openproject/frontend/app/timelines/models/mixins/ui.js

//-- copyright
// OpenProject is a project management system.
// Copyright (C) 2012-2015 the OpenProject Foundation (OPF)
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License version 3.
//
// OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
// Copyright (C) 2006-2013 Jean-Philippe Lang
// Copyright (C) 2010-2013 the ChiliProject Team
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// See doc/COPYRIGHT.rdoc for more details.
//++

// ╭───────────────────────────────────────────────────────────────╮
// │  _____ _                _ _                                   │
// │ |_   _(_)_ __ ___   ___| (_)_ __   ___  ___                   │
// │   | | | | '_ ` _ \ / _ \ | | '_ \ / _ \/ __|                  │
// │   | | | | | | | | |  __/ | | | | |  __/\__ \                  │
// │   |_| |_|_| |_| |_|\___|_|_|_| |_|\___||___/                  │
// ├───────────────────────────────────────────────────────────────┤
// │ Javascript library that fetches and plots timelines for the   │
// │ OpenProject timelines module.                                 │
// ╰───────────────────────────────────────────────────────────────╯

module.exports = function($timeout) {

  // ╭───────────────────────────────────────────────────────────────────╮
  // │ UI and Plotting                                                   │
  // ╰───────────────────────────────────────────────────────────────────╯

  var UI = {

    DEFAULT_COLOR: '#999999',
    DEFAULT_FILL_COLOR_IN_COMPARISONS: 'none',
    DEFAULT_LANE_COLOR: '#000000',
    DEFAULT_LANE_WIDTH: 1,
    DEFAULT_PARENT_COLOR: '#666666',
    DEFAULT_STROKE_COLOR: '#000000',
    DEFAULT_STROKE_COLOR_IN_COMPARISONS: '#000000',
    DEFAULT_STROKE_DASHARRAY_IN_COMPARISONS: '', // other examples: '-', '- ', '-- '
    DEFAULT_COMPARISON_OFFSET: 5,

    DAY_WIDTH: 16,

    MIN_CHART_WIDTH: 200,
    RENDER_BUCKET_SIZE: 32,
    ORIGINAL_BORDER_WIDTH_CORRECTION: 3,
    BORDER_WIDTH_CORRECTION: 3,
    HOVER_THRESHOLD: 3,

    GROUP_BAR_INDENT: -10,

    PE_DARK_TEXT_COLOR: '#000000',    // color on light planning element.
    PE_DEFAULT_TEXT_COLOR: '#000000', // color on timelines background.
    PE_HEIGHT: 20,
    PE_LIGHT_TEXT_COLOR: '#ffffff',   // color on dark planning element.
    PE_LUMINANCE_THRESHOLD: 0.5,      // threshold above which dark text is rendered.
    PE_TEXT_ADDITIONAL_OUTSIDE_PADDING_WHEN_MILESTONE: 6,
    PE_TEXT_ADDITIONAL_OUTSIDE_PADDING_WHEN_EXPANDED_WITH_CHILDREN: 6,
    PE_TEXT_INSIDE_PADDING: 8,        // 4px padding on both sides of the planning element towards an inside labelelement towards an inside label.
    PE_TEXT_OUTSIDE_PADDING: 6,       // space between planning element and text to its right.
    PE_TEXT_AGGREGATED_LABEL_WIDTH_THRESHOLD: 5,

    USE_MODALS: true,

    scale: 1,
    zoomIndex: 0,

    // OUTLINE_LEVELS define possible OUTLINE_CONFIGURATIONS.
    OUTLINE_LEVELS: ['aggregation', 'level1', 'level2', 'level3', 'level4', 'level5', 'all'],
    OUTLINE_CONFIGURATIONS: {
      aggregation: { name: 'timelines.outlines.aggregation', level: 0 },
      level1:      { name: 'timelines.outlines.level1',      level: 1 },
      level2:      { name: 'timelines.outlines.level2',      level: 2 },
      level3:      { name: 'timelines.outlines.level3',      level: 3 },
      level4:      { name: 'timelines.outlines.level4',      level: 4 },
      level5:      { name: 'timelines.outlines.level5',      level: 5 },
      all:         { name: 'timelines.outlines.all',         level: Infinity }
    },

