def test2(ax):

    # bbox=round has two optional argument. pad and rounding_size.
    # They can be set during the initialization.
    p_fancy = FancyBboxPatch((bb.xmin, bb.ymin),
                             abs(bb.width), abs(bb.height),
                             boxstyle="round,pad=0.1",
                             fc=(1., .8, 1.),
                             ec=(1., 0.5, 1.))

    ax.add_patch(p_fancy)

    # boxstyle and its argument can be later modified with
    # set_boxstyle method. Note that the old attributes are simply
    # forgotten even if the boxstyle name is same.

    p_fancy.set_boxstyle("round,pad=0.1, rounding_size=0.2")
    # or
    # p_fancy.set_boxstyle("round", pad=0.1, rounding_size=0.2)

    ax.text(0.1, 0.8,
            ' boxstyle="round,pad=0.1\n rounding_size=0.2"',
            size=10, transform=ax.transAxes)

    # draws control points for the fancy box.
    # l = p_fancy.get_path().vertices
    # ax.plot(l[:,0], l[:,1], ".")

    draw_bbox(ax, bb)

    def __init__(self, child, pad=None, draw_frame=False, patch_attrs=None):
        """
        *pad* : boundary pad

        .. note::
          *pad* need to given in points and will be
          scale with the renderer dpi, while *width* and *hight*
          need to be in pixels.
        """

        super(PaddedBox, self).__init__()

        self.pad = pad
        self._children = [child]

        self.patch = FancyBboxPatch(
            xy=(0.0, 0.0), width=1., height=1.,
            facecolor='w', edgecolor='k',
            mutation_scale=1, #self.prop.get_size_in_points(),
            snap=True
            )

        self.patch.set_boxstyle("square",pad=0)

        if patch_attrs is not None:
            self.patch.update(patch_attrs)

        self._drawFrame =  draw_frame

 def _basic_outline(self, colors):
     if self.need != 0:
         #center = Circle(
         #    self.coords,
         #    self.r / float(20),
         #    color=color['lc'], zorder=4, facecolor=color['lc'], fill=True, alpha=self.alpha
         #)
         if self.layout_mode:
             border = Circle(
                 self.coords, 0.99 * self.r, color=colors['lc'], zorder=3, fill=False, edgecolor=colors['lc'],
                 alpha=self.alpha, linewidth=70 * self.scale
             )
             role_fill = Circle(
                 self.coords, self.r, color=self.role_color, zorder=4, facecolor=self.role_color, fill=True,
                 alpha=0.5 * self.alpha
             )
             self.basic_structure = [role_fill, border]
         else:
             border = Circle(
                 self.coords, self.r, color=colors['lc'], zorder=3, fill=False, edgecolor=colors['lc'],
                 alpha=self.alpha, linewidth=0.5
             )
             self.basic_structure = [border, ]#center]
     else:
         center = Circle(
             self.coords, self.r / self._transit_fraction, color=colors['lc'], zorder=4, facecolor=colors['lc'],
             fill=True, alpha=self.alpha
         )
         self.basic_structure = [center]
     if not self.functional:
         size = self.r if self.need != 0. else self.r / self._transit_fraction
         cross_bar = FancyBboxPatch(
             (0, 0), 2.4 * size, 0.2 * size,
             boxstyle="square,pad={}".format(0.05 * self.scale * self.label_scale),
             color=colors['ac'], alpha=min(1, 2 * self.alpha), zorder=6
         )
         rotator = Affine2D().rotate_deg(-40)
         corner_coords = (
             self.coords[0] - size,
             self.coords[1] + 0.7 * size
         )
         translator = Affine2D().translate(*corner_coords)
         transform = rotator + translator
         cross_bar.set_transform(transform)
         self.super_patch_collection.append(cross_bar)

class PaddedBox(OffsetBox):
    def __init__(self, child, pad=None, draw_frame=False, patch_attrs=None):
        """
        *pad* : boundary pad

