Curses - How to insert predefined name of INPUT items? - curses

Question

How to please insert predefined name of INPUT items ?
My efforts: (info: the character "_" is cursor)
def Edit_Item(stdscr, item_name)
stdscr.addstr(1, 2, "Item Name:")
r = stdscr.getstr(2, 16, 15)
return r
Edit_Item(stdscr, 'Foo')
Edit_Item(stdscr, 'Bar')
Result:
Item Name: _
Item Name: _
The desired result:
Item Name: Foo_
Item Name: Bar_
Thank you for your help.

Answer 1

#Thomas Dickey:
No :-( I will try to better describe what I need..
- Call function 'Edit_Item' with parameter 'Foo' # OK
- The screen prints 'Item Name: Foo' # OK
- Cursor is now behind the word 'Foo_' # OK
- Press the key arrow left (2x) to change the cursor 'F_o' # Not work
- Edit word 'Foo' to 'Fao'
It's to understand?
# # # # # # # # # # # # # # # # #
This is exactly what I need to do in curses.
Demonstration in Bash
read -e -i "Foo" -p "Edit Item Name: " ITEM

Answer 2

The window.getstr function reads new data from the keyboard (and puts it in the screen). Perhaps you meant window.instr, since you seem to assume that you can read back the data added in addstr calls.
The parameter item_name is not used in the sample function. You could have written that to the screen using window.addstr, along with padding underscores (that was not done). You could have done this:
def Edit_Item(stdscr, item_name)
stdscr.addstr(1, 2, "Item Name:" + item_name + "_" )
r = stdscr.getstr(2, 16, 15)
return r
The example which was given will first move the cursor to 2,16 on the screen (which is past the location of item_name — at column 10). The stdscr.getstr call will not return the value of item_name; it will return only the characters which you enter using the keyboard. As noted, window.instr provides a way to combine the value of item_name and the stdscr.getstr call.
However, even that combination is not enough, since stdscr.getstr will return characters from its starting point. So you could not, for instance, start the call at the end of the value written using addstr. If you do this:
def Edit_Item(stdscr, item_name)
stdscr.addstr(1, 2, "Item Name:" + item_name + "_" )
r = stdscr.getstr(2, 10, 15)
r = stdscr.instr(2, 10, 15)
return r
it would be closer to your intent, but (untested) will probably erase the characters past the cursor position when you press enter. If you revised the solution to use getch, you can decide what to echo, as well as handling things such as left/right cursor movement within the edited line. Fancy things like editing a template string are usually built up from simpler functions.

Answer 3

I usually do this:
import curses
screen = curses.initscr()
curses.noecho()
curses.cbreak()
curses.start_color()
screen.keypad( 1 )
screen.border( 0 )
curses.curs_set( 2 )
string = "Foo"
max_len = 40 #max len of string
screen.addstr( 3, 1, "Item Name: " )
screen.addstr( 3, 12, string )
screen.refresh()
position = len( string )
x = screen.getch( 3, 12 + position )
while x != 27:
if (x <= 122 and x >= 97) or x == 32 or (x <= 90 and x >= 65):
if position == len( string ):
if len( string ) < max_len:
string += chr( x )
position = len( string )
else:
string = string[ 0:position ] + chr( x ) + string[ position + 1: ]
if x == 263:
if position == len( string ):
string = string[ 0:len( string ) - 1 ]
position = len( string )
else:
string = string[ 0:position -1 ] + string[ position: ]
if position > 0:
position -= 1
if x == 330:
if position == len( string ) - 1:
string = string[ 0:len( string ) - 1 ]
else:
string = string[ 0:position +1] + string[ position + 2: ]
if x == curses.KEY_RIGHT:
if position < len( string ):
position += 1
if x == curses.KEY_LEFT:
if position > 0:
position -= 1
screen.erase()
screen.border( 0 )
screen.addstr( 3, 1, "Item Name: " )
screen.addstr( 3, 12, string )
x = screen.getch( 3, 12 + position )
curses.endwin()
exit()