edit.inc

一个用纯汇编 写的操作系统 源代码 是用 TASM 编译器写的

; Assembly Editor core
; Copyright (c) 2001-2006, Tomasz Grysztar.
; All rights reserved.

put_character:
	call	get_caret_segment
	inc	[caret_position]
    put_here:
	cmp	edx,SEGMENT_DATA_LENGTH
	jae	put_after_line_end
	call	store_segment_for_undo
	test	[editor_mode],AEMODE_OVERWRITE
	jnz	overwrite
	mov	ah,[esi+SEGMENT_HEADER_LENGTH+edx]
	shl	eax,8
	mov	al,ah
    insert_in_segment:
	lea	ebx,[esi+SEGMENT_HEADER_LENGTH+edx]
	mov	ecx,SEGMENT_DATA_LENGTH
	sub	ecx,edx
    shift_data_right:
	xchg	al,[ebx]
	inc	ebx
	loop	shift_data_right
	test	byte [esi],1
	jnz	shift_next_segment_right
	cmp	al,20h
	je	put_ok
    add_segment:
	push	eax
	call	allocate_segment
	jc	memory_shortage
	call	store_free_segment_for_undo
	mov	edi,eax
	or	eax,1
	xchg	eax,[esi]
	stosd
	mov	eax,esi
	or	eax,1
	stosd
	add	edi,SEGMENT_HEADER_LENGTH - 8
	pop	eax
	stosb
	mov	ecx,SEGMENT_DATA_LENGTH - 1
	mov	al,20h
	rep	stosb
	jmp	put_ok
    shift_next_segment_right:
	mov	esi,[esi]
	dec	esi
	call	store_segment_for_undo
	xor	edx,edx
	jmp	insert_in_segment
    put_after_line_end:
	push	eax
	call	attach_empty_segments
	pop	eax
	mov	[esi+SEGMENT_HEADER_LENGTH+edx],al
	mov	ah,20h
	shl	eax,8
    put_ok:
	test	[editor_style],AES_AUTOBRACKETS
	jz	insert_done
	shr	eax,8
	xchg	ah,al
	call	recognize_character
	jnc	insert_done
	cmp	ah,'('
	je	round
	cmp	ah,'['
	je	square
	cmp	ah,'{'
	je	brace
    insert_done:
	retn
    round:
	mov	al,')'
	jmp	auto_bracket
    square:
	mov	al,']'
	jmp	auto_bracket
    brace:
	mov	al,'}'
    auto_bracket:
	mov	edx,[caret_position]
	mov	esi,[caret_line]
	call	find_segment
	jmp	put_here
    overwrite:
	mov	[esi+SEGMENT_HEADER_LENGTH+edx],al
	retn
    attach_empty_segments:
	call	store_segment_for_undo
    attach_segment:
	push	edx
	call	allocate_segment
	jc	memory_shortage
	call	store_free_segment_for_undo
	pop	edx
	mov	ebx,esi
	mov	esi,eax
	mov	edi,eax
	or	eax,1
	xchg	eax,[ebx]
	stosd
	mov	eax,ebx
	or	eax,1
	stosd
	add	edi,SEGMENT_HEADER_LENGTH - 8
	mov	ecx,SEGMENT_DATA_LENGTH shr 2
	mov	eax,20202020h
	rep	stosd
	sub	edx,SEGMENT_DATA_LENGTH
	cmp	edx,SEGMENT_DATA_LENGTH
	jae	attach_segment
	retn
  recognize_character:
	cmp	al,20h
	jb	neutral_character
	cmp	al,30h
	jb	separator_character
	cmp	al,3Ah
	jb	neutral_character
	cmp	al,40h
	jb	separator_character
	cmp	al,5Bh
	jb	neutral_character
	cmp	al,5Fh
	jb	separator_character
	cmp	al,7Bh
	jb	neutral_character
	cmp	al,7Fh
	jb	separator_character
    neutral_character:
	clc
	retn
    separator_character:
	stc
	retn

