element.py

from io import BytesIO

import numpy as np
import bokeh
import bokeh.plotting
from bokeh.models import Range, HoverTool, Renderer
from bokeh.models.tickers import Ticker, BasicTicker, FixedTicker
from bokeh.models.widgets import Panel, Tabs

try:
    from bokeh import mpl
except ImportError:
    mpl = None
import param

from ...core import (Store, HoloMap, Overlay, DynamicMap,
                     CompositeOverlay, Element)
from ...core.options import abbreviated_exception
from ...core import util
from ...element import RGB
from ..plot import GenericElementPlot, GenericOverlayPlot
from ..util import dynamic_update
from .callbacks import Callbacks
from .plot import BokehPlot
from .util import mpl_to_bokeh, convert_datetime, update_plot, bokeh_version

if bokeh_version >= '0.12':
    from bokeh.models import FuncTickFormatter
else:
    FuncTickFormatter = None


# Define shared style properties for bokeh plots
line_properties = ['line_width', 'line_color', 'line_alpha',
                   'line_join', 'line_cap', 'line_dash']

fill_properties = ['fill_color', 'fill_alpha']

text_properties = ['text_font', 'text_font_size', 'text_font_style', 'text_color',
                   'text_alpha', 'text_align', 'text_baseline']

legend_dimensions = ['label_standoff', 'label_width', 'label_height', 'glyph_width',
                     'glyph_height', 'legend_padding', 'legend_spacing']



class ElementPlot(BokehPlot, GenericElementPlot):

    callbacks = param.ClassSelector(class_=Callbacks, doc="""
        Callbacks object defining any javascript callbacks applied
        to the plot.""")

    bgcolor = param.Parameter(default='white', doc="""
        Background color of the plot.""")

    border = param.Number(default=10, doc="""
        Minimum border around plot.""")

    fontsize = param.Parameter(default={'title': '12pt'}, allow_None=True,  doc="""
       Specifies various fontsizes of the displayed text.

       Finer control is available by supplying a dictionary where any
       unmentioned keys reverts to the default sizes, e.g:

          {'ticks': '20pt', 'title': '15pt', 'ylabel': '5px', 'xlabel': '5px'}""")

    invert_axes = param.Boolean(default=False, doc="""
        Whether to invert the x- and y-axis""")

    invert_xaxis = param.Boolean(default=False, doc="""
        Whether to invert the plot x-axis.""")

    invert_yaxis = param.Boolean(default=False, doc="""
        Whether to invert the plot y-axis.""")

    lod = param.Dict(default={'factor': 10, 'interval': 300,
                              'threshold': 2000, 'timeout': 500}, doc="""
        Bokeh plots offer "Level of Detail" (LOD) capability to
        accomodate large (but not huge) amounts of data. The available
        options are:

          * factor    - Decimation factor to use when applying
                        decimation.
          * interval  - Interval (in ms) downsampling will be enabled
                        after an interactive event.
          * threshold - Number of samples before downsampling is enabled.
          * timeout   - Timeout (in ms) for checking whether interactive
                        tool events are still occurring.""")

    show_grid = param.Boolean(default=True, doc="""
        Whether to show a Cartesian grid on the plot.""")

    show_legend = param.Boolean(default=True, doc="""
        Whether to show legend for the plot.""")

    shared_axes = param.Boolean(default=True, doc="""
        Whether to invert the share axes across plots
        for linked panning and zooming.""")

    default_tools = param.List(default=['save', 'pan', 'wheel_zoom',
                                        'box_zoom', 'reset'],
        doc="A list of plugin tools to use on the plot.")

    tools = param.List(default=[], doc="""
        A list of plugin tools to use on the plot.""")

    xaxis = param.ObjectSelector(default='bottom',
                                 objects=['top', 'bottom', 'bare', 'top-bare',
                                          'bottom-bare', None], doc="""
        Whether and where to display the xaxis, bare options allow suppressing
        all axis labels including ticks and xlabel. Valid options are 'top',
        'bottom', 'bare', 'top-bare' and 'bottom-bare'.""")

    logx = param.Boolean(default=False, doc="""
        Whether the x-axis of the plot will be a log axis.""")

