add Align vertical and horzonial center relative to key object

Align vertical and horizontal center to key object.sketchplugin

@@ -0,0 +1,4 @@
+// (cmd option control a)
+#import 'utility.js'
+
+align("center")

README.md

@@ -45,6 +45,7 @@ Select all layers you want to align, then select `Plugins ▸ AlignTo` in the Sk
 - Align bottom relative to key object: `CMD` + `Option` + `Ctrl` + `b`
 - Align horzonial center relative to key object: `CMD` + `Option` + `Ctrl` + `h`
 - Align vertical center relative to key object: `CMD` + `Option` + `Ctrl` + `v`
+- Align vertical and horzonial center relative to key object: `CMD` + `Option` + `Ctrl` + `a`
 
 ###Change Shortcut
 Open `AlignTo` directory, then open any `*.sketchplugin` file with text editor. Change shortcut you want in the first line.

utility.js

@@ -64,6 +64,16 @@ function align(direction){
 					[frame setMidX:keyCoordinate]
 				}
 				break;
+			case "center":
+				var getKeyPosition = function(keyFrame) {
+					keyCoordinateX = [keyFrame midX]
+					keyCoordinateY = [keyFrame midY]
+				}
+				var alignObj = function(frame){
+					[frame setMidX:keyCoordinateX]
+					[frame setMidY:keyCoordinateY]
+				}
+				break;
 		}
 
 		var choice = createSelect('Align ' + direction +' relative to', layers, 0)