Implemented light.Dim func.

2 files changed, 22 insertions, 1 deletions

diff --git a/light.go b/light.go
index 982938c..817c941 100644
--- a/light.go
+++ b/light.go
@@ -11,6 +11,7 @@ package hue
 import (
     "fmt"
     "time"
+    "errors"
 )
 
 // Light struct defines attributes of a light.
@@ -172,6 +173,24 @@ func (light *Light) SetColor(color *[2]float32) error {
     return nil
 }
 
+// Light.Dim will lower the brightness by a percent.
+// Note the required value is an integer, for example "20" is converted to 20%.
+func (light *Light) Dim(percent int) error {
+    if percent > 0 && percent <= 100 {
+        originalBri := light.State.Bri
+        decreaseBri := float32(originalBri)*float32((float32(percent)/100.0))
+        newBri := (originalBri-int(decreaseBri))
+        lightState := LightState{On: true, Bri: uint8(newBri)}
+        err := light.SetState(lightState)
+        if err != nil {
+            return err
+        }
+        return nil
+    } else {
+        return errors.New("Light.Dim percentage given is not between 1 and 100")
+    }
+}
+
 // Light.SetState modifyies light attributes. See `LightState` struct for attributes.
 // Brightness must be between 1 and 254 (inclusive)
 // Hue must be between 0 and 65535 (inclusive)
diff --git a/light_test.go b/light_test.go
index 436d652..086970f 100644
--- a/light_test.go
+++ b/light_test.go
@@ -10,7 +10,7 @@ package hue
 import (
     "testing"
     //"fmt"
-    "time"
+    //"time"
 )
 
 func TestSetLightState(t *testing.T) {
@@ -33,6 +33,8 @@ func TestSetLightState(t *testing.T) {
 
     selectedLight.Blink(3)
 
+    selectedLight.Dim(20)
+
     // selectedLight.SetColor(RED)
     // time.Sleep(time.Second)
     // selectedLight.SetColor(YELLOW)