Adding ability to set background

Author: DBenYaakov

Sources/Curses.swift

@@ -162,6 +162,13 @@ internal class Curses {
     func attributeSet(windowHandle:UnsafeMutablePointer<WINDOW>, attributeValue:Int) {
         CNCURSES.wattrset(windowHandle, Int32(attributeValue))
     }
+
+    func backgroundSet(windowHandle:UnsafeMutablePointer<WINDOW>, attributeValue:Int, character:Character) {
+        let unicodeScalars = character.unicodeScalars
+        let ascii = UInt(unicodeScalars[unicodeScalars.startIndex].value)
+        let attributeAndCharacter : UInt = UInt(attributeValue) + ascii
+        CNCURSES.wbkgd(windowHandle, attributeAndCharacter)
+    }
 
     var maxColorCount : Int {
         return Int(COLORS)

Sources/Window.swift

@@ -49,6 +49,11 @@ public class Window {
         curses.refresh(windowHandle:windowHandle)
     }
 
+    public func backgroundSet(attribute:Attribute, character:Character = " ") {
+        let attributeValue = attribute.value
+        curses.backgroundSet(windowHandle:windowHandle, attributeValue:attributeValue, character:character)
+    }
+
     public func clear() {
         curses.clear(windowHandle:windowHandle)
     }