    xrotation = param.Integer(default=None, bounds=(0, 360), doc="""
        Rotation angle of the xticks.""")

    xticks = param.Parameter(default=None, doc="""
        Ticks along x-axis specified as an integer, explicit list of
        tick locations or bokeh Ticker object. If set to None default
        bokeh ticking behavior is applied.""")

    yaxis = param.ObjectSelector(default='left',
                                      objects=['left', 'right', 'bare', 'left-bare',
                                               'right-bare', None], doc="""
        Whether and where to display the yaxis, bare options allow suppressing
        all axis labels including ticks and ylabel. Valid options are 'left',
        'right', 'bare' 'left-bare' and 'right-bare'.""")

    logy = param.Boolean(default=False, doc="""
        Whether the y-axis of the plot will be a log axis.""")

    yrotation = param.Integer(default=None, bounds=(0, 360), doc="""
        Rotation angle of the yticks.""")

    yticks = param.Parameter(default=None, doc="""
        Ticks along y-axis specified as an integer, explicit list of
        tick locations or bokeh Ticker object. If set to None
        default bokeh ticking behavior is applied.""")

    # The plot objects to be updated on each frame
    # Any entries should be existing keys in the handles
    # instance attribute.
    _update_handles = ['source', 'glyph']

    def __init__(self, element, plot=None, show_labels=['x', 'y'], **params):
        self.show_labels = show_labels
        self.current_ranges = None
        super(ElementPlot, self).__init__(element, **params)
        self.handles = {} if plot is None else self.handles['plot']
        element_ids = self.hmap.traverse(lambda x: id(x), [Element])
        self.static = len(set(element_ids)) == 1 and len(self.keys) == len(self.hmap)


    def _init_tools(self, element):
        """
        Processes the list of tools to be supplied to the plot.
        """
        tools = self.default_tools + self.tools
        if 'hover' in tools:
            tooltips = [(d.pprint_label, '@'+util.dimension_sanitizer(d.name))
                        for d in element.dimensions()]
            tools[tools.index('hover')] = HoverTool(tooltips=tooltips)
        return tools


    def _get_hover_data(self, data, element, empty=False):
        """
        Initializes hover data based on Element dimension values.
        If empty initializes with no data.
        """
        if 'hover' in self.default_tools + self.tools:
            for d in element.dimensions(label=True):
                sanitized = util.dimension_sanitizer(d)
                data[sanitized] = [] if empty else element.dimension_values(d)


    def _axes_props(self, plots, subplots, element, ranges):
        el = element.traverse(lambda x: x, [Element])
        el = el[0] if el else element
        dims = el.dimensions()
        xlabel, ylabel, zlabel = self._get_axis_labels(dims)
        if self.invert_axes:
            xlabel, ylabel = ylabel, xlabel

        plot_ranges = {}
        # Try finding shared ranges in other plots in the same Layout
        if plots and self.shared_axes:
            for plot in plots:
                if plot is None or not hasattr(plot, 'xaxis'): continue
                if plot.xaxis[0].axis_label == xlabel:
                    plot_ranges['x_range'] = plot.x_range
                if plot.xaxis[0].axis_label == ylabel:
                    plot_ranges['y_range'] = plot.x_range
                if plot.yaxis[0].axis_label == ylabel:
                    plot_ranges['y_range'] = plot.y_range
                if plot.yaxis[0].axis_label == xlabel:
                    plot_ranges['x_range'] = plot.y_range

        if el.get_dimension_type(0) is np.datetime64:
            x_axis_type = 'datetime'
        else:
            x_axis_type = 'log' if self.logx else 'auto'

        if len(dims) > 1 and el.get_dimension_type(1) is np.datetime64:
            y_axis_type = 'datetime'
        else:
            y_axis_type = 'log' if self.logy else 'auto'

