e3-16.asm

e3 是一个全屏的用户友好的文本编辑器

;
%ifdef ELKS
LookBackward:				;set di to 1 before EOL (0Ah) i.e., 2 before start of next line
	push cx	
	push bx
	xor bx,bx
	cmp byte[di-1],NEWLINE		;at BOL ?
	jz LBa3
	cmp byte[di],NEWLINE		;at EOL ?
	jnz LBa1
	dec di				;at EOL ? start search 1 char earlier
	inc bx				;increase counter
LBa1:	mov cx,9999
	mov al,NEWLINE
	std
	repne scasb
	mov ax,9997
	sub ax,cx
	add ax,bx
	pop bx
	pop cx
	jmp short CheckBOF
;-------
LBa3:	xor ax,ax
	pop bx
	pop cx
	dec di
	dec di
	jmp short CheckBOF
%else
LookBackward:push cx
	mov cx,9999
	mov al,0ah
	std
	repne scasb
	mov ax,9997
	sub ax,cx
	pop cx
	jmp short CheckBOF
%endif
LookForward:push cx
	mov cx,9999
%ifdef ELKS
	mov al,NEWLINE
%else
	mov al,0dh
%endif
	cld
	repne scasb
	mov ax,9998
	sub ax,cx
	pop cx
	dec di
CheckEOF:cmp di,bp			;ptr is eof-ptr?      
	jnz CheckEnd			;Z flag if eof             
	jmp short CheckENum
CheckBOF:cmp di,sot
	ja CheckEnd
CheckENum:mov byte [numeriere],1	;if bof
CheckEnd:ret
;-------
LookPgBegin:mov dx,[kurspos2]		;called by DispNewScreen to get sync with 1st char on screen
	mov cl,dh			;called by KeyCtrlQE  (go upper left)
	mov ch,0
	inc cl
	jmp short LookPU2
;-------
LookLineUp:mov cx,2			;2 lines: THIS line and line BEFORE
	dec word [linenr]
	jmp short LookPU2
;-------
LookLineDown:mov cx,2			;2 lines: THIS and NEXT line
	inc word [linenr]
	jmp short LookPD2
;-------
LookPageUp:mov cx,[lines]
	sub [linenr],cx 
	inc word [linenr]		;PgUp,PgDown one line less
LookPU2:call LookBackward
	jb LookPUEnd			;if BOF
%ifdef ELKS
	inc di
%endif
	loop LookPU2			;after loop di points to char left of 0ah
%ifdef ELKS
	dec di
%endif
LookPUEnd:inc di   
	inc di				;now points to 1st char on screen or line
	ret
;-------
LookPgDown:mov cx,[lines]
	add [linenr],cx
	dec word [linenr]
LookPD2:call LookForward
	jz LookPDEnd			;(jmp if EOF)
%ifndef ELKS
	inc di
%endif
	inc di				;1st char next line
	loop LookPD2
%ifndef ELKS
	dec di
%endif
	dec di				;last char last line
LookPDEnd:sub di,ax			;1st char last line
	ret
;----------------------------------------------------------------------
;
; some more CHECK functions
;
CheckBlock:cmp byte [showblock],1	;returns CY if error else ok: NC
	jc CheckBlockEnd
	mov si,[blockende]
	cmp si, sot
	jb CheckBlockEnd
	mov si,[blockbegin]		;side effect si points to block begin
	cmp si, sot
	jb CheckBlockEnd
	cmp [blockende],si		;^KK > ^KB ..OK if above!
CheckBlockEnd:ret
;-------
CheckImBlock:cmp [blockbegin],di	;^KB mark > di ?
	ja CImBlockEnd			;OK
	cmp di,[blockende]		;di > ^KK
CImBlockEnd:ret	          		;output:cy fehler / nc ok inside block
;-------
CheckMode:
%ifdef ELKS
	cmp byte [di],NEWLINE		;checks for INSERT status
%else
	cmp byte [di],0dh
%endif
	jz ChModeEnd
	cmp byte [insstat],1
ChModeEnd:ret				;Z flag for ins-mode
;-------
; a special case called by DeleteByteCheckMarker
;
CheckMarker:				;dx is blockbegin (^KB) 
					;bx is deleate area end --- di delete area start
	cmp di,dx			;delete area start < ^KB marker ?
	ja CMEnd			;no
	cmp bx,dx			;yes, but delete area end > ^KB ?
