousChild] as IRibbonGroupItem;
// Find the requested gap between them
_viewToGap.Add(child, childItem.ItemGap(previousItem));
}
else
{
// Default the gap
_viewToGap.Add(child, DEFAULT_GAP);
}
}
// Get requested size of the child
Size childSize = child.GetPreferredSize(context);
// Add to list of visible child sizes
_sizeList.Add(childSize);
_viewList.Add(child);
// Cache total visible width for later
totalWidth += childSize.Width;
// This is now the previous child
previousChild = child;
}
}
// Find the item size specific preferred calculation
switch (_currentSize)
{
case GroupItemSize.Large:
return(LargeMediumPreferredSize(totalWidth, ref _split1Large));
case GroupItemSize.Medium:
return(LargeMediumPreferredSize(totalWidth, ref _split1Medium));
case GroupItemSize.Small:
return(SmallPreferredSize(totalWidth));
default:
// Should never happen!
Debug.Assert(false);
return(Size.Empty);
}
}
private void SmallLayout(ViewLayoutContext context)
{
int x = ClientLocation.X;
int y = ClientLocation.Y;
// At design time we reserve space at the left side for the selection flap
if (_ribbon.InDesignHelperMode)
{
x += DesignTimeDraw.FlapWidth;
}
ViewBase previousChild = null;
// Position the visible items in turn
for (int i = 0, visibleIndex = 0; i < this.Count; i++)
{
ViewBase child = this[i];
// We only position visible items
if (child.Visible)
{
// Are we positioning a cluster?
if (child is ViewLayoutRibbonGroupCluster)
{
// Inform cluster if it is immediatley after another item and so needs a start separator
ViewLayoutRibbonGroupCluster clusterChild = (ViewLayoutRibbonGroupCluster)child;
clusterChild.StartSeparator = (previousChild != null) && !(previousChild is ViewLayoutRibbonGroupCluster);
clusterChild.EndSeparator = false;
}
if ((previousChild != null) && (previousChild is ViewLayoutRibbonGroupCluster))
{
// Inform cluster if it is before another item and so needs an end separator
ViewLayoutRibbonGroupCluster clusterChild = (ViewLayoutRibbonGroupCluster)previousChild;
clusterChild.EndSeparator = true;
// Need to layout the item again with the new setting
context.DisplayRectangle = new Rectangle(previousChild.ClientLocation.X, previousChild.ClientLocation.Y, previousChild.ClientWidth, previousChild.ClientHeight);
previousChild.Layout(context);
}
// If not the first item on the line, then get the pixel gap between them
if ((previousChild != null) && _viewToGap.ContainsKey(child))
{
x += _viewToGap[child];
}
// Get the size of the child item
Size childSize = _sizeList[visibleIndex];
// Define display rectangle for the group
context.DisplayRectangle = new Rectangle(x, y, childSize.Width, childSize.Height);
// Position the element
this[i].Layout(context);
// Do we need to split after this item
if ((_split1Small == visibleIndex) || (_split2Small == visibleIndex))
{
// Move back to start of line and downwards to next line
x = ClientLocation.X;
// At design time we reserve space at the left side for the selection flap
if (_ribbon.InDesignHelperMode)
{
x += DesignTimeDraw.FlapWidth;
}
y += _ribbon.CalculatedValues.GroupLineHeight;
// As last item on the line, there is no previous item on next line
previousChild = null;
}
else
{
// Move across to next position
x += childSize.Width;
// We have become the previous child
previousChild = child;
}
// Not all child items are visible, so track separately
visibleIndex++;
}
}
}
