As I'm typing a new document, dont let me get to the bottom of the screen before scolling

[carlbordum]

The cursor should be kept 4 or 5 lines above the bottom imo

[Akuli]

Currently I just let tkinter do whatever it wants with this. I'll probably fix this tomorrow.

[Akuli]

What kind of cursor movement would you like? When you go near the bottom should it scroll down line by line or half a page or so at a time? I checked how different editors do this. Vim and Geany work like porcupine works now, nano and emacs scroll down half a page at a time.

[carlbordum]

When you press enter: create new line if cursor is at one of the four last lines, also scroll one line

[Akuli]

So far I haven't seen any other editors actually do this. Can you name one? If you haven't it's OK and porcupine can still do this.

[carlbordum]

My own setup (Vim) does this. Am not sure where the option is, though.

[Akuli]

Vim didn't do that to me with default settings. I'll implement this some day :)

[Akuli]

What do you think?

import functools
import tkinter as tk
import tkinter.font as tkfont

class Zaab1tText(tk.Text):

    # see() is supposed to scroll the widget so that the index is
    # visible, so it makes sense to override it for this
    @functools.wraps(tk.Text.see)
    def see(self, index):
        # do whatever tkinter does by default
        super().see(index)

        # self['height'] is wrong if the widget has been stretched or
        # squeezed by pack or grid
        font = tkfont.Font(name=self['font'], exists=True)
        rowcount = self.winfo_height() // font.metrics('linespace')

        # make sure that we can also see n lines on either side, usually
        # n is 5 but it's smaller if the text widget is too big for 5
        space_on_each_side = (rowcount-1) // 2    # -1 is the current row
        n = min(space_on_each_side, 5)
        super().see('%s + %d lines' % (index, n))
        super().see('%s - %d lines' % (index, n))

if __name__ == '__main__':
    root = tk.Tk()
    text = Zaab1tText(root)
    text.pack(fill='both', expand=True)      # make it stretchable
    text.bind('<Return>', (lambda event: text.after_idle(text.see, 'insert')))
    with open(__file__, 'r') as f:
        text.insert('1.0', f.read())
    root.mainloop()

This code doesn't require porcupine in any way. Just run it in a python with tkinter installed.

[Akuli]

Tkinter doesn't seem to support scrolling down further than the bottom of the file, so the only possible workaround is to add a bunch of fake newlines at the end of the text widget and scroll down with these. I'd be happy to proved wrong though. Sorry :(

[carlbordum]

Damn, I still think this would be nice. You can go to the bottom of a document in vim and press zz to kind of see what I mean.

[Akuli]

I just did that, and it did what I expected it to do... Even though I can't do this at the end of the file, would you like to keep a distance between the cursor and the bottom of the view elsewhere? That's doable if there are lines to go between the cursor and the bottom of the text widget.

[Akuli]

@Zaab1t can you try the latest master? I added some magic to fix this and I think it's definitely a lot better than before. You'll see it if you navigate up and down with arrow keys in the middle of a long file.

[Akuli]

<Zaab1t> this si nice
<Akuli> go to the very end of the file
<Akuli> you'll notice that it doesn't scroll past the end
<Akuli> does that matter so much that i can't close ur github issue?
<Zaab1t> I like this
<Zaab1t> I haven't seen an editor with this feature
<Zaab1t> I still feel like typing at the end would be better WITH this
<Zaab1t> great work!
<Akuli> thanks :)

[Akuli]

reopening because i have an idea for making it scroll past the end: add bottom margin to text widget (if possible)

[Akuli]

related to #37