fix(virtualRepeat): Do not scroll past bottom Fixes #6279 Might also fix #4169

  Closes #6990

Author: kseamon

src/components/virtualRepeat/virtual-repeater.js

@@ -346,23 +346,23 @@ VirtualRepeatContainerController.prototype.resetScroll = function() {
 
 VirtualRepeatContainerController.prototype.handleScroll_ = function() {
   var offset = this.isHorizontal() ? this.scroller.scrollLeft : this.scroller.scrollTop;
-  if (offset === this.scrollOffset) return;
+  if (offset === this.scrollOffset || offset > this.scrollSize - this.size) return;
 
   var itemSize = this.repeater.getItemSize();
   if (!itemSize) return;
 
   var numItems = Math.max(0, Math.floor(offset / itemSize) - NUM_EXTRA);
 
-  var transform = this.isHorizontal() ? 'translateX(' : 'translateY(';
-      transform +=  (numItems * itemSize) + 'px)';
+  var transform = (this.isHorizontal() ? 'translateX(' : 'translateY(') +
+                  (numItems * itemSize) + 'px)';
 
   this.scrollOffset = offset;
   this.offsetter.style.webkitTransform = transform;
   this.offsetter.style.transform = transform;
 
   if (this.bindTopIndex) {
     var topIndex = Math.floor(offset / itemSize);
-    if (topIndex !== this.topIndex && topIndex < this.repeater.itemsLength) {
+    if (topIndex !== this.topIndex && topIndex < this.repeater.getItemCount()) {
       this.topIndex = topIndex;
       this.bindTopIndex.assign(this.$scope, topIndex);
       if (!this.$rootScope.$$phase) this.$scope.$digest();
@@ -627,6 +627,15 @@ VirtualRepeatController.prototype.getItemSize = function() {
 };
 
 
+/**
+ * Called by the container. Returns the size of a single repeated item.
+ * @return {?number} Size of a repeated item.
+ */
+VirtualRepeatController.prototype.getItemCount = function() {
+  return this.itemsLength;
+};
+
+
 /**
  * Updates the order and visible offset of repeated blocks in response to scrolling
  * or items updates.

src/components/virtualRepeat/virtual-repeater.spec.js

@@ -616,6 +616,21 @@ describe('<md-virtual-repeat>', function() {
     expect(offsetter.children().length).toBe(3);
   }));
 
+  it('should not scroll past the bottom', function() {
+    scope.items = createItems(101);
+    createRepeater();
+
+    scroller[0].scrollTop = ITEM_SIZE * 91;
+    scroller.triggerHandler('scroll');
+
+    expect(getTransform(offsetter)).toBe('translateY(880px)');
+
+    scroller[0].scrollTop++;
+    scroller.triggerHandler('scroll');
+
+    expect(getTransform(offsetter)).toBe('translateY(880px)');
+  });
+
   /**
    * Facade to access transform properly even when jQuery is used;
    * since jQuery's css function is obtaining the computed style (not wanted)