\b Escape character not working in drawings

otosclerosi

22
Canon IXUS160 with CHDK 1.5

« on: 06 / December / 2016, 12:27:59 »

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I'm trying to do a sort of keyboard for my camera
i was thinking how to include backspace
i have

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stringa="example" and i want to delete the "e", so i tried

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stringa=stringa.."\b \b"which is supposed to add to "example" a backspace escape character, a space (overriding the "e") and another backspace to set the cursor to the right position...
but instead of a backspace, a white box character is displayed, like "example[] []" when i try to do

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draw.add("string",..., stringa)
just wondering what i am doing wrong and how to achieve the result

edit: in "CHDK Lua local" run on a pc it works, on the camera it doesn't. Same results with

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stringa="ciao"
print(stringa.."\n")
stringa=stringa.."\b \b"
print(stringa)
wait_click(0)

on pc it shows "cia", on the camera it shows "ciao[] []"

« Last Edit: 06 / December / 2016, 13:08:19 by otosclerosi »

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reyalp

13353

Re: \b Escape character not working in drawings

« Reply #1 on: 06 / December / 2016, 13:39:07 »

CHDK text output doesn't generally understand control characters, except for some specific cases involving things like newlines.

Note that there is already support for keyboard input with the textbox function http://chdk.wikia.com/wiki/Script_commands#textbox

If you want to roll your own, you'll have to manage drawing the text and cursor yourself.

There's a Lua based text editor in scripts/editor/edi.lua

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otosclerosi

22
Canon IXUS160 with CHDK 1.5

Re: \b Escape character not working in drawings

« Reply #2 on: 06 / December / 2016, 17:48:14 »

I mean something like a graphical virtual keyboard to use in drawings project (i.e. that rpg)...
ok so i'll use a workaround by splitting the string and substituting last char with a ""...
something similar to

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for word in string.gmatch(stringa, '([^--[[HERE WILL BE THE RIGHT DELIMITER]] ]+)') do
--[[HERE I WILL DETECT THE LAST CHAR AND SUBSTITUTE IT]]
end

ty for the clarification...it should work...if it works, i'll post in complete scripts

Edit_1: in fact, working method

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        stringa="ciao"
 local splitted=""
 for i = 1, #stringa do
          local c = stringa:sub(i,i)
   if i==#stringa then 
     lastchar=c
   else 
     splitted=splitted..c
   end
        end
 stringa=splitted

« Last Edit: 06 / December / 2016, 18:02:38 by otosclerosi »

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