""" The legend module defines the Legend class, which is responsible for drawing legends associated with axes and/or figures. .. important:: It is unlikely that you would ever create a Legend instance manually. Most users would normally create a legend via the :meth:`~matplotlib.axes.Axes.legend` function. For more details on legends there is also a :ref:`legend guide `. The Legend class can be considered as a container of legend handles and legend texts. Creation of corresponding legend handles from the plot elements in the axes or figures (e.g., lines, patches, etc.) are specified by the handler map, which defines the mapping between the plot elements and the legend handlers to be used (the default legend handlers are defined in the :mod:`~matplotlib.legend_handler` module). Note that not all kinds of artist are supported by the legend yet by default but it is possible to extend the legend handler's capabilities to support arbitrary objects. See the :ref:`legend guide ` for more information. """ from __future__ import (absolute_import, division, print_function, unicode_literals) from matplotlib.externals import six from matplotlib.externals.six.moves import xrange import warnings import numpy as np from matplotlib import rcParams from matplotlib.artist import Artist, allow_rasterization from matplotlib.cbook import (is_string_like, iterable, silent_list, safezip) from matplotlib.font_manager import FontProperties from matplotlib.lines import Line2D from matplotlib.patches import Patch, Rectangle, Shadow, FancyBboxPatch from matplotlib.collections import (LineCollection, RegularPolyCollection, CircleCollection, PathCollection, PolyCollection) from matplotlib.transforms import Bbox, BboxBase, TransformedBbox from matplotlib.transforms import BboxTransformTo, BboxTransformFrom from matplotlib.offsetbox import HPacker, VPacker, TextArea, DrawingArea from matplotlib.offsetbox import DraggableOffsetBox from matplotlib.container import ErrorbarContainer, BarContainer, StemContainer from . import legend_handler class DraggableLegend(DraggableOffsetBox): def __init__(self, legend, use_blit=False, update="loc"): """ update : If "loc", update *loc* parameter of legend upon finalizing. If "bbox", update *bbox_to_anchor* parameter. """ self.legend = legend if update in ["loc", "bbox"]: self._update = update else: raise ValueError("update parameter '%s' is not supported." % update) DraggableOffsetBox.__init__(self, legend, legend._legend_box, use_blit=use_blit) def artist_picker(self, legend, evt): return self.legend.contains(evt) def finalize_offset(self): loc_in_canvas = self.get_loc_in_canvas() if self._update == "loc": self._update_loc(loc_in_canvas) elif self._update == "bbox": self._update_bbox_to_anchor(loc_in_canvas) else: raise RuntimeError("update parameter '%s' is not supported." % self.update) def _update_loc(self, loc_in_canvas): bbox = self.legend.get_bbox_to_anchor() # if bbox has zero width or height, the transformation is # ill-defined. Fall back to the defaul bbox_to_anchor. if bbox.width == 0 or bbox.height == 0: self.legend.set_bbox_to_anchor(None) bbox = self.legend.get_bbox_to_anchor() _bbox_transform = BboxTransformFrom(bbox) self.legend._loc = tuple( _bbox_transform.transform_point(loc_in_canvas) ) def _update_bbox_to_anchor(self, loc_in_canvas): tr = self.legend.axes.transAxes loc_in_bbox = tr.transform_point(loc_in_canvas) self.legend.set_bbox_to_anchor(loc_in_bbox) class Legend(Artist): """ Place a legend on the axes at location loc. Labels are a sequence of strings and loc can be a string or an integer specifying the legend location The location codes are:: 'best' : 0, (only implemented for axes legends) '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, loc can be a tuple of the normalized coordinate values with respect its parent. """ codes = {'best': 0, # only implemented for axes legends '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, } zorder = 5 def __str__(self): return "Legend" def __init__(self, parent, handles, labels, loc=None, numpoints=None, # the number of points in the legend line markerscale=None, # the relative size of legend markers # vs. original markerfirst=True, # controls ordering (left-to-right) of # legend marker and label scatterpoints=None, # number of scatter points scatteryoffsets=None, prop=None, # properties for the legend texts fontsize=None, # keyword to set font size directly # spacing & pad defined as a fraction of the font-size borderpad=None, # the whitespace inside the legend border labelspacing=None, # the vertical space between the legend # entries handlelength=None, # the length of the legend handles handleheight=None, # the height of the legend handles handletextpad=None, # the pad between the legend handle # and text borderaxespad=None, # the pad between the axes and legend # border columnspacing=None, # spacing between columns ncol=1, # number of columns mode=None, # mode for horizontal distribution of columns. # None, "expand" fancybox=None, # True use a fancy box, false use a rounded # box, none use rc shadow=None, title=None, # set a title for the legend framealpha=None, # set frame alpha bbox_to_anchor=None, # bbox that the legend will be anchored. bbox_transform=None, # transform for the bbox frameon=None, # draw frame handler_map=None, ): """ - *parent*: the artist that contains the legend - *handles*: a list of artists (lines, patches) to be added to the legend - *labels*: a list of strings to label the legend Optional keyword arguments: ================ ==================================================== Keyword Description ================ ==================================================== loc a location code prop the font property fontsize the font size (used only if prop is not specified) markerscale the relative size of legend markers vs. original markerfirst If true, place legend marker to left of label If false, place legend marker to right of label numpoints the number of points in the legend for line scatterpoints the number of points in the legend for scatter plot scatteryoffsets a list of yoffsets for scatter symbols in legend frameon if True, draw a frame around the legend. If None, use rc fancybox if True, draw a frame with a round fancybox. If None, use rc shadow if True, draw a shadow behind legend framealpha If not None, alpha channel for the frame. ncol number of columns borderpad the fractional whitespace inside the legend border labelspacing the vertical space between the legend entries handlelength the length of the legend handles handleheight the height of the legend handles handletextpad the pad between the legend handle and text borderaxespad the pad between the axes and legend border columnspacing the spacing between columns title the legend title bbox_to_anchor the bbox that the legend will be anchored. bbox_transform the transform for the bbox. transAxes if None. ================ ==================================================== The pad and spacing parameters are measured in font-size units. e.g., a fontsize of 10 points and a handlelength=5 implies a handlelength of 50 points. Values from rcParams will be used if None. Users can specify any arbitrary location for the legend using the *bbox_to_anchor* keyword argument. bbox_to_anchor can be an instance of BboxBase(or its derivatives) or a tuple of 2 or 4 floats. See :meth:`set_bbox_to_anchor` for more detail. The legend location can be specified by setting *loc* with a tuple of 2 floats, which is interpreted as the lower-left corner of the legend in the normalized axes coordinate. """ # local import only to avoid circularity from matplotlib.axes import Axes from matplotlib.figure import Figure Artist.__init__(self) if prop is None: if fontsize is not None: self.prop = FontProperties(size=fontsize) else: 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._fontsize = self.prop.get_size_in_points() self.texts = [] self.legendHandles = [] self._legend_title_box = None #: A dictionary with the extra handler mappings for this Legend #: instance. self._custom_handler_map = handler_map locals_view = locals() for name in ["numpoints", "markerscale", "shadow", "columnspacing", "scatterpoints", "handleheight", 'borderpad', 'labelspacing', 'handlelength', 'handletextpad', 'borderaxespad']: if locals_view[name] is None: value = rcParams["legend." + name] else: value = locals_view[name] setattr(self, name, value) del locals_view 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.