# File lib/taskjuggler/TaskScenario.rb, line 24
    def initialize(task, scenarioIdx, attributes)
      super
      # Attributed are only really created when they are accessed the first
      # time. So make sure some needed attributes really exist so we don't
      # have to check for existance each time we access them.
      %w( allocate assignedresources booking charge chargeset complete
          criticalness depends duration effort end forward gauge length
          maxend maxstart minend minstart milestone pathcriticalness
          precedes priority scheduled shifts start status ).each do |attr|
        @property[attr, @scenarioIdx]
      end

      # A list of all allocated leaf resources.
      @candidates = []
      @dCache = DataCache.instance
    end

# File lib/taskjuggler/TaskScenario.rb, line 134
    def Xref
      @depends.each do |dependency|
        depTask = checkDependency(dependency, 'depends')
        @startpreds.push([ depTask, dependency.onEnd ])
        depTask[dependency.onEnd ? 'endsuccs' : 'startsuccs', @scenarioIdx].
          push([ @property, false ])
      end

      @precedes.each do |dependency|
        predTask = checkDependency(dependency, 'precedes')
        @endsuccs.push([ predTask, dependency.onEnd ])
        predTask[dependency.onEnd ? 'endpreds' : 'startpreds', @scenarioIdx].
          push([@property, true ])
      end
    end

# File lib/taskjuggler/TaskScenario.rb, line 1241
    def addBooking(booking)
      # This append operation will not trigger a copy to sub-scenarios.
      # Bookings are only valid for the scenario they are defined in.
      @booking << booking
    end

# File lib/taskjuggler/TaskScenario.rb, line 1674
    def assignedResources(interval)
      list = []

      if @property.container?
        @property.kids.each do |task|
          list += task.assignedResources(@scenarioIdx, interval)
        end
        list.uniq!
      else
        @assignedresources.each do |resource|
          if resource.allocated?(@scenarioIdx, interval, @property)
            list << resource
          end
        end
      end

      list
    end

# File lib/taskjuggler/TaskScenario.rb, line 793
    def calcCriticalness
      @criticalness = 0.0
      @pathcriticalness = nil

      # Users feel that milestones are somewhat important. So we use an
      # arbitrary value larger than 0 for them. We make it priority dependent,
      # so the user has some control over it. Priority 0 is 0, 500 is 1.0 and
      # 1000 is 2.0. These values are pretty much randomly picked and probably
      # require some more tuning based on real projects.
      if @milestone
        @criticalness = @priority / 500.0
      end

      # Task without efforts of allocations are not critical.
      return if @effort <= 0 || @candidates.empty?

      # Determine the average criticalness of all allocated resources.
      criticalness = 0.0
      @candidates.each do |resource|
        criticalness += resource['criticalness', @scenarioIdx]
      end
      criticalness /= @candidates.length

      # The task criticalness is the product of effort and average resource
      # criticalness.
      @criticalness = @effort * criticalness
    end

# File lib/taskjuggler/TaskScenario.rb, line 827
    def calcPathCriticalness(atEnd = false)
      # If we have computed this already, just return the value. If we are only
      # at the end of the task, we do not include the criticalness of this task
      # as it is not really part of the path.
      if @pathcriticalness
        return @pathcriticalness - (atEnd ? 0 : @criticalness)
      end

      maxCriticalness = 0.0

      if atEnd
        # At the end, we only care about pathes through the successors of this
        # task or its parent tasks.
        if (criticalness = calcPathCriticalnessEndSuccs) > maxCriticalness
          maxCriticalness = criticalness
        end
      else
        # At the start of the task, we have two options.
        if @property.container?
          # For container tasks, we ignore all dependencies and check the pathes
          # through all the children.
          @property.children.each do |task|
            if (criticalness = task.calcPathCriticalness(@scenarioIdx, false)) >
              maxCriticalness
              maxCriticalness = criticalness
            end
          end
        else
          # For leaf tasks, we check all pathes through the start successors and
          # then the pathes through the end successors of this task and all its
          # parent tasks.
          @startsuccs.each do |task, onEnd|
            if (criticalness = task.calcPathCriticalness(@scenarioIdx, onEnd)) >
              maxCriticalness
              maxCriticalness = criticalness
            end
          end

          if (criticalness = calcPathCriticalnessEndSuccs) > maxCriticalness
            maxCriticalness = criticalness
          end

          maxCriticalness += @criticalness
        end
      end

      @pathcriticalness = maxCriticalness
    end

# File lib/taskjuggler/TaskScenario.rb, line 1037
    def canInheritDate?(atEnd)
      # Inheriting a start or end date from the enclosing task or the project
      # is allowed for the following scenarios:
      #   -  --> -   inhS*1  -  <-- -   inhE*1
      #   -  --> |   inhS    |  <-- -   inhE
      #   -  x-> -   inhS    -  <-x -   inhE
      #   -  x-> |   inhS    |  <-x -   inhE
      #   -  x-> -D  inhS    -D <-x -   inhE
      #   -  x-> |D  inhS    |D <-x -   inhE
      #   -  --> -D  inhS    -D <-- -   inhE
      #   -  --> |D  inhS    |D <-- -   inhE
      #   -  <-- |   inhS    |  --> -   inhE
      #
      #   *1 when no bookings but allocations are present

      thisEnd, thatEnd = atEnd ? [ 'end', 'start' ] : [ 'start', 'end' ]
      # Return false if we already have a date for this end or if we have a
      # strong dependency for this end.
      return false if instance_variable_get('@' + thisEnd) ||
                      hasStrongDeps?(atEnd)

      # Containter task can inherit the date if they have no dependencies at
      # this end.
      return true if @property.container?

      hasThatSpec = !instance_variable_get('@' + thatEnd).nil? ||
                    hasStrongDeps?(!atEnd)

      # Check for tasks that have no start and end spec, no duration spec but
      # allocates. They can inherit the start and end date.
      return true if hasThatSpec && !@hasDurationSpec && !@allocate.empty?

      if @forward ^ atEnd
        # the scheduling direction is pointing away from this end
        return true if @hasDurationSpec || !@booking.empty?

        return hasThatSpec
      else
        # the scheduling direction is pointing towards this end
        return !instance_variable_get('@' + thatEnd).nil? &&
               !@hasDurationSpec && @booking.empty? #&& @allocate.empty?
      end
    end

# File lib/taskjuggler/TaskScenario.rb, line 763
    def candidates
      @candidates = []
      @allocate.each do |allocation|
        allocation.candidates.each do |candidate|
          candidate.allLeaves.each do |resource|
            @candidates << resource unless @candidates.include?(resource)
          end
        end
      end
      @candidates
    end

