diff --git a/dist/animations/SlideAnimation.js b/dist/animations/SlideAnimation.js
index 1ee5727..bcb5067 100644
--- a/dist/animations/SlideAnimation.js
+++ b/dist/animations/SlideAnimation.js
@@ -1 +1 @@
-Object.defineProperty(exports,"__esModule",{value:true});var _createClass=function(){function defineProperties(target,props){for(var i=0;i<props.length;i++){var descriptor=props[i];descriptor.enumerable=descriptor.enumerable||false;descriptor.configurable=true;if("value"in descriptor)descriptor.writable=true;Object.defineProperty(target,descriptor.key,descriptor);}}return function(Constructor,protoProps,staticProps){if(protoProps)defineProperties(Constructor.prototype,protoProps);if(staticProps)defineProperties(Constructor,staticProps);return Constructor;};}();var _reactNative=require('react-native');var _Animation2=require('./Animation');var _Animation3=_interopRequireDefault(_Animation2);function _interopRequireDefault(obj){return obj&&obj.__esModule?obj:{default:obj};}function _classCallCheck(instance,Constructor){if(!(instance instanceof Constructor)){throw new TypeError("Cannot call a class as a function");}}function _possibleConstructorReturn(self,call){if(!self){throw new ReferenceError("this hasn't been initialised - super() hasn't been called");}return call&&(typeof call==="object"||typeof call==="function")?call:self;}function _inherits(subClass,superClass){if(typeof superClass!=="function"&&superClass!==null){throw new TypeError("Super expression must either be null or a function, not "+typeof superClass);}subClass.prototype=Object.create(superClass&&superClass.prototype,{constructor:{value:subClass,enumerable:false,writable:true,configurable:true}});if(superClass)Object.setPrototypeOf?Object.setPrototypeOf(subClass,superClass):subClass.__proto__=superClass;}var _Dimensions$get=_reactNative.Dimensions.get('window'),SCREEN_WIDTH=_Dimensions$get.width,SCREEN_HEIGHT=_Dimensions$get.height;var SlideAnimation=function(_Animation){_inherits(SlideAnimation,_Animation);function SlideAnimation(){var _ref=arguments.length>0&&arguments[0]!==undefined?arguments[0]:{},_ref$initialValue=_ref.initialValue,initialValue=_ref$initialValue===undefined?0:_ref$initialValue,_ref$useNativeDriver=_ref.useNativeDriver,useNativeDriver=_ref$useNativeDriver===undefined?true:_ref$useNativeDriver,_ref$slideFrom=_ref.slideFrom,slideFrom=_ref$slideFrom===undefined?'bottom':_ref$slideFrom;_classCallCheck(this,SlideAnimation);var _this=_possibleConstructorReturn(this,(SlideAnimation.__proto__||Object.getPrototypeOf(SlideAnimation)).call(this,{initialValue:initialValue,useNativeDriver:useNativeDriver}));_this.slideFrom=slideFrom;return _this;}_createClass(SlideAnimation,[{key:'in',value:function _in(){var onFinished=arguments.length>0&&arguments[0]!==undefined?arguments[0]:function(){};_reactNative.Animated.spring(this.animate,{toValue:1,velocity:0,tension:65,friction:10,useNativeDriver:this.useNativeDriver}).start(onFinished);}},{key:'out',value:function out(){var onFinished=arguments.length>0&&arguments[0]!==undefined?arguments[0]:function(){};_reactNative.Animated.spring(this.animate,{toValue:0,velocity:0,tension:65,friction:10,useNativeDriver:this.useNativeDriver}).start(onFinished);}},{key:'getAnimations',value:function getAnimations(){var transform=[];if(this.slideFrom==='top'){transform.push({translateY:this.animate.interpolate({inputRange:[0,1],outputRange:[-SCREEN_HEIGHT,0]})});}if(this.slideFrom==='bottom'){transform.push({translateY:this.animate.interpolate({inputRange:[0,1],outputRange:[SCREEN_HEIGHT,0]})});}if(this.slideFrom==='left'){transform.push({translateX:this.animate.interpolate({inputRange:[0,1],outputRange:[-SCREEN_WIDTH,0]})});}if(this.slideFrom==='right'){transform.push({translateX:this.animate.interpolate({inputRange:[0,1],outputRange:[SCREEN_WIDTH,0]})});}return{transform:transform};}}]);return SlideAnimation;}(_Animation3.default);exports.default=SlideAnimation;