        .. note::
          *pad* need to given in points and will be
          scale with the renderer dpi, while *width* and *hight*
          need to be in pixels.
        """

        super(PaddedBox, self).__init__()

        self.pad = pad
        self._children = [child]

        self.patch = FancyBboxPatch(
            xy=(0.0, 0.0), width=1., height=1.,
            facecolor='w', edgecolor='k',
            mutation_scale=1, #self.prop.get_size_in_points(),
            snap=True
            )

        self.patch.set_boxstyle("square",pad=0)

        if patch_attrs is not None:
            self.patch.update(patch_attrs)

        self._drawFrame =  draw_frame


    def get_extent_offsets(self, renderer):
        """
        update offset of childrens and return the extents of the box
        """

        dpicor = renderer.points_to_pixels(1.)
        pad = self.pad * dpicor

        w, h, xd, yd = self._children[0].get_extent(renderer)

        return w + 2*pad, h + 2*pad, \
               xd+pad, yd+pad, \
               [(0, 0)]


    def draw(self, renderer):
        """
        Update the location of children if necessary and draw them
        to the given *renderer*.
        """

        width, height, xdescent, ydescent, offsets = self.get_extent_offsets(renderer)

        px, py = self.get_offset(width, height, xdescent, ydescent, renderer)

        for c, (ox, oy) in zip(self.get_visible_children(), offsets):
            c.set_offset((px+ox, py+oy))

        self.draw_frame(renderer)

        for c in self.get_visible_children():
            c.draw(renderer)

        #bbox_artist(self, renderer, fill=False, props=dict(pad=0.))

    def update_frame(self, bbox, fontsize=None):
        self.patch.set_bounds(bbox.x0, bbox.y0,
                              bbox.width, bbox.height)

        if fontsize:
            self.patch.set_mutation_scale(fontsize)

    def draw_frame(self, renderer):
        # update the location and size of the legend
        bbox = self.get_window_extent(renderer)
        self.update_frame(bbox)

        if self._drawFrame:
            self.patch.draw(renderer)

class AnnotationBbox(martist.Artist, _AnnotationBase):
    """
    Annotation-like class, but with offsetbox instead of Text.
    """

    zorder = 3

    def __str__(self):
        return "AnnotationBbox(%g,%g)"%(self.xy[0],self.xy[1])
    @docstring.dedent_interpd
    def __init__(self, offsetbox, xy,
                 xybox=None,
                 xycoords='data',
                 boxcoords=None,
                 frameon=True, pad=0.4, # BboxPatch
                 annotation_clip=None,
                 box_alignment=(0.5, 0.5),
                 bboxprops=None,
                 arrowprops=None,
                 fontsize=None,
                 **kwargs):
        """
        *offsetbox* : OffsetBox instance

        *xycoords* : same as Annotation but can be a tuple of two
           strings which are interpreted as x and y coordinates.

        *boxcoords* : similar to textcoords as Annotation but can be a
           tuple of two strings which are interpreted as x and y
           coordinates.

        *box_alignment* : a tuple of two floats for a vertical and
           horizontal alignment of the offset box w.r.t. the *boxcoords*.
           The lower-left corner is (0.0) and upper-right corner is (1.1).

        other parameters are identical to that of Annotation.
        """
        self.offsetbox = offsetbox

        self.arrowprops = arrowprops

        self.set_fontsize(fontsize)


        if arrowprops is not None:
            self._arrow_relpos = self.arrowprops.pop("relpos", (0.5, 0.5))
            self.arrow_patch = FancyArrowPatch((0, 0), (1,1),
                                               **self.arrowprops)
        else:
            self._arrow_relpos = None
            self.arrow_patch = None

        _AnnotationBase.__init__(self,
                                 xy, xytext=xybox,
                                 xycoords=xycoords, textcoords=boxcoords,
                                 annotation_clip=annotation_clip)

        martist.Artist.__init__(self, **kwargs)

        #self._fw, self._fh = 0., 0. # for alignment
        self._box_alignment = box_alignment

        # frame
        self.patch = FancyBboxPatch(
            xy=(0.0, 0.0), width=1., height=1.,
            facecolor='w', edgecolor='k',
            mutation_scale=self.prop.get_size_in_points(),
            snap=True
            )
        self.patch.set_boxstyle("square",pad=pad)
        if bboxprops:
            self.patch.set(**bboxprops)
        self._drawFrame =  frameon


    def contains(self,event):
        t,tinfo = self.offsetbox.contains(event)
        #if self.arrow_patch is not None:
        #    a,ainfo=self.arrow_patch.contains(event)
        #    t = t or a

        # self.arrow_patch is currently not checked as this can be a line - JJ

        return t,tinfo


    def get_children(self):
        children = [self.offsetbox, self.patch]
        if self.arrow_patch:
            children.append(self.arrow_patch)
        return children

    def set_figure(self, fig):

        if self.arrow_patch is not None:
            self.arrow_patch.set_figure(fig)
        self.offsetbox.set_figure(fig)
        martist.Artist.set_figure(self, fig)

    def set_fontsize(self, s=None):
#.........这里部分代码省略.........