        if not 'x_range' in plot_ranges:
            if 'x_range' in ranges:
                plot_ranges['x_range'] = ranges['x_range']
            else:
                l, b, r, t = self.get_extents(element, ranges)
                low, high = (b, t) if self.invert_axes else (l, r)
                if x_axis_type == 'datetime':
                    low = convert_datetime(low)
                    high = convert_datetime(high)
                elif low == high and low is not None:
                    offset = low*0.1 if low else 0.5
                    low -= offset
                    high += offset
                if all(x is not None and np.isfinite(x) for x in (low, high)):
                    plot_ranges['x_range'] = [low, high]

        if self.invert_xaxis:
            plot_ranges['x_ranges'] = plot_ranges['x_ranges'][::-1]

        if not 'y_range' in plot_ranges:
            if 'y_range' in ranges:
                plot_ranges['y_range'] = ranges['y_range']
            else:
                l, b, r, t = self.get_extents(element, ranges)
                low, high = (l, r) if self.invert_axes else (b, t)
                if y_axis_type == 'datetime':
                    low = convert_datetime(low)
                    high = convert_datetime(high)
                elif low == high and low is not None:
                    offset = low*0.1 if low else 0.5
                    low -= offset
                    high += offset
                if all(y is not None and np.isfinite(y) for y in (low, high)):
                    plot_ranges['y_range'] = [low, high]
        if self.invert_yaxis:
            yrange = plot_ranges['y_range']
            if isinstance(yrange, Range):
                plot_ranges['y_range'] = yrange.__class__(start=yrange.end,
                                                          end=yrange.start)
            else:
                plot_ranges['y_range'] = yrange[::-1]
        return (x_axis_type, y_axis_type), (xlabel, ylabel, zlabel), plot_ranges


    def _init_plot(self, key, element, plots, ranges=None):
        """
        Initializes Bokeh figure to draw Element into and sets basic
        figure and axis attributes including axes types, labels,
        titles and plot height and width.
        """
        subplots = list(self.subplots.values()) if self.subplots else []

        axis_types, labels, plot_ranges = self._axes_props(plots, subplots, element, ranges)
        xlabel, ylabel, _ = labels
        x_axis_type, y_axis_type = axis_types
        tools = self._init_tools(element)
        properties = dict(plot_ranges)
        properties['x_axis_label'] = xlabel if 'x' in self.show_labels else ' '
        properties['y_axis_label'] = ylabel if 'y' in self.show_labels else ' '

        if self.show_title:
            title = self._format_title(key, separator=' ')
        else:
            title = ''

        properties['webgl'] = self.renderer.webgl
        return bokeh.plotting.Figure(x_axis_type=x_axis_type,
                                     y_axis_type=y_axis_type, title=title,
                                     tools=tools, **properties)


    def _plot_properties(self, key, plot, element):
        """
        Returns a dictionary of plot properties.
        """
        plot_props = dict(plot_height=self.height, plot_width=self.width)
        if bokeh_version < '0.12':
            plot_props.update(self._title_properties(key, plot, element))
        if self.bgcolor:
            plot_props['background_fill_color'] = self.bgcolor
        if self.border is not None:
            for p in ['left', 'right', 'top', 'bottom']:
                plot_props['min_border_'+p] = self.border
        lod = dict(self.defaults()['lod'], **self.lod)
        for lod_prop, v in lod.items():
            plot_props['lod_'+lod_prop] = v
        return plot_props


    def _title_properties(self, key, plot, element):
        if self.show_title:
            title = self._format_title(key, separator=' ')
        else:
            title = ''

        if bokeh_version < '0.12':
            title_font = self._fontsize('title', 'title_text_font_size')
            return dict(title=title, title_text_color='black', **title_font)
        else:
            title_font = self._fontsize('title', 'text_font_size')
            return dict(text=title, text_color='black', **title_font)


    def _init_axes(self, plot):
        if self.xaxis is None:
            plot.xaxis.visible = False
        elif self.xaxis == 'top':
            plot.above = plot.below
            plot.below = []
            plot.xaxis[:] = plot.above

        if self.yaxis is None:
            plot.yaxis.visible = False
        elif self.yaxis == 'right':
            plot.right = plot.left
            plot.left = []
            plot.yaxis[:] = plot.right