# File lib/taskjuggler/TaskScenario.rb, line 596
    def checkForLoops(path, atEnd, fromOutside, forward)
      # Check if we have been here before on this path.
      if path.include?([ @property, atEnd ])
        warning('loop_detected',
                "Dependency loop detected at #{atEnd ? 'end' : 'start'} " +
                "of task #{@property.fullId}", false)
        skip = true
        path.each do |t, e|
          if t == @property && e == atEnd
            skip = false
            next
          end
          next if skip
          info("loop_at_#{e ? 'end' : 'start'}",
               "Loop ctnd. at #{e ? 'end' : 'start'} of task #{t.fullId}",
               t.sourceFileInfo)
        end
        error('loop_end', "Aborting")
      end
      # Used for debugging only
      if false
        pathText = ''
        path.each do |t, e|
          pathText += "#{t.fullId}(#{e ? 'end' : 'start'}) -> "
        end
        pathText += "#{@property.fullId}(#{atEnd ? 'end' : 'start'})"
        puts pathText
      end
      return if @deadEndFlags[(atEnd ? 2 : 0) + (fromOutside ? 1 : 0)]
      path << [ @property, atEnd ]

      # To find loops we have to traverse the graph in a certain order. When we
      # enter a task we can either come from outside or inside. The following
      # graph explains these definitions:
      #
      #             |      /          \      |
      #  outside    v    /              \    v   outside
      #          +------------------------------+
      #          |    /        Task        \    |
      #       -->|  o   <---          --->   o  |<--
      #          |/ Start                  End \|
      #         /+------------------------------+       #       /     ^                        ^            #             |         inside         |
      #
      # At the top we have the parent task. At the botton the child tasks.
      # The horizontal arrors are start predecessors or end successors.
      # As the graph is doubly-linked, we need to becareful to only find real
      # loops. When coming from outside, we only continue to the inside and vice
      # versa. Horizontal moves are only made when we are in a leaf task.
      unless atEnd
        if fromOutside
          if @property.container?
            #
            #         |
            #         v
            #       +--------
            #    -->| o--+
            #       +----|---
            #            |
            #            V
            #
            @property.children.each do |child|
              child.checkForLoops(@scenarioIdx, path, false, true, forward)
            end
          else
            #         |
            #         v
            #       +--------
            #    -->| o---->
            #       +--------
            #
            if (forward && @forward) || @milestone
              checkForLoops(path, true, false, true)
            end
          end
        else
          if @startpreds.empty?
            #
            #         ^
            #         |
            #       +-|------
            #       | o <--
            #       +--------
            #         ^
            #         |
            #
            if @property.parent
              @property.parent.checkForLoops(@scenarioIdx, path, false, false,
                                             forward)
            end
          else

            #       +--------
            #    <---- o <--
            #       +--------
            #          ^
            #          |
            #
            @startpreds.each do |task, targetEnd|
              task.checkForLoops(@scenarioIdx, path, targetEnd, true, forward)
            end
          end
        end
      else
        if fromOutside
          if @property.container?
            #
            #          |
            #          v
            #    --------+
            #       +--o |<--
            #    ---|----+
            #       |
            #       v
            #
            @property.children.each do |child|
              child.checkForLoops(@scenarioIdx, path, true, true, forward)
            end
          else
            #          |
            #          v
            #    --------+
            #     <----o |<--
            #    --------+
            #
            if (!forward && !@forward) || @milestone
              checkForLoops(path, false, false, false)
            end
          end
        else
          if @endsuccs.empty?
            #
            #          ^
            #          |
            #    ------|-+
            #      --> o |
            #    --------+
            #          ^
            #          |
            #
            if @property.parent
              @property.parent.checkForLoops(@scenarioIdx, path, true, false,
                                             forward)
            end
          else
            #    --------+
            #      --> o---->
            #    --------+
            #          ^
            #          |
            #
            @endsuccs.each do |task, targetEnd|
              task.checkForLoops(@scenarioIdx, path, targetEnd, true, forward)
            end
          end
        end
      end

      path.pop
      @deadEndFlags[(atEnd ? 2 : 0) + (fromOutside ? 1 : 0)] = true
      # puts "Finished with #{@property.fullId} #{atEnd ? 'end' : 'start'} " +
      #      "#{fromOutside ? 'outside' : 'inside'}"
    end

# File lib/taskjuggler/TaskScenario.rb, line 1566
    def collectTimeOffIntervals(iv, minDuration)
      # This function is often called recursively for the same parameters. We
      # store the results in the cache to avoid repeated computations of the
      # same results.
      @dCache.cached(self, :TaskScenarioCollectTimeOffIntervals, iv,
                     minDuration) do
        il = IntervalList.new
        il << TimeInterval.new(@project['start'], @project['end'])
        if @property.leaf?
          unless (resources = @assignedresources).empty?
            # The task has assigned resources, so we can use their common time
            # off intervals.
            resources.each do |resource|
              il &= resource.collectTimeOffIntervals(@scenarioIdx, iv,
                                                     minDuration)
            end
          else
            # The task has no assigned resources. We simply use the global time
            # off intervals.
            il &= @project.collectTimeOffIntervals(iv, minDuration)
          end
        else
          @property.kids.each do |task|
            il &= task.collectTimeOffIntervals(@scenarioIdx, iv, minDuration)
          end
        end

        il
      end
    end

# File lib/taskjuggler/TaskScenario.rb, line 779
    def countResourceAllocations
      return if @candidates.empty? || @effort <= 0

      avgEffort = @effort / @candidates.length
      @candidates.each do |resource|
        resource['alloctdeffort', @scenarioIdx] += avgEffort
      end
    end

# File lib/taskjuggler/TaskScenario.rb, line 1130
    def earliestStart
      # This is the date that we will return.
      startDate = nil
      @depends.each do |dependency|
        potentialStartDate =
          dependency.task[dependency.onEnd ? 'end' : 'start', @scenarioIdx]
        return nil if potentialStartDate.nil?