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 def _set_artist_props(self, a): """ set the boilerplate props for artists added to axes """ a.set_figure(self.figure) if self.isaxes: # a.set_axes(self.axes) a.axes = self.axes a.set_transform(self.get_transform()) def _set_loc(self, loc): # find_offset function will be provided to _legend_box and # _legend_box will draw itself at the location of the return # value of the find_offset. self._loc_real = loc if loc == 0: _findoffset = self._findoffset_best else: _findoffset = self._findoffset_loc # def findoffset(width, height, xdescent, ydescent): # return _findoffset(width, height, xdescent, ydescent, renderer) self._legend_box.set_offset(_findoffset) self._loc_real = loc self.stale = True def _get_loc(self): return self._loc_real _loc = property(_get_loc, _set_loc) def _findoffset_best(self, width, height, xdescent, ydescent, renderer): "Helper function to locate the legend at its best position" ox, oy = self._find_best_position(width, height, renderer) return ox + xdescent, oy + ydescent def _findoffset_loc(self, width, height, xdescent, ydescent, renderer): "Helper function to locate the legend using the location code" if iterable(self._loc) and len(self._loc) == 2: # when loc is a tuple of axes(or figure) coordinates. fx, fy = self._loc bbox = self.get_bbox_to_anchor() x, y = bbox.x0 + bbox.width * fx, bbox.y0 + bbox.height * fy else: bbox = Bbox.from_bounds(0, 0, width, height) x, y = self._get_anchored_bbox(self._loc, bbox, self.get_bbox_to_anchor(), renderer) return x + xdescent, y + ydescent @allow_rasterization def draw(self, renderer): "Draw everything that belongs to the legend" if not self.get_visible(): return renderer.open_group('legend') fontsize = renderer.points_to_pixels(self._fontsize) # if mode == fill, set the width of the legend_box to the # width of the paret (minus pads) if self._mode in ["expand"]: pad = 2 * (self.borderaxespad + self.borderpad) * fontsize self._legend_box.set_width(self.get_bbox_to_anchor().width - pad) # update the location and size of the legend. This needs to # be done in any case to clip the figure right. bbox = self._legend_box.get_window_extent(renderer) self.legendPatch.set_bounds(bbox.x0, bbox.y0, bbox.width, bbox.height) self.legendPatch.set_mutation_scale(fontsize) if self._drawFrame: if self.shadow: shadow = Shadow(self.legendPatch, 2, -2) shadow.draw(renderer) self.legendPatch.draw(renderer) self._legend_box.draw(renderer) renderer.close_group('legend') self.stale = False def _approx_text_height(self, renderer=None): """ Return the approximate height of the text. This is used to place the legend handle. """ if renderer is None: return self._fontsize else: return renderer.points_to_pixels(self._fontsize) # _default_handler_map defines the default mapping between plot # elements and the legend handlers. _default_handler_map = { StemContainer: legend_handler.HandlerStem(), ErrorbarContainer: legend_handler.HandlerErrorbar(), Line2D: legend_handler.HandlerLine2D(), Patch: legend_handler.HandlerPatch(), LineCollection: legend_handler.HandlerLineCollection(), RegularPolyCollection: legend_handler.HandlerRegularPolyCollection(), CircleCollection: legend_handler.HandlerCircleCollection(), BarContainer: legend_handler.HandlerPatch( update_func=legend_handler.update_from_first_child), tuple: legend_handler.HandlerTuple(), PathCollection: legend_handler.HandlerPathCollection(), PolyCollection: legend_handler.HandlerPolyCollection() } # (get|set|update)_default_handler_maps are public interfaces to # modify the default handler map. @classmethod def get_default_handler_map(cls): """ A class method that returns the default handler map. """ return cls._default_handler_map @classmethod def set_default_handler_map(cls, handler_map): """ A class method to set the default handler map. """ cls._default_handler_map = handler_map @classmethod def update_default_handler_map(cls, handler_map): """ A class method to update the default handler map. """ cls._default_handler_map.update(handler_map) def get_legend_handler_map(self): """ return the handler map. """ default_handler_map = self.get_default_handler_map() if