public override void PrepareLayout()
{
isPreparing = true;
layoutCache = new List <UICollectionViewLayoutAttributes>();
var numberOfItems = CollectionView.NumberOfItemsInSection(0);
nfloat currentY = 0;
for (var i = 0; i < numberOfItems; i++)
{
var viewSource = CollectionView.Source as ChatCollectionViewSource;
var indexPath = NSIndexPath.FromItemSection(i, 0);
var cell = viewSource.GetCell(CollectionView, indexPath) as ChatMessageCollectionViewCell;
var size = cell.ContentView.SystemLayoutSizeFittingSize(UIScreen.MainScreen.Bounds.Size);
CGRect frame = new CGRect
{
X = 0,
Y = currentY,
Width = size.Width,
Height = size.Height,
};
var attributes = UICollectionViewLayoutAttributes.CreateForCell(indexPath);
attributes.Frame = frame;
layoutCache.Add(attributes);
currentY += frame.Height;
}
contentHeight = currentY;
isPreparing = false;
}
public override UICollectionViewLayoutAttributes LayoutAttributesForItem(NSIndexPath path)
{
UICollectionViewLayoutAttributes attributes = UICollectionViewLayoutAttributes.CreateForCell(path);
attributes.Size = new CGSize(ItemSize, ItemSize);
attributes.Center = new CGPoint(
_center.X + _radius * (float)Math.Cos(2 * path.Row * Math.PI / _cellCount),
_center.Y + _radius * (float)Math.Sin(2 * path.Row * Math.PI / _cellCount));
return attributes;
}
public override UICollectionViewLayoutAttributes LayoutAttributesForItem(NSIndexPath path)
{
UICollectionViewLayoutAttributes attributes = UICollectionViewLayoutAttributes.CreateForCell(path);
attributes.Size = new SizeF(ItemSize, ItemSize);
attributes.Center = new PointF(center.X + radius * (float)Math.Cos(2 * path.Row * Math.PI / cellCount),
center.Y + radius * (float)Math.Sin(2 * path.Row * Math.PI / cellCount));
return(attributes);
}
// return layout attributes for a a specific item
public override UICollectionViewLayoutAttributes LayoutAttributesForItem(NSIndexPath path)
{
UICollectionViewLayoutAttributes attributes = UICollectionViewLayoutAttributes.CreateForCell(path);
attributes.Size = ItemSize;
attributes.Center = new PointF(center.X + radius * (float)Math.Cos(2 * path.Row * Math.PI / count),
center.Y + radius * (float)Math.Sin(2 * path.Row * Math.PI / count));
attributes.Transform3D = CATransform3D.MakeScale(0.5f, 0.5f, 1.0f);
return(attributes);
}
public override UICollectionViewLayoutAttributes LayoutAttributesForSupplementaryView(NSString kind, NSIndexPath indexPath)
{
var layoutAttributes = UICollectionViewLayoutAttributes.CreateForCell(indexPath);
var cachedAttrs = _cache.FirstOrDefault(x => x.IndexPath == indexPath && x.RepresentedElementCategory == UICollectionElementCategory.SupplementaryView);
if (cachedAttrs != null)
{
layoutAttributes = cachedAttrs;
}
return(layoutAttributes);
}
/// <summary>
/// Provides a UICollectionViewLayoutAttributes for the current ListViewSource.
/// </summary>
/// <remarks>
/// Use this method instead of UICollectionViewLayoutAttributes.CreateForCell, as the interop call
/// is quite costly.
/// </remarks>
protected UICollectionViewLayoutAttributes GetLayoutAttributesForIndexPath(int row, int section)
{
var key = CachedTuple.Create(row, section);
UICollectionViewLayoutAttributes attributes;
if (!_layoutAttributesForIndexPaths.TryGetValue(key, out attributes))
{
var indexPath = GetNSIndexPathFromRowSection(row, section);
_layoutAttributesForIndexPaths.Add(key, attributes = UICollectionViewLayoutAttributes.CreateForCell <UICollectionViewLayoutAttributes>(indexPath));
}
return(attributes);
}
/// <summary>
/// Layouts the attributes for item.