delete_character:
	call	get_caret_segment
    delete_here:
	cmp	edx,SEGMENT_DATA_LENGTH
	jae	delete_done
	call	store_segment_for_undo
	test	[editor_mode],AEMODE_OVERWRITE
	jnz	blank
	lea	ebx,[esi+SEGMENT_LENGTH]
	mov	ecx,SEGMENT_DATA_LENGTH
	sub	ecx,edx
	mov	al,20h
	mov	edi,[esi]
	test	edi,1
	jz	shift_data_left
	mov	al,[edi-1+SEGMENT_HEADER_LENGTH]
    shift_data_left:
	dec	ebx
	xchg	al,[ebx]
	loop	shift_data_left
	lea	esi,[edi-1]
	xor	edx,edx
	test	edi,1
	jnz	delete_here
    delete_done:
	retn
    blank:
	mov	byte [esi+SEGMENT_HEADER_LENGTH+edx],20h
	retn

insert_into_line:
	or	ecx,ecx
	jz	void_insert
	push	ecx esi
	call	get_caret_segment
	test	[editor_mode],AEMODE_OVERWRITE
	jnz	overwrite_in_line
	cmp	edx,SEGMENT_DATA_LENGTH
	jae	attach_after_line_end
	mov	eax,[esp+4]
	push	edx
	xor	edx,edx
	mov	ecx,SEGMENT_DATA_LENGTH
	div	ecx
	mov	ebx,esi
	push	esi
	or	edx,edx
	jnz	find_last_segment_to_shift
	call	store_segment_for_undo
	mov	esi,[esi]
	btr	esi,0
	jnc	following_segments_shifted
	call	store_segment_for_undo
	jmp	following_segments_shifted
    find_last_segment_to_shift:
	test	byte [ebx],1
	jz	shift_following_segments
	mov	ebx,[ebx]
	dec	ebx
	jmp	find_last_segment_to_shift
    shift_following_segments:
	push	edx
	call	allocate_segment
	jc	memory_shortage
	call	store_free_segment_for_undo
	pop	edx
	mov	edi,eax
	mov	esi,[ebx]
	mov	[edi],esi
	mov	eax,ebx
	or	eax,1
	mov	[edi+4],eax
	lea	edi,[edi+SEGMENT_HEADER_LENGTH+edx]
	mov	ecx,SEGMENT_DATA_LENGTH
	sub	ecx,edx
	mov	al,20h
	rep	stosb
	sub	edi,SEGMENT_LENGTH
    carry_to_next_segment:
	mov	esi,ebx
	call	store_segment_for_undo
	mov	eax,edi
	or	eax,1
	mov	[esi],eax
	add	esi,SEGMENT_LENGTH
	sub	esi,edx
	mov	ecx,edx
	add	edi,SEGMENT_HEADER_LENGTH
	rep	movsb
	cmp	ebx,[esp]
	je	following_segments_shifted
	mov	edi,ebx
	mov	ebx,[edi+4]
	btr	ebx,0
	push	edi
	add	edi,SEGMENT_LENGTH-1
	mov	esi,edi
	sub	esi,edx
	mov	ecx,SEGMENT_DATA_LENGTH
	sub	ecx,edx
	std
	rep	movsb
	cld
	pop	edi
	jmp	carry_to_next_segment
    following_segments_shifted:
	pop	esi edx
    insert_more_segments:
	mov	edi,esi
	mov	ecx,[esp+4]
    make_inserted_segment:
	sub	ecx,SEGMENT_DATA_LENGTH
	jb	fill_inserted_segments
	push	ecx edx
	call	allocate_segment
	jc	memory_shortage
	call	store_free_segment_for_undo
	pop	edx ecx
	mov	ebx,[edi]
	btr	ebx,0
	jnc	make_attached_segment