        # Determine the end date of a 'length' gap.
        dateAfterLengthGap = potentialStartDate
        gapLength = dependency.gapLength
        while gapLength > 0 && dateAfterLengthGap < @project['end'] do
          if @project.isWorkingTime(dateAfterLengthGap)
            gapLength -= 1
          end
          dateAfterLengthGap += @project['scheduleGranularity']
        end

        # Determine the end date of a 'duration' gap.
        if dateAfterLengthGap > potentialStartDate + dependency.gapDuration
          potentialStartDate = dateAfterLengthGap
        else
          potentialStartDate += dependency.gapDuration
        end

        startDate = potentialStartDate if startDate.nil? ||
                                          startDate < potentialStartDate
      end

      # If any of the parent tasks has an explicit start date, the task must
      # start at or after this date.
      task = @property
      while (task = task.parent) do
        if task['start', @scenarioIdx] &&
           (startDate.nil? || task['start', @scenarioIdx] > startDate)
          startDate = task['start', @scenarioIdx]
          break
        end
      end

      # When the computed start date is after the already determined end date
      # of the task, the start dependencies were too weak. This happens when
      # task B depends on A and they are specified this way:
      # task A: | --> D-
      # task B: -D <-- |
      if @end && startDate > @end
        error('weak_start_dep',
              "Task #{@property.fullId} has a too weak start dependencies " +
              "to be scheduled properly.")
      end

      startDate
    end

# File lib/taskjuggler/TaskScenario.rb, line 367
    def finishScheduling
      # Recursively descend into all child tasks.
      @property.children.each do |task|
        task.finishScheduling(@scenarioIdx)
      end

      @property.parents.each do |pTask|
        # Add the assigned resources to the parent task's list.
        @assignedresources.each do |resource|
          unless pTask['assignedresources', @scenarioIdx].include?(resource)
            pTask['assignedresources', @scenarioIdx] << resource
          end
        end
      end

      # These lists are no longer needed, so let's save some memory. Set it to
      # nil so we can detect accidental use.
      @candidates = nil
      @mandatories = nil
      @allLimits = nil
    end

# File lib/taskjuggler/TaskScenario.rb, line 1505
    def getAllocatedTime(startIdx, endIdx, resource = nil)
      return 0.0 if @milestone || startIdx >= endIdx ||
                    (resource && !@assignedresources.include?(resource))

      @dCache.cached(self, :TaskScenarioAllocatedTime, startIdx, endIdx, resource) do
        allocatedTime = 0.0
        if @property.container?
          @property.kids.each do |task|
            allocatedTime += task.getAllocatedTime(@scenarioIdx,
                                                   startIdx, endIdx, resource)
          end
        else
          if resource
            allocatedTime += resource.getAllocatedTime(@scenarioIdx,
                                                       startIdx, endIdx,
                                                       @property)
          else
            @assignedresources.each do |r|
              allocatedTime += r.getAllocatedTime(@scenarioIdx, startIdx, endIdx,
                                                  @property)
            end
          end
        end
        allocatedTime
      end
    end

# File lib/taskjuggler/TaskScenario.rb, line 1535
    def getEffectiveWork(startIdx, endIdx, resource = nil)
      # Make sure we have the real Resource and not a proxy.
      resource = resource.ptn if resource
      return 0.0 if @milestone || startIdx >= endIdx ||
                    (resource && !@assignedresources.include?(resource))

      @dCache.cached(self, :TaskScenarioEffectiveWork, startIdx, endIdx,
                     resource) do
        workLoad = 0.0
        if @property.container?
          @property.kids.each do |task|
            workLoad += task.getEffectiveWork(@scenarioIdx, startIdx, endIdx,
                                              resource)
          end
        else
          if resource
            workLoad += resource.getEffectiveWork(@scenarioIdx, startIdx,
                                                  endIdx, @property)
          else
            @assignedresources.each do |r|
              workLoad += r.getEffectiveWork(@scenarioIdx, startIdx, endIdx,
                                             @property)
            end
          end
        end
        workLoad
      end
    end

# File lib/taskjuggler/TaskScenario.rb, line 152
    def hasDependency?(depType, target, onEnd)
      a(depType).include?([target, onEnd])
    end

# File lib/taskjuggler/TaskScenario.rb, line 1658
    def hasResourceAllocated?(interval, resource)
      return false unless @assignedresources.include?(resource)

      if @property.leaf?
        return resource.allocated?(@scenarioIdx, interval, @property)
      else
        @property.kids.each do |t|
          return true if t.hasResourceAllocated?(@scenarioIdx, interval,
                                                 resource)
        end
      end
      false
    end

# File lib/taskjuggler/TaskScenario.rb, line 1600
    def isDependencyOf(task, depth, list = [])
      return true if task == @property

      # If this task is already in the list of traversed task, we can ignore
      # it.
      return false if list.include?(@property)
      list << @property

      @startsuccs.each do |t, onEnd|
        unless onEnd
          # must be a start->start dependency
          return true if t.isDependencyOf(@scenarioIdx, task, depth, list)
        end
      end

      # For task to depend on this task, the start of task must be after the
      # end of this task.
      if task['start', @scenarioIdx] && @end
        return false if task['start', @scenarioIdx] < @end
      end

      # Check if any of the parent tasks is a dependency of _task_.
      t = @property.parent
      while t
        # If the parent is a dependency, than all childs are as well.
        return true if t.isDependencyOf(@scenarioIdx, task, depth, list)
        t = t.parent
      end

      return false if depth == 1

      @endsuccs.each do |ta, onEnd|
        unless onEnd
          # must be an end->start dependency
          return true if ta.isDependencyOf(@scenarioIdx, task, depth - 1, list)
        end
      end

      false
    end

# File lib/taskjuggler/TaskScenario.rb, line 1643
    def isFeatureOf(task)
      sources = @property.all
      destinations = task.all

      sources.each do |s|
        destinations.each do |d|
          return true if s.isDependencyOf(@scenarioIdx, d, 0)
        end
      end

      false
    end

# File lib/taskjuggler/TaskScenario.rb, line 1187
    def latestEnd
      # This is the date that we will return.
      endDate = nil
      @precedes.each do |dependency|
        potentialEndDate =
          dependency.task[dependency.onEnd ? 'end' : 'start', @scenarioIdx]
        return nil if potentialEndDate.nil?

