source: xtideuniversalbios/trunk/Assembly_Library/Src/Keyboard/Keyboard.asm@ 50

Last change on this file since 50 was 48, checked in by Tomi Tilli, 14 years ago

Changes to Assembly Library:
Added functions to clear Menu Title and Information areas.
Implemented automatic line change when writing Menu Title and Information areas.
CGA snow related functions have been moved to CgaSnow.asm.
Keyboard input functions no longer produce beep for backspace.
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 : 7.10.2010
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 es
29 push di
30 push cx
31
32 eENTER_STRUCT BUFFER_SIZE_FOR_WORD_INPUT
33 call Memory_CopySSBPtoESDI
34
35 mov cx, BUFFER_SIZE_FOR_WORD_INPUT
36 call Char_GetFilterFunctionToDXforNumericBaseInBX
37 call Keyboard_ReadUserInputtedStringToESDIWhilePrinting
38 jz SHORT .Return
39
40 call Memory_ExchangeDSSIwithESDI
41 call String_ConvertWordToAXfromStringInDSSIwithBaseInBX
42 call Memory_ExchangeDSSIwithESDI
43.Return:
44 eLEAVE_STRUCT BUFFER_SIZE_FOR_WORD_INPUT
45 test cx, cx ; Set ZF if string length is zero
46 pop cx
47 pop di
48 pop es
49 ret
50
51
52;--------------------------------------------------------------------
53; Reads user inputted string to buffer. Character filter is
54; supported to ignore unwanted characters.
55; Function returns when ENTER or ESC will be pressed.
56;
57; Keyboard_ReadUserInputtedStringToESDIWhilePrinting
58; Parameters:
59; CX: Buffer size (with NULL)
60; ES:DI: Ptr to destination buffer
61; CS:DX: Ptr to character filter function:
62; Parameters:
63; AL: Character inputted by user
64; Returns:
65; CF: Set if character is accepted
66; Cleared if character is rejected
67; Corrupts registers:
68; Nothing
69; Returns:
70; CX: String length in characters (without NULL)
71; ZF: Set if user cancellation
72; Corrupts registers:
73; AX
74;--------------------------------------------------------------------
75ALIGN JUMP_ALIGN
76Keyboard_ReadUserInputtedStringToESDIWhilePrinting:
77 push di
78 push si
79 push bx
80 call .PrepareDisplayContextForKeyboardInput
81 jcxz .ReturnAfterUpdatingZF
82
83 xor bx, bx ; Zero character counter
84 dec cx ; Decrement buffer size for NULL
85 cld
86ALIGN JUMP_ALIGN
87.GetCharacterFromUser:
88 call Keyboard_GetKeystrokeToAXandWaitIfNecessary ; Get ASCII to AL
89 call .ProcessControlCharacter
90 jz SHORT .TerminateStringWithNULL
91 jc SHORT .PlayBellForRejectedCharacter
92 call dx ; Filter character
93 jnc SHORT .PlayBellForRejectedCharacter
94 inc bx ; Increment number of characters stored
95 stosb ; Store from AL to ES:DI
96 call Keyboard_PrintInputtedCharacter
97 loop .GetCharacterFromUser
98.PlayBellForRejectedCharacter:
99 cmp al, BS ; No bell for backspace
100 je SHORT .GetCharacterFromUser
101 call Keyboard_PlayBellForUnwantedKeystroke
102 jmp SHORT .GetCharacterFromUser
103
104.TerminateStringWithNULL:
105 stosb ; Terminate string with NULL
106 mov cx, bx ; String length now in CX
107
108.ReturnAfterUpdatingZF:
109 CALL_DISPLAY_LIBRARY PopDisplayContext
110 test cx, cx ; Clear or set ZF
111 pop bx
112 pop si
113 pop di
114 ret
115
116;--------------------------------------------------------------------
117; .PrepareDisplayContextForKeyboardInput
118; Parameters:
119; Nothing
120; Returns:
121; Nothing (Display context pushed to stack)
122; Corrupts registers:
123; AX, BX, SI
124;--------------------------------------------------------------------
125ALIGN JUMP_ALIGN
126.PrepareDisplayContextForKeyboardInput:
127 pop bx ; Pop return address to BX
128 mov si, di
129
130 CALL_DISPLAY_LIBRARY PushDisplayContext
131 mov ax, CURSOR_NORMAL
132 CALL_DISPLAY_LIBRARY SetCursorShapeFromAX
133 CALL_DISPLAY_LIBRARY SynchronizeDisplayContextToHardware
134
135 mov di, si
136 jmp bx
137
138
139;--------------------------------------------------------------------
140; .ProcessControlCharacter
141; Parameters:
142; AL: Character inputted by user
143; CX: Number of bytes left in buffer
144; BX: Total number of characters inputted
145; ES:DI: Ptr where to store next character
146; Returns:
147; AL: Character inputted by user or NULL if end of input
148; BX: Cleared if user cancellation
149; ZF: Set if user has ended or cancelled key input
150; CF: Set if character is rejected
151; Corrupts registers:
152; AH
153;--------------------------------------------------------------------
154ALIGN JUMP_ALIGN
155.ProcessControlCharacter:
156 cmp al, CR ; ENTER to terminate string?
