e3-16.asm

e3 是一个全屏的用户友好的文本编辑器

;-------------------------------------------------------------------------
;
;  Copyright (C) 2002 Albrecht Kleine  <[e-mail]>
;
;  This program is free software; you can redistribute it and/or
;  modify it under the terms of the GNU General Public License
;  as published by the Free Software Foundation; either
;  version 2 of the License, or (at your option) any later version.
;
;  This library is distributed in the hope that it will be useful,
;  but WITHOUT ANY WARRANTY; without even the implied warranty of
;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;  Library General Public License for more details.
;
;  You should have received a copy of the GNU Library General Public
;  License along with this library; if not, write to the Free Software
;  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
;
;--------------------------------------------------------------------------
;
; This is e3-16, a 16 bit derived work of 32 bit micro editor e3, ...
; ...running on ELKS (==Embeddable Linux Kernel Subset)  and DOS.
; Unlike e3 we are supporting WStar key bindings only.
; Unlike e3 "BAK-files" (*~) are not yet created.
;
TAB		equ 8
TABCHAR		equ 09h 		; ^I
SPACECHAR	equ ' '
CHANGED		equ '*'
UNCHANGED	equ SPACECHAR
NEWLINE		equ 0ah
errlen		equ 100
MAXERRNO	equ 30
ERRNOMEM	equ 12
ERRNOIO		equ 5
sBREITE    	equ 80			;cols
sHOEHE		equ 24			;rows
MAXLEN 		equ 0x7FFF
maxfilenamelen	equ 255
%ifdef ELKS
;;;; %define LESSWRITEOPS
 stdin		equ 0
 stdout 	equ 1
 O_WRONLY_CREAT_TRUNC equ 1101q
 O_RDONLY	equ 0
 PERMS		equ 644q
%else	;--------------
 normfarbe	equ 07h
 kursorfarbe	equ 70h
 slinefarbe	equ 1eh			;yellow on blue
 blockfarbe	equ 15
 O_WRONLY_CREAT_TRUNC equ 0
%endif

section .text
bits 16

global _start
global _main				; for ELKS and the ld86 linker
_start:	
_main:
EXE_startcode:
%ifdef EXESTUB
..start:
%endif
;-------
%ifdef ELKS
	call InitBSS
	pop ax
	pop bx
	pop si				;si points to first arg
%else
%ifdef COM
	org 100h
%else
%ifdef EXESTUB
	mov ax,data
	mov es,ax
	push ax
%else
%ifdef EXE
	EXE_realstacksize equ 0x800
	org 0e0h
header_start:
;EXE header adapted from a NASM contribution by Yann Guidon <[e-mail]>
	db 'M','Z'			; EXE file signature
	dw EXE_allocsize % 512
	dw (EXE_allocsize + 511) / 512
	dw 0				; relocation information: none
	dw (header_end-header_start)/16 ; header size in paragraphs
	dw (EXE_absssize + EXE_realstacksize) / 16 ; min extra mem
	dw (EXE_absssize + EXE_realstacksize) / 16 ; max extra mem
	dw -10h				; Initial SS (before fixup)
	dw EXE_endbss + EXE_realstacksize ; 2k
	dw 0				; (no) Checksum
	dw 100h				; Initial IP - start just after the header
	dw -10h				; Initial CS (before fixup)
	dw 0				; file offset to relocation table: none
	dw 0,0,0			; (no overlay)
header_end:				; here we go... (@ org 100h)
%endif
%endif
%endif
	call InitBSS
	call GetArg
%ifdef EXESTUB
	pop ds
%endif
%endif
;-----------------------------------------------------------------------
;
; start with OUTER editor loop
;
ReStart:call NewFile
	jc E3exit
MainCharLoop:call DispNewScreen
	call RestoreStatusLine
	call HandleChar
	cmp byte [endedit],0
	je MainCharLoop
	xor si,si			;just like if no arg is present
	cmp byte [endedit],2
	je ReStart			;^KD repeat edit using another file
E3exit:	call KursorStatusLine
;-------
%ifdef ELKS
	mov bx,stdout   		;file handle
	mov cx,newline			;enter next line on terminal
