Add night mode option

writeas/AppDelegate.swift

@@ -27,6 +27,12 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         }
     }
 
+    @IBAction func toggleNightMode(_ sender: NSMenuItem) {
+        let isOff = sender.state == NSOffState
+        vc?.toggle(isNight: isOff)
+        sender.state = isOff ? NSOnState : NSOffState
+    }
+
     @IBAction func saveDocument(_ sender: AnyObject) {
         vc?.saveDocument()
     }

writeas/Base.lproj/Main.storyboard

@@ -226,6 +226,18 @@
                                     </items>
                                 </menu>
                             </menuItem>
+                            <menuItem title="View" id="H8h-7b-M4v">
+                                <modifierMask key="keyEquivalentModifierMask"/>
+                                <menu key="submenu" title="View" id="HyV-fh-RgO">
+                                    <items>
+                                        <menuItem title="Night Mode" keyEquivalent="u" id="jYO-0u-qN9">
+                                            <connections>
+                                                <action selector="toggleNightMode:" target="Voe-Tx-rLC" id="Nmq-eG-y3w"/>
+                                            </connections>
+                                        </menuItem>
+                                    </items>
+                                </menu>
+                            </menuItem>
                             <menuItem title="Window" id="aUF-d1-5bR">
                                 <modifierMask key="keyEquivalentModifierMask"/>
                                 <menu key="submenu" title="Window" systemMenu="window" id="Td7-aD-5lo">

writeas/ViewController.swift

@@ -86,5 +86,18 @@ class ViewController: NSViewController, NSTextViewDelegate {
             print("ERROR loading: \(err)")
         }
     }
+
+    func toggle(isNight: Bool) {
+        let darkBG = NSColor(red:0.13, green:0.13, blue:0.13, alpha:1.0)
+        if isNight {
+            self.view.window!.backgroundColor = darkBG
+            self.writerText.backgroundColor = darkBG
+            self.writerText.textColor = NSColor.white
+        } else {
+            self.view.window!.backgroundColor = NSColor.white
+            self.writerText.backgroundColor = NSColor.white
+            self.writerText.textColor = NSColor.black
+        }
+    }
 }