NetNewsWire/Frameworks/Data/Protocols/Container.swift

151 lines
3.9 KiB
Swift

//
// Container.swift
// Evergreen
//
// Created by Brent Simmons on 4/17/16.
// Copyright © 2016 Ranchero Software, LLC. All rights reserved.
//
import Foundation
import RSCore
public typealias VisitBlock = (_ obj: AnyObject) -> Bool // Return true to stop
extension NSNotification.Name {
public static let ChildrenDidChange = Notification.Name("ChildrenDidChangeNotification")
}
public protocol Container: class {
//Recursive
func hasAtLeastOneFeed() -> Bool
func flattenedFeeds() -> Set<Feed>
func existingFeed(with feedID: String) -> Feed?
func existingFeed(withURL url: String) -> Feed?
func isChild(_ obj: AnyObject) -> Bool
// visitBlock should return true to stop visiting.
// visitObjects returns true if a visitBlock returned true.
func visitObjects(_ recurse: Bool, _ visitBlock: VisitBlock) -> Bool
//
//// func objectIsChild(_ obj: AnyObject) -> Bool
//// func objectIsDescendant(_ obj: AnyObject) -> Bool
////
//// func fetchArticles() -> [Article]
//
// // visitBlock should return true to stop visiting.
// // visitObjects returns true if a visitBlock returned true.
//// func visitObjects(_ recurse: Bool, visitBlock: VisitBlock) -> Bool
//// func visitChildren(visitBlock: VisitBlock) -> Bool // Above with recurse = false
////
//// func findObject(_ recurse: Bool, visitBlock: VisitBlock) -> AnyObject?
//
// func canAddItem(_ item: AnyObject) -> Bool
// func addItem(_ item: AnyObject) -> Bool // Return true even if item already exists.
// func addItems(_ items: [AnyObject]) -> Bool // Return true even if some items already exist.
//
// func canAddFolderWithName(_ folderName: String) -> Bool // Special case: folder with name exists. Return true in that case.
// func ensureFolderWithName(_ folderName: String) -> Folder? // Return folder even if item already exists.
//
// // Does not recurse.
// func existingFolderWithName(_ name: String) -> Folder?
//
// // Doesn't add feed. Just creates instance.
// func createFeedWithName(_ name: String?, editedName: String?, urlString: String) -> Feed?
//
// func deleteItems(_ items: [AnyObject])
}
public extension Container {
func hasAtLeastOneFeed() -> Bool {
let foundObject = findObject(true, visitBlock: { (oneDescendant) -> Bool in
return oneDescendant is Feed
})
return foundObject != nil
}
func existingFeed(with feedID: String) -> Feed? {
let foundObject = findObject(true) { (oneDescendant) -> Bool in
if let oneFeed = oneDescendant as? Feed, oneFeed.feedID == feedID {
return true
}
return false
}
return foundObject as! Feed?
}
func existingFeed(withURL url: String) -> Feed? {
let foundObject = findObject(true) { (oneDescendant) -> Bool in
if let oneFeed = oneDescendant as? Feed, oneFeed.url == url {
return true
}
return false
}
return foundObject as! Feed?
}
func visitChildren(visitBlock: VisitBlock) -> Bool {
return visitObjects(false, visitBlock)
}
func findObject(_ recurse: Bool, visitBlock: @escaping VisitBlock) -> AnyObject? {
var foundObject: AnyObject?
let _ = visitObjects(recurse) { (oneObject) in
if let _ = foundObject {
return true
}
if visitBlock(oneObject) {
foundObject = oneObject
return true
}
return false
}
return foundObject
}
func objectIsChild(_ obj: AnyObject) -> Bool {
return visitObjects(false) { (oneObject) in
return obj === oneObject
}
}
func objectIsDescendant(_ obj: AnyObject) -> Bool {
return visitObjects(true) { (oneObject) in
return obj === oneObject
}
}
func existingFolderWithName(_ name: String) -> Folder? {
let foundObject = findObject(false) { (oneObject) in
if let oneFolder = oneObject as? Folder, oneFolder.nameForDisplay == name {
return true
}
return false
}
return foundObject as! Folder?
}
public func postChildrenDidChangeNotification() {
NotificationCenter.default.post(name: .ChildrenDidChange, object: self)
}
}