	xor dx,dx
	inc dx				;mov dx,1
	push dx
	call WriteFile
	pop ax				;mov ax,1
	xor bx,bx			;return 0
	int 80h
%else
	mov ah,4ch
	int 21h
%endif
;----------------------------------------------------------------------
;
; MAIN function for processing keys
;
HandleChar:call ReadChar
	jz ExtAscii			;DOS version got ah=0 by int 16 for F-keys and cursor keys
	cmp al,19h			;^Y is the last
	ja NormChar
	mov bl,al
	add bl,jumps1
	jmp short CompJump2
NormChar:call CheckMode
	jnz OverWriteChar
	push ax
	xor ax,ax
	inc ax
	call InsertByte
	pop ax
	jc InsWriteEnd			;error: text buffer full
OverWriteChar:cld
	stosb
	mov byte [changed],CHANGED
InsWriteEnd:ret
;-------
;
; helper for HandleChar
;
CtrlKMenu:mov bx,Ktable
	mov cx,4b5eh			;^K
	jmp short Menu
CtrlQMenu:mov bx,Qtable
	mov cx,515eh			;^Q
Menu:	call MakeScanCode
	jc EndeRet			;if no valid scancode
ExtAscii:mov bl,ah			;don't use al (carries char e.g. TAB)
	sub bl,lowest			;= scan code first key in jumptab1
	jb EndeRet
	cmp bl,jumps1
	jae EndeRet
CompJump2:and bx,0ffh
	shl bx,1			;2*bx is due 2 byte per entry
;-------
	call [bx+jumptab1]
;-------
	cmp byte [numeriere],1		;after return from functions...
	jnz BZNret			;...decide whether count current line number
	mov word [linenr],0
	push di
	mov si,sot
	xchg si,di
BZNLoop:inc word [linenr]
	call LookForward
	inc di				;point to start of next line
%ifndef ELKS
	inc di				;for DOS one extra 
%endif
	cmp di,si
	jbe BZNLoop
	pop di
	mov byte [numeriere],0
BZNret:	ret
;-------
MakeScanCode:call WriteTwo		;bx expects xlat-table
	push bx
	call GetChar
	pop bx
	and al,01fh
	cmp al,26
	jnb exit
	xlatb
	mov ah,al			;returns pseudo "scancode"
	stc
exit:	cmc				;ok=nc
EndeRet:ret
;----------------------------------------------------------------------
;
; processing special keys: cursor, ins, del
;
KeyRet:	call CheckMode
	jnz  OvrRet
	call CountToLineBegin		;set si / returns ax
	inc si
	inc si
	xor bx,bx
	or ax,ax
	jz KeyRetNoIndent
	dec bx
KeyRetSrch:inc bx			;search non (SPACE or TABCHAR)
	cmp byte [si+bx],SPACECHAR
	je KeyRetSrch
	cmp byte [si+bx],TABCHAR
	je KeyRetSrch
KeyRetNoIndent:
	push si
	push bx			;ax is 0 or =indented chars
	call GoDown
	pop ax

	push ax
	inc ax				;1 extra for 0ah
%ifndef ELKS
	inc ax
%endif
	call InsertByte
	pop cx				;# blanks
	pop si				;where to copy
	jc SimpleRet
	inc word [linenr]
	cld
%ifdef ELKS
	mov al,NEWLINE
	stosb
%else
	mov ax,0a0dh
	stosw
%endif
	jcxz SimpleRet
	rep movsb			;copy upper line i.e. SPACES,TABS into next
SimpleRet:ret
OvrRet:	mov word [ch2linebeg],0
	jmp short DownRet
;-------
KeyDown:call CountColToLineBeginVis
DownRet:call GoDown
	call LookLineDown
	jmp short SetColumn
;-------
KeyUp:	call GoUp
	call CountColToLineBeginVis
	call LookLineUp
	jmp short SetColumn
;-------
KeyPgUp:call CountColToLineBeginVis
	call LookPageUp
	jmp short SetColumn
;-------
KeyPgDn:call CountColToLineBeginVis
	call LookPgDown			;1st char last line
;-------
SetColumn:mov cx,[ch2linebeg]		;maximal columns
	xor dx,dx			;counts visible columns i.e. expand TABs
	dec di
lod:	inc di
	cmp dx,cx			;from CountColToLineBeginVis
	jae fert
%ifdef ELKS
	cmp byte [di],NEWLINE		;don't go beyond line earlier line end
%else
	cmp byte [di],0dh
%endif
	jz fert
	cmp byte [di],TABCHAR
	jz isTab
	inc dx				;count columns
	jmp short lod
isTab:	call SpacesForTab
	add dl,ah
	cmp dx,cx			;this tab to far away right?
