Add basic ExtensionPoint support.

Shared/ExtensionPoints/ExtensionPoint.swift

@@ -0,0 +1,20 @@
+//
+//  ExtensionPoint.swift
+//  NetNewsWire
+//
+//  Created by Maurice Parker on 4/7/20.
+//  Copyright © 2020 Ranchero Software. All rights reserved.
+//
+
+import Foundation
+import RSCore
+
+protocol ExtensionPoint {
+
+	/// The title of the command.
+	var title: String { get }
+
+	/// The template image for the command.
+	var templateImage: RSImage { get }
+
+}

Shared/ExtensionPoints/ExtensionPointManager.swift

@@ -0,0 +1,49 @@
+//
+//  ExtensionPointManager.swift
+//  NetNewsWire
+//
+//  Created by Maurice Parker on 4/7/20.
+//  Copyright © 2020 Ranchero Software. All rights reserved.
+//
+
+import Foundation
+import FeedProvider
+import RSCore
+
+struct ExtensionPointManager {
+	
+	static let shared = ExtensionPointManager()
+	
+	let marsEdit = SendToMarsEditCommand()
+	let microblog = SendToMicroBlogCommand()
+	let twitter = TwitterFeedProvider()
+	
+	let availableExtensionPoints: [ExtensionPoint]
+	let activeSendToCommands: [SendToCommand]
+	let activeFeedProviders: [FeedProvider]
+	
+	init() {
+		#if os(macOS)
+		#if DEBUG
+		availableExtensionPoints = [marsEdit, microblog, twitter]
+		activeSendToCommands = [marsEdit, microblog]
+		activeFeedProviders = [twitter]
+		#else
+		availableExtensionPoints = [marsEdit, microblog, twitter]
+		activeSendToCommands = [marsEdit, microblog]
+		activeFeedProviders = [twitter]
+		#endif
+		#else
+		#if DEBUG
+		availableExtensionPoints = [twitter]
+		activeSendToCommands = []()
+		activeFeedProviders = [twitter]
+		#else
+		availableExtensionPoints = [twitter]
+		activeSendToCommands = []()
+		activeFeedProviders = [twitter]
+		#endif
+		#endif
+	}
+	
+}

Shared/ExtensionPoints/ExtensionPointType.swift

@@ -0,0 +1,14 @@
+//
+//  ExtensionPointType.swift
+//  NetNewsWire
+//
+//  Created by Maurice Parker on 4/7/20.
+//  Copyright © 2020 Ranchero Software. All rights reserved.
+//
+
+import Foundation
+
+enum ExtensionPoint: Int, Codable {
+	case sentToCommand = 1
+	case feedProvider = 2
+}

Shared/ExtensionPoints/SendToMarsEditCommand.swift

@@ -10,14 +10,16 @@ import AppKit
 import RSCore
 import Articles
 
-final class SendToMarsEditCommand: SendToCommand {
+final class SendToMarsEditCommand: ExtensionPoint, SendToCommand {
 
-	let title = "MarsEdit"
+	let title = NSLocalizedString("MarsEdit", comment: "MarsEdit")
+	let templateImage = AppAssets.extensionPointMarsEdit
 
 	var image: NSImage? {
 		return appToUse()?.icon ?? nil
 	}
 
+
 	private let marsEditApps = [UserApp(bundleID: "com.red-sweater.marsedit4"), UserApp(bundleID: "com.red-sweater.marsedit")]
 
 	func canSendObject(_ object: Any?, selectedText: String?) -> Bool {

Shared/ExtensionPoints/SendToMicroBlogCommand.swift

@@ -12,9 +12,10 @@ import RSCore
 
 // Not undoable.
 
-final class SendToMicroBlogCommand: SendToCommand {
+final class SendToMicroBlogCommand: ExtensionPoint, SendToCommand {
 
-	let title = "Micro.blog"
+	let title = NSLocalizedString("Micro.blog", comment: "Micro.blog")
+	let templateImage = AppAssets.extensionPointMicroblog
 
 	var image: NSImage? {
 		return microBlogApp.icon

Shared/ExtensionPoints/TwitterFeedProvider+Extensions.swift

@@ -0,0 +1,23 @@
+//
+//  TwitterFeedProvider+Extensions.swift
+//  NetNewsWire
+//
+//  Created by Maurice Parker on 4/7/20.
+//  Copyright © 2020 Ranchero Software. All rights reserved.
+//
+
+import Foundation
+import FeedProvider
+import RSCore
+
+extension TwitterFeedProvider: ExtensionPoint {
+	
+	var title: String {
+		return NSLocalizedString("Twitter", comment: "Twitter")
+	}
+
+	var templateImage: RSImage {
+		return AppAssets.extensionPointTwitter
+	}
+
+}