        # Determine the end date of a 'length' gap.
        dateBeforeLengthGap = potentialEndDate
        gapLength = dependency.gapLength
        while gapLength > 0 && dateBeforeLengthGap > @project['start'] do
          if @project.isWorkingTime(dateBeforeLengthGap -
                                    @project['scheduleGranularity'])
            gapLength -= 1
          end
          dateBeforeLengthGap -= @project['scheduleGranularity']
        end

        # Determine the end date of a 'duration' gap.
        if dateBeforeLengthGap < potentialEndDate - dependency.gapDuration
          potentialEndDate = dateBeforeLengthGap
        else
          potentialEndDate -= dependency.gapDuration
        end

        endDate = potentialEndDate if endDate.nil? || endDate > potentialEndDate
      end

      # If any of the parent tasks has an explicit end date, the task must end
      # at or before this date.
      task = @property
      while (task = task.parent) do
        if task['end', @scenarioIdx] &&
           (endDate.nil? || task['end', @scenarioIdx] < endDate)
          endDate = task['end', @scenarioIdx]
          break
        end
      end

      # When the computed end date is before the already determined start date
      # of the task, the end dependencies were too weak. This happens when
      # task A precedes B and they are specified this way:
      # task A: | --> D-
      # task B: -D <-- |
      if @start && (endDate.nil? || endDate > @start)
        error('weak_end_dep',
              "Task #{@property.fullId} has a too weak end dependencies " +
              "to be scheduled properly.")
      end

      endDate
    end

# File lib/taskjuggler/TaskScenario.rb, line 392
    def postScheduleCheck
      @errors = 0
      @property.children.each do |task|
        @errors += 1 unless task.postScheduleCheck(@scenarioIdx)
      end

      # There is no point to check the parent if the child(s) have errors.
      return false if @errors > 0

      # Same for runaway tasks. They have already been reported.
      if @isRunAway
        error('sched_runaway', "Some tasks did not fit into the project time " +
              "frame.")
      end

      # Make sure the task is marked complete
      unless @scheduled
        error('not_scheduled',
              "Task #{@property.fullId} has not been marked as scheduled.")
      end

      # If the task has a follower or predecessor that is a runaway this task
      # is also incomplete.
      (@startsuccs + @endsuccs).each do |task, onEnd|
        return false if task.isRunAway(@scenarioIdx)
      end
      (@startpreds + @endpreds).each do |task, onEnd|
        return false if task.isRunAway(@scenarioIdx)
      end

      # Check if the start time is ok
      if @start.nil?
        error('task_start_undef',
              "Task #{@property.fullId} has undefined start time")
      end
      if @start < @project['start'] || @start > @project['end']
        error('task_start_range',
              "The start time (#{@start}) of task #{@property.fullId} " +
              "is outside the project interval (#{@project['start']} - " +
              "#{@project['end']})")
      end
      if !@minstart.nil? && @start < @minstart
        warning('minstart',
               "The start time (#{@start}) of task #{@property.fullId} " +
               "is too early. Must be after #{@minstart}.")
      end
      if !@maxstart.nil? && @start > @maxstart
        warning('maxstart',
               "The start time (#{@start}) of task #{@property.fullId} " +
               "is too late. Must be before #{@maxstart}.")
      end
      # Check if the end time is ok
      error('task_end_undef',
            "Task #{@property.fullId} has undefined end time") if @end.nil?
      if @end < @project['start'] || @end > @project['end']
        error('task_end_range',
              "The end time (#{@end}) of task #{@property.fullId} " +
              "is outside the project interval (#{@project['start']} - " +
              "#{@project['end']})")
      end
      if !@minend.nil? && @end < @minend
        warning('minend',
                "The end time (#{@end}) of task #{@property.fullId} " +
                "is too early. Must be after #{@minend}.")
      end
      if !@maxend.nil? && @end > @maxend
        warning('maxend',
                "The end time (#{@end}) of task #{@property.fullId} " +
                "is too late. Must be before #{@maxend}.")
      end
      # Make sure the start is before the end
      if @start > @end
        error('start_after_end',
              "The start time (#{@start}) of task #{@property.fullId} " +
              "is after the end time (#{@end}).")
      end


      # Check that tasks fits into parent task.
      unless (parent = @property.parent).nil? ||
              parent['start', @scenarioIdx].nil? ||
              parent['end', @scenarioIdx].nil?
        if @start < parent['start', @scenarioIdx]
          error('task_start_in_parent',
                "The start date (#{@start}) of task #{@property.fullId} " +
                "is before the start date (#{parent['start', @scenarioIdx]}) " +
                "of the enclosing task.")
        end
        if @end > parent['end', @scenarioIdx]
          error('task_end_in_parent',
                "The end date (#{@end}) of task #{@property.fullId} " +
                "is after the end date (#{parent['end', @scenarioIdx]}) " +
                "of the enclosing task.")
        end
      end

      # Check that all preceding tasks start/end before this task.
      @depends.each do |dependency|
        task = dependency.task
        limit = task[dependency.onEnd ? 'end' : 'start', @scenarioIdx]
        next if limit.nil?
        if @start < limit
          error('task_pred_before',
                "Task #{@property.fullId} (#{@start}) must start after " +
                "#{dependency.onEnd ? 'end' : 'start'} (#{limit}) of task " +
                "#{task.fullId}.")
        end
        if dependency.gapDuration > 0
          if limit + dependency.gapDuration > @start
            error('task_pred_before_gd',
                  "Task #{@property.fullId} must start " +
                  "#{dependency.gapDuration / (60 * 60 * 24)} days after " +
                  "#{dependency.onEnd ? 'end' : 'start'} of task " +
                  "#{task.fullId}. TaskJuggler cannot enforce this condition " +
                  "because the task is scheduled ALAP (finish-to-start) or " +
                  "has a fixed #{dependency.onEnd ? 'end' : 'start'} date.")
          end
        end
        if dependency.gapLength > 0
          if calcLength(limit, @start) < dependency.gapLength
            error('task_pred_before_gl',
                  "Task #{@property.fullId} must start " +
                  "#{@project.slotsToDays(dependency.gapLength)} " +
                  "working days after " +
                  "#{dependency.onEnd ? 'end' : 'start'} of task " +
                  "#{task.fullId}. TaskJuggler cannot enforce this condition " +
                  "because the task is scheduled ALAP (finish-to-start) or " +
                  "has a fixed #{dependency.onEnd ? 'end' : 'start'} date.")
          end
        end
      end

      # Check that all following tasks end before this task
      @precedes.each do |dependency|
        task = dependency.task
        limit = task[dependency.onEnd ? 'end' : 'start', @scenarioIdx]
        next if limit.nil?
        if limit < @end
          error('task_succ_after',
                "Task #{@property.fullId} (#{@end}) must end before " +
                "#{dependency.onEnd ? 'end' : 'start'} (#{limit}) of task " +
                "#{task.fullId}.")
        end
        if dependency.gapDuration > 0
          if limit - dependency.gapDuration < @end
            error('task_succ_after_gd',
                  "Task #{@property.fullId} must end " +
                  "#{dependency.gapDuration / (60 * 60 * 24)} days before " +
                  "#{dependency.onEnd ? 'end' : 'start'} of task " +
                  "#{task.fullId}. TaskJuggler cannot enforce this condition " +
                  "because the task is scheduled ASAP (start-to-finish) or " +
                  "has a fixed #{dependency.onEnd ? 'end' : 'start'} date.")
          end
        end
        if dependency.gapLength > 0
          if calcLength(@end, limit) < dependency.gapLength
            error('task_succ_after_gl',
                  "Task #{@property.fullId} must end " +
                  "#{@project.slotsToDays(dependency.gapLength)} " +
                  "working days before " +
                  "#{dependency.onEnd ? 'end' : 'start'} of task " +
                  "#{task.fullId}. TaskJuggler cannot enforce this condition " +
                  "because the task is scheduled ASAP (start-to-finish) or " +
                  "has a fixed #{dependency.onEnd ? 'end' : 'start'} date.")
          end
        end
      end

