TextView to scroll automatically when text is added?

[AAnkeriasniemi]

Hello

What I’m trying to do is a console view for the ui. It wouldn’t be that nice for it to not scroll when something is printed out of the bounds, in this case the user would have to scroll down manually every time text is printed.

An obvious solution to this would be to print so that the old text would go out of the bounds, and new text would be printed above the old. But I don’t want this because that’s not how a standard console works like and can confuse many users: textview.text = f”{newtextstring}\n{textview.text}”

This is the current method for me to print text to the makeshift console:

def fakeprint(newtextstring):
  consoletextview.text = f”{consoletextview.text}\n{newtextstring}”

but because there will be be so many rows after the print-text height has reached the textview-height that the print-text will continue downwards and then the user will have to scroll down manually to see new prints. Basically, I want it to scroll along with new prints so that the user won’t have to, any ideas?

Let me know if you can’t understand this.

[JonB]

You might consider installing stash, and using that as your display. I believe some of the classes used in pythonista_ui.py can be used standalone, and give you color, scrolling, etc

The scrolling code in ShTerminal looks like

    @on_main_thread
    def scroll_to_end(self):
        content_height = self.content_size[1]
        # rect_height is the visible rect's height
        # rect_y is the y location where the visible rect locates in the
        # coordinate of content_size
        _, rect_height, _, rect_y = self.visible_rect
        # If the space below rect_y is more than the visible rect's height,
        # or if the visible rect is over-scrolled, scroll to the last line.
        if content_height - rect_y > rect_height or \
                (content_height > rect_height > content_height - rect_y):  # over-scroll
            self.tvo.scrollRangeToVisible_((len(self.text), 0))

Where self.tvo is the textview's .objc_instance.

Textview's are subclasses of scroll views, so the content_inset, etc allow you to control the scroll.

[cvp]

@AAnkeriasniemi following @JonB 's advice, test this

import ui
from objc_util import *

class MyTextFieldDelegate():
	def textfield_should_return(self, textfield):
		global consoletextview
		consoletextview.text += f"\n{textfield.text}"
		ObjCInstance(consoletextview).scrollRangeToVisible_((len(consoletextview.text), 0))
		textfield.text = ''
		#textfield.end_editing()
		return True

v = ui.View()
v.background_color = 'white'
v.frame = (0,0,400,400)
consoletextview = ui.TextView()
consoletextview.frame = (0,0,400,370)
v.add_subview(consoletextview)
tf = ui.TextField()
tf.frame = (0,370,400,30)
tf.delegate = MyTextFieldDelegate()
v.add_subview(tf)
tf.begin_editing()
v.present('sheet')

[AAnkeriasniemi]

Thank you both! It works now