webogram scroll

ui-height.js

      var atBottom = true
      var scrollTopInitial = -1
      $(scrollableWrap).on('scroll', function (e) {
        if (!element.is(':visible') ||
          $(scrollableWrap).hasClass('im_history_to_bottom') ||
          curAnimation) {
          return
        }
        var st = scrollableWrap.scrollTop
        atBottom = st >= scrollableWrap.scrollHeight - scrollableWrap.clientHeight
        if (scrollTopInitial >= 0 && scrollTopInitial != st) {
          scrollTopInitial = -1
        }

        if (!moreNotified && st <= 300) {
          moreNotified = true
          $scope.$emit('history_need_more')
        } else if (!lessNotified && st >= scrollableWrap.scrollHeight - scrollableWrap.clientHeight - 300) {
          lessNotified = true
          $scope.$emit('history_need_less')
        }
      })

      function updateSizes (heightOnly) {
        if (!element.is(':visible') && !$(element[0].parentNode.parentNode).is(':visible')) {
          return
        }
        if ($(sendFormWrap).is(':visible')) {
          if (!sendForm || !sendForm.offsetHeight) {
            sendForm = $('.im_send_form', element)[0]
          }
          $(sendFormWrap).css({
            height: $(sendForm).height()
          })
        }

        if (!headWrap || !headWrap.offsetHeight) {
          headWrap = $('.tg_page_head')[0]
        }
        if (!footer || !footer.offsetHeight) {
          footer = $('.footer_wrap')[0]
        }
        var footerHeight = footer ? footer.offsetHeight : 0
        if (footerHeight) {
          footerHeight++ // Border bottom
        }
        var historyH = $($window).height() - bottomPanelWrap.offsetHeight - (headWrap ? headWrap.offsetHeight : 48) - footerHeight
        $(historyWrap).css({
          height: historyH
        })

        updateBottomizer()

        if (heightOnly === true) return
        if (atBottom) {
          onContentLoaded(function () {
            // console.log('change scroll bottom')
            scrollableWrap.scrollTop = scrollableWrap.scrollHeight
            updateScroller()
          })
        }
        updateScroller(100)
      }

      function updateBottomizer () {
        $(historyMessagesEl).css({marginTop: 0})
        var marginTop = scrollableWrap.offsetHeight -
        historyMessagesEl.offsetHeight -
        emptyWrapEl.offsetHeight -
        (Config.Mobile ? 0 : 39)

        if (historyMessagesEl.offsetHeight > 0 && marginTop > 0) {
          $(historyMessagesEl).css({marginTop: marginTop})
        }
        $(historyWrap).nanoScroller()
      }

      $($window).on('resize', updateSizes)

      updateSizes()

webogram-scroll.js

      $scope.$on('ui_history_prepend', function () {
        var sh = scrollableWrap.scrollHeight
        var st = scrollableWrap.scrollTop
        var pr = parseInt($(scrollableWrap).css('paddingRight'))
        var ch = scrollableWrap.clientHeight

        $(scrollableWrap).addClass('im_history_to_bottom')
        scrollableWrap.scrollHeight // Some strange Chrome bug workaround
        $(scrollable).css({bottom: -(sh - st - ch), paddingRight: pr})

        var upd = function () {
          $(scrollableWrap).removeClass('im_history_to_bottom')
          $(scrollable).css({bottom: '', paddingRight: ''})
          if (scrollTopInitial >= 0) {
            changeScroll()
          } else {
            // console.log('change scroll prepend')
            scrollableWrap.scrollTop = st + scrollableWrap.scrollHeight - sh
          }

          updateBottomizer()
          moreNotified = false

          $timeout(function () {
            if (scrollableWrap.scrollHeight != sh) {
              $(scrollableWrap).trigger('scroll')
            }
          })

          clearTimeout(timer)
          unreg()
        }
        var timer = setTimeout(upd, 0)
        var unreg = $scope.$on('$viewContentLoaded', upd)
      })

      $scope.$on('ui_history_append', function () {
        var sh = scrollableWrap.scrollHeight
        onContentLoaded(function () {
          atBottom = false
          updateBottomizer()
          lessNotified = false

          if (scrollTopInitial >= 0) {
            changeScroll()
          }

          $timeout(function () {
            if (scrollableWrap.scrollHeight != sh) {
              $(scrollableWrap).trigger('scroll')
            }
          })
        })
      })