	jna lod				;no
fert:	ret
;-------
KeyHome:call CountToLineBegin
	sub di,ax
	ret
;-------
KeyEnd:	call CountToLineEnd
	add di,ax			;points to a 0ah char
	ret
;-------
KeyIns:	not byte [insstat]
	ret
;-------
KeyDell:call KeyLeft
	jz KeyDell2
KeyDel:	cmp di,bp
	jnb KeyLeftEnd
	mov ax,1			;delete one @ cursor
%ifndef ELKS
	cmp byte [di],0dh
	jnz KeyDell3
	inc ax
%endif
KeyDell3:jmp DeleteByte
KeyDell2:call CheckBOF			;cmp di,sot  	delete newline char
	jbe KeyLeftEnd
	dec word [linenr]
	dec di
%ifndef ELKS
	dec di
%endif
	jmp BisNeueZeile
;-------
KeyLeft:cmp byte [di-1],NEWLINE		;FIXME another check of BOF
	jz KeyLeftEnd			;jmp if at BOL
	dec di
KeyLeftEnd:ret
;-------
KeyRight:
%ifdef ELKS
	cmp byte [di],NEWLINE
%else
	cmp byte [di],0dh
%endif
	jz KeyRightEnd			;at right margin
	inc di
KeyRightEnd:ret
;-------
KeyCLeft3:call CheckBOF			;cmp di,sot  bzw sot-1
	jbe KeyCLEnd
	dec di
%ifndef ELKS
	dec di
%endif
KeyCtrlLeft:call KeyLeft
	jz KeyCLeft3
	cmp byte [di],2fh
	jbe KeyCtrlLeft
	cmp byte [di-1],2fh
	ja KeyCtrlLeft
KeyCLEnd:ret
;-------
KeyCRight3:call CheckEOF
	jae KeyCREnd
	inc di
KeyCtrlRight:call KeyRight
	jz KeyCRight3
	cmp byte [di],2fh
	jbe KeyCtrlRight
	cmp byte [di-1],2fh
	ja KeyCtrlRight
KeyCREnd:ret
;
; processing special keys from the Ctrl-Q menu
;
;-------
KeyCtrlQA:call AskForReplace
	jc CtrlQFEnd
	mov byte [bereitsges],2
CQACtrlL:push di
	call FindText
	jc CtrlQFNotFound
	mov ax,[suchlaenge]
	call DeleteByte
	mov ax,[repllaenge]
	call InsertByte
	mov si, replacetext
	call MoveBlock
	jmp short CQFFound
;-------
KeyCtrlQF:call AskForFind
	jc CtrlQFEnd
	mov byte [bereitsges],1
CQFCtrlL:push di
	call FindText
	jc CtrlQFNotFound
CQFFound:pop si				;dummy
CQFNum:	mov byte [numeriere],1
	ret
CtrlQFNotFound:pop di
CtrlQFEnd:ret
;-------
KeyCtrlQC:mov di,bp
	jmp short CQFNum
;-------
KeyCtrlQR:mov di,sot
	jmp short CQFNum
;-------
KeyCtrlQP:mov di,[veryold]
	jmp short CQFNum	
;-------
KeyCtrlL:mov al,[bereitsges]		;2^QA   1^QF   0else
	dec al
	jz CQFCtrlL
	dec al
	jz CQACtrlL
SimpleRet4:ret
;-------
KeyCtrlQB:mov ax,di
	mov di,[blockbegin]
CtrlQB2:or di,di			;exit of no marker set
	jnz CQFNum
	xchg di,ax			;old mov di,ax
	ret
;-------
KeyCtrlQK:xchg ax,di			;old mov ax,di
	mov di,[blockende]
	jmp short CtrlQB2
;-------
KeyCtrlQY:call CountToLineEnd
	jmp short CtrlTEnd1
;-------
KeyCtrlY:call CountToLineBegin