    // ZOOM_SCALES define possible ZOOM_CONFIGURATIONS.
    ZOOM_SCALES: ['yearly', 'quarterly', 'monthly', 'weekly', 'daily'],
    ZOOM_CONFIGURATIONS: {
      daily:     {name: 'timelines.zoom.days',     scale: 1.40, config: ['months', 'weeks', 'actualDays', 'weekDays']},
      weekly:    {name: 'timelines.zoom.weeks',    scale: 0.89, config: ['months', 'weeks', 'weekDays']},
      monthly:   {name: 'timelines.zoom.months',   scale: 0.53, config: ['years', 'months', 'weeks']},
      quarterly: {name: 'timelines.zoom.quarters', scale: 0.21, config: ['year-quarters', 'months', 'weeks']},
      yearly:    {name: 'timelines.zoom.years',    scale: 0.10, config: ['years', 'quarters', 'months']}
    },
    getScale: function() {
      var day = this.DAY_WIDTH * this.scale;
      var week = day * 7;
      var height = Timeline.PE_HEIGHT;

      return {
        height: height,
        week: week,
        day: day
      };
    },
    setScale: function(scale) {
      // returns width for specified scale
      if (!scale) {
        scale = this.scale;
      } else {
        this.scale = scale;
      }

      return this.getDaysForCurrentScale();
    },
    getDaysForCurrentScale: function() {
      var days = this.getDaysBetween(
        this.getBeginning(),
        this.getEnd()
      );
      return days * this.DAY_WIDTH * this.scale;
    },
    getWidth: function() {

      // width is the wider of the currently visible chart dimensions
      // (adjusted_width) and the minimum space the timeline needs.
      return Math.max(this.adjusted_width, this.getDaysForCurrentScale() + 200);
    },
    resetWidth: function() {
      delete this.adjusted_width;
    },
    adjustWidth: function(width) {
      // adjusts for the currently visible chart dimensions.
      var old_adjusted_width = this.adjusted_width;

      this.adjusted_width = this.adjusted_width === undefined?
        width: Math.max(old_adjusted_width, Math.max(width, this.adjusted_width));

      if (old_adjusted_width < this.adjusted_width) {
        this.rebuildAll();
      }

      return this.adjusted_width;
    },
    getHeight: function() {
      return this.getMeasuredHeight() - this.getMeasuredScrollbarHeight();
    },
    scaleToFit: function(width) {
      var scale = width / (this.DAY_WIDTH * this.getDaysBetween(
        this.getBeginning(),
        this.getEnd()
      ));
      this.setScale(scale);
      return scale;
    },
    getColorParts: function(color) {
      return jQuery.map(color.match(/[0-9a-fA-F]{2}/g), function(e, i) {
        return parseInt(e, 16);
      });
    },
    getLuminanceFor: function(color) {
      var parts = this.getColorParts(color);
      var result = (0.299 * parts[0] + 0.587 * parts[1] + 0.114 * parts[2]) / 256;
      return result;
    },
    expandTo: function(index) {
      var outlineLevel;
      index = Math.max(index, 0);
      this.expansionIndex = index;
      this.expandToOutlineLevel(Timeline.OUTLINE_LEVELS[index]);
    },
    expandToOutlineLevel: function(outlineLevel) {
      var currentOutlineConfig = Timeline.OUTLINE_CONFIGURATIONS[outlineLevel];
      if(currentOutlineConfig) {
        var level = currentOutlineConfig.level;
        if (this.options.hide_tree_root) {
          level++;
        }
        level = this.getLefthandTree().expandTo(level);
        this.rebuildAll();
      }
    },
    zoom: function(index) {
      if (index === undefined) {
        index = this.zoomIndex;
      }
      index = Math.max(Math.min(this.ZOOM_SCALES.length - 1, index), 0);
      var zoomScale = this.ZOOM_SCALES[index];
      var scale = this.ZOOM_CONFIGURATIONS[zoomScale].scale;

      this.zoomIndex = index;
      this.scale = scale;