    def _label(self, colors):
        """
        Method to create an edges label

        :return:
        """

        its_label = '{:g}'.format(abs(self.edge.capacity) if self.edge.capacity is not None else '')
        status_color = colors['bc']
        if not self.layout_mode:
            in_percent = int(round(100 * self.edge.flux / float(self.edge.capacity), 0))
            if in_percent < 100:
                status_color = colors['wc']
            its_label += '; {:g}%'.format(in_percent)
        # get the label coordinates based on self.segments (use the end of the first segment if several segments are
        # present, if it is a single, place the label half the way

        s_coords, e_coords = self.segments[0]
        edge_vec = Vec(s_coords, e_coords)
        start_vec = Vec(s_coords)
        # maybe always use the last part...
        if len(self.segments) == 1:  # single segment: place it half way
            part_way_vec = start_vec + self.label_position * edge_vec
            coords_label = part_way_vec.coords[:2]
        else:  # several segments: place label at the end of the first
            #half_way_vec = start_vec + 0.5 * edge_vec
            #coords_label = half_way_vec.coords[:2]
            coords_label = e_coords
        if self.with_label:
            self.labels = [
                # so far there is just a single label for an edge
                (
                    its_label,
                    coords_label,
                    {
                        'horizontalalignment': 'center',
                        'verticalalignment': 'center',
                        'size': self.scale * 200 * self.label_scale,
                        'color': colors['tc'],
                        'box_fc': status_color
                    }
                )
            ]
        else:
            self.labels = None
        # cross through the label if it is not functional
        if not self.functional:
            cross_bar = FancyBboxPatch(
                (0, 0), self.scale * self.label_scale, 0.07 * self.scale * self.label_scale,
                boxstyle="square,pad={}".format(0.05 * self.scale * self.label_scale),
                color=colors['ac'], alpha=min(1, 2 * self.alpha), zorder=6
            )
            rotator = Affine2D().rotate_deg(-45)
            corner_coords = (
                coords_label[0] - 0.4 * self.scale * self.label_scale,
                coords_label[1] + 0.3 * self.scale * self.label_scale
            )
            translator = Affine2D().translate(*corner_coords)
            transform = rotator + translator
            cross_bar.set_transform(transform)
            self.super_patch_collection.append(cross_bar)

#.........这里部分代码省略.........

        del localdict

        handles = list(handles)
        if len(handles)<2:
            ncol = 1
        self._ncol = ncol

        if self.numpoints <= 0:
            raise ValueError("numpoints must be > 0; it was %d"% numpoints)

        # introduce y-offset for handles of the scatter plot
        if scatteryoffsets is None:
            self._scatteryoffsets = np.array([3./8., 4./8., 2.5/8.])
        else:
            self._scatteryoffsets = np.asarray(scatteryoffsets)
        reps =  int(self.scatterpoints / len(self._scatteryoffsets)) + 1
        self._scatteryoffsets = np.tile(self._scatteryoffsets, reps)[:self.scatterpoints]

        # _legend_box is an OffsetBox instance that contains all
        # legend items and will be initialized from _init_legend_box()
        # method.
        self._legend_box = None

        if isinstance(parent,Axes):
            self.isaxes = True
            self.set_axes(parent)
            self.set_figure(parent.figure)
        elif isinstance(parent,Figure):
            self.isaxes = False
            self.set_figure(parent)
        else:
            raise TypeError("Legend needs either Axes or Figure as parent")
        self.parent = parent

        if loc is None:
            loc = rcParams["legend.loc"]
            if not self.isaxes and loc in [0,'best']:
                loc = 'upper right'
        if is_string_like(loc):
            if loc not in self.codes:
                if self.isaxes:
                    warnings.warn('Unrecognized location "%s". Falling back on "best"; '
                                  'valid locations are\n\t%s\n'
                                  % (loc, '\n\t'.join(self.codes.iterkeys())))
                    loc = 0
                else:
                    warnings.warn('Unrecognized location "%s". Falling back on "upper right"; '
                                  'valid locations are\n\t%s\n'
                                   % (loc, '\n\t'.join(self.codes.iterkeys())))
                    loc = 1
            else:
                loc = self.codes[loc]
        if not self.isaxes and loc == 0:
            warnings.warn('Automatic legend placement (loc="best") not implemented for figure legend. '
                          'Falling back on "upper right".')
            loc = 1

        self._mode = mode
        self.set_bbox_to_anchor(bbox_to_anchor, bbox_transform)

        # We use FancyBboxPatch to draw a legend frame. The location
        # and size of the box will be updated during the drawing time.