      if @milestone && @start != @end
        error('milestone_times_equal',
              "Milestone #{@property.fullId} must have identical start and " +
              "end date.")
      end

      if @property.leaf? && @effort == 0 && !@milestone && !@allocate.empty? &&
         @assignedresources.empty?
        # The user used an 'allocate' for the task, but did not specify any
        # 'effort'. Actual allocations will only happen when resources are
        # available by chance. If there are no assigned resources, we generate
        # a warning as this is probably not what the user intended.
        warning('allocate_no_assigned',
                "Task #{@property.id} has resource allocation requested, but " +
                "did not get any resources assigned. Either use 'effort' " +
                "to ensure allocations or use a higher 'priority'.")
      end

      @errors == 0
    end

# File lib/taskjuggler/TaskScenario.rb, line 178
    def preScheduleCheck
      # Accounts can have sub accounts added after being used in a chargetset.
      # So we need to re-test here.
      @chargeset.each do |chargeset|
        chargeset.each do |account, share|
          unless account.leaf?
            error('account_no_leaf',
                "Chargesets may not include group account #{account.fullId}.")
          end
        end
      end

      # Leaf tasks can be turned into containers after bookings have been added.
      # We need to check for this.
      unless @property.leaf? || @booking.empty?
        error('container_booking',
              "Container task #{@property.fullId} may not have bookings.")
      end

      # Milestones may not have bookings.
      if @milestone && !@booking.empty?
        error('milestone_booking',
              "Milestone #{@property.fullId} may not have bookings.")
      end

      # All 'scheduled' tasks must have a fixed start and end date.
      if @scheduled && (@start.nil? || @end.nil?)
        error('not_scheduled',
              "Task #{@property.fullId} is marked as scheduled but does not " +
              'have a fixed start and end date.')
      end

      # If an effort has been specified resources must be allocated as well.
      if @effort > 0 && @allocate.empty?
        error('effort_no_allocations',
              "Task #{@property.fullId} has an effort but no resource " +
              "allocations.")
      end

      durationSpecs = 0
      durationSpecs += 1 if @effort > 0
      durationSpecs += 1 if @length > 0
      durationSpecs += 1 if @duration > 0
      durationSpecs += 1 if @milestone

      # The rest of this function performs a number of plausibility tests with
      # regards to task start and end critiria. To explain the various cases,
      # the following symbols are used:
      #
      # |: fixed start or end date
      # -: no fixed start or end date
      # M: Milestone
      # D: start or end dependency
      # x->: ASAP task with duration criteria
      # <-x: ALAP task with duration criteria
      # -->: ASAP task without duration criteria
      # <--: ALAP task without duration criteria

      if @property.container?
        if durationSpecs > 0
          error('container_duration',
                "Container task #{@property.fullId} may not have a duration " +
                "or be marked as milestones.")
        end
      elsif @milestone
        if durationSpecs > 1
          error('milestone_duration',
                "Milestone task #{@property.fullId} may not have a duration.")
        end
        # Milestones can have the following cases:
        #
        #   |  M -   ok     |D M -   ok     - M -   err1   -D M -   ok
        #   |  M |   err2   |D M |   err2   - M |   ok     -D M |   ok
        #   |  M -D  ok     |D M -D  ok     - M -D  ok     -D M -D  ok
        #   |  M |D  err2   |D M |D  err2   - M |D  ok     -D M |D  ok

        # err1: no start and end
        # already handled by 'start_undetermed' or 'end_undetermed'

        # err2: differnt start and end dates
        if @start && @end && @start != @end
          error('milestone_start_end',
                "Start (#{@start}) and end (#{@end}) dates of " +
                "milestone task #{@property.fullId} must be identical.")
        end
      else
        #   Error table for non-container, non-milestone tasks:
        #   AMP: Automatic milestone promotion for underspecified tasks when
        #        no bookings or allocations are present.
        #   AMPi: Automatic milestone promotion when no bookings or
        #   allocations are present. When no bookings but allocations are
        #   present the task inherits start and end date.
        #   Ref. implicitXref()|
        #   inhS: Inherit start date from parent task or project
        #   inhE: Inherit end date from parent task or project
        #
        #   | x-> -   ok     |D x-> -   ok     - x-> -   inhS   -D x-> -   ok
        #   | x-> |   err1   |D x-> |   err1   - x-> |   inhS   -D x-> |   err1
        #   | x-> -D  ok     |D x-> -D  ok     - x-> -D  inhS   -D x-> -D  ok
        #   | x-> |D  err1   |D x-> |D  err1   - x-> |D  inhS   -D x-> |D  err1
        #   | --> -   AMP    |D --> -   AMP    - --> -   AMPi   -D --> -   AMP
        #   | --> |   ok     |D --> |   ok     - --> |   inhS   -D --> |   ok
        #   | --> -D  ok     |D --> -D  ok     - --> -D  inhS   -D --> -D  ok
        #   | --> |D  ok     |D --> |D  ok     - --> |D  inhS   -D --> |D  ok
        #   | <-x -   inhE   |D <-x -   inhE   - <-x -   inhE   -D <-x -   inhE
        #   | <-x |   err1   |D <-x |   err1   - <-x |   ok     -D <-x |   ok
        #   | <-x -D  err1   |D <-x -D  err1   - <-x -D  ok     -D <-x -D  ok
        #   | <-x |D  err1   |D <-x |D  err1   - <-x |D  ok     -D <-x |D  ok
        #   | <-- -   inhE   |D <-- -   inhE   - <-- -   AMP    -D <-- -   inhE
        #   | <-- |   ok     |D <-- |   ok     - <-- |   AMP    -D <-- |   ok
        #   | <-- -D  ok     |D <-- -D  ok     - <-- -D  AMP    -D <-- -D  ok
        #   | <-- |D  ok     |D <-- |D  ok     - <-- |D  AMP    -D <-- |D  ok

        # These cases are normally autopromoted to milestones or inherit their
        # start or end dates. But this only works for tasks that have no
        # allocations or bookings.
        #   -  --> -
        #   |  --> -
        #   |D --> -
        #   -D --> -
        #   -  <-- -
        #   -  <-- |
        #   -  <-- -D
        #   -  <-- |D
        if durationSpecs == 0 &&
           ((@forward && @end.nil? && !hasDependencies(true)) ||
            (!@forward && @start.nil? && !hasDependencies(false)))
          error('task_underspecified',
                "Task #{@property.fullId} has too few specifations to be " +
                "scheduled.")
        end