self._custom_handler_map: hm = default_handler_map.copy() hm.update(self._custom_handler_map) return hm else: return default_handler_map @staticmethod def get_legend_handler(legend_handler_map, orig_handle): """ return a legend handler from *legend_handler_map* that corresponds to *orig_handler*. *legend_handler_map* should be a dictionary object (that is returned by the get_legend_handler_map method). It first checks if the *orig_handle* itself is a key in the *legend_hanler_map* and return the associated value. Otherwise, it checks for each of the classes in its method-resolution-order. If no matching key is found, it returns None. """ legend_handler_keys = list(six.iterkeys(legend_handler_map)) if orig_handle in legend_handler_keys: handler = legend_handler_map[orig_handle] else: for handle_type in type(orig_handle).mro(): if handle_type in legend_handler_map: handler = legend_handler_map[handle_type] break else: handler = None return handler def _init_legend_box(self, handles, labels, markerfirst=True): """ Initialize the legend_box. The legend_box is an instance of the OffsetBox, which is packed with legend handles and texts. Once packed, their location is calculated during the drawing time. """ fontsize = self._fontsize # legend_box is a HPacker, horizontally packed with # columns. Each column is a VPacker, vertically packed with # legend items. Each legend item is HPacker packed with # legend handleBox and labelBox. handleBox is an instance of # offsetbox.DrawingArea which contains legend handle. labelBox # is an instance of offsetbox.TextArea which contains legend # text. text_list = [] # the list of text instances handle_list = [] # the list of text instances label_prop = dict(verticalalignment='baseline', horizontalalignment='left', fontproperties=self.prop, ) labelboxes = [] handleboxes = [] # The approximate height and descent of text. These values are # only used for plotting the legend handle. descent = 0.35 * self._approx_text_height() * (self.handleheight - 0.7) # 0.35 and 0.7 are just heuristic numbers and may need to be improved. height = self._approx_text_height() * self.handleheight - descent # each handle needs to be drawn inside a box of (x, y, w, h) = # (0, -descent, width, height). And their coordinates should # be given in the display coordinates. # The transformation of each handle will be automatically set # to self.get_trasnform(). If the artist does not use its # default transform (e.g., Collections), you need to # manually set their transform to the self.get_transform(). legend_handler_map = self.get_legend_handler_map() for orig_handle, lab in zip(handles, labels): handler = self.get_legend_handler(legend_handler_map, orig_handle) if handler is None: warnings.warn( "Legend does not support {!r} instances.\nA proxy artist " "may be used instead.\nSee: " "http://matplotlib.org/users/legend_guide.html" "#using-proxy-artist".format(orig_handle) ) # We don't have a handle for this artist, so we just defer # to None. handle_list.append(None) else: textbox = TextArea(lab, textprops=label_prop, multilinebaseline=True, minimumdescent=True) text_list.append(textbox._text) labelboxes.append(textbox) handlebox = DrawingArea(width=self.handlelength * fontsize, height=height, xdescent=0., ydescent=descent) handleboxes.append(handlebox) # Create the artist for the legend which represents the # original artist/handle. handle_list.append(handler.legend_artist(self, orig_handle, fontsize, handlebox)) if len(handleboxes) > 0: # We calculate number of rows in each column. The first # (num_largecol) columns will have (nrows+1) rows, and remaining # (num_smallcol) columns will have (nrows) rows. ncol = min(self._ncol, len(handleboxes)) nrows, num_largecol = divmod(len(handleboxes), ncol) num_smallcol = ncol - num_largecol # starting index of each column and number of rows in it. largecol = safezip(list(xrange(0, num_largecol * (nrows + 1), (nrows + 1))), [nrows + 1] * num_largecol) smallcol = safezip(list(xrange(num_largecol * (nrows + 1), len(handleboxes), nrows)), [nrows] * num_smallcol) else: largecol, smallcol = [], [] handle_label = safezip(handleboxes, labelboxes) columnbox = [] for i0, di in largecol + smallcol: # pack handleBox