source: xtideuniversalbios/trunk/Assembly_Library/Src/Keyboard/Keyboard.asm@ 52

Last change on this file since 52 was 52, checked in by Tomi Tilli, 14 years ago

Changes to Assembly Library:
Completely rewritten line splitting (slower but no need to modify string).
Some changes to string processing functions.
Saved few bytes from CGA detection.
File size: 7.9 KB
Line 
1; File name : Keyboard.asm
2; Project name : Assembly Library
3; Created date : 5.7.2010
4; Last update : 12.10.2010
5; Author : Tomi Tilli
6; Description : Functions for managing keyboard.
7
8BUFFER_SIZE_FOR_WORD_INPUT EQU 6 ; 5 chars + NULL
9
10; Section containing code
11SECTION .text
12
13;--------------------------------------------------------------------
14; Reads user inputted word.
15; Function returns when ENTER or ESC will be pressed.
16;
17; Keyboard_ReadUserInputtedWordWhilePrinting
18; Parameters
19; BX: Numeric base (10 or 16)
20; Returns:
21; AX: User inputted word
22; ZF: Set if user cancellation
23; Corrupts registers:
24; DX
25;--------------------------------------------------------------------
26ALIGN JUMP_ALIGN
27Keyboard_ReadUserInputtedWordWhilePrinting:
28 push ds
29 push si
30 push cx
31
32 mov cx, BUFFER_SIZE_FOR_WORD_INPUT
33 call Memory_ReserveCXbytesFromStackToDSSI
34
35 call Char_GetFilterFunctionToDXforNumericBaseInBX
36 call Memory_ExchangeDSSIwithESDI
37 call Keyboard_ReadUserInputtedStringToESDIWhilePrinting
38 call Memory_ExchangeDSSIwithESDI ; Does not modify FLAGS
39 jz SHORT .CancelledByUser
40
41 call String_ConvertWordToAXfromStringInDSSIwithBaseInBX
42.CancelledByUser:
43 add sp, BYTE BUFFER_SIZE_FOR_WORD_INPUT
44 test cx, cx ; Set ZF if string length is zero
45 pop cx
46 pop si
47 pop ds
48 ret
49
50
51;--------------------------------------------------------------------
52; Reads user inputted string to buffer. Character filter is
53; supported to ignore unwanted characters.
54; Function returns when ENTER or ESC will be pressed.
55;
56; Keyboard_ReadUserInputtedStringToESDIWhilePrinting
57; Parameters:
58; CX: Buffer size (with NULL)
59; ES:DI: Ptr to destination buffer
60; CS:DX: Ptr to character filter function:
61; Parameters:
62; AL: Character inputted by user
63; Returns:
64; CF: Set if character is accepted
65; Cleared if character is rejected
66; Corrupts registers:
67; Nothing
68; Returns:
69; CX: String length in characters (without NULL)
70; ZF: Set if user cancellation
71; Corrupts registers:
72; AX
73;--------------------------------------------------------------------
74ALIGN JUMP_ALIGN
75Keyboard_ReadUserInputtedStringToESDIWhilePrinting:
76 push di
77 push si
78 push bx
79 call .PrepareDisplayContextForKeyboardInput
80 jcxz .ReturnAfterUpdatingZF
81
82 xor bx, bx ; Zero character counter
83 dec cx ; Decrement buffer size for NULL
84 cld
85ALIGN JUMP_ALIGN
86.GetCharacterFromUser:
87 call Keyboard_GetKeystrokeToAXandWaitIfNecessary ; Get ASCII to AL
88 call .ProcessControlCharacter
89 jz SHORT .TerminateStringWithNULL
90 jc SHORT .PlayBellForRejectedCharacter
91 call dx ; Filter character
92 jnc SHORT .PlayBellForRejectedCharacter
93 inc bx ; Increment number of characters stored
94 stosb ; Store from AL to ES:DI
95 call Keyboard_PrintInputtedCharacter
96 loop .GetCharacterFromUser
97.PlayBellForRejectedCharacter:
98 cmp al, BS ; No bell for backspace
99 je SHORT .GetCharacterFromUser
100 call Keyboard_PlayBellForUnwantedKeystroke
101 jmp SHORT .GetCharacterFromUser
102
103.TerminateStringWithNULL:
104 stosb ; Terminate string with NULL
105 mov cx, bx ; String length now in CX
106
107.ReturnAfterUpdatingZF:
108 CALL_DISPLAY_LIBRARY PopDisplayContext
109 test cx, cx ; Clear or set ZF
110 pop bx
111 pop si
112 pop di
113 ret
114
115;--------------------------------------------------------------------
116; .PrepareDisplayContextForKeyboardInput
117; Parameters:
118; Nothing
119; Returns:
120; Nothing (Display context pushed to stack)
121; Corrupts registers:
122; AX, BX, SI
123;--------------------------------------------------------------------
124ALIGN JUMP_ALIGN
125.PrepareDisplayContextForKeyboardInput:
126 pop bx ; Pop return address to BX
127 mov si, di
128
129 CALL_DISPLAY_LIBRARY PushDisplayContext
130 mov ax, CURSOR_NORMAL
131 CALL_DISPLAY_LIBRARY SetCursorShapeFromAX
132 CALL_DISPLAY_LIBRARY SynchronizeDisplayContextToHardware
133
134 mov di, si
135 jmp bx
136
137
138;--------------------------------------------------------------------
139; .ProcessControlCharacter
140; Parameters:
141; AL: Character inputted by user
142; CX: Number of bytes left in buffer
143; BX: Total number of characters inputted
144; ES:DI: Ptr where to store next character
145; Returns:
146; AL: Character inputted by user or NULL if end of input
147; BX: Cleared if user cancellation
148; ZF: Set if user has ended or cancelled key input
149; CF: Set if character is rejected
150; Corrupts registers:
151; AH
152;--------------------------------------------------------------------
153ALIGN JUMP_ALIGN
154.ProcessControlCharacter:
155 cmp al, CR ; ENTER to terminate string?
