Python tkinter文本修改后的回调

时间:2016-11-15 18:51:30

标签: python tkinter callback

在python 2.7中,每次在Tkinter Text小部件中更改某些内容时,我都会尝试进行回调。

该程序根据此处的代码使用多个框架:Switch between two frames in tkinter

回调部分取自以下示例:http://code.activestate.com/recipes/464635-call-a-callback-when-a-tkintertext-is-modified/

两个代码都可以单独使用,但是将这两个代码组合起来对我来说很难。 这是我尝试使用尽可能简单的代码。

import Tkinter as tk

class Texter(tk.Tk):

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)

        container = tk.Frame(self)
        container.pack()

        self.frames = {}

        for F in (ConnectPage, EditorPage):
            frame = F(container, self)
            self.frames[F] = frame
            frame.grid(row=0, column=0, sticky="nsew")

        page_name = EditorPage.__name__
        self.frames[page_name] = frame
        self.show_frame(ConnectPage)


    def show_frame(self, cont):
        frame = self.frames[cont]
        frame.tkraise()

    def get_page(self, page_name):
        return self.frames[page_name]


class ConnectPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)

        button1 = tk.Button(self, text="SecondPage",
                            command=lambda: controller.show_frame(EditorPage))
        button1.grid(row=2, column=3, padx=15)


class EditorPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)

        self.text = tk.Text(self, height=25, width=80)
        self.text.grid(column=0, row=0, sticky="nw")

        button2 = tk.Button(self, text="FirstPage",
                            command=lambda: controller.show_frame(ConnectPage))
        button2.grid(row=2, column=3, padx=15)

        self.clearModifiedFlag()
        self.bind_all('<<Modified>>', self._beenModified)

    def _beenModified(self, event=None):
        if self._resetting_modified_flag: return

        self.clearModifiedFlag()
        print("Hello!")
        #self.beenModified(event)

    def clearModifiedFlag(self):
        self._resetting_modified_flag = True

        try:
            self.tk.call(self._w, 'edit', 'modified', 0)

        finally:
            self._resetting_modified_flag = False


if __name__ == '__main__':
    gui = Texter()
    gui.mainloop()

我尝试从回调示例中仅获取必要的部分。 代码确实进行了回调(如果 self.tk.call(self._w,'edit','modified',0)行被注释掉)修改文本时,但重置修改后的flag不起作用,因此只注册了第一个修改。

目前我收到以下错误:
第67行,在clearModifiedFlag中     self.tk.call(self._w,'edit','modified',0) _tkinter.TclError:错误选项“编辑”:必须是cget或configure

在回调示例代码中,“编辑”工作正常。

编辑:这是工作代码

import Tkinter as tk

class Texter(tk.Tk):

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)

        container = tk.Frame(self)
        container.pack()

        self.frames = {}

        for F in (ConnectPage, EditorPage):
            frame = F(container, self)
            self.frames[F] = frame
            frame.grid(row=0, column=0, sticky="nsew")

        page_name = EditorPage.__name__
        self.frames[page_name] = frame
        self.show_frame(ConnectPage)


    def show_frame(self, cont):
        frame = self.frames[cont]
        frame.tkraise()

    def get_page(self, page_name):
        return self.frames[page_name]


class ConnectPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)

        button1 = tk.Button(self, text="SecondPage",
                            command=lambda: controller.show_frame(EditorPage))
        button1.grid(row=2, column=3, padx=15)


class EditorPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)

        self.text = CustomText(self, height=25, width=80)
        self.text.grid(column=0, row=0, sticky="nw")
        self.text.bind("<<TextModified>>", self.onModification)

        button2 = tk.Button(self, text="FirstPage",
                            command=lambda: controller.show_frame(ConnectPage))
        button2.grid(row=2, column=3, padx=15)

    def onModification(self, event):
        print("Yellow!")


class CustomText(tk.Text):
    def __init__(self, *args, **kwargs):
        """A text widget that report on internal widget commands"""
        tk.Text.__init__(self, *args, **kwargs)

        # create a proxy for the underlying widget
        self._orig = self._w + "_orig"
        self.tk.call("rename", self._w, self._orig)
        self.tk.createcommand(self._w, self._proxy)

    def _proxy(self, command, *args):
        cmd = (self._orig, command) + args
        result = self.tk.call(cmd)

        if command in ("insert", "delete", "replace"):
            self.event_generate("<<TextModified>>")

        return result

if __name__ == '__main__':
    gui = Texter()
    gui.mainloop()

2 个答案:

答案 0 :(得分:5)