/// </summary>
/// <returns>The attributes for item.</returns>
/// <param name="path">Path.</param>
public override UICollectionViewLayoutAttributes LayoutAttributesForItem(NSIndexPath path)
{
var attributes = UICollectionViewLayoutAttributes.CreateForCell(path);
var item = _items[path.Row];
var scale = widthScales[item.Layout];
var width = CollectionViewContentSize.Width * scale;
// make sure top and left elements aren't spaced from borders
// if cell wants spacing disabled, we set spacing to 0
var xSpacing = item.UseXSpacing ? _currentX > 0 ? _itemXSpacing : 0 : 0;
var ySpacing = item.UseYSpacing ? _currentY > 0 ? _itemYSpacing : 0 : 0;
// check first if we have started a new, we want to record the total height from everyline to resize the content size
if (_currentLine < 0.01)
{
_currentHeight += item.Height + ySpacing;
}
_currentLine += scale + item.XSpacingScale;
// avoids tiny gaps when not using x spacing
var minorAdj = item.UseXSpacing ? 0 : 0.1;
// HeightCalculated determines whether we want the layout to calculate the height, this is used when we dont want the collection view scrollable,
// so the layout will calculate space available and divide between all other items with HeightCalculated set to true
attributes.Frame = new CGRect(_currentX + xSpacing - minorAdj, _currentY + ySpacing, width - xSpacing + minorAdj, item.Height);
// we only jump to a new line when we are on a cell with right or fill layout
if (_currentLine < 0.99)
{
_currentX += width + (CollectionViewContentSize.Width * item.XSpacingScale);
}
else
{
_currentX = 0;
_currentLine = 0;
}
// check again for a new line to increase the currentY for the starting element on a new line
if (_currentLine < 0.01)
{
_currentY += item.Height + ySpacing;
_numberOfLines++;
}
return(attributes);
}
private void PlaceItem()
{
for (int i = 0; i < itemCount; i++)
{
var indexPath = NSIndexPath.FromItemSection(i, 0);
var itemHeight = Delegate.HeightForItem(CollectionView, this, indexPath);
var columnIndex = ShortestColumnIndex();
var xOffset = sectionInset.Left + (itemWidth + interItemSpacing) * columnIndex;
var yOffset = columnHeights[columnIndex];
var attributes = UICollectionViewLayoutAttributes.CreateForCell(indexPath);
attributes.Frame = new RectangleF(xOffset, yOffset, itemWidth, itemHeight);
itemAttributes.Add(attributes);
columnHeights[columnIndex] = yOffset + itemHeight + interItemSpacing;
}
}
public override void PrepareLayout()
{
base.PrepareLayout();
calculatedAttributes.Clear();
contentWidth = CollectionView.Frame.Width;
nfloat columnWidth = contentWidth / NumberOfColumns;
nfloat height = columnWidth * 1.25f; // Our cells height is a 25% greater than their width
for (int i = 0; i < columnsXOffset.Length; i++)
{
columnsXOffset[i] = i * columnWidth;
}
for (int i = 0; i < columnsYOffset.Length; i++)
{
columnsYOffset[i] = 0;
}
UICollectionViewLayoutAttributes attribute1 = UICollectionViewLayoutAttributes.CreateForCell(NSIndexPath.FromItemSection(0, 0));
attribute1.Frame = new CGRect(columnsXOffset[1], 0, columnWidth, buttonHeight);
calculatedAttributes.Add(attribute1);
columnsYOffset[1] = buttonHeight; // Second column has a vertical offset (due to sell button height)
int column = 0;
for (int i = 0; i < CollectionView.NumberOfItemsInSection(1); i++)
{
var indexPath = NSIndexPath.FromItemSection(i, 1);
var frame = new CGRect(columnsXOffset[column], columnsYOffset[column], columnWidth, height);
var insetFrame = RectangleFExtensions.Inset(frame, 0f, 0f);
UICollectionViewLayoutAttributes attribute = UICollectionViewLayoutAttributes.CreateForCell(indexPath);
attribute.Frame = insetFrame;
calculatedAttributes.Add(attribute);
contentHeight = System.NMath.Max(contentHeight, RectangleFExtensions.GetMaxY(frame));