      this.resetWidth();
      this.triggerResize();
      this.rebuildAll();
    },
    zoomIn: function() {
      this.zoom(this.zoomIndex + 1);
    },
    zoomOut: function() {
      this.zoom(this.zoomIndex - 1);
    },
    getSwimlaneStyles: function() {
      return [{
          textColor: '#000000',
          laneColor: '#e7e7e7'
        }, {
          textColor: '#000000',
          laneColor: '#797979'
        }, {
          // laneWidth: 1.5,
          textColor: '#000000',
          laneColor: '#424242'
        }, {
          // laneWidth: 2,
          textColor: '#000000',
          laneColor: '#000000'
        }];
    },
    getSwimlaneConfiguration: function() {
      return {
        'actualDays': {
          // actual days
          delimiter: this.getBeginning().moveToFirstDayOfMonth().moveToDayOfWeek(Date.CultureInfo.firstDayOfWeek, -1),
          caption: function() { return this.delimiter.toString('d'); },
          next: function() { return this.delimiter.addDays(1); },
          overrides: ['weekDays']
        },
        'weekDays': {
          // weekdays
          delimiter: this.getBeginning().moveToFirstDayOfMonth().moveToDayOfWeek(Date.CultureInfo.firstDayOfWeek, -1),
          caption: function() { return this.delimiter.toString('ddd')[0]; },
          next: function() { return this.delimiter.addDays(1); },
          overrides: ['actualDays']
        },
        'weeks': {
          // weeks
          delimiter: this.getBeginning().moveToFirstDayOfMonth().moveToDayOfWeek(Date.CultureInfo.firstDayOfWeek, -1),
          caption: function() { return this.delimiter.getWeekOfYear(); },
          next: function() { return this.delimiter.addWeeks(1); },
          overrides: ['weekDays', 'actualDays']
        },
        'months': {
          // months
          delimiter: this.getBeginning().moveToFirstDayOfMonth(),
          caption: function() { return Date.CultureInfo.abbreviatedMonthNames[this.delimiter.getMonth()]; },
          next: function() { return this.delimiter.addMonths(1); },
          overrides: ['actualDays', 'weekDays', 'quarters']
        },
        'year-quarters': {
          // quarters
          delimiter: this.getBeginning().moveToMonth(0, -1).moveToFirstDayOfMonth(),
          caption: function() { return Date.CultureInfo.abbreviatedQuarterNames[this.delimiter.getQuarter()] + " " + this.delimiter.toString('yyyy'); },
          next: function() { return this.delimiter.addQuarters(1); },
          overrides: ['actualDays', 'weekDays', 'months', 'quarters']
        },
        'quarters': {
          // quarters
          delimiter: this.getBeginning().moveToMonth(0, -1).moveToFirstDayOfMonth(),
          caption: function() { return Date.CultureInfo.abbreviatedQuarterNames[this.delimiter.getQuarter()]; },
          next: function() { return this.delimiter.addQuarters(1); },
          overrides: ['actualDays', 'weekDays', 'months']
        },
        'years': {
          // years
          delimiter: this.getBeginning().moveToMonth(0, -1).moveToFirstDayOfMonth(),
          caption: function() { return this.delimiter.toString('yyyy'); },
          next: function() { return this.delimiter.addYears(1); },
          overrides: ['actualDays', 'weekDays', 'months', 'quarters']
        }};
    },
    getUiRoot: function() {
      return this.uiRoot;
    },
    getEventHandlerSuffix: function() {
      if (this.event_handler_suffix === undefined) {
        this.event_handler_suffix = this.getUiRoot().attr('id');
      }
      return this.event_handler_suffix;
    },
    getTooltip: function() {
      var tooltip = this.getUiRoot().find('.tl-tooltip');

      return tooltip;
    },
    getChart: function() {
      return this.getUiRoot().find('.tl-chart');
    },
    getMeasuredHeight: function() {
      return this.getUiRoot().find('.tl-left-main').height();
    },
    getMeasuredScrollbarHeight: function() {
      var p, div, h, hh;

      // this method is built on the assumption that the width of a
      // vertical scrollbar is equal o the height of a horizontal one. if
      // that symmetry is broken, this method will need to be repaired.