	sub di,ax        		;di at begin
	call CountToLineEnd
	call DeleteByteCheckMarker
	jmp short BisNeueZeile
;-------
KeyCtrlT:call CountToWordBegin
%ifdef ELKS
	cmp byte [di],NEWLINE
%else
	cmp byte [di],0dh
%endif
	jnz CtrlTEnd1
BisNeueZeile:call CheckEOF
	jz SimpleRet4
%ifdef ELKS
	mov ax,1			;0ah
%else
	mov ax,2			;0dh,0ah	
%endif
CtrlTEnd1:jmp DeleteByteCheckMarker
;-------
KeyCtrlQI:mov dx,asklineno
	call GetAsciiToInteger
	jbe CtrlQFEnd			;CY or ZR set
	mov di,sot
	call LookPD2
	jmp CheckENum
;----------------------------------------------------------------------
;
; processing special Keys from Ctrl-K menu
;
KeyCtrlKY:call CheckBlock
	jc SimpleRet3			;no block: no action
	mov ax,[blockende]
	mov di,[blockbegin]
	sub ax,si			;block length
	mov di,si			;begin
	call DeleteByte			;out cx:=0
	mov [blockende],cx
	mov [blockbegin],cx
	jmp CQFNum
;-------
KeyCtrlKH:xor byte [showblock],1 	;flip flop
SimpleRet3:ret
;-------
KeyCtrlKK:mov [blockende],di
	jmp short KCKB
;-------
KeyCtrlKW:call CheckBlock
	jc SimpleRet2   ;no action
	call SaveBlock
	jmp short CtrlKREnd
;-------
KeyCtrlKC:call CopyBlock
	jc SimpleRet2
CtrlKC2:mov [blockbegin],di
	add ax,di
	mov [blockende],ax
	ret
;-------
KeyCtrlKV:call CopyBlock
	jc SimpleRet2
	push di
	cmp di,[blockbegin]
	pushf
	mov di,[blockbegin]
	call DeleteByte
	popf
	pop di
	jb CtrlKC2
	mov [blockende],di
	sub di,ax
KeyCtrlKB:mov [blockbegin],di
KCKB:	mov byte [showblock],1
SimpleRet2:ret
;-------
KeyCtrlKR:call ReadBlock
	jc CtrlKREnd
	call KeyCtrlKB
	add cx,di
	mov [blockende],cx
CtrlKREnd:jmp RestKursPos
;-------
KeyCtrlKS:call SaveFile
	pushf				;(called by ^kd)
	call RestKursPos
	popf
	jc CtrlKSEnd
	mov byte [changed],UNCHANGED
CtrlKSEnd:ret
;-------
KeyCtrlKQ:cmp byte [changed],UNCHANGED
	jz CtrlKQ2
	mov dx, asksave
	call DE1
	call RestKursPos
	and al,0dfh
	cmp al,'N'			;confirm
	jnz KeyCtrlKX
CtrlKQ2:mov byte [endedit],1
	ret 
KeyCtrlKD:call KeyCtrlKS
	jc CtrlKSEnd
	mov byte [endedit],2
	ret
KeyCtrlKX:call KeyCtrlKS
	jc CtrlKSEnd
	inc byte [endedit]
KeyKXend:ret
;---------------------------------------------------------------------
;
; the general PAGE DISPLAY function: called after any pressed key
;
; side effect: sets 'columne' for RestoreStatusLine function (displays columne)
; variable kurspos: for placing the cursor at new position
; register bh counts lines
; register bl counts columns visible on screen (w/o left scrolled)