columnsYOffset[column] = columnsYOffset[column] + height;
column = column >= (NumberOfColumns - 1) ? 0 : ++column;
}
}
public override void PrepareLayout()
{
Cache.Clear();
var standardHeight = CustomFlowLayoutConstants.Cell.standardHeight;
var featuredHeight = CustomFlowLayoutConstants.Cell.featuredHeight;
var frame = CGRect.Empty;
nfloat y = 0;
for (int item = 0; item < NumberOfItems; item++)
{
var indexPath = NSIndexPath.FromItemSection(item, 0);
var attributes = UICollectionViewLayoutAttributes.CreateForCell(indexPath);
attributes.ZIndex = item;
var height = standardHeight;
if ((indexPath.Item == FeaturedItemIndex))
{
var yOffset = standardHeight * NextItemPercentageOffset;
y = CollectionView.ContentOffset.Y - yOffset;
height = featuredHeight;
}
else if ((indexPath.Item == (FeaturedItemIndex + 1)) && (indexPath.Item != NumberOfItems))
{
var y0 = y;
var maxY = y + standardHeight;
height = standardHeight + (nfloat)Math.Max((featuredHeight - standardHeight) * NextItemPercentageOffset, 0);
y = maxY - height;
var fr = Cache[FeaturedItemIndex].Frame;
fr.Height -= y0 - y;
Cache[FeaturedItemIndex].Frame = fr;
}
else
{
height = standardHeight;
}
frame = new CGRect(0, y, Width, height);
attributes.Frame = frame;
Cache.Add(attributes);
y = frame.GetMaxY();
}
}
public override UICollectionViewLayoutAttributes LayoutAttributesForItem(NSIndexPath indexPath)
{
var cellAttributes = UICollectionViewLayoutAttributes.CreateForCell(indexPath);
var column = indexPath.Item % columnCount;
var row = (int)indexPath.Item / columnCount;
var frame = new CGRect
{
X = cellWidth * column + CollectionView.Frame.Width * indexPath.Section,
Y = CellHeight * row,
Width = cellWidth,
Height = CellHeight
};
cellAttributes.Frame = frame;
return(cellAttributes);
}
public override void PrepareLayout()
{
CGSize size = CollectionView.Bounds.Size;
CGPoint center = new CGPoint(size.Width / 2.0f, size.Height / 2.0f);
int itemCount = (int)CollectionView.NumberOfItemsInSection(0);
if (attributesArray == null)
{
attributesArray = new List <UICollectionViewLayoutAttributes> (itemCount);
}
angles.Clear();
float maxAngle = (float)(1 / Math.PI / 3.0f);
float minAngle = -maxAngle;
float diff = maxAngle - minAngle;
angles.Add(0);
for (int i = 1; i < stackCount * 10; i++)
{
int hash = (int)(i * 2654435761 % 2 ^ 32);
hash = (int)(hash * 2654435761 % 2 ^ 32);
float currentAngle = (float)((hash % 1000) / 1000.0 * diff) + minAngle;
angles.Add(currentAngle);
}
for (int i = 0; i < itemCount; i++)
{
int angleIndex = i % (stackCount * 10);
float angle = angles [angleIndex];
var path = NSIndexPath.FromItemSection(i, 0);
UICollectionViewLayoutAttributes attributes = UICollectionViewLayoutAttributes.CreateForCell(path);
attributes.Size = new CGSize(150, 200);
attributes.Center = center;
attributes.Transform = CGAffineTransform.MakeRotation(angle);
attributes.Alpha = (i > stackCount) ? 0.0f : 1.0f;
attributes.ZIndex = (itemCount - i);
attributesArray.Add(attributes);
}
}
public override UICollectionViewLayoutAttributes LayoutAttributesForItem(NSIndexPath indexPath)
{
var attributes = UICollectionViewLayoutAttributes.CreateForCell(indexPath);
var item = DataSourceItems[(int)indexPath.Item];
if (0 < ItemSize.Width && 0 < ItemSize.Height)
{
attributes.Frame = new CGRect(Offset.X, Offset.Y, ItemSize.Width - ContentEdgeInsets.Left - ContentEdgeInsets.Right, ItemSize.Height - ContentEdgeInsets.Top - ContentEdgeInsets.Bottom);
}
else if (ScrollDirection == UICollectionViewScrollDirection.Vertical)
{
attributes.Frame = new CGRect(ContentEdgeInsets.Left, Offset.Y, CollectionView.Bounds.Width - ContentEdgeInsets.Left - ContentEdgeInsets.Right, item.Height == null ? CollectionView.Bounds.Height : item.Height.Value);
