matplotlib & pandas

Python/matplotlab/gallery/widgets/menu.md

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+# 菜单
+
+![菜单示例](https://matplotlib.org/_images/sphx_glr_menu_001.png)
+
+输出：
+
+```python
+100 371 91 29
+100 342 91 29
+100 313 91 29
+100 284 91 29
+100 255 91 29
+```
+
+```python
+import numpy as np
+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.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()
+```
+
+## 下载这个示例
+            
+- [下载python源码: menu.py](https://matplotlib.org/_downloads/menu.py)
+- [下载Jupyter notebook: menu.ipynb](https://matplotlib.org/_downloads/menu.ipynb)