        #   err1: Overspecified (12 cases)
        #   |  x-> |
        #   |  <-x |
        #   |  x-> |D
        #   |  <-x |D
        #   |D x-> |
        #   |D <-x |
        #   |D <-x |D
        #   |D x-> |D
        #   -D x-> |
        #   -D x-> |D
        #   |D <-x -D
        #   |  <-x -D
        if durationSpecs > 1
          error('multiple_durations',
                "Tasks may only have either a duration, length or effort or " +
                "be a milestone.")
        end
        startSpeced = @property.provided('start', @scenarioIdx)
        endSpeced = @property.provided('end', @scenarioIdx)
        if ((startSpeced && endSpeced) ||
            (hasDependencies(false) && @forward && endSpeced) ||
            (hasDependencies(true) && !@forward && startSpeced)) &&
           durationSpecs > 0 && !@property.provided('scheduled', @scenarioIdx)
          error('task_overspecified',
                "Task #{@property.fullId} has a start, an end and a " +
                'duration specification.')
        end
      end

      if !@booking.empty? && !@forward && !@scheduled
        error('alap_booking',
              'A task scheduled in ALAP mode may only have bookings if it ' +
              'has been marked as fully scheduled. Keep in mind that ' +
              'certain attributes like \'end\' or \'precedes\' automatically ' +
              'switch the task to ALAP mode.')
      end

      @startsuccs.each do |task, onEnd|
        unless task['forward', @scenarioIdx]
          task.data[@scenarioIdx].error(
            'onstart_wrong_direction',
            'Tasks with on-start dependencies must be ASAP scheduled')
        end
      end
      @endpreds.each do |task, onEnd|
        if task['forward', @scenarioIdx]
          task.data[@scenarioIdx].error(
            'onend_wrong_direction',
            'Tasks with on-end dependencies must be ALAP scheduled')
        end
      end
    end

# File lib/taskjuggler/TaskScenario.rb, line 43
    def prepareScheduling
      @property['startpreds', @scenarioIdx] = []
      @property['startsuccs', @scenarioIdx] = []
      @property['endpreds', @scenarioIdx] = []
      @property['endsuccs', @scenarioIdx] = []

      @isRunAway = false

      # And as global scoreboard index
      @currentSlotIdx = nil
      # The 'done' variables count scheduled values in number of time slots.
      @doneDuration = 0
      @doneLength = 0
      # Due to the 'efficiency' factor the effort slots must be a float.
      @doneEffort = 0.0

      @projectionMode = @project.scenario(@scenarioIdx).get('projection')
      @nowIdx = @project.dateToIdx(@project['now'])

      @startIsDetermed = nil
      @endIsDetermed = nil

      # To avoid multiple calls to propagateDate() we use these flags to know
      # when we've done it already.
      @startPropagated = false
      @endPropagated = false

      @durationType =
        if @effort > 0
          @hasDurationSpec = true
          :effortTask
        elsif @length > 0
          @hasDurationSpec = true
          :lengthTask
        elsif @duration > 0
          @hasDurationSpec = true
          :durationTask
        else
          # If the task is set as milestone is has a duration spec.
          @hasDurationSpec = @milestone
          :startEndTask
        end

      markMilestone

      # For start-end-tasks without allocation, we don't have to do
      # anything but to set the 'scheduled' flag.
      if @durationType == :startEndTask && @start && @end && @allocate.empty?
        @scheduled = true
        Log.msg { "Task #{@property.fullId}: #{period_to_s}" }
      end

      # Collect the limits of this task and all parent tasks into a single
      # Array.
      @allLimits = []
      task = @property
      # Reset the counters of all limits of this task.
      task['limits', @scenarioIdx].reset if task['limits', @scenarioIdx]
      until task.nil?
        if task['limits', @scenarioIdx]
          @allLimits << task['limits', @scenarioIdx]
        end
        task = task.parent
      end

      # Collect the mandatory allocations.
      @mandatories = []
      @allocate.each do |allocation|
        @mandatories << allocation if allocation.mandatory
        allocation.lockedResource = nil
      end

      bookBookings

      if @durationType == :startEndTask
        @startIdx = @project.dateToIdx(@start) if @start
        @endIdx = @project.dateToIdx(@end) if @end
      end
    end

# File lib/taskjuggler/TaskScenario.rb, line 948
    def propagateDate(date, atEnd, ignoreEffort = false)
      logTag = "propagateDate_#{@property.id}_#{atEnd ? 'end' : 'start'}"
      Log.enter(logTag, "Propagating #{atEnd ? 'end' : 'start'} date " +
                        "to task #{@property.id}")
      thisEnd = atEnd ? 'end' : 'start'
      otherEnd = atEnd ? 'start' : 'end'
      #puts "Propagating #{thisEnd} date #{date} of #{@property.fullId} " +
      #     "#{ignoreEffort ? "ignoring effort" : "" }"

      # These flags are just used to avoid duplicate calls of this function
      # during propagateInitialValues().
      if atEnd
        @endPropagated = true
      else
        @startPropagated = true
      end

      # For leaf tasks, propagate start may set the date. Container task dates
      # are only set in scheduleContainer().
      if @property.leaf?
        instance_variable_set(('@' + thisEnd).intern, date)
        if @durationType == :startEndTask
          instance_variable_set(('@' + thisEnd + 'Idx').intern,
                                @project.dateToIdx(date))
        end
        Log.msg { "Task #{@property.fullId}: #{period_to_s}" }
      end

      if @milestone
        # Start and end date of a milestone are identical.
        @scheduled = true
        if a(otherEnd).nil?
          propagateDate(a(thisEnd), !atEnd)
        end
        Log.msg { "Milestone #{@property.fullId}: #{period_to_s}" }
      elsif !@scheduled && @start && @end &&
            !(@length == 0 && @duration == 0 && @effort == 0 &&
              !@allocate.empty?)
        @scheduled = true
        Log.msg { "Task #{@property.fullId} has been scheduled" }
      end

      # Propagate date to all dependent tasks. Don't do this for start
      # successors or end predecessors if this task is effort based. In this
      # case, the date might still change to align with the first/last
      # allocation. In these cases, bookResource() has to propagate the final
      # date.
      if atEnd
        if ignoreEffort || @effort == 0
          @endpreds.each do |task, onEnd|
            propagateDateToDep(task, onEnd)
          end
        end
        @endsuccs.each do |task, onEnd|
          propagateDateToDep(task, onEnd)
        end
      else
        if ignoreEffort || @effort == 0
          @startsuccs.each do |task, onEnd|
            propagateDateToDep(task, onEnd)
          end
        end
        @startpreds.each do |task, onEnd|
          propagateDateToDep(task, onEnd)
        end
      end