    def _axis_properties(self, axis, key, plot, dimension,
                         ax_mapping={'x': 0, 'y': 1}):
        """
        Returns a dictionary of axis properties depending
        on the specified axis.
        """
        axis_props = {}
        if ((axis == 'x' and self.xaxis in ['bottom-bare', 'top-bare']) or
            (axis == 'y' and self.yaxis in ['left-bare', 'right-bare'])):
            axis_props['axis_label'] = ''
            axis_props['major_label_text_font_size'] = '0pt'
            axis_props['major_tick_line_color'] = None
            axis_props['minor_tick_line_color'] = None
        else:
            rotation = self.xrotation if axis == 'x' else self.yrotation
            if rotation:
                axis_props['major_label_orientation'] = np.radians(rotation)
            ticker = self.xticks if axis == 'x' else self.yticks
            if isinstance(ticker, Ticker):
                axis_props['ticker'] = ticker
            elif isinstance(ticker, int):
                axis_props['ticker'] = BasicTicker(desired_num_ticks=ticker)
            elif isinstance(ticker, (tuple, list)):
                if all(isinstance(t, tuple) for t in ticker):
                    pass
                else:
                    axis_props['ticker'] = FixedTicker(ticks=ticker)

        if FuncTickFormatter is not None and ax_mapping and dimension:
            formatter = None
            if dimension.value_format:
                formatter = dimension.value_format
            elif dimension.type in dimension.type_formatters:
                formatter = dimension.type_formatters[dimension.type]
            if formatter:
                msg = ('%s dimension formatter could not be '
                       'converted to tick formatter. ' % dimension.name)
                try:
                    formatter = FuncTickFormatter.from_py_func(formatter)
                except RuntimeError:
                    self.warning(msg+'Ensure Flexx is installed '
                                 '("conda install -c bokeh flexx" or '
                                 '"pip install flexx")')
                except Exception as e:
                    error = 'Pyscript raised an error: {0}'.format(e)
                    error = error.replace('%', '%%')
                    self.warning(msg+error)
                else:
                    axis_props['formatter'] = formatter
        return axis_props


    def _update_plot(self, key, plot, element=None):
        """
        Updates plot parameters on every frame
        """
        el = element.traverse(lambda x: x, [Element])
        dimensions = el[0].dimensions() if el else el.dimensions()
        plot.set(**self._plot_properties(key, plot, element))
        props = {axis: self._axis_properties(axis, key, plot, dim)
                 for axis, dim in zip(['x', 'y'], dimensions)}
        plot.xaxis[0].set(**props['x'])
        plot.yaxis[0].set(**props['y'])

        if bokeh_version >= '0.12' and not self.overlaid:
            plot.title.set(**self._title_properties(key, plot, element))

        if not self.show_grid:
            plot.xgrid.grid_line_color = None
            plot.ygrid.grid_line_color = None


    def _update_ranges(self, element, ranges):
        framewise = self.lookup_options(element, 'norm').options.get('framewise')
        l, b, r, t = self.get_extents(element, ranges)
        if not framewise and not self.dynamic:
            return
        plot = self.handles['plot']
        if self.invert_axes:
            l, b, r, t = b, l, t, r
        if l == r:
            offset = abs(l*0.1 if l else 0.5)
            l -= offset
            r += offset
        if b == t:
            offset = abs(b*0.1 if b else 0.5)
            b -= offset
            t += offset
        plot.x_range.start = l
        plot.x_range.end   = r
        plot.y_range.start = b
        plot.y_range.end   = t


    def _process_legend(self):
        """
        Disables legends if show_legend is disabled.
        """
        for l in self.handles['plot'].legend:
            l.legends[:] = []
            l.border_line_alpha = 0
            l.background_fill_alpha = 0


    def _init_glyph(self, plot, mapping, properties):
        """
        Returns a Bokeh glyph object.
        """
        properties = mpl_to_bokeh(properties)
        plot_method = self._plot_methods.get('batched' if self.batched else 'single')
        renderer = getattr(plot, plot_method)(**dict(properties, **mapping))
        return renderer, renderer.glyph


    def _glyph_properties(self, plot, element, source, ranges):
        properties = self.style[self.cyclic_index]