        self.legendPatch = FancyBboxPatch(
            xy=(0.0, 0.0), width=1., height=1.,
            facecolor=rcParams["axes.facecolor"],
            edgecolor=rcParams["axes.edgecolor"],
            mutation_scale=self._fontsize,
            snap=True
            )

        # The width and height of the legendPatch will be set (in the
        # draw()) to the length that includes the padding. Thus we set
        # pad=0 here.
        if fancybox is None:
            fancybox = rcParams["legend.fancybox"]

        if fancybox == True:
            self.legendPatch.set_boxstyle("round",pad=0,
                                          rounding_size=0.2)
        else:
            self.legendPatch.set_boxstyle("square",pad=0)

        self._set_artist_props(self.legendPatch)

        self._drawFrame = frameon
        if frameon is None:
            self._drawFrame = rcParams["legend.frameon"]

        # init with null renderer
        self._init_legend_box(handles, labels)

        self._loc = loc

        self.set_title(title)

        self._last_fontsize_points = self._fontsize

        self._draggable = None

#.........这里部分代码省略.........
            self.set_figure(parent)
        else:
            raise TypeError("Legend needs either Axes or Figure as parent")
        self.parent = parent

        if loc is None:
            loc = rcParams["legend.loc"]
            if not self.isaxes and loc in [0,'best']:
                loc = 'upper right'
        if is_string_like(loc):
            if loc not in self.codes:
                if self.isaxes:
                    warnings.warn('Unrecognized location "%s". Falling back on "best"; '
                                  'valid locations are\n\t%s\n'
                                  % (loc, '\n\t'.join(self.codes.keys())))
                    loc = 0
                else:
                    warnings.warn('Unrecognized location "%s". Falling back on "upper right"; '
                                  'valid locations are\n\t%s\n'
                                   % (loc, '\n\t'.join(self.codes.keys())))
                    loc = 1
            else:
                loc = self.codes[loc]
        if not self.isaxes and loc == 0:
            warnings.warn('Automatic legend placement (loc="best") not implemented for figure legend. '
                          'Falling back on "upper right".')
            loc = 1

        self._loc = loc
        self._mode = mode

        # We use FancyBboxPatch to draw a legend frame. The location
        # and size of the box will be updated during the drawing time.
        self.legendPatch = FancyBboxPatch(
            xy=(0.0, 0.0), width=1., height=1.,
            facecolor='w', edgecolor='k',
            mutation_scale=self.fontsize,
            snap=True
            )

        # The width and height of the legendPatch will be set (in the
        # draw()) to the length that includes the padding. Thus we set
        # pad=0 here.
        if fancybox is None:
            fancybox = rcParams["legend.fancybox"]

        if fancybox == True:
            self.legendPatch.set_boxstyle("round",pad=0,
                                          rounding_size=0.2)
        else:
            self.legendPatch.set_boxstyle("square",pad=0)

        self._set_artist_props(self.legendPatch)

        self._drawFrame = True
        
        # init with null renderer
        self._init_legend_box(handles, labels)

        self._last_fontsize_points = self.fontsize


    def _set_artist_props(self, a):
        """
        set the boilerplate props for artists added to axes
        """

#.........这里部分代码省略.........
        else:
            raise TypeError("Legend needs either Axes or Figure as parent")
        self.parent = parent

        self._loc_used_default = loc is None
        if loc is None:
            loc = rcParams["legend.loc"]
            if not self.isaxes and loc in [0, 'best']:
                loc = 'upper right'
        if isinstance(loc, str):
            if loc not in self.codes:
                if self.isaxes:
                    cbook.warn_deprecated(
                        "3.1", message="Unrecognized location {!r}. Falling "
                        "back on 'best'; valid locations are\n\t{}\n"
                        "This will raise an exception %(removal)s."
                        .format(loc, '\n\t'.join(self.codes)))
                    loc = 0
                else:
                    cbook.warn_deprecated(
                        "3.1", message="Unrecognized location {!r}. Falling "
                        "back on 'upper right'; valid locations are\n\t{}\n'"
                        "This will raise an exception %(removal)s."
                        .format(loc, '\n\t'.join(self.codes)))
                    loc = 1
            else:
                loc = self.codes[loc]
        if not self.isaxes and loc == 0:
            cbook.warn_deprecated(
                "3.1", message="Automatic legend placement (loc='best') not "
                "implemented for figure legend. Falling back on 'upper "
                "right'. This will raise an exception %(removal)s.")
            loc = 1

        self._mode = mode
        self.set_bbox_to_anchor(bbox_to_anchor, bbox_transform)

        # We use FancyBboxPatch to draw a legend frame. The location
        # and size of the box will be updated during the drawing time.