      if (this.scrollbar_height !== undefined) {
        return this.scrollbar_height;
      }

      p = jQuery('<p/>').css({
        'width':  "100%",
        'height': "200px"
      });

      div = jQuery('<div/>').css({
        'position':   "absolute",
        'top':        "0",
        'left':       "0",
        'visibility': "hidden",
        'width':      "200px",
        'height':     "150px",
        'overflow':   "hidden"
      });

      div.append(p);
      jQuery('body').append(div);
      h = p[0].offsetWidth;
      div.css({'overflow': 'scroll'});
      hh = p[0].offsetWidth;
      if (h === hh) {
        hh = div[0].clientWidth;
      }
      div.remove();

      this.scrollbar_height = (h - hh);
      return this.scrollbar_height;
    },
    escape: function(string) {
      return jQuery('<div/>').text(string).html();
    },
    psub: function(string, map) {
      return string.replace(/#\{(.+?)\}/g, function(m, p, o, s) { return map[p]; });
    },
    pnum: function(string) {
      return parseInt(string.replace(/[^\d\-]/g, ''), 10);
    },
    /**
     * Filter helper for multi select filters based on IDs.
     *
     * Assumption is that array is an array of strings while object is a object
     * with an id field which contains a number
     */
    filterOutBasedOnArray: function (array, object) {
      return !Timeline.idInArray(array, object);
    },
    idInArray: function (array, object) {
      // when object is not set, check if the (none) a.k.a. -1 option is selected
      var id = object ? object.id + '' : '-1';

      if (jQuery.isArray(array) && array.length > 0) {
        return jQuery.inArray(id, array) !== -1;
      }
      else {
        // if there is no array, we just accept.
        return true;
      }
    },

    rebuildAll: function() {
      var timeline = this;
      var root = timeline.getUiRoot();

      delete this.table_offset;

      $timeout.cancel(this.rebuildTimeout);
      this.rebuildTimeout = $timeout(function() {
        // The minimum width of the whole timeline should be the actual
        // width of the table added to the minimum chart width. That way,
        // the floats never break.

        if (timeline.options.hide_chart === null) {
          root.find('.timeline').css({
            'min-width': root.find('.tl-left-main').width() +
                           Timeline.MIN_CHART_WIDTH
          });
        }

        if (timeline.options.hide_chart !== 'yes') {
          timeline.rebuildGraph();
        } else {
          var chart = timeline.getUiRoot().find('.tl-chart');
          chart.css({ display: 'none'});
        }
        timeline.adjustScrollingForChangedContent();
      });
    },

    adjustScrollingForChangedContent: function() {
      var current_height = Math.max(jQuery("body").height(), jQuery("#content").height());
      if(current_height < jQuery(window).scrollTop()) {
        jQuery(window).scrollTop(current_height - jQuery(window).height());
      }
    },
    scrollbarBox: function() {
      var scrollbar_height = this.getMeasuredScrollbarHeight();
      return jQuery('<div class="tl-invisible"/>').css({
        'height': scrollbar_height,
        'width':  scrollbar_height
      });
    },
    decoHeight: function() {
      var config = Timeline.ZOOM_SCALES[this.zoomIndex];
      var lanes = Timeline.ZOOM_CONFIGURATIONS[config].config.length;
      return 12 * lanes; // -1 is for coordinates starting at 0.
    },
    getPaper: function() {
      return this.paper;
    },
    rebuildGraph: function() {
      var timeline = this;
      var tree = timeline.getLefthandTree();
      var chart = timeline.getUiRoot().find('.tl-chart');

      chart.css({'display': 'none'});

      var width = timeline.getWidth();
      var height = timeline.getHeight();

      // clear and resize
      timeline.paper.clear();
      timeline.paper.setSize(width, height);

      $timeout(function() {
        // rebuild content
        timeline.bustVerticalOffsetCache(tree);
        timeline.rebuildBackground(tree, width, height);
        chart.css({'display': 'block'});
        timeline.rebuildForeground(tree);
      });
    },
    finishGraph: function() {
      var root = this.getUiRoot();
      var info = jQuery('<span class="tl-hidden-info tl-finished"></span>');

      // this will be called asynchronously and finishes up the graph
      // building process.
      this.setupEventHandlers();

      root.append(info);
    },
    rebuildBackground: function(tree, width, height) {
      var beginning = this.getBeginning();
      var scale = this.getScale();
      var end = this.getEnd();
      var deco = this.decoHeight();

      deco--;

      this.paper.rect(0, deco, width, height).attr({
        'fill': '#fff',
        'stroke': '#fff', //
        'stroke-opacity': 0,
        'stroke-width': 0
      });

