[英]Python, Tkinter: Can a list be modified within a button callback without using global variables or defining new classes?
[英]Python tkinter text modified callback
在 python 2.7 中,每次在 Tkinter Text 小部件中更改某些內容時,我都會嘗試獲取回調。
該程序根據此處找到的代碼使用多個幀: 在 tkinter 中的兩個幀之間切換
回調部分取自以下示例: http : //code.activestate.com/recipes/464635-call-a-callback-when-a-tkintertext-is-modified/
兩個代碼單獨工作都很好,但是將這兩個代碼結合起來對我來說很困難。 這是我嘗試使用盡可能簡單的代碼。
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()
我嘗試只從回調示例中提取必要的部分。 當文本被修改時,代碼確實做了一個回調(如果self.tk.call(self._w, 'edit', 'modified', 0)行被注釋掉了),但是重置修改后的標志不起作用,所以只有第一個修改被注冊。
目前我收到以下錯誤:
第 67 行,在 clearModifiedFlag self.tk.call(self._w, 'edit', 'modified', 0) _tkinter.TclError: bad option "edit": must be cget or configure
在回調示例代碼中,“編輯”工作正常。
編輯:這是工作代碼
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()
我建議一個更簡單的方法。 您可以為小部件設置代理,並且在該代理中,您可以檢測到何時插入或刪除了任何內容。 您可以使用該信息來生成虛擬事件,該事件可以像任何其他事件一樣綁定。
讓我們首先創建一個自定義文本小部件類,您將像使用任何其他文本小部件一樣使用它:
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
本例中的代理做了三件事:
您可以像使用任何其他 Text 小部件一樣使用此小部件,並且可以綁定到<<TextModified>>
。
例如,如果您想在文本小部件中顯示字符數,您可以執行以下操作:
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()
我在我的代碼中集成了上面的
<<TextModified
>> 示例並且它運行得很好,除了它干擾了一些edit_modified()
命令。幸運的是,tkinter 文本窗口有一個記錄不佳的功能,它同樣好並且與
edit_modified()
獲取或設置命令完全兼容:預定義的<<Modified
>> 標簽。 您甚至不必創建它,它開箱即用。以下是我的代碼的相關部分:
刪除了“self”前綴,可能需要進行一些調整
將其放入您的文本小工具代碼中:
title = set_title(fname, numbr)
text.bind("<<Modified>>", lambda dummy: save_indicator(title))
確保這些功能可見:
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
這是一個帶有預定義
<<Modified
>> 標簽的完整工作示例:
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()
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.