text: from .GraphicsWidget import GraphicsWidget
  from .LabelItem import LabelItem
  from ..Qt import QtGui, QtCore
  from .. import functions as fn
  from ..Point import Point
  from .ScatterPlotItem import ScatterPlotItem, drawSymbol
  from .PlotDataItem import PlotDataItem
  from .GraphicsWidgetAnchor import GraphicsWidgetAnchor
  __all__ = ['LegendItem']
  
  class LegendItem(GraphicsWidget, GraphicsWidgetAnchor):
      """
      Displays a legend used for describing the contents of a plot.
      LegendItems are most commonly created by calling PlotItem.addLegend().
  
      Note that this item should not be added directly to a PlotItem. Instead,
      Make it a direct descendant of the PlotItem::
  
          legend.setParentItem(plotItem)
  
      """
      def __init__(self, size=None, offset=None):
          """
          ==============  ===============================================================
          **Arguments:**
          size            Specifies the fixed size (width, height) of the legend. If
                          this argument is omitted, the legend will autimatically resize
                          to fit its contents.
          offset          Specifies the offset position relative to the legend's parent.
                          Positive values offset from the left or top; negative values
                          offset from the right or bottom. If offset is None, the
                          legend must be anchored manually by calling anchor() or
                          positioned by calling setPos().
          ==============  ===============================================================
          
          """
          
          
          GraphicsWidget.__init__(self)
          GraphicsWidgetAnchor.__init__(self)
          self.setFlag(self.ItemIgnoresTransformations)
          self.layout = QtGui.QGraphicsGridLayout()
          self.setLayout(self.layout)
          self.items = []
          self.size = size
          self.offset = offset
          if size is not None:
              self.setGeometry(QtCore.QRectF(0, 0, self.size[0], self.size[1]))
          
      def setParentItem(self, p):
          ret = GraphicsWidget.setParentItem(self, p)
          if self.offset is not None:
              offset = Point(self.offset)
              anchorx = 1 if offset[0] <= 0 else 0
              anchory = 1 if offset[1] <= 0 else 0
              anchor = (anchorx, anchory)
              self.anchor(itemPos=anchor, parentPos=anchor, offset=offset)
          return ret
          
      def addItem(self, item, name):
          """
          Add a new entry to the legend. 
  
          ==============  ========================================================
          **Arguments:**
          item            A PlotDataItem from which the line and point style
                          of the item will be determined or an instance of
                          ItemSample (or a subclass), allowing the item display
                          to be customized.
          title           The title to display for this item. Simple HTML allowed.
          ==============  ========================================================
          """
          label = LabelItem(name)
          if isinstance(item, ItemSample):
              sample = item
          else:
              sample = ItemSample(item)        
          row = self.layout.rowCount()
          self.items.append((sample, label))
          self.layout.addItem(sample, row, 0)
          self.layout.addItem(label, row, 1)
          self.updateSize()
      
      def removeItem(self, item):
          """
          Removes one item from the legend. 
  
          ==============  ========================================================
          **Arguments:**
          item            The item to remove or its name.
          ==============  ========================================================
          """
          # Thanks, Ulrich!
          # cycle for a match
          for sample, label in self.items:
              if sample.item is item or label.text == item:
                  self.items.remove( (sample, label) )    # remove from itemlist
                  self.layout.removeItem(sample)          # remove from layout
                  sample.close()                          # remove from drawing
                  self.layout.removeItem(label)
                  label.close()
                  self.updateSize()                       # redraq box
  
      def updateSize(self):
          if self.size is not None:
              return
              
          height = 0
          width = 0
          #print("-------")
          for sample, label in self.items:
              height += max(sample.height(), label.height()) + 3
              width = max(width, sample.width()+label.width())
              #print(width, height)
          #print width, height
          self.setGeometry(0, 0, width+25, height)
      
      def boundingRect(self):
          return QtCore.QRectF(0, 0, self.width(), self.height())
      
      def paint(self, p, *args):
          p.setPen(fn.mkPen(255,255,255,100))
          p.setBrush(fn.mkBrush(100,100,100,50))
          p.drawRect(self.boundingRect())
  
      def hoverEvent(self, ev):
          ev.acceptDrags(QtCore.Qt.LeftButton)
          
      def mouseDragEvent(self, ev):
          if ev.button() == QtCore.Qt.LeftButton:
              dpos = ev.pos() - ev.lastPos()
              self.autoAnchor(self.pos() + dpos)
  
  
  class ItemSample(GraphicsWidget):
      """ Class responsible for drawing a single item in a LegendItem (sans label).
      
      This may be subclassed to draw custom graphics in a Legend.
      """
      ## Todo: make this more generic; let each item decide how it should be represented.
      def __init__(self, item):
          GraphicsWidget.__init__(self)
          self.item = item
      
      def boundingRect(self):
          return QtCore.QRectF(0, 0, 20, 20)
          
      def paint(self, p, *args):
          #p.setRenderHint(p.Antialiasing)  # only if the data is antialiased.
          opts = self.item.opts
          
          if opts.get('fillLevel',None) is not None and opts.get('fillBrush',None) is not None:
              p.setBrush(fn.mkBrush(opts['fillBrush']))
              p.setPen(fn.mkPen(None))
              p.drawPolygon(QtGui.QPolygonF([QtCore.QPointF(2,18), QtCore.QPointF(18,2), QtCore.QPointF(18,18)]))
          
          if not isinstance(self.item, ScatterPlotItem):
              p.setPen(fn.mkPen(opts['pen']))
              p.drawLine(2, 18, 18, 2)
          
          symbol = opts.get('symbol', None)
          if symbol is not None:
              if isinstance(self.item, PlotDataItem):
                  opts = self.item.scatter.opts
                  
              pen = fn.mkPen(opts['pen'])
              brush = fn.mkBrush(opts['brush'])
              size = opts['size']
              
              p.translate(10,10)
              path = drawSymbol(p, symbol, size, pen, brush)
          
          
          
          
  