}
else
{
attributes.Frame = new CGRect(Offset.X, ContentEdgeInsets.Top, item.Width == null? CollectionView.Bounds.Width : item.Width.Value, CollectionView.Bounds.Height - ContentEdgeInsets.Top - ContentEdgeInsets.Bottom);
}
return(attributes);
}
public override void PrepareLayout()
{
if (_cache.Count > 0 || CollectionView == null)
{
return;
}
_contentHeight = 0;
var columnWidth = (float)CollectionView.Frame.Width / ColumnCount;
var xOffsets = new List <float>();
var yOffsets = new List <float>();
for (var i = 0; i < ColumnCount; i++)
{
xOffsets.Add(i * columnWidth);
yOffsets.Add(0);
}
if (Header != null)
{
var indexPath = NSIndexPath.FromRowSection(0, 0);
var frame = new CGRect(0, 0, CollectionView.Frame.Width, Header.HeightRequest);
var attrs = UICollectionViewLayoutAttributes.CreateForSupplementaryView(UICollectionElementKindSection.Header, indexPath);
attrs.Frame = frame;
_cache.Add(attrs);
for (var i = 0; i < ColumnCount; i++)
{
yOffsets[i] = (float)frame.Height;
}
}
var column = 0;
for (var r = 0; r < ItemsSource.Count; r++)
{
var isHeader = HeaderIndexes.Contains(r);
var width = columnWidth;
double cellHeight;
if (GetHeightForCellDelegate != null)
{
cellHeight = GetHeightForCellDelegate(ItemsSource[r]);
}
else
{
cellHeight = new Random().Next((int)MinCellHeight, (int)MaxCellHeight);
}
var y = yOffsets[column];
if (isHeader) // HEADER
{
width = (float)CollectionView.Frame.Width;
cellHeight = HeaderTemplateHeight;
y = (float)_contentHeight;
column = 0;
}
var indexPath = NSIndexPath.FromRowSection(r, 0);
var frame = new CGRect(xOffsets[column], y, width, cellHeight);
var attrs = UICollectionViewLayoutAttributes.CreateForCell(indexPath);
attrs.Frame = frame;
_contentHeight = Math.Max((float)_contentHeight, (float)frame.GetMaxY());
if (isHeader)
{
for (var i = 0; i < ColumnCount; i++)
{
yOffsets[i] = (float)_contentHeight;
}
column = 0;
}
else
{
yOffsets[column] = (float)(yOffsets[column] + cellHeight);
column = column == ColumnCount - 1 ? 0 : column + 1;
}
_cache.Add(attrs);
}
}
public override void PrepareLayout()
{
base.PrepareLayout();
// Get the number of sections
var numberofSections = CollectionView.NumberOfSections();
if (numberofSections == 0)
{
return;
}
// Reset collections
_headersAttributes.Clear();
_footersAttributes.Clear();
_unionRects.Clear();
_columnHeights.Clear();
_allItemAttributes.Clear();
_sectionItemAttributes.Clear();
// Initialize column heights
for (int n = 0; n < ColumnCount; n++)
{
_columnHeights.Add((nfloat)0);
}
// Process all sections
nfloat top = 0.0f;
var attributes = new UICollectionViewLayoutAttributes();
var columnIndex = 0;
for (nint section = 0; section < numberofSections; ++section)
{
// Calculate section specific metrics
var minimumInterItemSpacing = (MinimumInterItemSpacingForSection == null) ? MinimumColumnSpacing :
MinimumInterItemSpacingForSection(CollectionView, this, section);
// Calculate widths
var width = CollectionView.Bounds.Width - SectionInset.Left - SectionInset.Right;
var itemWidth = (nfloat)Math.Floor((width - ((ColumnCount - 1) * MinimumColumnSpacing)) / ColumnCount);
// Calculate section header
var heightHeader = (HeightForHeader == null) ? HeaderHeight :
HeightForHeader(CollectionView, this, section);
if (heightHeader > 0)
{
attributes = UICollectionViewLayoutAttributes.CreateForSupplementaryView(UICollectionElementKindSection.Header, NSIndexPath.FromRowSection(0, section));
attributes.Frame = new CGRect(0, top, CollectionView.Bounds.Width, heightHeader);
_headersAttributes.Add(section, attributes);
_allItemAttributes.Add(attributes);
top = attributes.Frame.GetMaxY();
}
top += SectionInset.Top;
for (int n = 0; n < ColumnCount; n++)
{
_columnHeights [n] = top;
}
