gtk textview 小部件中的 Python 自动滚动

Question

I just have a new project, i just want to learn more about gtk, threads, sockets and classes, so i decided to develop a simple IRC client.

I have some code but i can not find a solution for this:

How do i forbid horizontal scrolling in the textview widget of gtk, and also automatically scroll the textview widget to the bottom?

thanks in advance!

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk, Pango

class TextViewWindow(Gtk.Window):

    def __init__(self):
        Gtk.Window.__init__(self, title="TinyIRC")

        self.set_default_size(700, 500)

        self.grid = Gtk.Grid()
        self.add(self.grid)

        self.create_chatbox()
        self.create_entry()

    def create_chatbox(self):
        scrolledwindow = Gtk.ScrolledWindow()
        scrolledwindow.set_hexpand(True)
        scrolledwindow.set_vexpand(True)
        self.grid.attach(scrolledwindow, 0, 1, 3, 1)

        self.textview = Gtk.TextView()
        self.textbuffer = self.textview.get_buffer()
        start_iter = self.textbuffer.get_start_iter()

        self.textbuffer.insert(start_iter, "This is some text ")
        self.textbuffer.insert_markup(self.textbuffer.get_end_iter(), "<b>and some bold text</b>", -1)

        scrolledwindow.add(self.textview)

    def create_entry(self):
        self.entry_box = Gtk.Entry()
        self.grid.attach(self.entry_box, 0, 2 ,3 ,1)
        self.entry_box.connect("activate", self.enter_pressed)

    def enter_pressed(self, widget):
        given_msg=self.entry_box.get_text()
        send_msg=given_msg
        print(given_msg)
        end_iter = self.textbuffer.get_end_iter()
        self.textbuffer.insert(end_iter, send_msg+'\n')
        self.entry_box.set_text("")






win = TextViewWindow()
win.connect("delete-event", Gtk.main_quit)
win.show_all()
Gtk.main()

Answer 1

Changing the horizontal scrolling settings

Using ScrolledWindow.set_policy() , you can control whether it scrolls horizontally or not. If you want it not to scroll horizontally, you would add this line right after creating scrolledwindow :

scrolledwindow.set_policy(Gtk.PolicyType.NEVER, Gtk.PolicyType.AUTOMATIC)

The first argument of set_policy() controls the horizontal scrolling, and the second controls the vertical scrolling. Setting the horizontal scrolling to Gtk.PolicyType.NEVER makes sure that scrolledwindow never scrolls horizontally.

Scrolling to the end after inserting the text

To scroll to the end after inserting all the text, you can create a mark at the end, and use textbuffer.scroll_mark_onscreen() to scroll down to the end. Here is what that would look like:

# Create a mark at the end of all the text
mark = self.textbuffer.create_mark("end", self.textbuffer.get_end_iter(), False)

# Scroll so we can see the end mark
self.textview.scroll_mark_onscreen(mark)

The full code

When we apply these principles to your code, we get something like this (note that I insert much more text so that you can see how the scrolling works):

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk, Pango

class TextViewWindow(Gtk.Window):

    def __init__(self):
        Gtk.Window.__init__(self, title="TinyIRC")

        self.set_default_size(700, 500)

        self.grid = Gtk.Grid()
        self.add(self.grid)

        self.create_chatbox()
        self.create_entry()

    def create_chatbox(self):
        scrolledwindow = Gtk.ScrolledWindow()
        
        # Make sure that the window doesn't scroll horizontally
        scrolledwindow.set_policy(Gtk.PolicyType.NEVER, Gtk.PolicyType.AUTOMATIC)

        scrolledwindow.set_hexpand(True)
        scrolledwindow.set_vexpand(True)
        self.grid.attach(scrolledwindow, 0, 1, 3, 1)

        self.textview = Gtk.TextView()
        self.textbuffer = self.textview.get_buffer()
        start_iter = self.textbuffer.get_start_iter()

        self.textbuffer.insert(start_iter, (("This is some text"*10) + "\n")*200)
        end_iter = self.textbuffer.get_end_iter()
        self.textbuffer.insert(end_iter, "This should be the end.")

        scrolledwindow.add(self.textview)

        # Create a mark at the end, and scroll down to it
        mark = self.textbuffer.create_mark("end", self.textbuffer.get_end_iter(), False)
        self.textview.scroll_mark_onscreen(mark)

    def create_entry(self):
        self.entry_box = Gtk.Entry()
        self.grid.attach(self.entry_box, 0, 2 ,3 ,1)
        self.entry_box.connect("activate", self.enter_pressed)

    def enter_pressed(self, widget):
        given_msg=self.entry_box.get_text()
        send_msg=given_msg
        print(given_msg)
        end_iter = self.textbuffer.get_end_iter()
        self.textbuffer.insert(end_iter, send_msg+'\n')
        self.entry_box.set_text("")

win = TextViewWindow()
win.connect("delete-event", Gtk.main_quit)
win.show_all()
Gtk.main()