minIndex modified by the datasource

Author: mfeingold

demo/examples/customviewport.html

@@ -13,11 +13,11 @@
 <h2 style="position: fixed; left: 150px; top: 0;">is loading: {{loading}}; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="../index.html"> browse sample code</a></h2>
 <h2> The list </h2>
 <div ui-scroll-viewport style="height:200px">
-    <div ui-scroll="item in datasource" is-loading="loading" buffer-size='4'>*one {{item}}*</div>
+    <div id="1" ui-scroll="item in datasource" is-loading="loading" buffer-size='4'>*one {{item}}*</div>
 </div>
 <h2> One more list </h2>
 <div ui-scroll-viewport style="height:200px; border-style: solid; border-width: 1px;">
-    <div ui-scroll="item in datasource" is-loading="loading">
+    <div id="2" ui-scroll="item in datasource" is-loading="loading">
 			*two {{item}}*
 		<ul ng-hide="parseInt(item.substring(9))%6" class="div-ul">
 			<li ng-repeat="line in ['line1','line2','line3']">{{line}}</li>

src/ui-scroll.coffee

@@ -128,19 +128,16 @@ angular.module('ui.scroll', [])
 			reset()
 
 			buffer.minIndex = (value) ->
-				#console.log "before ds #{datasource.minIndex} local #{buffer.localMinIndex}"
 				if arguments.length
 					if buffer.bof
 						datasource.minIndex = value
 					else
 						datasource.minIndex = Math.min value, datasource.minIndex || Number.MAX_VALUE
 					buffer.localMinIndex = datasource.minIndex
-					#console.log "after ds #{datasource.minIndex} local #{buffer.localMinIndex}"
 				else
 					offset = buffer.localMinIndex - (datasource.minIndex || origin)
 					buffer.localMinIndex -= offset
-					#console.log "after ds #{datasource.minIndex} local #{buffer.localMinIndex} , #{offset}"
-					offset: offset
+					offset: offset #if minIndex is decremented outside of the scroller offset value is by how much
 					value: buffer.localMinIndex
 
 			buffer.maxIndex  = -> datasource.maxIndex || origin
@@ -171,7 +168,7 @@ angular.module('ui.scroll', [])
 			topPadding = null
 			bottomPadding = null
 
-			bufferPadding = -> viewport.outerHeight() * Math.max(0.1, +padding || 0.1) # some extra space to initiate preload
+			bufferPadding = -> viewport.outerHeight() * Math.max(0.1, +padding.padding || 0.1) # some extra space to initiate preload
 
 			viewport.createPaddingElements = (template) ->
 				topPadding = new Padding template
@@ -198,7 +195,6 @@ angular.module('ui.scroll', [])
 			viewport.clipBottom = ->
 				# clip the invisible items off the bottom
 				overage = 0
-				#calculateAverageItemHeight()
 				overageBottom = viewport.outerHeight() + viewport.averageItemHeight * (buffer.size)
 				for i in [buffer.length-1..0]
 					item = buffer[i]
@@ -217,7 +213,6 @@ angular.module('ui.scroll', [])
 				# clip the invisible items off the top
 				overage = 0
 				heightIncrement = 0
-				#calculateAverageItemHeight()
 				overageTop = (-1) * viewport.averageItemHeight * buffer.size
 				for item in buffer
 					if item.element.offset().top < overageTop
@@ -229,21 +224,16 @@ angular.module('ui.scroll', [])
 					buffer.remove(0, overage)
 					buffer.first += overage
 
-			calculateAverageItemHeight = () ->
-				viewport.averageItemHeight = 0
+			viewport.adjustPadding = () ->
 				return if not buffer.length
 				viewport.averageItemHeight = (buffer[buffer.length-1].element.offset().top +
 					buffer[buffer.length-1].element.outerHeight(true) -
 					buffer[0].element.offset().top) / buffer.length
-				console.log "avg #{viewport.averageItemHeight}"
-
-			viewport.adjustPadding = () ->
-				return if not buffer.length
-				calculateAverageItemHeight()
 				minIndex = buffer.minIndex()
-				#console.log "offs #{minIndex.offset}"
-				viewport.adjustScrollTop(minIndex.offset * viewport.averageItemHeight)
 				topPadding.height (buffer.first - minIndex.value) * viewport.averageItemHeight
+				if minIndex.offset
+					viewport.scrollTop(minIndex.offset * viewport.averageItemHeight)
+				#console.log "id #{padding.id} min #{minIndex.value} top #{viewport.scrollTop()} offs #{minIndex.offset * viewport.averageItemHeight}"
 				bottomPadding.height (buffer.maxIndex() - buffer.next + 1) * viewport.averageItemHeight
 
 			viewport.adjustScrollTop = (height) ->
@@ -366,7 +356,7 @@ angular.module('ui.scroll', [])
 
 				buffer = new Buffer(itemName, $scope, linker, datasource, bufferSize)
 
-				viewport = new Viewport(buffer, element, controllers, $attr.padding)
+				viewport = new Viewport(buffer, element, controllers, $attr)
 
 				adapter = new Adapter $attr, viewport, buffer,
 					->
@@ -452,7 +442,7 @@ angular.module('ui.scroll', [])
 						for wrapper in toBePrepended
 							keepFetching = insertWrapperContent(wrapper) || keepFetching
 							wrapper.op = 'none'
-							adjustedPaddingHeight += wrapper.element.height()
+							adjustedPaddingHeight += wrapper.element.outerHeight(true)
 						viewport.adjustScrollTop(adjustedPaddingHeight)
 
 					# re-index the buffer
@@ -543,7 +533,6 @@ angular.module('ui.scroll', [])
 								buffer.minIndex buffer.first
 								adjustBufferAfterFetch rid
 
-
 				# events and bindings
 
 				resizeAndScrollHandler = ->