\ No newline at end of file
+Object.defineProperty(exports,"__esModule",{value:true});var _createClass=function(){function defineProperties(target,props){for(var i=0;i<props.length;i++){var descriptor=props[i];descriptor.enumerable=descriptor.enumerable||false;descriptor.configurable=true;if("value"in descriptor)descriptor.writable=true;Object.defineProperty(target,descriptor.key,descriptor);}}return function(Constructor,protoProps,staticProps){if(protoProps)defineProperties(Constructor.prototype,protoProps);if(staticProps)defineProperties(Constructor,staticProps);return Constructor;};}();var _reactNative=require('react-native');var _Animation2=require('./Animation');var _Animation3=_interopRequireDefault(_Animation2);function _interopRequireDefault(obj){return obj&&obj.__esModule?obj:{default:obj};}function _classCallCheck(instance,Constructor){if(!(instance instanceof Constructor)){throw new TypeError("Cannot call a class as a function");}}function _possibleConstructorReturn(self,call){if(!self){throw new ReferenceError("this hasn't been initialised - super() hasn't been called");}return call&&(typeof call==="object"||typeof call==="function")?call:self;}function _inherits(subClass,superClass){if(typeof superClass!=="function"&&superClass!==null){throw new TypeError("Super expression must either be null or a function, not "+typeof superClass);}subClass.prototype=Object.create(superClass&&superClass.prototype,{constructor:{value:subClass,enumerable:false,writable:true,configurable:true}});if(superClass)Object.setPrototypeOf?Object.setPrototypeOf(subClass,superClass):subClass.__proto__=superClass;}var _Dimensions$get=_reactNative.Dimensions.get('window'),SCREEN_WIDTH=_Dimensions$get.width,SCREEN_HEIGHT=_Dimensions$get.height;var SlideAnimation=function(_Animation){_inherits(SlideAnimation,_Animation);function SlideAnimation(){var _ref=arguments.length>0&&arguments[0]!==undefined?arguments[0]:{},_ref$initialValue=_ref.initialValue,initialValue=_ref$initialValue===undefined?0:_ref$initialValue,_ref$useNativeDriver=_ref.useNativeDriver,useNativeDriver=_ref$useNativeDriver===undefined?true:_ref$useNativeDriver,_ref$slideFrom=_ref.slideFrom,slideFrom=_ref$slideFrom===undefined?SlideAnimation.SLIDE_FROM_BOTTOM:_ref$slideFrom;_classCallCheck(this,SlideAnimation);var _this=_possibleConstructorReturn(this,(SlideAnimation.__proto__||Object.getPrototypeOf(SlideAnimation)).call(this,{initialValue:initialValue,useNativeDriver:useNativeDriver}));_this.slideFrom=slideFrom;return _this;}_createClass(SlideAnimation,[{key:'in',value:function _in(){var onFinished=arguments.length>0&&arguments[0]!==undefined?arguments[0]:function(){};_reactNative.Animated.spring(this.animate,{toValue:1,velocity:0,tension:65,friction:10,useNativeDriver:this.useNativeDriver}).start(onFinished);}},{key:'out',value:function out(){var onFinished=arguments.length>0&&arguments[0]!