[kit] Implement the notification infrastructure

MetaballsKit/Metaballs.swift

@@ -117,6 +117,7 @@ public class Field {
 
     private(set) var balls = [Ball]()
 
+    public var defaults = UserDefaults.standard
     private var parameters: Parameters
 
     internal var bounds: CGRect {
@@ -125,6 +126,11 @@ public class Field {
 
     public init(parameters p: Parameters) {
         parameters = p
+        NotificationCenter.default.addObserver(self, selector: #selector(Field.preferencesDidChange(note:)), name: PreferencesDidChange_Color, object: nil)
+    }
+
+    deinit {
+        NotificationCenter.default.removeObserver(self, name: PreferencesDidChange_Color, object: nil)
     }
 
     public func update() {
@@ -246,4 +252,40 @@ public class Field {
         populateParametersBuffer()
         populateBallBuffer()
     }
+
+    // MARK: - Notifications
+
+    @objc
+    func preferencesDidChange(note: Notification) {
+        guard let userInfo = note.userInfo else { return }
+        var didChange = false
+        if let color = userInfo["color0"] as? NSColor {
+            let cf = Float4(color: color)
+            parameters.color0 = cf
+            defaults.color0 = cf
+            didChange = true
+        }
+        if let color = userInfo["color1"] as? NSColor {
+            let cf = Float4(color: color)
+            parameters.color1 = cf
+            defaults.color1 = cf
+            didChange = true
+        }
+        if let color = userInfo["color2"] as? NSColor {
+            let cf = Float4(color: color)
+            parameters.color2 = cf
+            defaults.color2 = cf
+            didChange = true
+        }
+        if let color = userInfo["color3"] as? NSColor {
+            let cf = Float4(color: color)
+            parameters.color3 = cf
+            defaults.color3 = cf
+            didChange = true
+        }
+
+        if didChange {
+            populateParametersBuffer()
+        }
+    }
 }

MetaballsKit/Preferences.swift

@@ -52,7 +52,11 @@ extension UserDefaults {
         return Float4(values[0], values[1], values[2], values[3])
     }
 
-    func set(value: Float4, forKey key: String) {
-        set([Float](float4: value), forKey: key)
+    func set(_ value: Float4?, forKey key: String) {
+        if let value = value {
+            set([Float](float4: value), forKey: key)
+        } else {
+            set(nil as Any?, forKey: key)
+        }
     }
 }

MetaballsKit/PreferencesViewController.swift

@@ -91,12 +91,9 @@ class PreferencesViewController: NSViewController {
     }
 
     private func prepareColorViews() {
-        guard let colors = defaults.array(forKey: "colors") else { return }
         for (idx, cv) in colorViews.enumerated() {
-            if idx >= colors.count {
-                continue
-            }
-            if let color = colors[idx] as? NSColor {
+            if let fColor = defaults.float4(forKey: "color\(idx)") {
+                let color = NSColor(float4: fColor)
                 cv.colorWell.color = color
             }
         }
@@ -111,20 +108,16 @@ class PreferencesViewController: NSViewController {
 
     func colorPanelDidUpdateValue(_ colorPanel: NSColorPanel) {
         // TODO: Post a notification about color change.
-        print("color panel did update: \(colorPanel.color)")
-        var info = [String:Any]()
-        if let currentStyleItem = styleMenu.selectedItem {
-            info["style"] = ColorStyle(rawValue: UInt16(currentStyleItem.tag))!
-        }
+//        print("color panel did update: \(colorPanel.color)")
+        var info = [String:NSColor]()
         for (idx, cv) in colorViews.enumerated() {
-            let key = "color\(idx)"
             if cv.colorWell.isActive {
-                info[key] = colorPanel.color
+                info["color\(idx)"] = colorPanel.color
             } else {
-                info[key] = cv.colorWell.color
+                info["color\(idx)"] = cv.colorWell.color
             }
         }
-        NotificationCenter.default.post(name: PreferencesDidChange_Color, object: self, userInfo: info)
+        NotificationCenter.default.post(name: PreferencesDidChange_Color, object: nil, userInfo: info)
     }
 }