156 je SHORT .EndCharacterInput
157 cmp al, ESC ; Cancel input?
158 je SHORT .CancelCharacterInput
159 cmp al, BS ; Backspace?
160 je SHORT .Backspace
161 jcxz .RejectCharacter
162 test al, al ; Clear ZF and CF
163 ret
164
165.Backspace:
166 test bx, bx ; At the beginning?
167 jz SHORT .RejectCharacter
168 inc cx ; Increment bytes left
169 dec bx ; Decrement characters inputted
170 dec di
171 call Keyboard_PrintBackspace
172 mov al, BS ; Restore character
173.RejectCharacter:
174 test al, al ; Clear ZF...
175 stc ; ...and set CF
176 ret
177
178.CancelCharacterInput:
179 xor bx, bx
180.EndCharacterInput:
181 xor al, al ; Set ZF and clear CF
182 ret
183
184
185;--------------------------------------------------------------------
186; Keyboard_PrintBackspace
187; Parameters:
188; Nothing
189; Returns:
190; Nothing
191; Corrupts registers:
192; AX
193;--------------------------------------------------------------------
194ALIGN JUMP_ALIGN
195Keyboard_PrintBackspace:
196 mov al, BS
197 call Keyboard_PrintInputtedCharacter
198 mov al, ' '
199 call Keyboard_PrintInputtedCharacter
200 mov al, BS
201 jmp SHORT Keyboard_PrintInputtedCharacter
202
203
204;--------------------------------------------------------------------
205; Keyboard_PlayBellForUnwantedKeystroke
206; Parameters:
207; Nothing
208; Returns:
209; Nothing
210; Corrupts registers:
211; AX
212;--------------------------------------------------------------------
213ALIGN JUMP_ALIGN
214Keyboard_PlayBellForUnwantedKeystroke:
215 mov al, BELL
216 ; Fall to Keyboard_PrintInputtedCharacter
217
218;--------------------------------------------------------------------
219; Keyboard_PrintInputtedCharacter
220; Parameters:
221; AL: Character inputted by user
222; Returns:
223; Nothing
224; Corrupts registers:
225; AX
226;--------------------------------------------------------------------
227ALIGN JUMP_ALIGN
228Keyboard_PrintInputtedCharacter:
229 push di
230 CALL_DISPLAY_LIBRARY PrintCharacterFromAL
231 CALL_DISPLAY_LIBRARY SynchronizeDisplayContextToHardware ; Hardware cursor
232 pop di
233 ret
234
235
236;--------------------------------------------------------------------
237; Keyboard_RemoveAllKeystrokesFromBuffer
238; Parameters:
239; Nothing
240; Returns:
241; Nothing
242; Corrupts registers:
243; AX
244;--------------------------------------------------------------------
245ALIGN JUMP_ALIGN
246Keyboard_RemoveAllKeystrokesFromBuffer:
247 call Keyboard_GetKeystrokeToAX
248 jnz SHORT Keyboard_RemoveAllKeystrokesFromBuffer
249 ret
250
251
252;--------------------------------------------------------------------
253; Keyboard_GetKeystrokeToAX
254; Keyboard_GetKeystrokeToAXandLeaveItToBuffer
255; Keyboard_GetKeystrokeToAXandWaitIfNecessary
256; Parameters:
257; Nothing
258; Returns:
259; AL: ASCII character (if keystroke available)
260; AH: BIOS scan code (if keystroke available)
261; ZF: Set if no keystroke available
262; Cleared if keystroke available
263; Corrupts registers:
264; Nothing
265;--------------------------------------------------------------------
266ALIGN JUMP_ALIGN
267Keyboard_GetKeystrokeToAX:
268 call Keyboard_GetKeystrokeToAXandLeaveItToBuffer
269 jnz SHORT Keyboard_GetKeystrokeToAXandWaitIfNecessary
270 ret
271ALIGN JUMP_ALIGN
272Keyboard_GetKeystrokeToAXandLeaveItToBuffer:
273 mov ah, CHECK_FOR_KEYSTROKE
274 int BIOS_KEYBOARD_INTERRUPT_16h
275 ret
276ALIGN JUMP_ALIGN
277Keyboard_GetKeystrokeToAXandWaitIfNecessary:
278 xor ah, ah ; GET_KEYSTROKE
279 int BIOS_KEYBOARD_INTERRUPT_16h
280 test ax, ax ; Clear ZF
281 ret
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