example.rb

# A simple example of creating a UIView with a UICollectionView as a subview
# in RubyMotion using Teacup for styling
# 
# Your controller will need to set the stylesheet:  stylesheet :example
# and create this view like so:  subview Example, :my_example_view
class Example < UIView 

  CELL_IDENTIFIER = 'example_cell'

  def initWithFrame(frame)
    if super

      # Create UICollection View
      layout = UICollectionViewFlowLayout.alloc.init
      cv = UICollectionView.alloc.initWithFrame(self.bounds, collectionViewLayout: layout)
      cv.registerClass(ExampleCell, forCellWithReuseIdentifier: CELL_IDENTIFIER)
      @collection = subview(cv, :collection, delegate: self, dataSource: self)

    end

    self
  end

  def numberOfSectionsInCollectionView(view)
    30 # Number of sections
  end

  def collectionView(view, numberOfItemsInSection: section)
    rand(10) # Number of cells in this section
  end
    
  def collectionView(view, cellForItemAtIndexPath: index_path)
    view.dequeueReusableCellWithReuseIdentifier(CELL_IDENTIFIER, forIndexPath: index_path).tap do |cell|

      layout(cell.contentView, :cell) do 
        # No not add subviews here, as this cell may already exist. Add them in ExampleCell below
        cell.label.text = "#{index_path.section}/#{index_path.row}"
      end

    end
  end

end

class ExampleCell < UICollectionViewCell 
  attr_accessor :label
 
  def initWithFrame(frame)
    if super

      layout self.contentView do
        # Add subviews here
        @label = subview(UILabel, :cell_label)
      end

    end
    self
  end
 
end


Teacup::Stylesheet.new :example do

  style :collection,
    frame: :full,
    backgroundColor: UIColor.clearColor,
    autoresizingMask: UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight,
    allowsSelection: false,
    collectionViewLayout: {
      itemSize: [100, 40],
      sectionInset: [10,10,10,10],
      minimumInteritemSpacing: 5,
      minimumLineSpacing: 5 
    }

  style :cell,
    frame: :full,
    backgroundColor: UIColor.whiteColor
  style :cell_label,
    height: 15, width: 50, top: 5, left: 5,
    textColor: UIColor.blackColor,
    backgroundColor: UIColor.clearColor

end