	jl CMEnd			;no
	mov dx,di			;yes so block start (^KB) to delete area start
CMEnd:	ret
;----------------------------------------------------------------------
;
; C O U N T  functions
; to return number of chars up to some place
; (all of them are wrappers of Look....functions anyway)
;
CountToLineEnd:push di
	call LookForward
	pop di
	ret				;ax=chars up to line end
;-------
CountColToLineBeginVis:			;counts columns represented by chars in ax
	call CountToLineBegin		;i.e. EXPAND any TAB chars found
	push si
	xor dx,dx
	mov si,di			;startpoint	
	sub si,ax			;to bol
	dec si
CCV1:	inc si
	cmp si,di
	jae CCVend
	cmp byte [si],TABCHAR
	jz CCVTab
	inc dx				;count visible chars
	jmp short CCV1
CCVTab:	call SpacesForTab		;return space_up_to_next_tab in ah
	add dl,ah			;FIXME: now using 8 bits only
	jmp short CCV1
CCVend:  mov [ch2linebeg],dx		;ch2linebeg: interface to Key... functions
	mov ax,dx			;ax: interface to DispNewScreen
	pop si
	ret
;-------
CountToLineBegin:push di		;output ax=chars up there
	call LookBackward
	mov si,di			;side effect: set di to 1st char in line
	pop di
	ret
;-------
CountToWordBegin:			;output ax=chars up there
	mov si,di
CountNLoop:inc si
%ifdef ELKS
	cmp byte [si],NEWLINE
%else
	cmp byte [si],0dh
%endif
	jz fertig2
	cmp byte [si],SPACECHAR		;below SPACE includes tab chars
	jbe CountNLoop
	cmp byte [si-1],2fh
	ja CountNLoop 
fertig2:mov ax,si
	sub ax,di			;maybe =0
	ret
;---------------------------------------------------------------------
;
; some CURSOR control functions
;
GoUp:	mov al,0
	mov ah,-1
	jmp short UpDown
GoDown:	mov al,byte [lines]
	dec al
	mov ah,1
UpDown:	mov dx,[kurspos2]		;former was call getkurspos
	cmp dh,al
	jz Goret
	add dh,ah			;ONLY here we change curent line of cursor
	jmp short SetKursPos 
Goret:	ret       
;-------
; set cursor to some desired places
;
KursorStatusLine:mov dh,[lines]
	mov dl,stdtxtlen
	jmp short SetKursPos
RestKursPos:mov dx,[kurspos]
SetKursPos:mov [kurspos2],dx		;saves reading cursor pos   (0,0)
%ifndef ELKS
sys_writeKP:
	push ax
	mov ah,2
	mov bh,0
	int 10h
	pop ax
	ret
%else	;---------------------------------------------------------------
sys_writeKP:
	push ax
	push bx
	push cx
	push dx
	push si
	push di
	push bp
	call make_KPstr
	mov bx,stdout			;file handle (stdout)
	mov cx,setkp 			;second argument: pointer to message to write
	mov dx,setkplen			;third argument: message length
	call WriteFile
	pop bp
	pop di
	pop si
	pop dx
	pop cx
	pop bx
	pop ax
	ret
;-------
; make ESC sequence appropriate to most important terminals
;
make_KPstr:
	inc dl				;expecting cursor pos in dh/dl (0,0)
	inc dh 				;both line (dh) col (dl) are counted now from 1
	cld
	mov di,setkp			;build cursor control esc string db 27,'[000;000H'
	mov ax,0x5B1B			;line starts at setkp+2, col starts at setkp+6
	stosw
	mov ax,'00'
	stosw
	mov ax,'0;'			;init memory
	stosw
	mov ax,'00'
	stosw
	mov ax,'0H'			;init memory
	stosw
	mov di,setkp+1+3		;line end
	xor ax,ax
	mov al,dh			;DH=line
	push dx
	call IntegerToAscii		;make number string
	pop dx
	cld
	mov di,setkp+1+3+4		;column end
	xor ax,ax
	mov al,dl			;DL=col
	jmp IntegerToAscii	
%endif
;-----------------------------------------------------------------------
;
; functions for INSERTING, COPYING and DELETING chars in text
;
InsertByte:or ax,ax			;input: ax = #bytes ,  di = ptr
	jz Ins3
	mov byte [changed],CHANGED
	mov cx,MAXLEN			;max_len+offset-eofptr=freespace(cx)
	add cx,sot
	sub cx,bp
