Loadmoreable.rb

module ProMotion
  module Table
    module LoadmoreClassMethods
      def load_moreable=(val)
        @load_moreable = val
      end
      def load_moreable
        @load_moreable || false
      end
      def load_more_options=(val)
        @load_more_options = val
      end
      def load_more_options
        @load_more_options || false
      end

      def loadmoreable(options={})
        self.load_moreable = true
        self.load_more_options = options
      end
    end

    module Loadmoreable
      def loadmore_footer_view
        return @footerview if @footerview.present?
        @footerview = UIView.alloc.initWithFrame(CGRectMake(0,0,self.view.frame.size.width,footerLoadMoreHeight))
        @load_more_label = UILabel.alloc.initWithFrame(CGRectMake(0,15,self.view.frame.size.width,footerLoadMoreHeight-15))
        @load_more_label.text = @options[:pull_message]
        @load_more_label.textAlignment = NSTextAlignmentCenter 
        @footerview.addSubview(@load_more_label)
        @footerview
        @footerview
      end

      def load_footer_active
        @footer_activity_view = UIActivityIndicatorView.alloc.initWithActivityIndicatorStyle(UIActivityIndicatorViewStyleGray)
        @footerview.addSubview(@footer_activity_view)
        @load_more_label.text = @options[:loading_message]
        @footer_activity_view.frame = CGRectMake((self.view.frame.size.width/2)-10,10,20,20)
        @footer_activity_view.startAnimating
      end

      def start_load_more
        @isLoadingMore = true
        load_footer_active
        self.send(@options[:callback])
      end

      def done_load_more
        @isLoadingMore = false
        hide_footer
      end

      def load_more
        done_load_more
      end

      def screen_setup
        super
        set_up_loademoreable
      end

      def canLoadMore(scrollView)
        offset = scrollView.contentInset.top
        offsetBottom = scrollView.contentInset.bottom
        contentHeight = scrollView.contentSize.height
        viewPortHeight = scrollView.frame.size.height
        scrollPosition = scrollView.contentOffset.y
        (contentHeight+offset+offsetBottom > viewPortHeight)
      end

      def set_up_loademoreable
        if self.class.load_moreable
          @loadingMore = false
          @isLoadingMore = false
          self.make_loadmoreable(self.class.load_more_options)
        end
      end

      def loadmore_defaults
        {
          :callback => :load_more,
          :pull_message => "Pull to Load More...",
          :loading_message => "Loading More"
        }
      end

      def make_loadmoreable(params={})
        @options = loadmore_defaults.merge(params)
        self.tableView.setDelegate(self)
      end

      def footerLoadMoreHeight
          70
      end
      def show_footer
        unless @footerVisible
          @footerVisible = true
          self.tableView.tableFooterView = self.loadmore_footer_view
        end
      end
      def hide_footer
        if @footerVisible
          scrollView = self.tableView
          offset = scrollView.contentInset.top
          offsetBottom = scrollView.contentInset.bottom
          contentHeight = scrollView.contentSize.height
          viewPortHeight = scrollView.frame.size.height
          scrollPosition = scrollView.contentOffset.y
          positionBottom =  contentHeight-(viewPortHeight-offsetBottom)-footerLoadMoreHeight
          UIView.animateWithDuration 0.4, animations:lambda {
            self.tableView.setContentOffset(CGPointMake(0, positionBottom), animated:false)
          }, completion:lambda {|finished|
            self.tableView.tableFooterView = nil
            @footer_activity_view.removeFromSuperview if @footer_activity_view.present?
            @load_more_label.text = @options[:pull_message] if @load_more_label.present?
            @footerVisible = false
          } 
          
        end
      end
      def scrollViewDidEndDragging(scrollView, willDecelerate:decel)
        if superclass.respond_to?(:scrollViewDidScroll)
          super(scrollView)
        end
        offset = scrollView.contentInset.top
        offsetBottom = scrollView.contentInset.bottom
        contentHeight = scrollView.contentSize.height
        viewPortHeight = scrollView.frame.size.height
        scrollPosition = scrollView.contentOffset.y
        positionBottom = contentHeight-viewPortHeight-scrollPosition+offsetBottom
        if @footerVisible 
          if positionBottom < 0
            start_load_more
          else
            unless decel
              hide_footer
            end
          end
        end
      end

  


      def scrollViewDidScroll(scrollView)
        if superclass.respond_to?(:scrollViewDidScroll)
          super(scrollView)
        end
        if scrollView.contentSize.height > 0
          if canLoadMore(scrollView)
            offset = scrollView.contentInset.top
            offsetBottom = scrollView.contentInset.bottom
            contentHeight = scrollView.contentSize.height
            viewPortHeight = scrollView.frame.size.height
            scrollPosition = scrollView.contentOffset.y
            positionBottom = contentHeight-viewPortHeight-scrollPosition+offsetBottom
            if positionBottom < 0
              unless @footerVisible
                show_footer
              end
            else
              
            end
          end
        end
      end



      def self.included(base)
        base.extend(ProMotion::Table::LoadmoreClassMethods)
      end
    end
  end
end