and labelBox into itemBox itemBoxes = [HPacker(pad=0, sep=self.handletextpad * fontsize, children=[h, t] if markerfirst else [t, h], align="baseline") for h, t in handle_label[i0:i0 + di]] # minimumdescent=False for the text of the last row of the column if markerfirst: itemBoxes[-1].get_children()[1].set_minimumdescent(False) else: itemBoxes[-1].get_children()[0].set_minimumdescent(False) # pack columnBox if markerfirst: alignment = "baseline" else: alignment = "right" columnbox.append(VPacker(pad=0, sep=self.labelspacing * fontsize, align=alignment, children=itemBoxes)) if self._mode == "expand": mode = "expand" else: mode = "fixed" sep = self.columnspacing * fontsize self._legend_handle_box = HPacker(pad=0, sep=sep, align="baseline", mode=mode, children=columnbox) self._legend_title_box = TextArea("") self._legend_box = VPacker(pad=self.borderpad * fontsize, sep=self.labelspacing * fontsize, align="center", children=[self._legend_title_box, self._legend_handle_box]) self._legend_box.set_figure(self.figure) self.texts = text_list self.legendHandles = handle_list def _auto_legend_data(self): """ Returns list of vertices and extents covered by the plot. Returns a two long list. First element is a list of (x, y) vertices (in display-coordinates) covered by all the lines and line collections, in the legend's handles. Second element is a list of bounding boxes for all the patches in the legend's handles. """ # should always hold because function is only called internally assert self.isaxes ax = self.parent bboxes = [] lines = [] for handle in ax.lines: assert isinstance(handle, Line2D) path = handle.get_path() trans = handle.get_transform() tpath = trans.transform_path(path) lines.append(tpath) for handle in ax.patches: assert isinstance(handle, Patch) if isinstance(handle, Rectangle): transform = handle.get_data_transform() bboxes.append(handle.get_bbox().transformed(transform)) else: transform = handle.get_transform() bboxes.append(handle.get_path().get_extents(transform)) try: vertices = np.concatenate([l.vertices for l in lines]) except ValueError: vertices = np.array([]) return [vertices, bboxes, lines] def draw_frame(self, b): 'b is a boolean. Set draw frame to b' self.set_frame_on(b) def get_children(self): 'return a list of child artists' children = [] if self._legend_box: children.append(self._legend_box) children.append(self.get_frame()) return children def get_frame(self): 'return the Rectangle instance used to frame the legend' return self.legendPatch def get_lines(self): 'return a list of lines.Line2D instances in the legend' return [h for h in self.legendHandles if isinstance(h, Line2D)] def get_patches(self): 'return a list of patch instances in the legend' return silent_list('Patch', [h for h in self.legendHandles if isinstance(h, Patch)]) def get_texts(self): 'return a list of text.Text instance in the legend' return silent_list('Text', self.texts) def set_title(self, title, prop=None): """ set the legend title. Fontproperties can be optionally set with *prop* parameter. """ self._legend_title_box._text.set_text(title) if prop is not None: if isinstance(prop, dict): prop = FontProperties(**prop) self._legend_title_box._text.set_fontproperties(prop) if title: self._legend_title_box.set_visible(True) else: self._legend_title_box.set_visible(False) self.stale = True def get_title(self): 'return Text instance for the legend title' return self._legend_title_box._text def get_window_extent(self, *args, **kwargs): 'return a extent of the legend' return self.legendPatch.get_window_extent(*args, **kwargs) def get_frame_on(self): """ Get whether the legend box patch is drawn """ return self._drawFrame def set_frame_on(self, b): """ Set whether the legend box patch is drawn ACCEPTS: [ *True* | *False* ] """ self._drawFrame = b self.stale = True def get_bbox_to_anchor(self): """ return the bbox that the legend will be anchored """ if self._bbox_to_anchor is None: return self.parent.bbox else: return self._bbox_to_anchor def set_bbox_to_anchor(self, bbox, transform=None): """ set the bbox that the legend will be anchored. *bbox* can be a BboxBase instance, a tuple of [left, bottom, width, height] in the given transform (normalized axes coordinate