==undefined?arguments[0]:function(){};_reactNative.Animated.spring(this.animate,{toValue:0,velocity:0,tension:65,friction:10,useNativeDriver:this.useNativeDriver}).start(onFinished);}},{key:'getAnimations',value:function getAnimations(){var transform=[];if(this.slideFrom===SlideAnimation.SLIDE_FROM_TOP){transform.push({translateY:this.animate.interpolate({inputRange:[0,1],outputRange:[-SCREEN_HEIGHT,0]})});}else if(this.slideFrom===SlideAnimation.SLIDE_FROM_BOTTOM){transform.push({translateY:this.animate.interpolate({inputRange:[0,1],outputRange:[SCREEN_HEIGHT,0]})});}else if(this.slideFrom===SlideAnimation.SLIDE_FROM_LEFT){transform.push({translateX:this.animate.interpolate({inputRange:[0,1],outputRange:[-SCREEN_WIDTH,0]})});}else if(this.slideFrom===SlideAnimation.SLIDE_FROM_RIGHT){transform.push({translateX:this.animate.interpolate({inputRange:[0,1],outputRange:[SCREEN_WIDTH,0]})});}else{throw new Error('\n        slideFrom: '+this.slideFrom+' not supported. \'slideFrom\' must be \'top\' | \'bottom\' | \'left\' | \'right\'\n      ');}return{transform:transform};}}]);return SlideAnimation;}(_Animation3.default);SlideAnimation.SLIDE_FROM_TOP='top';SlideAnimation.SLIDE_FROM_BOTTOM='bottom';SlideAnimation.SLIDE_FROM_LEFT='left';SlideAnimation.SLIDE_FROM_RIGHT='right';exports.default=SlideAnimation;
\ No newline at end of file
diff --git a/src/animations/SlideAnimation.js b/src/animations/SlideAnimation.js
index f055ec2..ee4e7c5 100644
--- a/src/animations/SlideAnimation.js
+++ b/src/animations/SlideAnimation.js
@@ -3,20 +3,28 @@
 import { Animated, Dimensions } from 'react-native';
 import Animation, { type AnimationConfig } from './Animation';
 
+const {
+  width: SCREEN_WIDTH,
+  height: SCREEN_HEIGHT,
+} = Dimensions.get('window');
+
 type SlideFrom = 'top' | 'bottom' | 'left' | 'right';
 type SlideAnimationConfig = AnimationConfig & {
   slideFrom?: SlideFrom,
 }
 
-const { width: SCREEN_WIDTH, height: SCREEN_HEIGHT } = Dimensions.get('window');
-
 export default class SlideAnimation extends Animation {
-  slideFrom: SlideFrom
+  slideFrom: SlideFrom;
+
+  static SLIDE_FROM_TOP = 'top';
+  static SLIDE_FROM_BOTTOM = 'bottom';
+  static SLIDE_FROM_LEFT = 'left';
+  static SLIDE_FROM_RIGHT = 'right';
 
   constructor({
     initialValue = 0,
     useNativeDriver = true,
-    slideFrom = 'bottom',
+    slideFrom = SlideAnimation.SLIDE_FROM_BOTTOM,
   }: SlideAnimationConfig = {}) {
     super({ initialValue, useNativeDriver });
     this.slideFrom = slideFrom;
@@ -44,37 +52,38 @@ export default class SlideAnimation extends Animation {
 
   getAnimations(): Object {
     const transform = [];
-    if (this.slideFrom === 'top') {
+    if (this.slideFrom === SlideAnimation.SLIDE_FROM_TOP) {
       transform.push({
         translateY: this.animate.interpolate({
           inputRange: [0, 1],
           outputRange: [-SCREEN_HEIGHT, 0],
         }),
       });
-    }
-    if (this.slideFrom === 'bottom') {
+    } else if (this.slideFrom === SlideAnimation.SLIDE_FROM_BOTTOM) {
       transform.push({
         translateY: this.animate.interpolate({
           inputRange: [0, 1],
           outputRange: [SCREEN_HEIGHT, 0],
         }),
       });
-    }
-    if (this.slideFrom === 'left') {
+    } else if (this.slideFrom === SlideAnimation.SLIDE_FROM_LEFT) {
       transform.push({
         translateX: this.animate.interpolate({
           inputRange: [0, 1],
           outputRange: [-SCREEN_WIDTH, 0],
         }),
       });
-    }
-    if (this.slideFrom === 'right') {
+    } else if (this.slideFrom === SlideAnimation.SLIDE_FROM_RIGHT) {
       transform.push({
         translateX: this.animate.interpolate({
           inputRange: [0, 1],
           outputRange: [SCREEN_WIDTH, 0],
         }),
       });
+    } else {
+      throw new Error(`
+        slideFrom: ${this.slideFrom} not supported. 'slideFrom' must be 'top' | 'bottom' | 'left' | 'right'
+      `);
     }
     return {
       transform,