; register dx counts columns in text lines
; register cx screen line counter and helper for rep stos
; register si text index
; register di screen line buffer index
;
DispNewScreen:call GetEditScreenSize	;check changed tty size
	xor ax,ax
%ifdef ELKS
	mov byte[isbold],al
	mov byte[inverse],al
%endif
	mov [zloffset],ax
	mov [columne],ax
	mov [fileptr],di		;for seeking current cursor pos
	call CountColToLineBeginVis	;i.e. expanding TABs
	cmp ax,[columns]
	jb DispShortLine
	sub ax,[columns]
	inc ax
	mov [zloffset],ax
DispShortLine:call LookPgBegin 		;go on 1st char upper left on screen
	mov si,di			;si for reading chars from text
	mov cx,[lines]
	jcxz KeyKXend			;window appears too small
	cld
%ifndef ELKS
	dec si
%endif
	mov bh,0
	dec bh
DispNewLine:
%ifndef ELKS
	inc si
%endif
	inc bh				;new line
	mov di,screenline		;line display buffer
	xor dx,dx			;reset char counter
	mov bl,0			;reset screen column
%ifdef LESSWRITEOPS
	cmp cx,1			;not in status line
	jz DCL0
	call SetColor2			;set initial character color per each line
DCL0:
%endif
DispCharLoop:
	cmp si,[fileptr]		;display char @ cursor postion ?
	jnz DispCharL1
	cmp byte[tabcnt],0
	jnz DispCharL1
	mov [kurspos],bx
	mov byte [columne],bl
	mov ax,[zloffset]		;chars scrolled left hidden
	add [columne],ax
%ifdef ELKS
	stc
	call SetInverseStatus
	jnc DispEndLine
%else
	mov ah,kursorfarbe
	cmp byte [insstat],1
	jz DispEndLine
%endif
DispCharL1:call SetColor
;-------
DispEndLine:cmp si,bp
	ja FillLine			;we have passed EOF, so now fill rest of screen
	cmp byte[tabcnt],0
	jz ELZ
	dec byte[tabcnt]
	jmp short ELZ2
ELZ:	cmp si,bp
	jnz ELZ6
	inc si				;set si>bp will later trigger  "ja FillLine"
	jmp short ELZ2	
ELZ6:	lodsb
	cmp al,TABCHAR
	jnz ELZ3
	push ax				;preserve color attribute
	call SpacesForTab		;ah = space_up_to_next_tab location
	dec ah				;count out the tab char itself
	mov byte[tabcnt],ah
	pop ax
ELZ2:	mov al,SPACECHAR
ELZ3:	
%ifdef ELKS
	cmp al,NEWLINE
%else
	cmp al,0dh
%endif
	jz FillLine
	cmp al,SPACECHAR
	jae ELZ9			;simply ignore chars like carriage_return etc.
	mov al,'.'
ELZ9:	cmp al,7fh
	jne ELZ8
	mov al,'.'
ELZ8:	cmp bl,byte [columns]		;screen width
	jae DispEndLine			;continue reading line until end
	inc dx				;also count hidden chars (left margin)
KZA6:	cmp dx,[zloffset]
	jbe DispCharLoop		;load new char (but no display)
%ifdef ELKS
	stosB