Routines
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26116: Handler: User Input
Used by the routines at Handler_UnknownWord, GameLoop and ActionRead.
Read a line of text, then turn it into vocabulary tokens.
Reset the cursor to the default text position.
Handler_UserInput 26116 CALL SetDefaultScreenPosition Call SetDefaultScreenPosition.
Clear the command buffer.
26119 LD HL,25183 Blank CommandBuffer with 50 spaces.
26122 LD A,32
26124 LD B,50
Handler_UserInput_Loop1 26126 LD (HL),A Write spaces through the command buffer.
26127 INC HL
26128 DJNZ Handler_UserInput_Loop1
Print the ">" prompt.
26130 CALL PrintInputPrompt Call PrintInputPrompt.
Collect keypresses into the command buffer.
26133 LD HL,25183 Start at the beginning of CommandBuffer.
Wait for the next key.
Handler_UserInput_Loop2 26136 CALL GetUserInput Call GetUserInput.
DELETE rubs out a character. ENTER finishes the line. Any other control key is ignored.
26139 CP 12 Jump to Handler_UserInput_Step1 if DELETE was pressed.
26141 JR Z,Handler_UserInput_Step1
26143 CP 13 Jump to Handler_UserInput_Step2 if ENTER was pressed.
26145 JR Z,Handler_UserInput_Step2
26147 CP 32 Jump back to Handler_UserInput_Loop2 when the key is below SPACE.
26149 JR C,Handler_UserInput_Loop2
Is the command buffer full?
26151 EX DE,HL Jump back to Handler_UserInput_Loop2 once the pointer has reached the end of CommandBuffer.
26152 LD HL,25232
26155 AND A
26156 SBC HL,DE
26158 EX DE,HL
26159 JR Z,Handler_UserInput_Loop2
The key is valid, so store it and print it.
26161 LD (HL),A Write the key into the buffer and echo it.
26162 CALL SwitchToNormalScreenOutput
26165 CALL PrintCharacter
26168 INC HL
26169 JR Handler_UserInput_Loop2
The player pressed DELETE.
Handler_UserInput_Step1 26171 EX DE,HL Jump back to Handler_UserInput_Loop2 when the buffer is still empty.
26172 LD HL,25183
26175 AND A
26176 SBC HL,DE
26178 EX DE,HL
26179 JR Z,Handler_UserInput_Loop2
Rub the previous character off the screen.
Print " ".
26181 PUSH HL Print " " and blank the previous character.
26182 LD HL,25315
26185 CALL PrintString
26188 POP HL
26189 DEC HL
26190 LD (HL),32
26192 JR Handler_UserInput_Loop2
The player pressed ENTER, so close the command and clear the tokens.
Handler_UserInput_Step2 26194 LD (HL),A Store ENTER as the terminator and echo the newline.
26195 CALL SwitchToNormalScreenOutput
26198 CALL PrintCharacter
Initialise the word token buffer. Up to 10 vocabulary tokens are stored at UserInput_FirstToken; 255 marks an empty slot.
26201 LD HL,25233 Point at UserInput_FirstToken and prepare the empty marker (255).
26204 LD A,255
26206 LD B,10
Handler_UserInput_Loop3 26208 LD (HL),A Write 255 into each of the 10 token slots.
26209 INC HL
26210 DJNZ Handler_UserInput_Loop3
26212 LD HL,25183 Start at the command and allow 10 words, then fall into Parser_MatchInputWord.
26215 LD C,10
Continue on to Parser_MatchInputWord.
View the equivalent code in;
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