        if facecolor is None:
            facecolor = rcParams["legend.facecolor"]
        if facecolor == 'inherit':
            facecolor = rcParams["axes.facecolor"]

        if edgecolor is None:
            edgecolor = rcParams["legend.edgecolor"]
        if edgecolor == 'inherit':
            edgecolor = rcParams["axes.edgecolor"]

        self.legendPatch = FancyBboxPatch(
            xy=(0.0, 0.0), width=1., height=1.,
            facecolor=facecolor,
            edgecolor=edgecolor,
            mutation_scale=self._fontsize,
            snap=True
            )

        # The width and height of the legendPatch will be set (in the
        # draw()) to the length that includes the padding. Thus we set
        # pad=0 here.
        if fancybox is None:
            fancybox = rcParams["legend.fancybox"]

        if fancybox:
            self.legendPatch.set_boxstyle("round", pad=0,
                                          rounding_size=0.2)
        else:
            self.legendPatch.set_boxstyle("square", pad=0)

        self._set_artist_props(self.legendPatch)

        self._drawFrame = frameon
        if frameon is None:
            self._drawFrame = rcParams["legend.frameon"]

        # init with null renderer
        self._init_legend_box(handles, labels, markerfirst)

        # If shadow is activated use framealpha if not
        # explicitly passed. See Issue 8943
        if framealpha is None:
            if shadow:
                self.get_frame().set_alpha(1)
            else:
                self.get_frame().set_alpha(rcParams["legend.framealpha"])
        else:
            self.get_frame().set_alpha(framealpha)

        tmp = self._loc_used_default
        self._set_loc(loc)
        self._loc_used_default = tmp  # ignore changes done by _set_loc

        # figure out title fontsize:
        if title_fontsize is None:
            title_fontsize = rcParams['legend.title_fontsize']
        tprop = FontProperties(size=title_fontsize)
        self.set_title(title, prop=tprop)
        self._last_fontsize_points = self._fontsize
        self._draggable = None

#.........这里部分代码省略.........
                    loc = 0
                else:
                    cbook.warn_deprecated(
                        "3.1", message="Unrecognized location {!r}. Falling "
                        "back on 'upper right'; valid locations are\n\t{}\n'"
                        "This will raise an exception %(removal)s."
                        .format(loc, '\n\t'.join(self.codes)))
                    loc = 1
            else:
                loc = self.codes[loc]
        if not self.isaxes and loc == 0:
            cbook.warn_deprecated(
                "3.1", message="Automatic legend placement (loc='best') not "
                "implemented for figure legend. Falling back on 'upper "
                "right'. This will raise an exception %(removal)s.")
            loc = 1

        self._mode = mode
        self.set_bbox_to_anchor(bbox_to_anchor, bbox_transform)

        # We use FancyBboxPatch to draw a legend frame. The location
        # and size of the box will be updated during the drawing time.

        if facecolor is None:
            facecolor = rcParams["legend.facecolor"]
        if facecolor == 'inherit':
            facecolor = rcParams["axes.facecolor"]

        if edgecolor is None:
            edgecolor = rcParams["legend.edgecolor"]
        if edgecolor == 'inherit':
            edgecolor = rcParams["axes.edgecolor"]

        self.legendPatch = FancyBboxPatch(
            xy=(0.0, 0.0), width=1., height=1.,
            facecolor=facecolor,
            edgecolor=edgecolor,
            mutation_scale=self._fontsize,
            snap=True
            )

        # The width and height of the legendPatch will be set (in the
        # draw()) to the length that includes the padding. Thus we set
        # pad=0 here.
        if fancybox is None:
            fancybox = rcParams["legend.fancybox"]

        if fancybox:
            self.legendPatch.set_boxstyle("round", pad=0,
                                          rounding_size=0.2)
        else:
            self.legendPatch.set_boxstyle("square", pad=0)

        self._set_artist_props(self.legendPatch)

        self._drawFrame = frameon
        if frameon is None:
            self._drawFrame = rcParams["legend.frameon"]

        # init with null renderer
        self._init_legend_box(handles, labels, markerfirst)

        # If shadow is activated use framealpha if not
        # explicitly passed. See Issue 8943
        if framealpha is None:
            if shadow:

#.........这里部分代码省略.........
                                  'on "best"; valid locations are\n\t%s\n'
                                  % (loc, '\n\t'.join(self.codes)))
                    loc = 0
                else:
                    warnings.warn('Unrecognized location "%s". Falling back '
                                  'on "upper right"; '
                                  'valid locations are\n\t%s\n'
                                  % (loc, '\n\t'.join(self.codes)))
                    loc = 1
            else:
                loc = self.codes[loc]
        if not self.isaxes and loc == 0:
            warnings.warn('Automatic legend placement (loc="best") not '
                          'implemented for figure legend. '
                          'Falling back on "upper right".')
            loc = 1

        self._mode = mode
        self.set_bbox_to_anchor(bbox_to_anchor, bbox_transform)

        # We use FancyBboxPatch to draw a legend frame. The location
        # and size of the box will be updated during the drawing time.

        if facecolor is None:
            facecolor = rcParams["legend.facecolor"]
        if facecolor == 'inherit':
            facecolor = rcParams["axes.facecolor"]

        if edgecolor is None:
            edgecolor = rcParams["legend.edgecolor"]
        if edgecolor == 'inherit':
            edgecolor = rcParams["axes.edgecolor"]

        self.legendPatch = FancyBboxPatch(
            xy=(0.0, 0.0), width=1., height=1.,
            facecolor=facecolor,
            edgecolor=edgecolor,
            mutation_scale=self._fontsize,
            snap=True
            )

        # The width and height of the legendPatch will be set (in the
        # draw()) to the length that includes the padding. Thus we set
        # pad=0 here.
        if fancybox is None:
            fancybox = rcParams["legend.fancybox"]

        if fancybox:
            self.legendPatch.set_boxstyle("round", pad=0,
                                          rounding_size=0.2)
        else:
            self.legendPatch.set_boxstyle("square", pad=0)

        self._set_artist_props(self.legendPatch)

        self._drawFrame = frameon
        if frameon is None:
            self._drawFrame = rcParams["legend.frameon"]

        # init with null renderer
        self._init_legend_box(handles, labels, markerfirst)

        if framealpha is None:
            self.get_frame().set_alpha(rcParams["legend.framealpha"])
        else:
            self.get_frame().set_alpha(framealpha)

class AnchoredOffsetbox(OffsetBox):
    """
    An offset box placed according to the legend location
    loc. AnchoredOffsetbox has a single child. When multiple children
    is needed, use other OffsetBox class to enlose them.  By default,
    the offset box is anchored against its parent axes. You may
    explicitly specify the bbox_to_anchor.
    """

    zorder = 5 # zorder of the legend

    def __init__(self, loc,
                 pad=0.4, borderpad=0.5,
                 child=None, prop=None, frameon=True,
                 bbox_to_anchor=None,
                 bbox_transform=None,
                 **kwargs):
        """
        loc is a string or an integer specifying the legend location.
        The valid  location codes are::

        'upper right'  : 1,
        'upper left'   : 2,
        'lower left'   : 3,
        'lower right'  : 4,
        'right'        : 5,
        'center left'  : 6,
        'center right' : 7,
        'lower center' : 8,
        'upper center' : 9,
        'center'       : 10,

        pad : pad around the child for drawing a frame. given in
          fraction of fontsize.

        borderpad : pad between offsetbox frame and the bbox_to_anchor,

        child : OffsetBox instance that will be anchored.

        prop : font property. This is only used as a reference for paddings.

        frameon : draw a frame box if True.

        bbox_to_anchor : bbox to anchor. Use self.axes.bbox if None.

        bbox_transform : with which the bbox_to_anchor will be transformed.

        """

        super(AnchoredOffsetbox, self).__init__(**kwargs)

        self.set_bbox_to_anchor(bbox_to_anchor, bbox_transform)
        self.set_child(child)

        self.loc = loc
        self.borderpad=borderpad
        self.pad = pad

        if prop is None:
            self.prop=FontProperties(size=rcParams["legend.fontsize"])
        elif isinstance(prop, dict):
            self.prop=FontProperties(**prop)
            if "size" not in prop:
                self.prop.set_size(rcParams["legend.fontsize"])
        else:
            self.prop = prop

        self.patch = FancyBboxPatch(
            xy=(0.0, 0.0), width=1., height=1.,
            facecolor='w', edgecolor='k',
            mutation_scale=self.prop.get_size_in_points(),
            snap=True
            )
        self.patch.set_boxstyle("square",pad=0)
        self._drawFrame =  frameon




    def set_child(self, child):
        "set the child to be anchored"
        self._child = child

    def get_child(self):
        "return the child"
        return self._child

    def get_children(self):
        "return the list of children"
        return [self._child]


    def get_extent(self, renderer):
        """
        return the extent of the artist. The extent of the child
        added with the pad is returned
        """
        w, h, xd, yd =  self.get_child().get_extent(renderer)
        fontsize = renderer.points_to_pixels(self.prop.get_size_in_points())
        pad = self.pad * fontsize
#.........这里部分代码省略.........

#.........这里部分代码省略.........
        # _legend_box is an OffsetBox instance that contains all
        # legend items and will be initialized from _init_legend_box()
        # method.
        self._legend_box = None

        if isinstance(parent, Axes):
            self.isaxes = True
            self.axes = parent
            self.set_figure(parent.figure)
        elif isinstance(parent, Figure):
            self.isaxes = False
            self.set_figure(parent)
        else:
            raise TypeError("Legend needs either Axes or Figure as parent")
        self.parent = parent

        if loc is None:
            loc = rcParams["legend.loc"]
            if not self.isaxes and loc in [0, 'best']:
                loc = 'upper right'
        if is_string_like(loc):
            if loc not in self.codes:
                if self.isaxes:
                    warnings.warn('Unrecognized location "%s". Falling back '
                                  'on "best"; valid locations are\n\t%s\n'
                                  % (loc, '\n\t'.join(
                                    six.iterkeys(self.codes))))
                    loc = 0
                else:
                    warnings.warn('Unrecognized location "%s". Falling back '
                                  'on "upper right"; '
                                  'valid locations are\n\t%s\n'
                                  % (loc, '\n\t'.join(
                                    six.iterkeys(self.codes))))
                    loc = 1
            else:
                loc = self.codes[loc]
        if not self.isaxes and loc == 0:
            warnings.warn('Automatic legend placement (loc="best") not '
                          'implemented for figure legend. '
                          'Falling back on "upper right".')
            loc = 1

        self._mode = mode
        self.set_bbox_to_anchor(bbox_to_anchor, bbox_transform)

        # We use FancyBboxPatch to draw a legend frame. The location
        # and size of the box will be updated during the drawing time.

        if rcParams["legend.facecolor"] == 'inherit':
            facecolor = rcParams["axes.facecolor"]
        else:
            facecolor = rcParams["legend.facecolor"]

        if rcParams["legend.edgecolor"] == 'inherit':
            edgecolor = rcParams["axes.edgecolor"]
        else:
            edgecolor = rcParams["legend.edgecolor"]

        self.legendPatch = FancyBboxPatch(
            xy=(0.0, 0.0), width=1., height=1.,
            facecolor=facecolor,
            edgecolor=edgecolor,
            mutation_scale=self._fontsize,
            snap=True
            )

        # The width and height of the legendPatch will be set (in the
        # draw()) to the length that includes the padding. Thus we set
        # pad=0 here.
        if fancybox is None:
            fancybox = rcParams["legend.fancybox"]

        if fancybox:
            self.legendPatch.set_boxstyle("round", pad=0,
                                          rounding_size=0.2)
        else:
            self.legendPatch.set_boxstyle("square", pad=0)

        self._set_artist_props(self.legendPatch)

        self._drawFrame = frameon
        if frameon is None:
            self._drawFrame = rcParams["legend.frameon"]

        # init with null renderer
        self._init_legend_box(handles, labels, markerfirst)

        if framealpha is None:
            self.get_frame().set_alpha(rcParams["legend.framealpha"])
        else:
            self.get_frame().set_alpha(framealpha)

        self._loc = loc
        self.set_title(title)
        self._last_fontsize_points = self._fontsize
        self._draggable = None

        if displace is not None:
            self.set_displace(displace)

#.........这里部分代码省略.........
        else:
            raise TypeError("Legend needs either Axes or Figure as parent")
        self.parent = parent

        if loc is None:
            loc = rcParams["legend.loc"]
            if not self.isaxes and loc in [0,'best']:
                loc = 'upper right'
        if is_string_like(loc):
            if loc not in self.codes:
                if self.isaxes:
                    warnings.warn('Unrecognized location "%s". Falling back on "best"; '
                                  'valid locations are\n\t%s\n'
                                  % (loc, '\n\t'.join(self.codes.iterkeys())))
                    loc = 0
                else:
                    warnings.warn('Unrecognized location "%s". Falling back on "upper right"; '
                                  'valid locations are\n\t%s\n'
                                   % (loc, '\n\t'.join(self.codes.iterkeys())))
                    loc = 1
            else:
                loc = self.codes[loc]
        if not self.isaxes and loc == 0:
            warnings.warn('Automatic legend placement (loc="best") not implemented for figure legend. '
                          'Falling back on "upper right".')
            loc = 1

        self._mode = mode
        self.set_bbox_to_anchor(bbox_to_anchor, bbox_transform)

        # We use FancyBboxPatch to draw a legend frame. The location
        # and size of the box will be updated during the drawing time.

        self.legendPatch = FancyBboxPatch(
            xy=(0.0, 0.0), width=1., height=1.,
            facecolor=rcParams["axes.facecolor"],
            edgecolor=rcParams["axes.edgecolor"],
            mutation_scale=self._fontsize,
            snap=True
            )

        # The width and height of the legendPatch will be set (in the
        # draw()) to the length that includes the padding. Thus we set
        # pad=0 here.
        if fancybox is None:
            fancybox = rcParams["legend.fancybox"]

        if fancybox == True:
            self.legendPatch.set_boxstyle("round",pad=0,
                                          rounding_size=0.2)
        else:
            self.legendPatch.set_boxstyle("square",pad=0)

        self._set_artist_props(self.legendPatch)

        self._drawFrame = frameon
        if frameon is None:
            self._drawFrame = rcParams["legend.frameon"]

        # init with null renderer
        self._init_legend_box(handles, labels)

        self._loc = loc

        self.set_title(title)

#.........这里部分代码省略.........

        # convert values of deprecated keywords (ginve in axes coords)
        # to new vaules in a fraction of the font size

        # conversion factor
        bbox = parent.bbox
        axessize_fontsize = min(bbox.width, bbox.height)/self.fontsize
        
        for k, v in deprecated_kwds.items():
            # use deprecated value if not None and if their newer
            # counter part is None.
            if localdict[k] is not None and localdict[v] is None:
                warnings.warn("Use '%s' instead of '%s'." % (v, k),
                              DeprecationWarning)
                setattr(self, v, localdict[k]*axessize_fontsize)
                continue

            # Otherwise, use new keywords
            if localdict[v] is None:
                setattr(self, v, rcParams["legend."+v])
            else:
                setattr(self, v, localdict[v])

        del localdict
        
        self._ncol = ncol

        if self.numpoints <= 0:
            raise ValueError("numpoints must be >= 0; it was %d"% numpoints)

        # introduce y-offset for handles of the scatter plot
        if scatteryoffsets is None:
            self._scatteryoffsets = np.array([3./8., 4./8., 2.5/8.])
        else:
            self._scatteryoffsets = np.asarray(scatteryoffsets)
        reps =  int(self.numpoints / len(self._scatteryoffsets)) + 1
        self._scatteryoffsets = np.tile(self._scatteryoffsets, reps)[:self.scatterpoints]

        # _legend_box is an OffsetBox instance that contains all
        # legend items and will be initialized from _init_legend_box()
        # method.
        self._legend_box = None

        if isinstance(parent,Axes):
            self.isaxes = True
            self.set_figure(parent.figure)
        elif isinstance(parent,Figure):
            self.isaxes = False
            self.set_figure(parent)
        else:
            raise TypeError("Legend needs either Axes or Figure as parent")
        self.parent = parent

        if loc is None:
            loc = rcParams["legend.loc"]
            if not self.isaxes and loc in [0,'best']:
                loc = 'upper right'
        if is_string_like(loc):
            if loc not in self.codes:
                if self.isaxes:
                    warnings.warn('Unrecognized location "%s". Falling back on "best"; '
                                  'valid locations are\n\t%s\n'
                                  % (loc, '\n\t'.join(self.codes.keys())))
                    loc = 0
                else:
                    warnings.warn('Unrecognized location "%s". Falling back on "upper right"; '
                                  'valid locations are\n\t%s\n'
                                   % (loc, '\n\t'.join(self.codes.keys())))
                    loc = 1
            else:
                loc = self.codes[loc]
        if not self.isaxes and loc == 0:
            warnings.warn('Automatic legend placement (loc="best") not implemented for figure legend. '
                          'Falling back on "upper right".')
            loc = 1

        self._loc = loc
        self._mode = mode

        # We use FancyBboxPatch to draw a legend frame. The location
        # and size of the box will be updated during the drawing time.
        self.legendPatch = FancyBboxPatch(
            xy=(0.0, 0.0), width=1., height=1.,
            facecolor='w', edgecolor='k',
            mutation_scale=self.fontsize,
            )

        # The width and height of the legendPatch will be set (in the
        # draw()) to the length that includes the padding. Thus we set
        # pad=0 here.
        self.legendPatch.set_boxstyle("round",pad=0, #self.borderpad,
                                      rounding_size=0.2)

        self._set_artist_props(self.legendPatch)

        self._drawFrame = True

        # populate the legend_box with legend items.
        self._init_legend_box(handles, labels)
        self._legend_box.set_figure(self.figure)