将上述代码增加画直线，画圆，圆弧等功能

下面是增加画直线，画圆和圆弧功能的wxpython程序示例：

import wx
import math

class DrawingPanel(wx.Panel):
    def __init__(self, parent):
        wx.Panel.__init__(self, parent)
        self.SetBackgroundColour("WHITE")
        self.Bind(wx.EVT_PAINT, self.on_paint)
        self.Bind(wx.EVT_LEFT_DOWN, self.on_left_down)
        self.Bind(wx.EVT_LEFT_UP, self.on_left_up)
        self.Bind(wx.EVT_MOTION, self.on_motion)
        self.lines = []
        self.current_line = None
        self.shapes = []
        self.current_shape = None
        self.mode = "line"

    def on_paint(self, event):
        dc = wx.PaintDC(self)
        dc.SetPen(wx.Pen("BLACK", 2))
        for line in self.lines:
            dc.DrawLine(*line)
        for shape in self.shapes:
            if shape[0] == "line":
                dc.DrawLine(*shape[1:])
            elif shape[0] == "circle":
                dc.DrawCircle(*shape[1:])
            elif shape[0] == "arc":
                dc.DrawArc(*shape[1:])

    def on_left_down(self, event):
        if self.mode == "line":
            self.current_line = [event.GetPosition()]
        elif self.mode == "circle":
            self.current_shape = ["circle", event.GetPosition(), 0]
        elif self.mode == "arc":
            self.current_shape = ["arc", event.GetPosition(), 0, 0]

    def on_left_up(self, event):
        if self.mode == "line":
            if self.current_line:
                self.current_line.append(event.GetPosition())
                self.lines.append(self.current_line)
                self.current_line = None
                self.Refresh()
        elif self.mode == "circle":
            if self.current_shape:
                radius = math.sqrt((event.GetX() - self.current_shape[1][0])**2 + (event.GetY() - self.current_shape[1][1])**2)
                self.current_shape[2] = radius
                self.shapes.append(self.current_shape)
                self.current_shape = None
                self.Refresh()
        elif self.mode == "arc":
            if self.current_shape:
                end_pos = event.GetPosition()
                radius = math.sqrt((end_pos[0] - self.current_shape[1][0])**2 + (end_pos[1] - self.current_shape[1][1])**2)
                start_angle = math.atan2(self.current_shape[1][1] - end_pos[1], end_pos[0] - self.current_shape[1][0])
                end_angle = math.atan2(end_pos[1] - self.current_shape[1][1], self.current_shape[1][0] - end_pos[0])
                self.current_shape[2] = radius
                self.current_shape[3] = (start_angle, end_angle)
                self.shapes.append(self.current_shape)
                self.current_shape = None
                self.Refresh()

    def on_motion(self, event):
        if self.mode == "line":
            if self.current_line:
                self.current_line.append(event.GetPosition())
                self.Refresh()
        elif self.mode == "circle":
            if self.current_shape:
                radius = math.sqrt((event.GetX() - self.current_shape[1][0])**2 + (event.GetY() - self.current_shape[1][1])**2)
                self.current_shape[2] = radius
                self.Refresh()
        elif self.mode == "arc":
            if self.current_shape:
                end_pos = event.GetPosition()
                radius = math.sqrt((end_pos[0] - self.current_shape[1][0])**2 + (end_pos[1] - self.current_shape[1][1])**2)
                start_angle = math.atan2(self.current_shape[1][1] - end_pos[1], end_pos[0] - self.current_shape[1][0])
                end_angle = math.atan2(end_pos[1] - self.current_shape[1][1], self.current_shape[1][0] - end_pos[0])
                self.current_shape[2] = radius
                self.current_shape[3] = (start_angle, end_angle)
                self.Refresh()

    def set_mode(self, mode):
        self.mode = mode

class DrawingFrame(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None, title="CAD-like Drawing Program")
        self.panel = DrawingPanel(self)
        self.status_bar = self.CreateStatusBar()
        self.draw_line_btn = wx.Button(self, label="Line")
        self.draw_circle_btn = wx.Button(self, label="Circle")
        self.draw_arc_btn = wx.Button(self, label="Arc")
        self.draw_line_btn.Bind(wx.EVT_BUTTON, self.on_draw_line)
        self.draw_circle_btn.Bind(wx.EVT_BUTTON, self.on_draw_circle)
        self.draw_arc_btn.Bind(wx.EVT_BUTTON, self.on_draw_arc)
        self.mode_box = wx.StaticBox(self, -1, "Mode")
        self.mode_sizer = wx.StaticBoxSizer(self.mode_box, wx.VERTICAL)
        self.mode_sizer.Add(self.draw_line_btn, 0, wx.ALL | wx.EXPAND, 5)
        self.mode_sizer.Add(self.draw_circle_btn, 0, wx.ALL | wx.EXPAND, 5)
        self.mode_sizer.Add(self.draw_arc_btn, 0, wx.ALL | wx.EXPAND, 5)
        self.sizer = wx.BoxSizer(wx.HORIZONTAL)
        self.sizer.Add(self.panel, 1, wx.EXPAND)
        self.sizer.Add(self.mode_sizer, 0, wx.ALL | wx.EXPAND, 5)
        self.SetSizerAndFit(self.sizer)
        self.Show()

    def on_draw_line(self, event):
        self.panel.set_mode("line")
        self.status_bar.SetStatusText("Mode: Line")

    def on_draw_circle(self, event):
        self.panel.set_mode("circle")
        self.status_bar.SetStatusText("Mode: Circle")

    def on_draw_arc(self, event):
        self.panel.set_mode("arc")
        self.status_bar.SetStatusText("Mode: Arc")

if __name__ == "__main__":
    app = wx.App(False)
    frame = DrawingFrame()
    app.MainLoop()

在这个示例中，我们首先将DrawingPanel类进行了修改，以支持不同类型的图形绘制。我们增加了一个shapes列表来维护所有的图形，以及一个current_shape变量来跟踪当前正在绘制的图形。我们还增加了一个mode变量来跟踪当前绘图模式，以便在鼠标事件处理器中执行正确的绘图操作。

我们在on_paint方法中增加了绘制不同类型的图形的代码。在on_left_down方法中，我们检测当前绘图模式并创建相应类型的图形。在on_left_up方法中，我们完成当前正在绘制的图形，并将其添加到shapes列表中。在on_motion方法中，我们在当前正在绘制的图形上更新半径和角度，并在需要时重新绘制面板。

我们还创建了一些wx.Button和wx.StaticBox，用于在绘图模式之间切换，并在状态栏中显示当前模式。

当程序运行时，用户可以使用鼠标在DrawingPanel上绘制直线，圆和圆弧。用户可以使用按钮切换绘图模式。状态栏显示当前绘图模式。