      // horizontal bar.
      this.paper.path(
        this.psub('M0 #{y}H#{w}', {
          y: deco + 0.5, // the vertical line otherwise overlaps.
          w: width
        })
      );

      // *** beginning decorations ***

      var lastDivider, caption, captionElement, bbox, dividerPath;
      var padding = 2;

      lastDivider = 0;

      var swimlanes = this.getSwimlaneConfiguration();
      var styles = this.getSwimlaneStyles();
      var config = Timeline.ZOOM_SCALES[this.zoomIndex];

      var key, i, left, first, timeline = this;
      var m, x, y;

      var currentStyle = 0, lastOverrideGroup;

      for (i = Timeline.ZOOM_CONFIGURATIONS[config].config.length - 1; i >= 0; i--) {
        key = Timeline.ZOOM_CONFIGURATIONS[config].config[i];
        if (swimlanes.hasOwnProperty(key)) {

          // if the current swimlane has more overrides, we assume a
          // change in quality of the seperation and switch styles to a
          // more solid one. lastOverrideGroup is set to the length of the
          // override-array of the current swimlane.

          if (swimlanes[key].overrides.length > lastOverrideGroup) {
            currentStyle++;
          }
          lastOverrideGroup = swimlanes[key].overrides.length;

          lastDivider = 0;
          dividerPath = '';
          first = true;
          while (lastDivider < width || swimlanes[key].delimiter.compareTo(end) <= 0) {

            caption = swimlanes[key].caption() || '';
            if (caption.length === undefined) {
              caption = caption.toString(); // caption needs to be a string.
            }
            swimlanes[key].next();
            left = timeline.getDaysBetween(beginning, swimlanes[key].delimiter) * scale.day;
            bbox = {height: 8};

            captionElement = timeline.paper.text(0, 0, caption);
            captionElement.attr({
              'font-size': 10
            });

            x = (lastDivider + (left - lastDivider) / 2) - (jQuery(captionElement.node).width() / 16);
            y = (deco - padding);

            captionElement
              .translate(x, y)
              .attr({
                'fill': styles[currentStyle].textColor || timeline.DEFAULT_COLOR,
                'stroke': 'none'
              });

            lastDivider = left;
            dividerPath += timeline.psub('M#{x} #{y}v#{b} M#{x} #{d}v#{h}', {
              x: left,
              y: deco - bbox.height - 2 * padding,
              h: height,
              b: bbox.height + 2 * padding,
              d: timeline.decoHeight() + 1
            });
          }

          timeline.paper.path(dividerPath).attr({
            'stroke': styles[currentStyle].laneColor || timeline.DEFAULT_LANE_COLOR,
            'stroke-width': styles[currentStyle].laneWidth || timeline.DEFAULT_LANE_WIDTH,
            'stroke-linecap': 'butt' // the vertical line otherwise overlaps.
          });

          // altered deco ceiling for next decorations.
          deco -= bbox.height + 2 * padding;

          // horizontal bar.
          timeline.paper.path(
            timeline.psub('M0 #{y}H#{w}', {
              y: deco + 1 + bbox.height + 2 * padding,
              w: width
            })
          ).attr({
            'stroke': styles[currentStyle].textColor || timeline.DEFAULT_COLOR,
          });
        }
      }

      this.frameLine();
      this.nowLine();
    },
    previousRelativeVerticalOffset: 0,
    previousRelativeVerticalOffsetParameter: undefined,
    getRelativeVerticalOffset: function(offset) {
      if (offset === this.previousRelativeVerticalOffsetParameter) {
        return this.previousRelativeVerticalOffset;
      }
      var result = parseInt(offset.attr("data-vertical-offset"), 10);
      if (isNaN(result)) {
        if (this.table_offset === undefined) {
          result = this.table_offset = this.getUiRoot().find('.tl-left-main table').position().top;
        }
        result = offset.position().top - this.table_offset;
        offset.attr("data-vertical-offset", result);
      }