157 je SHORT .EndCharacterInput
158 cmp al, ESC ; Cancel input?
159 je SHORT .CancelCharacterInput
160 cmp al, BS ; Backspace?
161 je SHORT .Backspace
162 jcxz .RejectCharacter
163 test al, al ; Clear ZF and CF
164 ret
165
166.Backspace:
167 test bx, bx ; At the beginning?
168 jz SHORT .RejectCharacter
169 inc cx ; Increment bytes left
170 dec bx ; Decrement characters inputted
171 dec di
172 call Keyboard_PrintBackspace
173 mov al, BS ; Restore character
174.RejectCharacter:
175 test al, al ; Clear ZF...
176 stc ; ...and set CF
177 ret
178
179.CancelCharacterInput:
180 xor bx, bx
181.EndCharacterInput:
182 xor al, al ; Set ZF and clear CF
183 ret
184
185
186;--------------------------------------------------------------------
187; Keyboard_PrintBackspace
188; Parameters:
189; Nothing
190; Returns:
191; Nothing
192; Corrupts registers:
193; AX
194;--------------------------------------------------------------------
195ALIGN JUMP_ALIGN
196Keyboard_PrintBackspace:
197 mov al, BS
198 call Keyboard_PrintInputtedCharacter
199 mov al, ' '
200 call Keyboard_PrintInputtedCharacter
201 mov al, BS
202 jmp SHORT Keyboard_PrintInputtedCharacter
203
204
205;--------------------------------------------------------------------
206; Keyboard_PlayBellForUnwantedKeystroke
207; Parameters:
208; Nothing
209; Returns:
210; Nothing
211; Corrupts registers:
212; AX
213;--------------------------------------------------------------------
214ALIGN JUMP_ALIGN
215Keyboard_PlayBellForUnwantedKeystroke:
216 mov al, BELL
217 ; Fall to Keyboard_PrintInputtedCharacter
218
219;--------------------------------------------------------------------
220; Keyboard_PrintInputtedCharacter
221; Parameters:
222; AL: Character inputted by user
223; Returns:
224; Nothing
225; Corrupts registers:
226; AX
227;--------------------------------------------------------------------
228ALIGN JUMP_ALIGN
229Keyboard_PrintInputtedCharacter:
230 push di
231 CALL_DISPLAY_LIBRARY PrintCharacterFromAL
232 CALL_DISPLAY_LIBRARY SynchronizeDisplayContextToHardware ; Hardware cursor
233 pop di
234 ret
235
236
237;--------------------------------------------------------------------
238; Keyboard_RemoveAllKeystrokesFromBuffer
239; Parameters:
240; Nothing
241; Returns:
242; Nothing
243; Corrupts registers:
244; AX
245;--------------------------------------------------------------------
246ALIGN JUMP_ALIGN
247Keyboard_RemoveAllKeystrokesFromBuffer:
248 call Keyboard_GetKeystrokeToAX
249 jnz SHORT Keyboard_RemoveAllKeystrokesFromBuffer
250 ret
251
252
253;--------------------------------------------------------------------
254; Keyboard_GetKeystrokeToAX
255; Keyboard_GetKeystrokeToAXandLeaveItToBuffer
256; Keyboard_GetKeystrokeToAXandWaitIfNecessary
257; Parameters:
258; Nothing
259; Returns:
260; AL: ASCII character (if keystroke available)
261; AH: BIOS scan code (if keystroke available)
262; ZF: Set if no keystroke available
263; Cleared if keystroke available
264; Corrupts registers:
265; Nothing
266;--------------------------------------------------------------------
267ALIGN JUMP_ALIGN
268Keyboard_GetKeystrokeToAX:
269 call Keyboard_GetKeystrokeToAXandLeaveItToBuffer
270 jnz SHORT Keyboard_GetKeystrokeToAXandWaitIfNecessary
271 ret
272ALIGN JUMP_ALIGN
273Keyboard_GetKeystrokeToAXandLeaveItToBuffer:
274 mov ah, CHECK_FOR_KEYSTROKE
275 int BIOS_KEYBOARD_INTERRUPT_16h
276 ret
277ALIGN JUMP_ALIGN
278Keyboard_GetKeystrokeToAXandWaitIfNecessary:
279 xor ah, ah ; GET_KEYSTROKE
280 int BIOS_KEYBOARD_INTERRUPT_16h
281 test ax, ax ; Clear ZF
282 ret
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