limit the join network combobox to hex characters.

Join only clickable when a valid network is entered

ZeroTier One/JoinNetworkViewController.swift

@@ -8,11 +8,77 @@
 
 import Cocoa
 
-class JoinNetworkViewController: NSViewController {
+extension String {
+    func contains(find: String) -> Bool {
+        return self.rangeOfString(find) != nil
+    }
+
+    func trunc(length: Int, trailing: String? = "...") -> String {
+        if self.characters.count > length {
+            return self.substringToIndex(self.startIndex.advancedBy(length)) + (trailing ?? "")
+        } else {
+            return self
+        }
+    }
+}
+
+class JoinNetworkViewController: NSViewController, NSComboBoxDelegate {
+
+    @IBOutlet var network: NSComboBox!
+    @IBOutlet var joinButton: NSButton!
 
     override func viewDidLoad() {
         super.viewDidLoad()
-        // Do view setup here.
+        network.setDelegate(self)
     }
-    
+
+    @IBAction func onJoinClicked(sender: AnyObject?) {
+        let networkId = UInt64(network.stringValue, radix: 16)
+
+        // TODO: Execute join network call
+
+        network.stringValue = ""
+    }
+
+
+    // NSComboBoxDelegate Methods
+
+    override func controlTextDidChange(obj: NSNotification) {
+        let cb = obj.object as! NSComboBox
+        let value = cb.stringValue
+
+
+        let allowedCharacters = "abcdefABCDEF0123456789"
+
+        var outValue = ""
+
+        for char in value.characters {
+            if !allowedCharacters.contains(String(char)) {
+                NSBeep()
+            }
+            else {
+                outValue += String(char)
+            }
+        }
+
+
+
+        if outValue.lengthOfBytesUsingEncoding(NSUTF8StringEncoding) == 16 {
+            joinButton.enabled = true
+        }
+        else {
+
+            if outValue.lengthOfBytesUsingEncoding(NSUTF8StringEncoding) > 16 {
+                outValue = outValue.trunc(16, trailing: "")
+                NSBeep()
+                joinButton.enabled = true
+            }
+            else {
+                joinButton.enabled = false
+            }
+        }
+
+        cb.stringValue = outValue
+    }
+    // end NSComboBoxDelegate Methods
 }