        if self.show_legend:
            if self.overlay_dims:
                legend = ', '.join([d.pprint_value(v) for d, v in
                                    self.overlay_dims.items()])
            else:
                legend = element.label
            properties['legend'] = legend
        properties['source'] = source
        return properties


    def _update_glyph(self, glyph, properties, mapping):
        allowed_properties = glyph.properties()
        properties = mpl_to_bokeh(properties)
        merged = dict(properties, **mapping)
        glyph.set(**{k: v for k, v in merged.items()
                     if k in allowed_properties})


    def initialize_plot(self, ranges=None, plot=None, plots=None, source=None):
        """
        Initializes a new plot object with the last available frame.
        """
        # Get element key and ranges for frame
        element = self.hmap.last
        key = self.keys[-1]
        ranges = self.compute_ranges(self.hmap, key, ranges)
        self.current_ranges = ranges
        self.current_frame = element
        self.current_key = key
        style_element = element.last if self.batched else element
        ranges = util.match_spec(style_element, ranges)

        # Initialize plot, source and glyph
        if plot is None:
            plot = self._init_plot(key, style_element, ranges=ranges, plots=plots)
            self._init_axes(plot)
        self.handles['plot'] = plot

        # Get data and initialize data source
        empty = self.callbacks and self.callbacks.downsample
        if self.batched:
            data, mapping = self.get_batched_data(element, ranges, empty)
        else:
            data, mapping = self.get_data(element, ranges, empty)
        if source is None:
            source = self._init_datasource(data)
        self.handles['source'] = source

        properties = self._glyph_properties(plot, style_element, source, ranges)
        with abbreviated_exception():
            renderer, glyph = self._init_glyph(plot, mapping, properties)
        self.handles['glyph'] = glyph
        if isinstance(renderer, Renderer):
            self.handles['glyph_renderer'] = renderer

        # Update plot, source and glyph
        with abbreviated_exception():
            self._update_glyph(glyph, properties, mapping)
        if not self.overlaid:
            self._update_plot(key, plot, style_element)
        if self.callbacks:
            self.callbacks(self)
            self.callbacks.update(self)
        if not self.overlaid:
            self._process_legend()
        self.drawn = True

        return plot


    def update_frame(self, key, ranges=None, plot=None, element=None, empty=False):
        """
        Updates an existing plot with data corresponding
        to the key.
        """
        reused = isinstance(self.hmap, DynamicMap) and self.overlaid
        if not reused and element is None:
            element = self._get_frame(key)
        else:
            self.current_key = key
            self.current_frame = element
        style_element = element.last if self.batched else element

        glyph = self.handles.get('glyph', None)
        if hasattr(glyph, 'visible'):
            glyph.visible = bool(element)
        if not element:
            return

        self.style = self.lookup_options(style_element, 'style')

        ranges = self.compute_ranges(self.hmap, key, ranges)
        self.set_param(**self.lookup_options(style_element, 'plot').options)
        ranges = util.match_spec(style_element, ranges)
        self.current_ranges = ranges

        plot = self.handles['plot']
        source = self.handles['source']
        empty = (self.callbacks and self.callbacks.downsample) or empty
        if self.batched:
            data, mapping = self.get_batched_data(element, ranges, empty)
        else:
            data, mapping = self.get_data(element, ranges, empty)
        self._update_datasource(source, data)

        if glyph:
            properties = self._glyph_properties(plot, element, source, ranges)
            with abbreviated_exception():
                self._update_glyph(self.handles['glyph'], properties, mapping)
        if not self.overlaid:
            self._update_ranges(style_element, ranges)
            self._update_plot(key, plot, style_element)
        if self.callbacks:
            self.callbacks.update(self)