      this.previousRelativeVerticalOffset = result;
      this.previousRelativeVerticalOffsetParameter = offset;
      return result;
    },
    previousRelativeVerticalBottomOffset: 0,
    previousRelativeVerticalBottomOffsetParameter: undefined,
    getRelativeVerticalBottomOffset: function(offset) {
      if (offset === this.previousRelativeVerticalBottomOffsetParameter) {
        return this.previousRelativeVerticalBottomOffset;
      }
      var result = parseInt(offset.attr("data-vertical-bottom-offset"), 10);
      if (isNaN(result)) {
        result = this.getRelativeVerticalOffset(offset);
        if (offset.find("div").length === 1) {
          result -= jQuery(offset.find("div")[0]).height();
        }
        result += offset.outerHeight();
        offset.attr("data-vertical-bottom-offset", result);
      }
      this.previousRelativeVerticalBottomOffset = result;
      this.previousRelativeVerticalBottomOffsetParameter = offset;
      return result;
    },
    bustVerticalOffsetCache: function(tree) {
      tree.iterateWithChildren(function(node) {
        var currentElement = node.getDOMElement();
        if (currentElement) {
          currentElement.removeAttr("data-vertical-offset");
          currentElement.removeAttr("data-vertical-bottom-offset");
        }
      });
    },
    rebuildForeground: function(tree) {
      var timeline = this;
      var previousGrouping = -1;
      var grouping;
      var width = timeline.getWidth();
      var previousNode;
      var render_buckets = [[], [], [], []];
      var render_bucket_vertical = render_buckets[0];
      var render_bucket_element = render_buckets[1];
      var render_bucket_vertical_milestone = render_buckets[2];
      var render_bucket_text = render_buckets[3];

      // iterate over all planning elements and find vertical ones to draw.
      jQuery.each(timeline.verticalPlanningElementIds(), function (i, e) {
        var pl = timeline.getPlanningElement(e);

        // the planning element should have been loaded already. however,
        // it might not have been, or it might not even exist. in that
        // case, we simply ignore it.
        if (pl === undefined) {
          return;
        }

        var pet = pl.getPlanningElementType();

        var node = Object.create(TreeNode);
        node.setData(pl);

        if (pl.vertical) {
          if (pet && pet.is_milestone) {
            render_bucket_vertical_milestone.push(function () {
              pl.renderVertical(node);
            });
          } else {
            render_bucket_vertical.push(function () {
              pl.renderVertical(node);
            });
          }
        }
      });

      tree.iterateWithChildren(function(node, indent, index) {
        var currentElement = node.getDOMElement();
        if (!currentElement) {
          return;
        }
        var currentOffset = timeline.getRelativeVerticalOffset(currentElement);
        var previousElement, previousEnd, groupHeight;
        var groupingChanged = false;
        var pl = node.getData();

        // if the grouping changed, put a grey box here.

        if (timeline.isGrouping() && indent === 0 && pl.is(Project)) {
          grouping = pl.getFirstLevelGrouping();
          if (previousGrouping !== grouping) {

            groupingChanged = true;

            // previousEnd is the vertical position at which a previous
            // element ended. It is calculated by adding the previous
            // element's vertical offset to it's height.

            if (previousNode !== undefined) {
              previousElement = previousNode.getDOMElement();
              previousEnd = timeline.getRelativeVerticalOffset(previousElement) +
                  previousElement.outerHeight();
            } else {

              previousEnd = timeline.decoHeight();
            }

            // groupHeight is the height gap between the vertical position
            // at which the current element begins (currentOffset) and the
            // position the previous element ended (previousEnd).

            groupHeight = currentOffset - previousEnd;

            // draw grey box.

            timeline.paper.rect(
              Timeline.GROUP_BAR_INDENT,
              previousEnd,
              width - 2 * Timeline.GROUP_BAR_INDENT,
              groupHeight
            ).attr({
              'fill': '#bbb',
              'fill-opacity': 0.5,
              'stroke-width': 1,
              'stroke-opacity': 1,
              'stroke': Timeline.DEFAULT_STROKE_COLOR
            });

            previousGrouping = grouping;
          }

        }

        // if there is a new project, draw a black line.

        if (pl.is(Project)) {

          if (!groupingChanged) {

            // draw lines between projects
            timeline.paper.path(
              timeline.psub('M0 #{y}h#{w}', {
                y: currentOffset,
                w: width
              })
            ).attr({
              'stroke-width': 1,
              'stroke': Timeline.DEFAULT_STROKE_COLOR
            });

