Stuff…

TagTunes/SearchController.swift

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+//
+//  SearchController.swift
+//  TagTunes
+//
+//  Created by Kim Wittenburg on 06.03.16.
+//  Copyright © 2016 Kim Wittenburg. All rights reserved.
+//
+
+import SearchAPI
+import AppKitPlus
+
+/// A search delegate is notified when a `SearchController` selects an item.
+protocol SearchDelegate: class {
+
+    /// The view controller displaying the content.
+    var contentViewController: ContentViewController! { get }
+
+    /// Invoked when the `searchController` selected a item. In the
+    /// implementation the selected `searchResult` should be added to the
+    /// `contentViewController`.
+    func searchController(searchController: SearchController, didSelectSearchResult searchResult: TagTunesItem)
+
+}
+
+/// Manages the user interface for search results.
+public class SearchController: NSObject, PopUpSearchFieldDelegate {
+
+    /// This struct contains *magic numbers* like references to storyboard
+    /// identifiers.
+    private struct Constants {
+
+        /// The identifier used for the rows in the search results pop up.
+        static let AlbumTableCellViewIdentifier = "AlbumTableCellViewIdentifier"
+
+        /// The identifier used for the `No Results` row in the search results
+        /// pop up.
+        static let NoResultsTableCellViewIdentifier = "NoResultsTableCellViewIdentifier"
+
+    }
+
+    weak var delegate: SearchDelegate?
+
+    /// The search field. This should be set by the view controller containing
+    /// the user interface for searching.
+    public weak var searchField: PopUpSearchField! {
+        willSet {
+            searchField?.popUpDelegate = nil
+        }
+        didSet {
+            searchField?.popUpDelegate = self
+        }
+    }
+
+    /// Used for searching and loading search results
+    private let urlSession = NSURLSession(configuration: NSURLSessionConfiguration.defaultSessionConfiguration(), delegate: nil, delegateQueue: NSOperationQueue.mainQueue())
+
+    /// The URL task currently loading the search results.
+    private var searchTask: NSURLSessionTask? {
+        didSet {
+            searching = searchTask != nil
+        }
+    }
+
+    public private(set) dynamic var searching: Bool = false
+
+    /// The search results for the current search term.
+    private var searchResults = [Album]() {
+        didSet {
+            searchField.updatePopUp()
+        }
+    }
+
+    /// The error that occured during searching, if any.
+    private var searchError: NSError?
+
+    /// Begins searching for the `searchField`'s `stringValue`.
+    public func beginSearch() {
+        let searchString = searchField.stringValue
+        cancelSearch()
+        if searchString == "" {
+            searchResults = []
+        } else {
+            var request = SearchAPIRequest(searchRequestWithTerm: searchString)
+            request.mediaType = .Music
+            request.entity = .Album
+            request.maximumNumberOfResults = UInt(Preferences.sharedPreferences.numberOfSearchResults)
+            if Preferences.sharedPreferences.useEnglishTags {
+                request.language = .English
+            }
+            request.country = Preferences.sharedPreferences.iTunesStore
+            searchTask = urlSession.dataTaskWithURL(request.URL, completionHandler: processSearchResults)
+            searchTask!.resume()
+        }
+    }
+
+    /// Cancels the current search (if there is one) and removes the search
+    /// results.
+    private func cancelSearch() {
+        searchTask?.cancel()
+    }
+
+    /// Processes the data returned from a network request into the
+    /// `searchResults` array.
+    private func processSearchResults(data: NSData?, response: NSURLResponse?, error: NSError?) {
+        searchTask = nil
+        var newResults = [Album]()
+        if let theData = data where error == nil {
+            do {
+                let result = try SearchAPIResult(data: theData)
+                newResults = result.resultEntities.flatMap{ $0 as? Album }
+            } catch let error as NSError {
+                searchError = error
+            }
+        } else if let theError = error {
+            searchError = theError
+        }
+        searchResults = newResults
+    }
+
+    public func popUpSearchFieldWillHidePopUp(searchField: PopUpSearchField) {
+        cancelSearch()
+    }
+
+    public func popUpSearchFieldShouldShowPopUp(searchField: PopUpSearchField) -> Bool {
+        return !searchField.stringValue.isEmpty
+    }
+
+    public func popUpSearchField(searchField: PopUpSearchField, didSelectPopUpEntryAtRow row: Int) {
+        let searchResult = searchResults[row]
+        let albumItem = AlbumItem(entity: searchResult)
+        albumItem.beginLoadingChildren()
+        delegate?.searchController(self, didSelectSearchResult: albumItem)
+        searchField.reloadPopUpRow(row)
+    }
+
+    private var shouldDisplayNoResults: Bool {
+        return searchResults.isEmpty && !searchField.stringValue.isEmpty && searchTask == nil
+    }
+
+    public func numberOfRowsInTableView(tableView: NSTableView) -> Int {
+        if shouldDisplayNoResults {
+            return 1
+        }
+        return searchResults.count
+    }
+
+    public func tableView(tableView: NSTableView, heightOfRow row: Int) -> CGFloat {
+        return 39
+    }
+
+    public func tableView(tableView: NSTableView, viewForTableColumn tableColumn: NSTableColumn?, row: Int) -> NSView? {
+        if shouldDisplayNoResults {
+            var view = tableView.makeViewWithIdentifier(Constants.NoResultsTableCellViewIdentifier, owner: nil) as? CenteredTableCellView
+            if view == nil {
+                view = CenteredTableCellView()
+                view?.identifier = Constants.NoResultsTableCellViewIdentifier
+            }
+            view?.setupForNoResults()
+            return view
+        } else {
+            var view = tableView.makeViewWithIdentifier(Constants.AlbumTableCellViewIdentifier, owner: nil) as? AlbumTableCellView
+            if view == nil {
+                view = AlbumTableCellView()
+                view?.identifier = Constants.AlbumTableCellViewIdentifier
+            }
+            let searchResult = searchResults[row]
+            let height = self.tableView(tableView, heightOfRow: row)
+            let albumEnabled = delegate?.contentViewController.itemForEntity(searchResult) == nil
+            view?.setupForAlbum(searchResult, enabled: albumEnabled, height: height)
+            return view
+        }
+    }
+
+    public func tableView(tableView: NSTableView, shouldSelectRow row: Int) -> Bool {
+        if shouldDisplayNoResults {
+            return false
+        } else {
+            return delegate?.contentViewController?.itemForEntity(searchResults[row]) == nil
+        }
+    }
+
+}