#https://github.com/RobberPhex/GTK-Example-CalcArea from gi.repository import Gtk, Gdk, GdkPixbuf from PIL import Image, ImageDraw from io import BytesIO from math import pi class Model:     '''     模型类     存储半径，计算周长、面积、体积     '''     def __init__(self):         self._radius = 0     def setRadius(self, radius):         self._radius = float(radius)     def getRadius(self):         return self._radius     def getPerimeter(self):         return pi * self._radius * 2     def getArea(self):         return self._radius ** 2 * pi     def getVolume(self):         return 4 * pi * self._radius ** 3 / 3 class Controller:     '''     控制器类     控制视图和模型的更新     '''     def __init__(self, model):         self.model = model         self._observers = []     def addObserver(self, observer):         self._observers.append(observer)     def setRadius(self, radius):         model.setRadius(radius)         self.notify()     def notify(self):         for observer in self._observers:             observer.update() class TextView:     '''     文字视图类     处理文本输入框的视图     '''     def __init__(self, model, rEntry, pEntry, aEntry, vEntry):         '''         :type model Model         '''         self.model = model         self.rEntry = rEntry         self.pEntry = pEntry         self.aEntry = aEntry         self.vEntry = vEntry     def update(self):         self.rEntry.set_text('%2.2f' % self.model.getRadius())         self.pEntry.set_text('%2.2f' % self.model.getPerimeter())         self.aEntry.set_text('%2.2f' % self.model.getArea())         self.vEntry.set_text('%2.2f' % self.model.getVolume()) class ScaleView:     '''     拖动条视图     处理拖动条的视图     '''     def __init__(self, model, scale):         '''         :type model Model         '''         self.model = model         self.scale = scale     def update(self):         self.scale.set_value(self.model.getRadius()) class ImageView:     '''     图像视图     处理图像的视图     '''     @classmethod     def imgToPixbuf(cls, img):         '''         :type img Image         '''         buff = BytesIO()         img.save(buff, 'ppm')         contents = buff.getvalue()         buff.close()         loader = GdkPixbuf.PixbufLoader.new_with_type('pnm')         loader.write(contents)         pixbuf = loader.get_pixbuf()         loader.close()         return pixbuf     @classmethod     def ellipse(cls, radius):         '''         :type radius int         '''         image = Image.new("RGBA", (300, 300), "white")         draw = ImageDraw.Draw(image)         minor = 150 - radius         major = 150 + radius         draw.ellipse((minor, minor, major, major), outline='red')         pixbuf = ImageView.imgToPixbuf(image)         return pixbuf     def __init__(self, model, image):         self.model = model         self.image = image     def update(self):         radius = self.model.getRadius()         pixbuf = ImageView.ellipse(radius)         self.image.set_from_pixbuf(pixbuf) class MainWindow(Gtk.Window):     '''     主窗口类     负责整体界面的显示     '''     def textCallback(self, widget, controller):         '''         文本输入回调         '''         try:             radius = float(widget.get_text())             controller.setRadius(radius)         except ValueError as e:             pass     def scaleCallback(self, widget, controller):         '''         拖动条回调         '''         radius = widget.get_value()         controller.setRadius(radius)     def __init__(self):         Gtk.Window.__init__(self, title="Title")         self.set_default_size(600, 400)         self.set_position(Gtk.WindowPosition.CENTER)         hbox = Gtk.HBox(spacing=5)         self.add(hbox)         vbox = Gtk.VBox(spacing=5)         hbox.pack_start(vbox, True, True, 2)         table = Gtk.Table.new(4, 2, False)         vbox.pack_start(table, True, True, 2)         label = Gtk.Label('半径：')         table.attach_defaults(label, 0, 1, 0, 1)         label = Gtk.Label('周长：')         table.attach_defaults(label, 0, 1, 1, 2)         label = Gtk.Label('面积：')         table.attach_defaults(label, 0, 1, 2, 3)         label = Gtk.Label('体积：')         table.attach_defaults(label, 0, 1, 3, 4)         self.radiusEntry = Gtk.Entry.new()         self.radiusEntry.connect('changed', self.textCallback, controller)         table.attach_defaults(self.radiusEntry, 1, 2, 0, 1)         self.perimeterEntry = Gtk.Entry.new()         self.perimeterEntry.set_sensitive(False)         self.perimeterEntry.set_text('周长')         table.attach_defaults(self.perimeterEntry, 1, 2, 1, 2)         self.areaEntry = Gtk.Entry.new()         self.areaEntry.set_sensitive(False)         self.areaEntry.set_text('面积')         table.attach_defaults(self.areaEntry, 1, 2, 2, 3)         self.volumeEntry = Gtk.Entry.new()         self.volumeEntry.set_sensitive(False)         self.volumeEntry.set_text('体积')         table.attach_defaults(self.volumeEntry, 1, 2, 3, 4)         self.scale = Gtk.HScale.new_with_range(0, 100, 1)         self.scale.connect('value-changed', self.scaleCallback, controller)         vbox.pack_start(self.scale, False, False, 2)         pixbuf = GdkPixbuf.Pixbuf.new(GdkPixbuf.Colorspace.RGB, True, 8, 300, 300)         pixbuf.fill(0xaaaaaaaa)         self.image = Gtk.Image.new_from_pixbuf(pixbuf)         hbox.pack_start(self.image, True, True, 2)         self.connect('delete-event', Gtk.main_quit) model = Model() controller = Controller(model) if __name__ == '__main__':     Gdk.threads_init()     Gdk.threads_enter()     win = MainWindow()     iv = ImageView(model, win.image)     controller.addObserver(iv)     tv = TextView(model, win.radiusEntry, win.perimeterEntry, win.areaEntry, win.volumeEntry)     controller.addObserver(tv)     sv = ScaleView(model, win.scale)     controller.addObserver(sv)     win.show_all()     Gtk.main()     Gdk.threads_leave()