title: Text Display in Tkinter 01
tags: python tk

## Usage
```bash
tkt file.txt     # display file.txt
tkt f1 f2 f3     # display f1, f2, f3 concatenated
tkt -            # take text from stdin
tkt              # same as tkt -
tkt -c           # display clipboard contents (gets via pp)
```

## The Code
There is a pretty random feature I added for my own purposes: you can pass arguments
of the form `x=my command arg1 arg2` and instead of seeing this as a file, it sees
it as a keybinding, so pressing `x` will `execv('/bin/env',['env','my','command','arg1','arg2'])`.
Note that you can't do anything like quoting in the command passed in here (generally
I avoid the need to quote when giving files names). Note that the command will simply quit
if `env` fails to execute the command (this program has no idea whether the command will succeed,
and makes no attempt to find out -- a more robust version may use e.g. `shutil.which` to see
if the command exists, and use the result instead of being lazy and throwing the ball to `env`).
```py
#!/usr/bin/env python
from icecream import ic; ic.configureOutput(includeContext=True)

import re
import os
import tkinter as tk
import tkinter.font as tkfont
import sys
from subprocess import run

stdin = None
txts = []
args = sys.argv[1:]
if len(args) == 0:
  args = ["-"]
kmap = {}
for arg in args:
  if arg == "-":
    if stdin is None:
      stdin = sys.stdin.read()
    txts.append(stdin)
  elif "=" in arg:
    a,b = arg.split("=",1)
    bs = re.split(r"\s+",b.strip())
    kmap[a] = bs
  elif arg == "-c":
    txts.append(run("pp",capture_output=True).stdout.decode())
  else:
    with open(arg) as f:
      txts.append(f.read())

txt = "\n".join(txts)

def key_handler(event):
  print(event.char, event.keysym, event.keycode)
  ic(event)

  if event.char == "q":
    exit()
  match event.char:
    case "q":
      exit()
    case "\x03":
      sel = T.selection_get()
      root.clipboard_clear()
      root.clipboard_append(sel)
      print("Copied:",sel)
      return
  match event.keysym:
    case "Down":
      return T.yview(tk.SCROLL,1,tk.UNITS)
    case "Up":
      return T.yview(tk.SCROLL,-1,tk.UNITS)
    case "Prior":
      return T.yview(tk.SCROLL,-1,tk.PAGES)
    case "Next":
      return T.yview(tk.SCROLL,1,tk.PAGES)
  if event.char in kmap:
    cmd = kmap[event.char]
    os.execv("/bin/env",["env"]+cmd)

root = tk.Tk()
root.bind("<Key>", key_handler)

# get screen size
screen_width = root.winfo_screenwidth()
screen_height = root.winfo_screenheight()
win_width = int(screen_width * 0.7)
win_height = int(screen_height * 0.7)
win_xoffs = int((screen_width-win_width)/2)
win_yoffs = int((screen_height-win_height)/2)
geom = f"{win_width}x{win_height}+{win_xoffs}+{win_yoffs}"

desired_font = tkfont.Font(family="Hack Nerd Font Mono", size=14)

root.geometry(geom)
S = tk.Scrollbar(root)
T = tk.Text(root, height=4, width=50)
T.configure(font = desired_font,bg="#002",fg="#ffc")
S.pack(side=tk.RIGHT, fill=tk.Y)
T.pack(side=tk.LEFT, fill=tk.BOTH, expand=True)
S.config(command=T.yview)
T.config(yscrollcommand=S.set)
T.insert(tk.END, txt)
T.configure(state=tk.DISABLED)
tk.mainloop()
```