      # Propagate date to sub tasks which have only an implicit
      # dependency on the parent task and no other criteria for this end of
      # the task.
      @property.children.each do |task|
        if task.canInheritDate?(@scenarioIdx, atEnd)
          task.propagateDate(@scenarioIdx, date, atEnd)
        end
      end

      # The date propagation might have completed the date set of the enclosing
      # containter task. If so, we can schedule it as well.
      @property.parents.each do |parent|
        parent.scheduleContainer(@scenarioIdx)
      end
      Log.exit(logTag, "Finished propagation of " +
                       "#{atEnd ? 'end' : 'start'} date " +
                       "to task #{@property.id}")
    end

# File lib/taskjuggler/TaskScenario.rb, line 156
    def propagateInitialValues
      unless @startPropagated
        if @start
          propagateDate(@start, false, true)
        elsif @property.parent.nil? &&
              @property.canInheritDate?(@scenarioIdx, false)
          propagateDate(@project['start'], false, true)
        end
      end

      unless @endPropagated
        if @end
          propagateDate(@end, true, true)
        elsif @property.parent.nil? &&
              @property.canInheritDate?(@scenarioIdx, true)
          propagateDate(@project['end'], true, true)
        end
      end
    end

# File lib/taskjuggler/TaskScenario.rb, line 1247
    def query_activetasks(query)
      count = activeTasks(query)

      query.sortable = query.numerical = count
      # For the string output, we only use integer numbers.
      query.string = "#{count.to_i}"
    end

# File lib/taskjuggler/TaskScenario.rb, line 1255
    def query_closedtasks(query)
      count = closedTasks(query)

      query.sortable = query.numerical = count
      # For the string output, we only use integer numbers.
      query.string = "#{count.to_i}"
    end

# File lib/taskjuggler/TaskScenario.rb, line 1263
    def query_complete(query)
      # If we haven't calculated the value yet, calculate it first.
      unless @complete
        calcCompletion
      end

      query.sortable = query.numerical = @complete
      # For the string output, we only use integer numbers.
      query.string = "#{@complete.to_i}%"
    end

# File lib/taskjuggler/TaskScenario.rb, line 1277
    def query_cost(query)
      if query.costAccount
        query.sortable = query.numerical = cost =
          turnover(query.startIdx, query.endIdx, query.costAccount,
                   query.scopeProperty)
        query.string = query.currencyFormat.format(cost)
      else
        query.string = 'No \'balance\' defined!'
      end
    end

# File lib/taskjuggler/TaskScenario.rb, line 1290
    def query_duration(query)
      query.sortable = query.numerical = duration =
        (@end - @start) / (60 * 60 * 24)
      query.string = query.scaleDuration(duration)
    end

# File lib/taskjuggler/TaskScenario.rb, line 1324
    def query_effort(query)
      query.sortable = query.numerical = work =
        getEffectiveWork(query.startIdx, query.endIdx, query.scopeProperty)
      query.string = query.scaleLoad(work)
    end

# File lib/taskjuggler/TaskScenario.rb, line 1299
    def query_effortdone(query)
      # For this query, we always override the query period.
      query.sortable = query.numerical = effort =
        getEffectiveWork(@project.dateToIdx(@project['start'], false),
                         @project.dateToIdx(@project['now']),
                         query.scopeProperty)
      query.string = query.scaleLoad(effort)
    end

# File lib/taskjuggler/TaskScenario.rb, line 1312
    def query_effortleft(query)
      # For this query, we always override the query period.
      query.sortable = query.numerical = effort =
        getEffectiveWork(@project.dateToIdx(@project['now']),
                         @project.dateToIdx(@project['end'], false),
                         query.scopeProperty)
      query.string = query.scaleLoad(effort)
    end

# File lib/taskjuggler/TaskScenario.rb, line 1330
    def query_followers(query)
      list = []

      # First gather the task that depend on the start of this task.
      @startsuccs.each do |task, onEnd|
        if onEnd
          date = task['end', query.scenarioIdx].to_s(query.timeFormat)
          dep = "[->]"
        else
          date = task['start', query.scenarioIdx].to_s(query.timeFormat)
          dep = "[->["
        end
        list << generateDepencyListItem(query, task, dep, date)
      end
      # Than add the tasks that depend on the end of this task.
      @endsuccs.each do |task, onEnd|
        if onEnd
          date = task['end', query.scenarioIdx].to_s(query.timeFormat)
          dep = "]->]"
        else
          date = task['start', query.scenarioIdx].to_s(query.timeFormat)
          dep = "]->["
        end
        list << generateDepencyListItem(query, task, dep, date)
      end

      query.assignList(list)
    end

# File lib/taskjuggler/TaskScenario.rb, line 1359
    def query_gauge(query)
      # If we haven't calculated the schedule status yet, calculate it first.
      calcGauge unless @gauge

      query.string = @gauge
    end

# File lib/taskjuggler/TaskScenario.rb, line 1369
    def query_headcount(query)
      headcount = 0
      assignedResources(Interval.new(query.start, query.end)).each do |res|
        headcount += res['efficiency', @scenarioIdx].round
      end

      query.sortable = query.numerical = headcount
      query.string = query.numberFormat.format(headcount)
    end

# File lib/taskjuggler/TaskScenario.rb, line 1379
    def query_inputs(query)
      inputList = PropertyList.new(@project.tasks, false)
      inputs(inputList, true)
      inputList.delete(@property)
      inputList.setSorting([['start', true, @scenarioIdx],
                            ['seqno', true, -1 ]])
      inputList.sort!

      query.assignList(generateTaskList(inputList, query))
    end

# File lib/taskjuggler/TaskScenario.rb, line 1390
    def query_maxend(query)
      queryDateLimit(query, @maxend)
    end

# File lib/taskjuggler/TaskScenario.rb, line 1394
    def query_maxstart(query)
      queryDateLimit(query, @maxstart)
    end

# File lib/taskjuggler/TaskScenario.rb, line 1398
    def query_minend(query)
      queryDateLimit(query, @minend)
    end

# File lib/taskjuggler/TaskScenario.rb, line 1402
    def query_minstart(query)
      queryDateLimit(query, @minstart)
    end

# File lib/taskjuggler/TaskScenario.rb, line 1406
    def query_opentasks(query)
      count = openTasks(query)

      query.sortable = query.numerical = count
      # For the string output, we only use integer numbers.
      query.string = "#{count.to_i}"
    end