          }

        } else if (pl.is(PlanningElement)) {

        }

        previousNode = node;

        if (pl.is(PlanningElement)) {
          render_bucket_text.push(function () {
            pl.renderForeground(node);
          });
        }

        render_bucket_element.push(function() {
          pl.render(node);
        });
      });

      var buckets = Array.prototype.concat.apply([], render_buckets);

      var render_next_bucket = function() {
        if (buckets.length !== 0) {
          jQuery.each(buckets.splice(0, Timeline.RENDER_BUCKET_SIZE), function(i, e) {
            e.call();
          });
          $timeout(render_next_bucket);
        } else {
          timeline.finishGraph();
        }
      };

      render_next_bucket();
    },

    frameLine: function () {
      var timeline = this;
      var scale = timeline.getScale();
      var beginning = timeline.getBeginning();
      var decoHeight = timeline.decoHeight();
      var linePosition;

      this.calculateTimeFilter();

      if (this.frameStart) {
        linePosition = (timeline.getDaysBetween(beginning, this.frameStart)) * scale.day;

        timeline.paper.path(
          timeline.psub("M#{position} #{top}L#{position} #{height}", {
            'position': linePosition,
            'top': decoHeight,
            'height': this.getHeight()
          })
        ).attr({
          'stroke': 'blue',
          'stroke-dasharray': '- '
        });
      }

      if (this.frameEnd) {
        linePosition = ((timeline.getDaysBetween(beginning, this.frameEnd) + 1) * scale.day);

        timeline.paper.path(
          timeline.psub("M#{position} #{top}L#{position} #{height}", {
            'position': linePosition,
            'top': decoHeight,
            'height': this.getHeight()
          })
        ).attr({
          'stroke': 'blue',
          'stroke-dasharray': '- '
        });
      }
    },

    nowLine: function () {
      var timeline = this;
      var scale = timeline.getScale();
      var beginning = timeline.getBeginning();
      var ms_in_a_day = 86400000; // 24 * 60 * 60 * 1000

      var todayPosition = (timeline.getDaysBetween(beginning, Date.today())) * scale.day;
      todayPosition += (Date.now() - Date.today()) / ms_in_a_day * scale.day;

      var decoHeight = timeline.decoHeight();

      var currentTimeElement = timeline.paper.path(
        timeline.psub("M#{today} #{top}L#{today} #{height}", {
          'today': todayPosition,
          'top': decoHeight,
          'height': this.getHeight()
        })
      ).attr({
        'stroke': 'red',
        'stroke-dasharray': '3,3'
      });

      var setDateTime = 5 * 60 * 1000;

      var setDate = function () {
        var newTodayPosition = (timeline.getDaysBetween(beginning, Date.today())) * scale.day;
        newTodayPosition += (Date.now() - Date.today()) / ms_in_a_day * scale.day;

        if (Math.abs(newTodayPosition - todayPosition) > 0.1) {
          currentTimeElement.transform(
            timeline.psub("t#{trans},0", {
              'trans': newTodayPosition - todayPosition
            })
          );
        }

        if (scale.day === timeline.getScale().day) {
          window.setTimeout(setDate, setDateTime);
        }
      };

      window.setTimeout(setDate, setDateTime);
    },

    adjustTooltip: function(renderable, element) {
      renderable = renderable || this.currentNode;
      element = element || this.currentElement;
      if (!renderable) {
        return;
      }

      var chart = this.getChart();
      var offset = chart.position();
      var tooltip = this.getTooltip();
      var bbox = element.getBBox();
      var content = tooltip.find('.tl-tooltip-inner');
      var arrow = tooltip.find('.tl-tooltip-arrow');
      var arrowOffset = this.pnum(arrow.css('left'));
      var padding = (tooltip.outerWidth() - tooltip.width()) / 2;
      var duration = tooltip.css('display') !== 'none' ? 0 : 0;
      var info = "";
      var r = renderable.getResponsible();

      // construct tooltip content information.