我建议采用更简单的方法。您可以为窗口小部件设置代理,并且在该代理中,您可以检测何时插入或删除任何内容。您可以使用该信息生成虚拟事件,该事件可以像任何其他事件一样被绑定。

让我们首先创建一个自定义文本窗口小部件类,您将像任何其他文本窗口小部件一样使用它:

import Tkinter as tk

class CustomText(tk.Text):
    def __init__(self, *args, **kwargs):
        """A text widget that report on internal widget commands"""
        tk.Text.__init__(self, *args, **kwargs)

        # create a proxy for the underlying widget
        self._orig = self._w + "_orig"
        self.tk.call("rename", self._w, self._orig)
        self.tk.createcommand(self._w, self._proxy)

    def _proxy(self, command, *args):
        cmd = (self._orig, command) + args
        result = self.tk.call(cmd)

        if command in ("insert", "delete", "replace"):
            self.event_generate("<<TextModified>>")

        return result

此示例中的代理执行三项操作:

  1. 首先它调用实际的widget命令,传入它收到的所有参数。
  2. 接下来,它会为每个插入和每次删除生成一个事件
  3. 然后它会生成虚拟事件
  4. 最后它返回实际小部件命令的结果
  5. 您可以像使用任何其他文本小部件一样使用此小部件,还可以将其绑定到<<TextModified>>

    例如,如果要在文本小部件中显示字符数,可以执行以下操作:

    root = tk.Tk()
    label = tk.Label(root, anchor="w")
    text = CustomText(root, width=40, height=4)
    
    label.pack(side="bottom", fill="x")
    text.pack(side="top", fill="both", expand=True)
    
    def onModification(event):
        chars = len(event.widget.get("1.0", "end-1c"))
        label.configure(text="%s chars" % chars)
    
    text.bind("<<TextModified>>", onModification)
    
    root.mainloop()
    

答案 1 :(得分:1)

我在代码中集成了上面的<<TextModified >>示例, 工作很好,除了它干扰了一些 edit_modified()命令。

幸运的是,tkinter文本窗口的文档功能不完善 效果很好,并且与edit_modified() get完全兼容 或设置命令:预定义的<<Modified >>标记。你甚至都没有 要创建它,它是开箱即用的。

这是我代码的相关部分:

“自我”前缀已删除,可能需要进行一些调整

将其放入“文本”小工具代码中:

title = set_title(fname, numbr)

text.bind("<<Modified>>", lambda dummy: save_indicator(title))

确保这些功能可见:

def set_title(fname, numbr):  
    "Creates a window title showing the save indicator,"  
    "the file name and a window number"  
    fname = strip_path(fname)  
    if not fname:  
        fname = "(New Document)"  
    return "+ {} - Window no.{}".format(fname, numbr)  

def strip_path(fname):  
    return os.path.split(fname)[-1]

def save_indicator(title, event=None):  
    "Update the window title"  
    titre = toggle_star(title)  
    text.winfo_toplevel().title(title)  

def toggle_star(title):  
    "Change the first character of the title"  
    chr='+'; chr0='x'  
    if text.edit_modified():  
        title = chr0 + title[1:]  
    else:  
        title = chr + title[1:]  
    return title  

这是一个带有预定义<<Modified >>标记的完整工作示例:

def toggle_star(title):  
    "Change the color of the star in the title bar"  
    chr='+'; chr0='x'  
    if text.edit_modified():  
            title = chr0 + title[1:]  
    else:  
            title = chr + title[1:]  
    return title  

def set_title(fname, winno):  
    "Put save indicator, file name and window number in the title"  
    if not fname:  
            fname = "(New Document)"  
    return "+ {} - Window no.{}".format(fname, winno)  

def mockSave(title, event=None):  
    title = toggle_star(title)  
    root.winfo_toplevel().title(title)  
    text.edit_modified(0)  

def read_ed_mod():  
    print("text.edit_modified()=", text.edit_modified())  

def onModification(title, event=None):  
    title = toggle_star(title)  
    root.winfo_toplevel().title(title)  

from tkinter import *  

fname = 'blabla.txt'  
winno = 1 ;  

root = Tk()  
label = Label(root, anchor="w")  
text = Text(root, width=40, height=4)  
label.pack(side="bottom", fill="x")  
text.pack(side="top", fill="both", expand=True)  
Button(root, text='Mock Save', command= lambda: mockSave(title)).pack(side=LEFT)  
Button(root, text='Read ed_mod', command= lambda: read_ed_mod()).pack(side=RIGHT)  
text.bind('<<Modified>>', lambda event: onModification(title))  

title = set_title(fname, winno)  
root.winfo_toplevel().title(title)  
text.edit_modified(0)  

root.mainloop()