Make value getters/setters more consistent

See #6

swatch.go

@@ -36,6 +36,11 @@ func NewSwatch (value color.Color) *Swatch {
 	return swatch
 }
 
+// Value returns the color of the swatch.
+func (this *Swatch) Value () color.Color {
+	return this.value
+}
+
 // SetValue sets the color of the swatch.
 func (this *Swatch) SetValue (value color.Color) {
 	this.value = value
@@ -43,9 +48,10 @@ func (this *Swatch) SetValue (value color.Color) {
 	this.Invalidate()
 }
 
-// Value returns the color of the swatch.
-func (this *Swatch) Value () color.Color {
-	return this.value
+// OnValueChange specifies a function to be called when the swatch's color
+// is changed by the user.
+func (this *Swatch) OnValueChange (callback func ()) event.Cookie {
+	return this.on.valueChange.Connect(callback)
 }
 
 // RGBA satisfies the color.Color interface
@@ -54,12 +60,6 @@ func (this *Swatch) RGBA () (r, g, b, a uint32) {
 	return this.value.RGBA()
 }
 
-// OnValueChange specifies a function to be called when the swatch's color
-// is changed by the user.
-func (this *Swatch) OnValueChange (callback func ()) event.Cookie {
-	return this.on.valueChange.Connect(callback)
-}
-
 // OnEnter specifies a function to be called when the user selects "OK" in the
 // color picker.
 func (this *Swatch) OnEnter (callback func ()) event.Cookie {