gistfile1.swift

//
//  TableViewDataSource.swift
//  QuickReply
//
//  Created by Kristian Andersen on 31/07/14.
//  Copyright (c) 2014 Robocat. All rights reserved.
//

import UIKit

private protocol KSCollectionViewDataSource {
	func collectionView(collectionView: UICollectionView!, numberOfItemsInSection section: Int) -> Int
	func numberOfSectionsInCollectionView(collectionView: UICollectionView!) -> Int
	func collectionView(collectionView: UICollectionView!, cellForItemAtIndexPath indexPath: NSIndexPath!) -> UICollectionViewCell!
}

private protocol KSTableViewDataSource {
	func numberOfSectionsInTableView(tableView: UITableView!) -> Int
	func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int
	func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell!
}

private class BaseDataSource<CellType: UIView, ItemType>: KSCollectionViewDataSource, KSTableViewDataSource {
	private var cellReuseIdentifier: String
	private var configureClosure: (CellType, ItemType) -> Void
	private var proxy: DataSourceProxy!
	private unowned var view: UIView
	
	init(view: UIView, cellReuseIdentifier: String, configureClosure: (CellType, ItemType) -> Void) {
		self.cellReuseIdentifier = cellReuseIdentifier
		self.configureClosure = configureClosure
		self.view = view
		
		configureDataSource()
	}
	
	private func configureDataSource() {
		assert(view as? UITableView || view as? UICollectionView, "Passed view must be of type UITableView or UICollectionView")
		
		self.proxy = DataSourceProxy(self)
		
		if let tableView = view as? UITableView {
			tableView.dataSource = proxy
		}
		
		if let collectionView = view as? UICollectionView {
			collectionView.dataSource = proxy
		}
	}
	
	func collectionView(collectionView: UICollectionView!, numberOfItemsInSection section: Int) -> Int { return 0 }
	func numberOfSectionsInCollectionView(collectionView: UICollectionView!) -> Int { return 0}
	func collectionView(collectionView: UICollectionView!, cellForItemAtIndexPath indexPath: NSIndexPath!) -> UICollectionViewCell! { return nil }
	
	func numberOfSectionsInTableView(tableView: UITableView!) -> Int { return 0 }
	func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int { return 0 }
	func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! { return nil }
	
	private class DataSourceProxy: NSObject, UITableViewDataSource, UICollectionViewDataSource {
		private unowned var dataSource: BaseDataSource<UIView, Any>
		
		init(_ dataSource: AnyObject) {
			self.dataSource = dataSource as BaseDataSource<UIView, Any>
		}
		
		// MARK: UITableViewDataSource
		
		func numberOfSectionsInTableView(tableView: UITableView!) -> Int {
			return dataSource.numberOfSectionsInTableView(tableView)
		}
		
		func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int {
			return dataSource.tableView(tableView, numberOfRowsInSection: section)
		}
		
		func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
			return dataSource.tableView(tableView, cellForRowAtIndexPath: indexPath)
		}
		
		// MARK: - UICollectionViewDataSource
		
		func collectionView(collectionView: UICollectionView!, numberOfItemsInSection section: Int) -> Int {
			return dataSource.collectionView(collectionView, numberOfItemsInSection: section)
		}
		
		func numberOfSectionsInCollectionView(collectionView: UICollectionView!) -> Int {
			return dataSource.numberOfSectionsInCollectionView(collectionView)
		}
		
		func collectionView(collectionView: UICollectionView!, cellForItemAtIndexPath indexPath: NSIndexPath!) -> UICollectionViewCell! {
			return dataSource.collectionView(collectionView, cellForItemAtIndexPath: indexPath)
		}
	}
}

public class ArrayDataSource<CellType: UIView, ItemType> : BaseDataSource<CellType, ItemType> {
	private var items: [ItemType]
	
	public init(items: [ItemType], view: UIView, cellReuseIdentifier: String, configureClosure: (CellType, ItemType) -> Void) {
		self.items = items
		
		super.init(view: view, cellReuseIdentifier: cellReuseIdentifier, configureClosure: configureClosure)
	}
	
	public func itemAtIndexPath(indexPath: NSIndexPath) -> ItemType {
		return self.items[indexPath.row] as ItemType
	}
	
	public func configureCell(cell: CellType, atIndexPath indexPath:NSIndexPath) {
		let item = itemAtIndexPath(indexPath)
		self.configureClosure(cell, item)
	}
	
	override func numberOfSectionsInTableView(tableView: UITableView!) -> Int {
		if items.count <= 0 {
			return 0
		}
		
		return 1
	}
	
	override func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int {
		return self.items.count
	}
	
	override func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
		let cell = tableView.dequeueReusableCellWithIdentifier(self.cellReuseIdentifier, forIndexPath: indexPath) as CellType
		configureCell(cell, atIndexPath: indexPath)
		
		return cell as UITableViewCell
	}
	
	// MARK: - UICollectionViewDataSource
	
	override func collectionView(collectionView: UICollectionView!, numberOfItemsInSection section: Int) -> Int {
		return items.count
	}
	
	override func numberOfSectionsInCollectionView(collectionView: UICollectionView!) -> Int {
		if items.count <= 0 {
			return 0
		}
		
		return 1
	}
	
	override func collectionView(collectionView: UICollectionView!, cellForItemAtIndexPath indexPath: NSIndexPath!) -> UICollectionViewCell! {
		var cell = collectionView.dequeueReusableCellWithReuseIdentifier(cellReuseIdentifier, forIndexPath: indexPath) as CellType
		configureCell(cell, atIndexPath: indexPath)
		
		return cell as UICollectionViewCell
	}
}