      info += "<b>";
      info += this.escape(renderable.subject);
      info += "</b>";
      if (renderable.is(PlanningElement)) {
        info += " (#" + renderable.id + ")";
      }
      info += "<br/>";
      info += this.escape(renderable.start_date);
      if (renderable.due_date !== renderable.start_date) {
        // only have a second date if it is different.
        info += " – " + this.escape(renderable.due_date);
      }
      info += "<br/>";
      if (r && r.name) { // if there is a responsible, show the name.
        info += r.name;
      }

      content.html(info);

      // calculate position of tooltip
      var left = offset.left;
      left -= chart.scrollLeft();
      left += bbox.x;
      if (renderable.start_date && renderable.due_date) {
        left += bbox.width / 2;
      } else if (renderable.due_date) {
        left += bbox.width - Timeline.HOVER_THRESHOLD;
      } else {
        left += Timeline.HOVER_THRESHOLD;
      }
      left -= arrowOffset;

      var min_left = this.getUiRoot().find('.tl-left').position().left;
      min_left += this.getUiRoot().find('.tl-left').width();
      min_left -= arrowOffset;

      var max_left = this.getUiRoot().find('.tl-right').position().left;
      max_left -= tooltip.outerWidth();
      max_left -= padding;
      max_left += arrowOffset;

      left = Math.max(min_left, Math.min(max_left, left));

      var margin = offset.left;
      margin -= chart.scrollLeft();
      margin += (bbox.x);
      if (renderable.start_date && renderable.due_date) {
        margin += bbox.width / 2;
      } else if (renderable.due_date) {
        margin += bbox.width - Timeline.HOVER_THRESHOLD;
      } else {
        margin += Timeline.HOVER_THRESHOLD;
      }
      margin -= left;
      margin -= arrowOffset;

      var max_margin = tooltip.width();
      max_margin -= padding;
      max_margin -= arrowOffset;

      margin = Math.min(max_margin, Math.max(margin, 0));
      margin -= padding;

      var top = offset.top;
      top += bbox.y;
      top -= tooltip.outerHeight();
      top--; // random offset.

      if (top < jQuery(window).scrollTop() - 80) {
        top = jQuery(window).scrollTop() - 80;
      }

      this.currentNode = renderable;
      this.currentElement = element;
      tooltip.clearQueue();
      arrow.clearQueue();

      tooltip.animate({left: left, top: top}, duration, 'swing');
      arrow.animate({'margin-left': margin}, duration, 'swing');
    },

    setupEventHandlers: function() {
      var tree = this.getLefthandTree();
      this.setupResizeHandlers();
      //this.setupHoverHandlers(tree);
    },
    setupResizeHandlers: function() {
      var timeline = this, timeout;
      var handler_name = 'resize.' + timeline.getEventHandlerSuffix();

      jQuery(window).unbind(handler_name);
      jQuery(window).bind(handler_name, function() {

        window.clearTimeout(timeout);
        timeout = window.setTimeout(function() {
          timeline.triggerResize();
        }, 1087); // http://dilbert.com/strips/comic/2008-05-08/
      });
    },
    triggerResize: function() {
      var root = this.getUiRoot();
      if (!root) {
        return false;
      }
      var width = root.width() - root.find('.tl-left-main').width() -
                    Timeline.BORDER_WIDTH_CORRECTION;
      this.adjustWidth(width);
    },
    addHoverHandler: function(node, e) {
      var tooltip = this.getTooltip();
      var timeline = this;

      e.unhover();
      e.click(function(e) {
        var payload = node.getData();
        var url = payload.getUrl();

        window.open(url, '_blank');

        e.stopPropagation();
      });
      e.attr({'cursor': 'pointer'});
      e.hover(
        function() {
          timeline.adjustTooltip(node.getData(), e);
          tooltip.show();
        },
        function() {
          delete tooltip.currentNode;
          delete tooltip.currentElement;
          tooltip.hide();
        },
        node, node
      );
    },

    addPlanningElement: function() {
      var projects = this.projects;
      var project, projectID, possibleProjects = [];

      for (project in projects) {
        if (projects.hasOwnProperty(project)) {
          possibleProjects.push(projects[project]);
        }
      }

      projectID = possibleProjects[0].identifier;

      if (typeof projectID !== "undefined") {
        this.modalHelper.create(projectID);
      }
    }
  };

  return UI;
};