Difference between revisions of "84PCE:Syscalls:021320"
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'''Syscall Address:''' 021320h | '''Syscall Address:''' 021320h | ||
| − | Gets a string of input from the user, much like the common 'Input' command used in TI-Basic programs. This system call does not return until after the user presses enter, but allows for use of all OS menus and input variations, including the Alpha and 2nd Keys special abilities. It works by creating a temporary equation which it then makes the edit buffer. It can also display an optional prompt for the user, in order to be more user friendly. Note that when using this routine, the system monitor completely takes over, so it will act exactly as it does in TI-Basic programs, which may have unintended side effects. It is highly recommended you call [[84PCE:Syscalls:021578|DeleteTempEditEqu]] once you are finished with your input parsing. | + | Gets a string of input from the user, much like the common 'Input' command used in TI-Basic programs. This system call does not return until after the user presses enter, but allows for use of all OS menus and input variations, including the Alpha and 2nd Keys special abilities. It works by creating a temporary equation which it then makes the edit buffer. It can also display an optional prompt for the user, in order to be more user friendly. Note that when using this routine, the system monitor completely takes over, so it will act exactly as it does in TI-Basic programs, which may have unintended side effects. It is highly recommended you call [[84PCE:Syscalls:021578|DeleteTempEditEqu]] once you are finished with your input parsing. It basically calls _NewContext with 50h, _Mon, then _NewContext with 3Fh. |
=== Inputs === | === Inputs === | ||
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* [[84PCE:RAM:D00595|curRow]],[[84PCE:RAM:D00596|curCol]] - Set to the appropriate values for the location where to display the prompt and input string | * [[84PCE:RAM:D00595|curRow]],[[84PCE:RAM:D00596|curCol]] - Set to the appropriate values for the location where to display the prompt and input string | ||
* [[84PCE:RAM:D00596|curUnder]] - This is the character that is first displayed under the cursor. You should set it to 0, unless you want something under the cursor | * [[84PCE:RAM:D00596|curUnder]] - This is the character that is first displayed under the cursor. You should set it to 0, unless you want something under the cursor | ||
| + | * '''NOTE:''' You must reset 6,(iy+28) and set 7,(iy+9) before calling this function! | ||
=== Outputs === | === Outputs === | ||
| − | * [[84PCE:RAM:D0244E|editSym]] - Contains the VAT pointer to the temporary variable used for editing the input string. Can be used with VarNameToOP1HL to lookup the actual input data. | + | * [[84PCE:RAM:D0244E|editSym]] - Contains the VAT pointer to the temporary variable used for editing the input string. Can be used with [[84PCE:Syscalls:020AE8|VarNameToOP1HL]] to lookup the actual input data. |
=== Destroys === | === Destroys === | ||
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xor a,a | xor a,a | ||
ld (curUnder),a | ld (curUnder),a | ||
| + | ld b,(iy+9) | ||
| + | ld c,(iy+28) ;back up old flag values | ||
| + | res 6,(iy+28) | ||
| + | set 7,(iy+9) | ||
| + | push bc | ||
call _GetStringInput ; get the input from the user | call _GetStringInput ; get the input from the user | ||
| + | pop bc | ||
| + | res 4,b ;restore old flag values | ||
| + | ld (iy+9),b | ||
| + | ld (iy+28),c | ||
ld hl,(editSym) | ld hl,(editSym) | ||
call _VarNameToOP1HL ; lookup the temporary input symbol | call _VarNameToOP1HL ; lookup the temporary input symbol | ||
Latest revision as of 17:54, 25 September 2017
Synopsis
Hypothesized Official Name: GetStringInput
Syscall Address: 021320h
Gets a string of input from the user, much like the common 'Input' command used in TI-Basic programs. This system call does not return until after the user presses enter, but allows for use of all OS menus and input variations, including the Alpha and 2nd Keys special abilities. It works by creating a temporary equation which it then makes the edit buffer. It can also display an optional prompt for the user, in order to be more user friendly. Note that when using this routine, the system monitor completely takes over, so it will act exactly as it does in TI-Basic programs, which may have unintended side effects. It is highly recommended you call DeleteTempEditEqu once you are finished with your input parsing. It basically calls _NewContext with 50h, _Mon, then _NewContext with 3Fh.
Inputs
- ioPrompt - Copy the optional prompt string here, or write a null byte for no prompt
- curRow,curCol - Set to the appropriate values for the location where to display the prompt and input string
- curUnder - This is the character that is first displayed under the cursor. You should set it to 0, unless you want something under the cursor
- NOTE: You must reset 6,(iy+28) and set 7,(iy+9) before calling this function!
Outputs
- editSym - Contains the VAT pointer to the temporary variable used for editing the input string. Can be used with VarNameToOP1HL to lookup the actual input data.
Destroys
- All
Example
call _ClrScrn call _HomeUp ; clean up things ld hl,inputPrompt ld bc,inputPrompt_end-inputPrompt ld de,ioPrompt ldir ; copy the input prompt here xor a,a ld (curUnder),a ld b,(iy+9) ld c,(iy+28) ;back up old flag values res 6,(iy+28) set 7,(iy+9) push bc call _GetStringInput ; get the input from the user pop bc res 4,b ;restore old flag values ld (iy+9),b ld (iy+28),c ld hl,(editSym) call _VarNameToOP1HL ; lookup the temporary input symbol call _ChkFindSym jr c,SomeError ex de,hl call _LoadDEInd_s ; get the size of the the string push de pop bc ld de,pixelshadow ; copy it to saferam ldir xor a,a ld (de),a ; null terminate the string SomeError: call _DeleteTempEditEqu ; delete the temporary input call _ClrScrn jp _HomeUp ; clean up and leave inputPrompt: .db "Input:",0 ; Input prompt inputPrompt_end:
