# Source code for pyqtgraph.graphicsItems.LegendItem

    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, name):
            """
            Removes one item from the legend.

            ==============  ========================================================
            **Arguments:**
            title           The title displayed for this item.
            ==============  ========================================================
            """
            # Thanks, Ulrich!
            # cycle for a match
            for sample, label in self.items:
                if label.text == name:  # hit
                    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)