How to remove icursor from Tkinter canvas text item?

问题

I'm following along with Effbot's Tkinter page here: http://effbot.org/zone/editing-canvas-text-items.htm

The trouble I'm having is that after inserting the icursor, I can't seem to get it to go away!

How do I stop editing altogether?

As for examples, the one from the linked page will work:

# File: canvas-editing-example-1.py
#
# editing canvas items
#
# fredrik lundh, december 1998
#
# fredrik@pythonware.com
# http://www.pythonware.com
#

from tkinter import *
#Change to Tkinter to use python 2.x series
class MyCanvas(Frame):

    def __init__(self, root):
        Frame.__init__(self, root)

        self.canvas = Canvas(self)
        self.canvas.pack(fill=BOTH, expand=1)

        # standard bindings
        self.canvas.bind("<Double-Button-1>", self.set_focus)
        self.canvas.bind("<Button-1>", self.set_cursor)
        self.canvas.bind("<Key>", self.handle_key)

        # add a few items to the canvas
        self.canvas.create_text(50, 50, text="hello")
        self.canvas.create_text(50, 100, text="world")

    def highlight(self, item):
        # mark focused item.  note that this code recreates the
        # rectangle for each update, but that's fast enough for
        # this case.
        bbox = self.canvas.bbox(item)
        self.canvas.delete("highlight")
        if bbox:
            i = self.canvas.create_rectangle(
                bbox, fill="white",
                tag="highlight"
                )
            self.canvas.lower(i, item)

    def has_focus(self):
        return self.canvas.focus()

    def has_selection(self):
        # hack to work around bug in Tkinter 1.101 (Python 1.5.1)
        return self.canvas.tk.call(self.canvas._w, 'select', 'item')

    def set_focus(self, event):
        if self.canvas.type(CURRENT) != "text":
            return

        self.highlight(CURRENT)

        # move focus to item
        self.canvas.focus_set() # move focus to canvas
        self.canvas.focus(CURRENT) # set focus to text item
        self.canvas.select_from(CURRENT, 0)
        self.canvas.select_to(CURRENT, END)

    def set_cursor(self, event):
        # move insertion cursor
        item = self.has_focus()
        if not item:
            return # or do something else

        # translate to the canvas coordinate system
        x = self.canvas.canvasx(event.x)
        y = self.canvas.canvasy(event.y)

        self.canvas.icursor(item, "@%d,%d" % (x, y))
        self.canvas.select_clear()

    def handle_key(self, event):
        # widget-wide key dispatcher
        item = self.has_focus()
        if not item:
            return

        insert = self.canvas.index(item, INSERT)

        if event.char >= " ":
            # printable character
            if self.has_selection():
                self.canvas.dchars(item, SEL_FIRST, SEL_LAST)
                self.canvas.select_clear()
            self.canvas.insert(item, "insert", event.char)
            self.highlight(item)

        elif event.keysym == "BackSpace":
            if self.has_selection():
                self.canvas.dchars(item, SEL_FIRST, SEL_LAST)
                self.canvas.select_clear()
            else:
                if insert > 0:
                    self.canvas.dchars(item, insert-1, insert)
            self.highlight(item)

        # navigation
        elif event.keysym == "Home":
            self.canvas.icursor(item, 0)
            self.canvas.select_clear()
        elif event.keysym == "End":
            self.canvas.icursor(item, END)
            self.canvas.select_clear()
        elif event.keysym == "Right":
            self.canvas.icursor(item, insert+1)
            self.canvas.select_clear()
        elif event.keysym == "Left":
            self.canvas.icursor(item, insert-1)
            self.canvas.select_clear()

        else:
            pass # print event.keysym

# try it out (double-click on a text to enable editing)
c = MyCanvas(Tk())
c.pack()

mainloop()

After you double click on one of the items to be edited, I cannot make the cursor go away; I've tried moving focus and setting the index to -1, but neither seems to work.

回答1:

self.canvas.focus("")

To remove focus from the item, call this method with an empty string. Reference

you can add the following

self.canvas.focus_set() # move focus to canvas window
self.canvas.focus("") # remove focus from the current item that has it

def set_focus(self, event):
    if self.canvas.type(CURRENT) != "text":
        #Here
        return

So when the user double-clicks on any part or item of the canvas that isn't created by canvas.create_text the focus is removed from the current "text" item, hence stopping the edit.

Plus you can add

self.canvas.delete("highlight")

to remove the white rectangle around the text, when focus is removed.

来源：https://stackoverflow.com/questions/51576693/how-to-remove-icursor-from-tkinter-canvas-text-item

标签

python

tkinter

tkinter-canvas