Merge pull request #49 from yappbox/enhancement/aux-component

Pass verticalOffset to auxiliaryComponent in CollectionScrollView

Author: lukemelia

addon/components/collection-scroll-view/index.hbs

@@ -6,13 +6,11 @@
     @key={{@key}}
     @auxiliaryComponent={{if @auxiliaryComponent
       (component @auxiliaryComponent
-          cell-layout=this.cellLayout
-          items=@items
-          estimated-width=@estimated-width
-          estimated-height=@estimated-height
-          client-width=this.clientWidth
-          client-height=this.clientHeight
-          scroll-top=this.scrollTop
+        cellLayout=this.cellLayout
+        items=@items
+        clientSize=this.collectionClientSize
+        scrollTop=this.collectionScrollTop
+        verticalOffset=this.visibleHeaderHeight
       )
     }}
     @clientSizeChange={{this.clientSizeChange}}
@@ -50,9 +48,9 @@
 
   {{#if @revealService}}
     {{emitter-action
-        emitter=@revealService
-        eventName="revealItemById"
-        action=(fn this.scrollToItem scrollViewApi)
+      emitter=@revealService
+      eventName="revealItemById"
+      action=(fn this.scrollToItem scrollViewApi)
     }}
   {{/if}}
 </ScrollView>

addon/components/collection-scroll-view/index.js

@@ -72,6 +72,11 @@ export default class CollectionScrollView extends Component {
     return Math.max(0, scrollTop - headerHeight);
   }
 
+  get visibleHeaderHeight() {
+    let { headerHeight, scrollTop } = this;
+    return Math.max(0, headerHeight - scrollTop);
+  }
+
   @action updateHeaderDimensions(scrollViewApi, entry) {
     let isFirstMeasure = !this.headerDimensions;
     this.headerDimensions = { width: entry.contentRect.width, height: entry.contentRect.height };