在 Gtk.ScrolledWindow 中添加 Gtk.TreeView 时，滚动条光标超出比例

Question

如果我想让 Gtk.TreeView 可滚动，我将它嵌入到 Gtk.ScrolledWindow 中。嵌入 TreeView 会产生一个超出比例的光标（太大了）。

TreeView 中还有 7 行，在显示的 3 行下方。我希望滚动条光标缩放到 1/3，让我可以舒适地滚动。

我可以用鼠标上的滚轮正常滚动，用键盘上的方向键滚动。

这是创建 TextView 的代码：

        self.segment_store = Gtk.ListStore(str, str, str, str, str, str)
        self.segment_view = Gtk.TreeView(model = self.segment_store,
                    hexpand = True)
        
        self.segment_scroller = Gtk.ScrolledWindow()
        self.segment_scroller.add(self.segment_view)

ScrolledWindow 本身被打包到一个 Gtk.Grid 中。

我怀疑滚动条中有一个属性指定了一个 最小尺寸，并尝试修改页面尺寸 - 再次失败。

这是一个完整的最小示例。 MainWindow中的

if True

可以 更改为 False，以启用/禁用 ScrollWindow 的使用。

create_segment_table

中提到vadj的三行可以评论 禁用我的页面大小限制实验。

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
#  test_embedded_treeview.py
#
#  Copyright 2023 John Coppens <[email protected]>
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA 02110-1301, USA.
#
#


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

class MainWindow(Gtk.Window):
    def __init__(self):
        super(MainWindow, self).__init__()
        self.connect("destroy", lambda x: Gtk.main_quit())
        self.set_default_size(400, 300)

        self.create_segment_table()
        for i in range(10):
            self.segment_store.append( ('0', )*6 )

        if True:
            grid = Gtk.Grid()
            grid.attach(self.segment_scroller, 1, 1, 1, 1)

            self.add(grid)
        else:
            self.add(self.segment_scroller)

        self.show_all()

    def run(self):
        Gtk.main()


    def create_segment_table(self):
        self.segment_store = Gtk.ListStore(str, str, str, str, str, str)
        self.segment_view = Gtk.TreeView(model = self.segment_store,
                    hexpand = True)
        #   La tabla puede crecer demasiado, asi que agregamos un 'scroller'
        self.segment_scroller = Gtk.ScrolledWindow()
        self.segment_scroller.add(self.segment_view)

        # Trying to change the page size of the scrollbar
        vadj = self.segment_scroller.get_vadjustment()
        vadj.set_page_size(20)
        self.segment_scroller.set_vadjustment(vadj)

        # Creamos las columnas para la tabla
        for colnr, header in enumerate( ('X0', 'Y0', 'Z0', 'X1', 'Y1', 'Z1') ):
            renderer = Gtk.CellRendererText(editable = True)
            # ~ renderer.connect('edited', self.on_cell_edited, colnr)
            col = Gtk.TreeViewColumn(header, renderer, text = colnr)
            col.set_expand(True)
            self.segment_view.append_column(col)


def main(args):
    mainwdw = MainWindow()
    mainwdw.run()

    return 0

if __name__ == '__main__':
    import sys
    sys.exit(main(sys.argv))