Added Cocoa Bindings Example

examples/bindtest.nim

@@ -0,0 +1,34 @@
+import Cocoa / [NSWindow, NSFunctions, NSCheckBox,
+                NSTextField, NSSlider]
+
+const
+    winStyle = NSWindowStyleMaskTitled or NSWindowStyleMaskClosable
+
+type
+    GUI = object
+        win:    ID
+        label:  ID
+        chk:    ID
+        slider: ID
+        txt:    ID
+
+var self: GUI
+
+Cocoa_Init()
+
+self.win = newWindow("Cocoa Bindings Demo 1", 462, 128, winStyle)
+
+self.chk = newCheckBox(self.win, "Enabled?", 18, 18, 78, 22) #iVar="state"
+self.txt = newTextField(self.win, "", 102, 18, 340, 22)
+self.slider = newSlider(self.win, 18, 48, 428, 19, nil) #iVar="Value"
+
+# Bind TextBox and Slider value
+# Each can update the other
+self.txt.link("value",self.slider,"Value")
+self.slider.link("value", self.slider,"Value")
+
+# Bind Checkbox and Slider state. 
+# Checkbox controls enabled/disabled state of Slider!
+self.slider.link("enabled", self.chk,"state")
+
+Cocoa_Run(self.win)