	cmp cx,ax			;cmp freespace - newbytes  ;>= 0 ok/ NC  <0 bad / CY
	jnc SpaceAva
	mov word[errno],ERRNOMEM
	call DosError
	call RestKursPos
	stc
	ret
SpaceAva:push di
	mov si,bp			;end of text
	mov cx,bp
	add cx,ax
	sub cx,di			;space count
	mov di,bp
	add di,ax
	std
	rep movsB
	pop di
;-------
	add bp,ax
	cmp di,[blockende]
	ja Ins1
	add [blockende],ax
Ins1:	cmp di,[blockbegin]
	ja Ins2
        add [blockbegin],ax
Ins2:	clc
Ins3:	ret				;output:nc=ok / cy=bad
;-------
CopyBlock:call CheckBlock		;copy block, called by ^KC, ^KV
	jc MoveBlEnd
	call CheckImBlock
	jc MoveBlEnd
	mov ax,[blockende]
	sub ax,si			;block len
	call InsertByte
	jc MoveBlEnd
	mov si,[blockbegin]
MoveBlock:push di			;input : si=^KB di=current
	mov cx,ax
	cld
	rep movsb
	pop di
	clc				;nocarry->ok
MoveBlEnd:ret
;-------
DeleteByteCheckMarker:			;di points to begin
	mov bx,di
	add bx,ax
	mov dx,[blockbegin]
	call CheckMarker
	mov [blockbegin],dx
	mov dx,[blockende]
	call CheckMarker
	mov [blockende],dx
DeleteByte:or ax,ax			;input in ax
	jz DeleteByteEnd
	mov byte [changed],CHANGED
	push di
	push si
	mov cx,bp			;end
	sub cx,di
	mov si,di
	add si,ax
	sub cx,ax
	add cx,3
	shr cx,1
	cld
	rep movsW
	pop si
	pop di
	sub bp,ax
	cmp di,[blockende]
	jae Del1
	sub [blockende],ax
Del1:	cmp di,[blockbegin]
	jae DeleteByteEnd
	sub [blockbegin],ax
DeleteByteEnd:ret
;---------------------------------------------------------------------
; read a file name for block operations
; expecting message text ptr in dx
;
getBlockName:
	push ax
	push bx
	push cx
	push dx
	push si
	push di
	push bp
	call WriteMess9MachRand
	mov cx,blockpath
	mov dx,maxfilenamelen
	call InputString		;cy if empty string
	pushf
	call RestKursPos
	popf
	pop bp
	pop di
	pop si
	pop dx
	pop cx
	pop bx
	pop ax
	ret
;----------------------------------------------------------------------
;
; functions reading/writing  text or blocks  from/into  files
;
NewFile:call InitVars
	call DelEditScreen
	or si,si
	jz noarg
	cld
	mov di,filepath
ccc:	lodsb
	stosb
	or al,al
	jnz ccc
	jmp short GetFile
;-------
noarg:	mov dx, filename
	call WriteMess9MachRand
	mov cx,filepath
	mov dx,maxfilenamelen
	call InputString
	jc NFEnd2			;empty string not allowed here
;-------
GetFile:mov bx,filepath
	xor cx,cx			;i.e O_RDONLY
	call OpenFile
	mov di,sot
	mov bp,di
	mov bx,ax			;file descriptor
	js NewFileEnd	
OldFile:
%ifdef SYS_FSTAT
	call Fstat			;kernel returns error 38
	js DosEjmp0
	mov ax,[fstatbuf+8]		;better define some structure
	and ax,777q
	mov [perms],ax
%endif
;-------
	mov dx,MAXLEN
	mov cx,di			;sot
	call ReadFile
	mov dx,ax			;bytes read
	js DosEjmp0			;DosError
	call CloseFile
	js DosEjmp0			;DosError
;-------
	mov word [errno],ERRNOMEM
	cmp dx,MAXLEN			;MAXLEN read amount is too much
	jnz XX2
	jmp DosError
XX2:
;-------
	mov bp,sot			;eof_ptr=filesize+start_of_text
	add bp,dx
NewFileEnd:
%ifdef ELKS
	mov byte [ds:bp],NEWLINE	;eof-marker
%else
	mov word [ds:bp],0a0dh
%endif
	clc
NFEnd2:	ret
;-------
;  save file (called by ^KS,^KX)
;
SaveFile:cmp byte [changed],UNCHANGED
	jz SaveFile3			;no changes: nothing to save
	mov dx,filesave
	call WriteMess9
	mov cx,O_WRONLY_CREAT_TRUNC
	mov bx,filepath
%ifdef ELKS
	mov dx,[perms]
	call OpenFile
%else
	call CreateFile
%endif
DosEjmp0:js DosEjmp			;DosError
	mov cx,sot			;cx=bof
	mov dx,bp			;eof
SaveFile2:sub dx,cx			;dx=filesize= eof-bof
	mov bx,ax			;file descriptor
	call WriteFile
	js DosEjmp			;DosError
	mov word[errno],ERRNOIO		;just in case of....