if None), or a tuple of [left, bottom] where the width and height will be assumed to be zero. """ if bbox is None: self._bbox_to_anchor = None return elif isinstance(bbox, BboxBase): self._bbox_to_anchor = bbox else: try: l = len(bbox) except TypeError: raise ValueError("Invalid argument for bbox : %s" % str(bbox)) if l == 2: bbox = [bbox[0], bbox[1], 0, 0] self._bbox_to_anchor = Bbox.from_bounds(*bbox) if transform is None: transform = BboxTransformTo(self.parent.bbox) self._bbox_to_anchor = TransformedBbox(self._bbox_to_anchor, transform) self.stale = True def _get_anchored_bbox(self, loc, bbox, parentbbox, renderer): """ Place the *bbox* inside the *parentbbox* according to a given location code. Return the (x,y) coordinate of the bbox. - loc: a location code in range(1, 11). This corresponds to the possible values for self._loc, excluding "best". - bbox: bbox to be placed, display coodinate units. - parentbbox: a parent box which will contain the bbox. In display coordinates. """ assert loc in range(1, 11) # called only internally BEST, UR, UL, LL, LR, R, CL, CR, LC, UC, C = list(xrange(11)) anchor_coefs = {UR: "NE", UL: "NW", LL: "SW", LR: "SE", R: "E", CL: "W", CR: "E", LC: "S", UC: "N", C: "C"} c = anchor_coefs[loc] fontsize = renderer.points_to_pixels(self._fontsize) container = parentbbox.padded(-(self.borderaxespad) * fontsize) anchored_box = bbox.anchored(c, container=container) return anchored_box.x0, anchored_box.y0 def _find_best_position(self, width, height, renderer, consider=None): """ Determine the best location to place the legend. `consider` is a list of (x, y) pairs to consider as a potential lower-left corner of the legend. All are display coords. """ # should always hold because function is only called internally assert self.isaxes verts, bboxes, lines = self._auto_legend_data() bbox = Bbox.from_bounds(0, 0, width, height) if consider is None: consider = [self._get_anchored_bbox(x, bbox, self.get_bbox_to_anchor(), renderer) for x in range(1, len(self.codes))] # tx, ty = self.legendPatch.get_x(), self.legendPatch.get_y() candidates = [] for l, b in consider: legendBox = Bbox.from_bounds(l, b, width, height) badness = 0 # XXX TODO: If markers are present, it would be good to # take their into account when checking vertex overlaps in # the next line. badness = legendBox.count_contains(verts) badness += legendBox.count_overlaps(bboxes) for line in lines: # FIXME: the following line is ill-suited for lines # that 'spiral' around the center, because the bbox # may intersect with the legend even if the line # itself doesn't. One solution would be to break up # the line into its straight-segment components, but # this may (or may not) result in a significant # slowdown if lines with many vertices are present. if line.intersects_bbox(legendBox): badness += 1 ox, oy = l, b if badness == 0: return ox, oy candidates.append((badness, (l, b))) # rather than use min() or list.sort(), do this so that we are assured # that in the case of two equal badnesses, the one first considered is # returned. # NOTE: list.sort() is stable.But leave as it is for now. -JJL minCandidate = candidates[0] for candidate in candidates: if candidate[0] < minCandidate[0]: minCandidate = candidate ox, oy = minCandidate[1] return ox, oy def contains(self, event): return self.legendPatch.contains(event) def draggable(self, state=None, use_blit=False, update="loc"): """ Set the draggable state -- if state is * None : toggle the current state * True : turn draggable on * False : turn draggable off If draggable is on, you can drag the legend on the canvas with the mouse. The DraggableLegend helper instance is returned if draggable is on. The update parameter control which parameter of the legend changes when dragged. If update is "loc", the *loc* paramter of the legend is changed. If "bbox", the *bbox_to_anchor* parameter is changed. """ is_draggable = self._draggable is not None # if state is None we'll toggle if state is None: state = not is_draggable if state: if self._draggable is None: self._draggable = DraggableLegend(self, use_blit, update=update) else: if self._draggable is not None: self._draggable.disconnect() self._draggable = None return self._draggable