/// <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);
}
}
protected void CreateViewList(IList <Type> viewTypes)
{
var frame = new RectangleF(0, 0, ContentView.Bounds.Width, ContentView.Bounds.Height);
if (ViewList != null)
{
foreach (var view in ViewList)
{
view.Dispose();
}
ViewList.Clear();
ViewList = null;
}
ViewList = new List <UIView>();
if (viewTypes != null)
{
foreach (var viewType in viewTypes)
{
if (viewType == null)
{
continue;
}
UIView view = null;
var hasFrameCtor = viewType.GetConstructor(new Type[] { typeof(RectangleF) }) != null;
if (hasFrameCtor)
{
view = Activator.CreateInstance(viewType, new object[] { frame }) as UIView;
if (ListSource.RowHeights[ListSource.BaseIndexPath] != view.Frame.Height)
{
if (ListSource.RowHeights.ContainsKey(IndexPath))
{
ListSource.RowHeights[IndexPath] = view.Frame.Height;
}
else
{
ListSource.RowHeights.Add(IndexPath, view.Frame.Height);
}
}
}
else
{
view = Activator.CreateInstance(viewType) as UIView;
}
var dc = view as IDataContext <object>;
if (dc != null)
{
var item = ListSource.GetSectionData(0)[IndexPath.Row];
dc.DataContext = item;
}
var initializeCell = view as IInitializeCell;
if (initializeCell != null)
{
initializeCell.Cell = this;
initializeCell.Controller = ListSource.Controller;
var newCellStyle = initializeCell.CellStyle;
if (newCellStyle != Style)
{
Style = newCellStyle;
break;
}
}
var themeable = view as IThemeable;
if (themeable != null)
{
if (themeable.Theme == null)
{
var theme = view.GetType().GetCustomAttribute <ThemeAttribute>();
if (theme != null)
{
var cellViewTheme = Theme.CreateTheme(theme.ThemeType);
if (cellViewTheme != null)
{
if (Theme != null)
{
Theme.MergeTheme(cellViewTheme);
}
else
{
Theme = cellViewTheme;
}
themeable.Theme = Theme;
}
}
}
themeable.InitializeTheme(this);
}
var cellContent = view as ICellContent;
if (cellContent != null)
{
if (cellContent.CellContentView != null)
{
_CompositeView.AddSubview(cellContent.CellContentView);
}
}
ViewList.Add(view);
}
}
}