	cmp ax,dx			;all written?
	jz XX4
	jmp DosError
XX4:	call CloseFile
	js DosEjmp			;DosError
SaveFile3:ret
;------------------------------
;  save block (called by ^KW)
;
SaveBlock:mov dx,blocksave
	call getBlockName
	jnc XX3
	jmp DE2
XX3:	mov cx,O_WRONLY_CREAT_TRUNC
	mov bx,blockpath
%ifdef ELKS
	mov dx,[perms]
	call OpenFile
%else
	call CreateFile
%endif
	js DosEjmp			;DosError
	mov cx,si			;= block begin
	mov dx,[blockende]
	jmp short SaveFile2
;-------
; read a block into buffer (by ^KR)
;
ReadBlock:mov dx,blockread
	call getBlockName
	jnc XX5
	jmp DE2
XX5:	xor cx,cx			;i.e O_RDONLY
	mov bx,blockpath
	call OpenFile
DosEjmp:js DosError
	mov bx,ax			;file desc
	mov dx,2
	call SeekFile			;end
	js DosError
	push dx
	push ax
	xor dx,dx
	call SeekFile			;home
	pop ax
	pop dx
	js DosError
	or dx,dx
	mov word [errno],ERRNOMEM
	jnz DosError
	push ax
	call InsertByte
	pop dx				;file size
	jc DosError
	mov cx,di			;^offset akt ptr
	call ReadFile
	js preDosError			;to delete inserted bytes (# in dx)
	mov cx,ax    			;bytes read
	call CloseFile
	js DosError
	mov word[errno],ERRNOIO		;just in case of....
	cmp dx,cx			;all read?
	jnz DosError
ReadBlock2:jmp NewFileEnd
;------------------------------------------------------------
;
; Error handler
;
preDosError:mov ax,dx			;count bytes
	call DeleteByte			;delete space reserved for insertation
DosError:push di
	mov di,error+8			;where to store ASCII value of errno
	mov ax,[errno]
	push ax
	call IntegerToAscii		;TODO: print a string instead of errno value
	pop cx
	cmp cx,MAXERRNO
	ja DE0
	mov di,errmsgs
	call LookPD2			;look message x in line number x
	mov si,di
	mov di,error+9
	mov ax,' :'
	stosw
	mov cx,80			;max strlen / compare errlen equ 100
	rep movsb
DE0:	mov dx,error
	pop di
DE1:	call WriteMess9
	call GetChar
DE2:	call RestoreStatusLine
	stc				;error status
	ret
;----------------------------------------------------------------------
;
; some GENERAL helper functions
;
IntegerToAscii:
	mov cx,10
	std
	mov bx,ax			;bx=quotient
Connum1:mov ax,bx
	sub dx,dx
	div cx
	mov bx,ax			;save quotient (new low word)
	mov al,dl
	call Hexnibble
	or bx,bx
	jne Connum1
	cld
	ret
Hexnibble:and al,0fh
	add al,'0'	
	cmp al,':'
	jb noHex
	add al,7			;(should never be due cx==10)
noHex:	stosb
	ret
;-------
;
; GetAsciiToInteger reads integer value from keyboard (only > 0)
;
GetAsciiToInteger:call WriteMess9MachRand
	mov cx,blockpath
	mov dx,maxfilenamelen
	call InputString
	call AskFor_Ex			;repair status line & set cursor pos / preserve flags
	mov ax,0			;preserve flags
	mov cx,ax
	mov bl,9			;bl == base-1
	jc AIexit2
	mov si,blockpath
	cld
AIload:	lodsb
	sub al,'0'
	js AIexit
	cmp al,bl
	ja AIexit
	mov dx,cx	
	shl cx,3			;* 8
	add cx,dx			;+ 1
	add cx,dx			;+ 1
	add cx,ax			;+digit
	jmp short AIload
AIexit:	or cx,cx			;ret ecx
AIexit2:ret				;CY or ZR if error
;-------
;
; expects curent column in dx
; returns # spaces up to next tabulated location in AH
;
SpacesForTab:push cx
	mov ax,dx
	mov cl,TAB
	div cl
	neg ah				;ah = modulo division
	add ah,TAB			;TAB - pos % TAB
	pop cx
	ret
;-------
; a little helper for SetColor* functions
;
IsShowBlock:cmp byte [showblock],0
	je SBlock