Merge pull request #27 from ethwitt/ethan-changes

Fix track style error and alter beforeChange signature

Author: chrishinrichs

README.md

@@ -113,7 +113,7 @@ content.
 `PropTypes.func`
 
 Optional callback which will be invoked before a slide change occurs. Should have method signature
-`function(newIndex, prevIndex)`
+`function(newIndex, prevIndex, direction)`
 
 #### afterChange
 `PropTypes.func`

src/index.js

@@ -272,7 +272,7 @@ export default class Carousel extends Component {
 
     this._animating = true;
 
-    beforeChange && beforeChange(index, currentSlide);
+    beforeChange && beforeChange(index, currentSlide, direction);
     this.setState({
       transitionDuration
     }, () => {
@@ -386,7 +386,7 @@ export default class Carousel extends Component {
       width: viewportWidth,
       height: viewportHeight || slideHeight || 'auto'
     });
-    let trackStyle = style.track || {};
+    let trackStyle = merge({}, style.track || {});
     if (transition !== 'fade') {
       const leftPos = leftOffset + dragOffset;
       trackStyle = merge({}, trackStyle, {