    @property
    def current_handles(self):
        """
        Returns a list of the plot objects to update.
        """
        handles = []
        if self.static and not self.dynamic:
            return handles
        for handle in self._update_handles:
            if handle in self.handles:
                handles.append(self.handles[handle])

        if self.overlaid:
            return handles

        plot = self.state
        handles.append(plot)
        if bokeh_version >= '0.12':
            handles.append(plot.title)

        if self.current_frame:
            if self.subplots:
                current_frames = [(sp.current_frame if isinstance(sp.current_frame, Element)
                                   else sp.current_frame.values()[0])
                                  for sp in self.subplots.values()
                                  if sp.current_frame]
                framewise = any(self.lookup_options(frame, 'norm').options.get('framewise')
                                for frame in current_frames)
            else:
                opts = self.lookup_options(self.current_frame, 'norm')
                framewise = opts.options.get('framewise')
            if framewise or isinstance(self.hmap, DynamicMap):
                handles += [plot.x_range, plot.y_range]
        return handles



class BokehMPLWrapper(ElementPlot):
    """
    Wraps an existing HoloViews matplotlib plot and converts
    it to bokeh.
    """

    def __init__(self, element, plot=None, **params):
        super(ElementPlot, self).__init__(element, **params)
        if isinstance(element, HoloMap):
            etype = element.type
        else:
            etype = type(element)
        plot = Store.registry['matplotlib'][etype]
        params = dict({k: v.default for k, v in self.params().items()
                       if k in ['bgcolor']})
        params = dict(params, **self.lookup_options(element, 'plot').options)
        style = self.lookup_options(element, 'style')
        self.mplplot = plot(element, style=style, **params)


    def initialize_plot(self, ranges=None, plot=None, plots=None):
        self.mplplot.initialize_plot(ranges)

        plot = plot if plot else self.handles.get('plot')
        new_plot = mpl.to_bokeh(self.mplplot.state)
        if plot:
            update_plot(plot, new_plot)
        else:
            plot = new_plot

        self.handles['plot'] = plot
        if not self.overlaid:
            self._update_plot(self.keys[-1], plot, self.hmap.last)
        return plot


    def _update_plot(self, key, plot, element=None):
        """
        Updates plot parameters on every frame
        """
        plot.set(**self._plot_properties(key, plot, element))

    def update_frame(self, key, ranges=None, plot=None, element=None, empty=False):
        self.mplplot.update_frame(key, ranges)

        reused = isinstance(self.hmap, DynamicMap) and self.overlaid
        if not reused and element is None:
            element = self._get_frame(key)
        else:
            self.current_key = key
            self.current_frame = element

        plot = mpl.to_bokeh(self.mplplot.state)
        update_plot(self.handles['plot'], plot)
        if not self.overlaid:
            self._update_plot(key, self.handles['plot'], element)


class BokehMPLRawWrapper(BokehMPLWrapper):
    """
    Wraps an existing HoloViews matplotlib plot, renders it as
    an image and displays it as a HoloViews object.
    """

    def initialize_plot(self, ranges=None, plot=None, plots=None):
        element = self.hmap.last
        self.mplplot.initialize_plot(ranges)
        plot = self._render_plot(element, plot)
        self.handles['plot'] = plot
        return plot

    def _render_plot(self, element, plot=None):
        from .raster import RGBPlot
        bytestream = BytesIO()
        renderer = self.mplplot.renderer.instance(dpi=120)
        renderer.save(self.mplplot, bytestream, fmt='png')
        group = ('RGB' if element.group == type(element).__name__ else
                 element.group)
        rgb = RGB.load_image(bytestream, bare=True, group=group,
                             label=element.label)
        plot_opts = self.lookup_options(element, 'plot').options
        rgbplot = RGBPlot(rgb, **plot_opts)
        return rgbplot.initialize_plot(plot=plot)


    def update_frame(self, key, ranges=None, element=None):
        element = self.get_frame(key)
        if key in self.hmap:
            self.mplplot.update_frame(key, ranges)
            self.handles['plot'] = self._render_plot(element)


class OverlayPlot(GenericOverlayPlot, ElementPlot):

    legend_position = param.ObjectSelector(objects=["top_right",
                                                    "top_left",
                                                    "bottom_left",
                                                    "bottom_right"],
                                                    default="top_right",
                                                    doc="""
        Allows selecting between a number of predefined legend position
        options. The predefined options may be customized in the
        legend_specs class attribute.""")