// Calculate Section Items
var itemCount = CollectionView.NumberOfItemsInSection(section);
List <UICollectionViewLayoutAttributes> itemAttributes = new List <UICollectionViewLayoutAttributes> ();
for (nint n = 0; n < itemCount; n++)
{
var indexPath = NSIndexPath.FromRowSection(n, section);
columnIndex = NextColumnIndexForItem(n);
var xOffset = SectionInset.Left + (itemWidth + MinimumColumnSpacing) * (nfloat)columnIndex;
var yOffset = _columnHeights [columnIndex];
var itemSize = (SizeForItem == null) ? new CGSize(0, 0) : SizeForItem(CollectionView, this, indexPath);
nfloat itemHeight = 0.0f;
if (itemSize.Height > 0.0f && itemSize.Width > 0.0f)
{
itemHeight = (nfloat)Math.Floor(itemSize.Height * itemWidth / itemSize.Width);
}
attributes = UICollectionViewLayoutAttributes.CreateForCell(indexPath);
attributes.Frame = new CGRect(xOffset, yOffset, itemWidth, itemHeight);
itemAttributes.Add(attributes);
_allItemAttributes.Add(attributes);
_columnHeights [columnIndex] = attributes.Frame.GetMaxY() + MinimumInterItemSpacing;
}
_sectionItemAttributes.Add(itemAttributes);
// Calculate Section Footer
nfloat footerHeight = 0.0f;
columnIndex = LongestColumnIndex();
top = _columnHeights [columnIndex] - MinimumInterItemSpacing + SectionInset.Bottom;
footerHeight = (HeightForFooter == null) ? FooterHeight : HeightForFooter(CollectionView, this, section);
if (footerHeight > 0)
{
attributes = UICollectionViewLayoutAttributes.CreateForSupplementaryView(UICollectionElementKindSection.Footer, NSIndexPath.FromRowSection(0, section));
attributes.Frame = new CGRect(0, top, CollectionView.Bounds.Width, footerHeight);
_footersAttributes.Add(section, attributes);
_allItemAttributes.Add(attributes);
top = attributes.Frame.GetMaxY();
}
for (int n = 0; n < ColumnCount; n++)
{
_columnHeights [n] = top;
}
}
var i = 0;
var attrs = _allItemAttributes.Count;
while (i < attrs)
{
var rect1 = _allItemAttributes [i].Frame;
i = (int)Math.Min(i + _unionSize, attrs) - 1;
var rect2 = _allItemAttributes [i].Frame;
_unionRects.Add(CGRect.Union(rect1, rect2));
i++;
}
}
public override void PrepareLayout()
{
if (_cache.IsNullOrEmpty())
{
var cellSizes = new CGSize[CollectionView.NumberOfItemsInSection(0)];
for (int index = 0; index < cellSizes.Length; index++)
{
var indexPath = NSIndexPath.FromRowSection(index, 0);
var cellSize = Delegate?.SizeForCellAtIndexPath(CollectionView, indexPath) ?? CGSize.Empty;
cellSizes[index] = cellSize;
}
var column = 0;
var yOffset = new nfloat[NumberOfColumns];
var supplementaryAttr = UICollectionViewLayoutAttributes.CreateForSupplementaryView(UICollectionElementKindSection.Header, NSIndexPath.FromRowSection(0, 0));
supplementaryAttr.Frame = new CGRect(CGPoint.Empty, HeaderReferenceSize);
_cache.Add(supplementaryAttr);
//add begin Y offset to each column
for (int i = 0; i < NumberOfColumns; i++)
{
yOffset[i] = HeaderReferenceSize.Height == 0 ? 0 : HeaderReferenceSize.Height + MinimumLineSpacing / 2;
}
var previousCellPoint = CGPoint.Empty;
for (int index = 0; index < CollectionView.NumberOfItemsInSection(0); index++)
{
CGSize previousCellSize = index == 0 ? CGSize.Empty : cellSizes[index - 1];
CGSize currentCellSize = cellSizes[index];
var width = currentCellSize.Width + (MinimumInteritemSpacing * 2);
var height = currentCellSize.Height + MinimumLineSpacing;
//check that width of next cell in column [1; NumberOfColumns) does not go beyond the borders of content width
var previuosCellsWidth = previousCellPoint.X + previousCellSize.Width + MinimumInteritemSpacing;
if (column != 0 && previuosCellsWidth + width > ContentWidth)
{
//add Y offset to current column
yOffset[column] = yOffset[column] + height;
//switch column number to zero
column = 0;
previousCellPoint = CGPoint.Empty;