# File lib/taskjuggler/TaskScenario.rb, line 1414
    def query_precursors(query)
      list = []

      # First gather the task that depend on the start of this task.
      @startpreds.each do |task, onEnd|
        if onEnd
          date = task['end', query.scenarioIdx].to_s(query.timeFormat)
          dep = "]->["
        else
          date = task['start', query.scenarioIdx].to_s(query.timeFormat)
          dep = "[->["
        end
        list << generateDepencyListItem(query, task, dep, date)
      end
      # Than add the tasks that depend on the end of this task.
      @endpreds.each do |task, onEnd|
        if onEnd
          date = task['end', query.scenarioIdx].to_s(query.timeFormat)
          dep = "]->]"
        else
          date = task['start', query.scenarioIdx].to_s(query.timeFormat)
          dep = "[->]"
        end
        list << generateDepencyListItem(query, task, dep, date)
      end

      query.assignList(list)
    end

# File lib/taskjuggler/TaskScenario.rb, line 1445
    def query_resources(query)
      list = []
      iv = TimeInterval.new(query.start, query.end)
      assignedResources(iv).each do |resource|
        if resource.allocated?(@scenarioIdx, iv, @property)
          if query.listItem
            rti = RichText.new(query.listItem, RTFHandlers.create(@project)).
              generateIntermediateFormat
            unless rti
              error('bad_resource_ts_query',
                    "Syntax error in query statement for task attribute " +
                    "'resources'.")
            end
            q = query.dup
            q.property = resource
            rti.setQuery(q)
            list << "<nowiki>#{rti.to_s}</nowiki>"
          else
            list << "<nowiki>#{resource.name} (#{resource.fullId})</nowiki>"
          end
        end
      end
      query.assignList(list)
    end

# File lib/taskjuggler/TaskScenario.rb, line 1473
    def query_revenue(query)
      if query.revenueAccount
        query.sortable = query.numerical = revenue =
          turnover(query.startIdx, query.endIdx, query.revenueAccount,
                   query.scopeProperty)
        query.string = query.currencyFormat.format(revenue)
      else
        query.string = 'No \'balance\' defined!'
      end
    end

# File lib/taskjuggler/TaskScenario.rb, line 1484
    def query_status(query)
      # If we haven't calculated the completion yet, calculate it first.
      calcStatus if @status.empty?

      query.string = @status
    end

# File lib/taskjuggler/TaskScenario.rb, line 1491
    def query_targets(query)
      targetList = PropertyList.new(@project.tasks, false)
      targets(targetList, true)
      targetList.delete(@property)
      targetList.setSorting([['start', true, @scenarioIdx],
                             ['seqno', true, -1 ]])
      targetList.sort!

      query.assignList(generateTaskList(targetList, query))
    end

# File lib/taskjuggler/TaskScenario.rb, line 879
    def readyForScheduling?
      # If the tasks has already been scheduled, we still call it 'ready' so
      # it will be removed from the todo list.
      return true if @scheduled

      return false if @isRunAway

      if @forward
        return true if @start && (@hasDurationSpec || @end)
      else
        return true if @end && (@hasDurationSpec || @start)
      end

      false
    end

# File lib/taskjuggler/TaskScenario.rb, line 581
    def resetLoopFlags
      @deadEndFlags = Array.new(4, false)
    end

# File lib/taskjuggler/TaskScenario.rb, line 899
    def schedule
      # Check if the task has already been scheduled e. g. by propagateDate().
      return true if @scheduled

      logTag = "schedule_#{@property.id}"
      Log.enter(logTag, "Scheduling task #{@property.id}")
      # Compute the date of the next slot this task wants to have scheduled.
      # This must either be the first slot ever or it must be directly
      # adjecent to the previous slot. If this task has not yet been scheduled
      # at all, @currentSlotIdx is still nil. Otherwise it contains the index
      # of the last scheduled slot.
      if @forward
        # On first call, the @currentSlotIdx is not set yet. We set it to the
        # start slot index or the 'now' slot if we are in projection mode and
        # the tasks has allocations.
        if @currentSlotIdx.nil?
          @currentSlotIdx = @project.dateToIdx(
            @projectionMode && (@project['now'] > @start) && !@allocate.empty? ?
            @project['now'] : @start)
        end
      else
        # On first call, the @currentSlotIdx is not set yet. We set it to the
        # slot index of the slot before the end slot.
        if @currentSlotIdx.nil?
          @currentSlotIdx = @project.dateToIdx(@end) - 1
        end
      end

      # Schedule all time slots from slot in the scheduling direction until
      # the task is completed or a problem has been found.
      # The task may not excede the project interval.
      lowerLimit = @project.dateToIdx(@project['start'])
      upperLimit = @project.dateToIdx(@project['end'])
      delta = @forward ? 1 : -1
      while scheduleSlot
        @currentSlotIdx += delta
        if @currentSlotIdx < lowerLimit || upperLimit < @currentSlotIdx
          markAsRunaway
          Log.exit(logTag, "Scheduling of task #{@property.id} failed")
          return false
        end
      end

      Log.exit(logTag, "Scheduling of task #{@property.id} completed")
      true
    end

# File lib/taskjuggler/TaskScenario.rb, line 1083
    def scheduleContainer
      return if @scheduled || !@property.container?

      nStart = nil
      nEnd = nil

      @property.kids.each do |task|
        # Abort if a child has not yet been scheduled. Since we haven't done
        # the consistency check yet, we can't rely on start and end being set
        # if 'scheduled' is set.
        return if (!task['scheduled', @scenarioIdx] ||
                   task['start', @scenarioIdx].nil? ||
                   task['end', @scenarioIdx].nil?)

        if nStart.nil? || task['start', @scenarioIdx] < nStart
          nStart = task['start', @scenarioIdx]
        end
        if nEnd.nil? || task['end', @scenarioIdx] > nEnd
          nEnd = task['end', @scenarioIdx]
        end
      end

      startSet = endSet = false
      # Propagate the dates to other dependent tasks.
      if @start.nil? || @start > nStart
        @start = nStart
        startSet = true
      end
      if @end.nil? || @end < nEnd
        @end = nEnd
        endSet = true
      end
      unless @start && @end
        raise "Start (#{@start}) and end (#{@end}) must be set"
      end
      @scheduled = true
      Log.msg { "Container task #{@property.fullId} completed: #{period_to_s}" }

      # If we have modified the start or end date, we need to communicate this
      # new date to surrounding tasks.
      propagateDate(nStart, false) if startSet
      propagateDate(nEnd, true) if endSet
    end