    tabs = param.Boolean(default=False, doc="""
        Whether to display overlaid plots in separate panes""")

    style_opts = legend_dimensions + line_properties + text_properties

    _update_handles = ['source']

    def _process_legend(self):
        plot = self.handles['plot']
        if not self.show_legend or len(plot.legend) == 0:
            for l in plot.legend:
                l.legends[:] = []
                l.border_line_alpha = 0
                l.background_fill_alpha = 0
            return

        options = {}
        properties = self.lookup_options(self.hmap.last, 'style')[self.cyclic_index]
        for k, v in properties.items():
            if k in line_properties:
                k = 'border_' + k
            elif k in text_properties:
                k = 'label_' + k
            options[k] = v

        legend_labels = []
        if not plot.legend:
            return
        plot.legend[0].set(**options)
        legend_fontsize = self._fontsize('legend', 'size').get('size',False)
        if legend_fontsize:
            plot.legend[0].label_text_font_size = legend_fontsize

        plot.legend.location = self.legend_position
        legends = plot.legend[0].legends
        new_legends = []
        for label, l in legends:
            if label in legend_labels:
               continue
            legend_labels.append(label)
            new_legends.append((label, l))
        plot.legend[0].legends[:] = new_legends


    def _init_tools(self, element):
        """
        Processes the list of tools to be supplied to the plot.
        """
        tools = []
        hover = False
        for key, subplot in self.subplots.items():
                el = element.get(key)
                if el is not None:
                    el_tools = subplot._init_tools(el)
                    el_tools = [t for t in el_tools
                                if not (isinstance(t, HoverTool) and hover)]
                    tools += el_tools
                    if any(isinstance(t, HoverTool) for t in el_tools):
                        hover = True
        return list(set(tools))


    def initialize_plot(self, ranges=None, plot=None, plots=None):
        key = self.keys[-1]
        element = self._get_frame(key)
        ranges = self.compute_ranges(self.hmap, key, ranges)
        if plot is None and not self.tabs and not self.batched:
            plot = self._init_plot(key, element, ranges=ranges, plots=plots)
            self._init_axes(plot)
        if plot and not self.overlaid:
            self._update_plot(key, plot, element)
        self.handles['plot'] = plot

        panels = []
        for key, subplot in self.subplots.items():
            if self.tabs: subplot.overlaid = False
            child = subplot.initialize_plot(ranges, plot, plots)
            if self.batched:
                self.handles['plot'] = child
            if self.tabs:
                if self.hmap.type is Overlay:
                    title = ' '.join(key)
                else:
                    title = ', '.join([d.pprint_value_string(k) for d, k in
                                       zip(self.hmap.last.kdims, key)])
                panels.append(Panel(child=child, title=title))
            if isinstance(element, CompositeOverlay):
                frame = element.get(key, None)
                subplot.current_frame = frame

        if self.tabs:
            self.handles['plot'] = Tabs(tabs=panels)
        elif not self.overlaid:
            self._process_legend()
        self.drawn = True

        return self.handles['plot']


    def update_frame(self, key, ranges=None, element=None, empty=False):
        """
        Update the internal state of the Plot to represent the given
        key tuple (where integers represent frames). Returns this
        state.
        """
        if element is None:
            element = self._get_frame(key)
        else:
            self.current_frame = element
            self.current_key = key

        if isinstance(self.hmap, DynamicMap):
            range_obj = element
            items = element.items()
        else:
            range_obj = self.hmap
            items = element.items()

        all_empty = empty
        ranges = self.compute_ranges(range_obj, key, ranges)
        for k, subplot in self.subplots.items():
            empty, el = False, None
            if isinstance(self.hmap, DynamicMap):
                idx = dynamic_update(self, subplot, k, element, items)
                empty = idx is None
                if not empty:
                    _, el = items.pop(idx)
            subplot.update_frame(key, ranges, element=el, empty=(empty or all_empty))

        if isinstance(self.hmap, DynamicMap) and items:
            raise Exception("Some Elements returned by the dynamic callback "
                            "were not initialized correctly and could not be "
                            "rendered.")

        if not self.overlaid and not self.tabs and not self.batched:
            self._update_ranges(element, ranges)
            self._update_plot(key, self.handles['plot'], element)