 
    from __future__ import division, print_function
import numpy as np
import matplotlib
import matplotlib.colors as colors
import matplotlib.patches as patches
import matplotlib.mathtext as mathtext
import matplotlib.pyplot as plt
import matplotlib.artist as artist
import matplotlib.image as image
class ItemProperties(object):
    def __init__(self, fontsize=14, labelcolor='black', bgcolor='yellow',
                 alpha=1.0):
        self.fontsize = fontsize
        self.labelcolor = labelcolor
        self.bgcolor = bgcolor
        self.alpha = alpha
        self.labelcolor_rgb = colors.to_rgba(labelcolor)[:3]
        self.bgcolor_rgb = colors.to_rgba(bgcolor)[:3]
class MenuItem(artist.Artist):
    parser = mathtext.MathTextParser("Bitmap")
    padx = 5
    pady = 5
    def __init__(self, fig, labelstr, props=None, hoverprops=None,
                 on_select=None):
        artist.Artist.__init__(self)
        self.set_figure(fig)
        self.labelstr = labelstr
        if props is None:
            props = ItemProperties()
        if hoverprops is None:
            hoverprops = ItemProperties()
        self.props = props
        self.hoverprops = hoverprops
        self.on_select = on_select
        x, self.depth = self.parser.to_mask(
            labelstr, fontsize=props.fontsize, dpi=fig.dpi)
        if props.fontsize != hoverprops.fontsize:
            raise NotImplementedError(
                'support for different font sizes not implemented')
        self.labelwidth = x.shape[1]
        self.labelheight = x.shape[0]
        self.labelArray = np.zeros((x.shape[0], x.shape[1], 4))
        self.labelArray[:, :, -1] = x/255.
        self.label = image.FigureImage(fig, origin='upper')
        self.label.set_array(self.labelArray)
        # we'll update these later
        self.rect = patches.Rectangle((0, 0), 1, 1)
        self.set_hover_props(False)
        fig.canvas.mpl_connect('button_release_event', self.check_select)
    def check_select(self, event):
        over, junk = self.rect.contains(event)
        if not over:
            return
        if self.on_select is not None:
            self.on_select(self)
    def set_extent(self, x, y, w, h):
        print(x, y, w, h)
        self.rect.set_x(x)
        self.rect.set_y(y)
        self.rect.set_width(w)
        self.rect.set_height(h)
        self.label.ox = x + self.padx
        self.label.oy = y - self.depth + self.pady/2.
        self.rect._update_patch_transform()
        self.hover = False
    def draw(self, renderer):
        self.rect.draw(renderer)
        self.label.draw(renderer)
    def set_hover_props(self, b):
        if b:
            props = self.hoverprops
        else:
            props = self.props
        r, g, b = props.labelcolor_rgb
        self.labelArray[:, :, 0] = r
        self.labelArray[:, :, 1] = g
        self.labelArray[:, :, 2] = b
        self.label.set_array(self.labelArray)
        self.rect.set(facecolor=props.bgcolor, alpha=props.alpha)
    def set_hover(self, event):
        'check the hover status of event and return true if status is changed'
        b, junk = self.rect.contains(event)
        changed = (b != self.hover)
        if changed:
            self.set_hover_props(b)
        self.hover = b
        return changed
class Menu(object):
    def __init__(self, fig, menuitems):
        self.figure = fig
        fig.suppressComposite = True
        self.menuitems = menuitems
        self.numitems = len(menuitems)
        maxw = max([item.labelwidth for item in menuitems])
        maxh = max([item.labelheight for item in menuitems])
        totalh = self.numitems*maxh + (self.numitems + 1)*2*MenuItem.pady
        x0 = 100
        y0 = 400
        width = maxw + 2*MenuItem.padx
        height = maxh + MenuItem.pady
        for item in menuitems:
            left = x0
            bottom = y0 - maxh - MenuItem.pady
            item.set_extent(left, bottom, width, height)
            fig.artists.append(item)
            y0 -= maxh + MenuItem.pady
        fig.canvas.mpl_connect('motion_notify_event', self.on_move)
    def on_move(self, event):
        draw = False
        for item in self.menuitems:
            draw = item.set_hover(event)
            if draw:
                self.figure.canvas.draw()
                break
fig = plt.figure()
fig.subplots_adjust(left=0.3)
props = ItemProperties(labelcolor='black', bgcolor='yellow',
                       fontsize=15, alpha=0.2)
hoverprops = ItemProperties(labelcolor='white', bgcolor='blue',
                            fontsize=15, alpha=0.2)
menuitems = []
for label in ('open', 'close', 'save', 'save as', 'quit'):
    def on_select(item):
        print('you selected %s' % item.labelstr)
    item = MenuItem(fig, label, props=props, hoverprops=hoverprops,
                    on_select=on_select)
    menuitems.append(item)
menu = Menu(fig, menuitems)
plt.show()
Keywords: python, matplotlib, pylab, example, codex (see Search examples)