}
//get cell real frame
var frame = new CGRect(column == 0 ? 0 : previuosCellsWidth, yOffset[column], width, height + MinimumLineSpacing);
var insetFrame = frame.Inset(MinimumInteritemSpacing, MinimumLineSpacing);
//get cell atribute for frame
var indexPath = NSIndexPath.FromRowSection(index, 0);
var attributes = UICollectionViewLayoutAttributes.CreateForCell(indexPath);
attributes.Frame = insetFrame;
//add attribute to cache
_cache.Add(attributes);
//update content height
_contentHeight = (nfloat)Math.Max(_contentHeight, frame.Bottom);
//add Y offset to column
yOffset[column] = yOffset[column] + height;
//save previous cell point
previousCellPoint = column >= (NumberOfColumns - 1) ? CGPoint.Empty : new CGPoint(insetFrame.X, insetFrame.Y);
//increment column number
column = column >= (NumberOfColumns - 1) ? 0 : ++column;
}
}
}
public override void PrepareLayout()
{
base.PrepareLayout();
var sectionCount = CollectionView.NumberOfSections();
if (sectionCount == 0)
{
return;
}
// Reset Cache
_cachedAttributes.Clear();
_contentBounds = new CGRect(CGPoint.Empty, CollectionView.Bounds.Size);
var itemCount = CollectionView.NumberOfItemsInSection(0);
var currentIndex = 0;
var itemStyle = DetermineItemStyle(itemCount);
var lastFrame = CGRect.Empty;
var cvWidth = CollectionView.Bounds.Width;
var cvHeight = CollectionView.Bounds.Height;
while (currentIndex < itemCount)
{
CGRect segmentFrame;
var segmentRects = new List <CGRect>();
switch (itemStyle)
{
case MosaicStyle.FullWidth:
segmentFrame = new CGRect(0, lastFrame.GetMaxY() + 1, cvWidth, cvHeight);
segmentRects.Add(segmentFrame);
break;
case MosaicStyle.HalfWidth:
segmentFrame = new CGRect(0, lastFrame.GetMaxY() + 1, cvWidth, cvHeight / 2);
var slices = segmentFrame.DividedIntegral((nfloat)0.5, CGRectEdge.MinXEdge);
segmentRects.Add(slices["First"]);
segmentRects.Add(slices["Second"]);
break;
case MosaicStyle.TwoThirdsByOneThird:
segmentFrame = new CGRect(0, lastFrame.GetMaxY() + 1, cvWidth, cvHeight / 3);
var twoThirdsHorizontalSlices = segmentFrame.DividedIntegral((nfloat)(2.0 / 3.0), CGRectEdge.MinXEdge);
var twoThirdsVerticalSlices = segmentFrame.DividedIntegral((nfloat)0.5, CGRectEdge.MinYEdge);
segmentRects.Add(twoThirdsHorizontalSlices["First"]);
segmentRects.Add(twoThirdsVerticalSlices["First"]);
segmentRects.Add(twoThirdsVerticalSlices["Second"]);
break;
case MosaicStyle.OneThirdByTwoThirds:
segmentFrame = new CGRect(0, lastFrame.GetMaxY() + 1, cvWidth, cvHeight / 3);
var oneThirdHorizontalSlices = segmentFrame.DividedIntegral((nfloat)(1.0 / 3.0), CGRectEdge.MinXEdge);
var oneThirdVerticalSlices = segmentFrame.DividedIntegral((nfloat)0.5, CGRectEdge.MinYEdge);
segmentRects.Add(oneThirdVerticalSlices["First"]);
segmentRects.Add(oneThirdVerticalSlices["Second"]);
segmentRects.Add(oneThirdHorizontalSlices["Second"]);
break;
}
// cache attributes.
foreach (var rect in segmentRects)
{
var indexPath = NSIndexPath.FromRowSection(currentIndex, 0);
var attributes = UICollectionViewLayoutAttributes.CreateForCell(indexPath);
attributes.Frame = rect;
_cachedAttributes.Add(attributes);
_contentBounds = _contentBounds.UnionWith(lastFrame);
currentIndex++;
lastFrame = rect;
}
// determine style for next segment
switch (itemCount - currentIndex)
{
case 1:
itemStyle = MosaicStyle.FullWidth;
break;
case 2:
itemStyle = MosaicStyle.HalfWidth;
break;
default:
switch (itemStyle)
{
case MosaicStyle.FullWidth:
itemStyle = MosaicStyle.HalfWidth;
break;
case MosaicStyle.HalfWidth:
itemStyle = MosaicStyle.TwoThirdsByOneThird;
break;
case MosaicStyle.TwoThirdsByOneThird:
itemStyle = MosaicStyle.OneThirdByTwoThirds;
break;
case MosaicStyle.OneThirdByTwoThirds:
itemStyle = MosaicStyle.HalfWidth;
break;
}
break;
}
}
}