	or	eax,1
	mov	[edi],eax
	mov	[ebx+4],eax
	and	eax,not 1
	or	ebx,1
	mov	[eax],ebx
	or	edi,1
	mov	[eax+4],edi
	mov	edi,eax
	jmp	make_inserted_segment
    make_attached_segment:
	or	eax,1
	mov	[edi],eax
	and	eax,not 1
	mov	[eax],ebx
	or	edi,1
	mov	[eax+4],edi
	mov	edi,eax
	jmp	make_inserted_segment
    fill_inserted_segments:
	mov	eax,SEGMENT_DATA_LENGTH
	add	ecx,eax
	sub	eax,edx
	sub	eax,ecx
	jbe	all_shifts_done
	mov	ecx,eax
	lea	edi,[edi+SEGMENT_LENGTH-1]
	push	esi
	lea	esi,[esi+SEGMENT_HEADER_LENGTH+ecx-1]
	add	esi,edx
	std
	rep	movsb
	cld
	pop	esi
    all_shifts_done:
	mov	edi,esi
	pop	esi ebx
    fill_new_segment:
	mov	ecx,SEGMENT_DATA_LENGTH
	sub	ecx,edx
	cmp	ecx,ebx
	jbe	length_for_inserting_ok
	mov	ecx,ebx
    length_for_inserting_ok:
	sub	ebx,ecx
	push	edi
	lea	edi,[edi+SEGMENT_HEADER_LENGTH+edx]
	or	esi,esi
	jz	insert_blank_string
	rep	movsb
	jmp	string_inserted
    insert_blank_string:
	mov	al,20h
	rep	stosb
    string_inserted:
	pop	edi
	mov	edi,[edi]
	and	edi,not 1
	xor	edx,edx
	or	ebx,ebx
	jnz	fill_new_segment
	retn
    attach_after_line_end:
	call	attach_empty_segments
	mov	ebx,esi
	pop	esi
	or	esi,esi
	jnz	attach_string
	pop	ecx
	retn
    attach_string:
	mov	ecx,[esp]
	mov	eax,SEGMENT_DATA_LENGTH
	sub	eax,edx
	cmp	eax,ecx
	jae	length_to_attach_ok
	mov	ecx,eax
    length_to_attach_ok:
	sub	[esp],ecx
	lea	edi,[ebx+SEGMENT_HEADER_LENGTH+edx]
	rep	movsb
	mov	ecx,[esp]
	jecxz	attach_ok
	call	allocate_segment
	jc	memory_shortage
	call	store_free_segment_for_undo
	mov	edi,eax
	or	eax,1
	xchg	eax,[ebx]
	mov	[edi],eax
	or	ebx,1
	mov	[edi+4],eax
	mov	ebx,edi
	xor	edx,edx
	jmp	attach_string
    attach_ok:
	pop	eax
	lea	ecx,[ebx+SEGMENT_LENGTH]
	sub	ecx,edi
	mov	al,20h
	rep	stosb
    void_insert:
	retn
    overwrite_in_line:
	cmp	edx,SEGMENT_DATA_LENGTH
	jb	position_for_overwrite_ok
	call	attach_empty_segments
    position_for_overwrite_ok:
	mov	edi,esi
	pop	esi ebx
    overwrite_segment:
	xchg	esi,edi
	call	store_segment_for_undo
	xchg	esi,edi
	mov	ecx,SEGMENT_DATA_LENGTH
	sub	ecx,edx
	cmp	ecx,ebx
	jbe	length_to_overwrite_ok
	mov	ecx,ebx
    length_to_overwrite_ok:
	sub	ebx,ecx
	push	edi
	lea	edi,[edi+SEGMENT_HEADER_LENGTH+edx]
	or	esi,esi
	jz	overwrite_with_blank
	rep	movsb
	jmp	overwritten_ok
    overwrite_with_blank:
	mov	al,20h
	rep	stosb
    overwritten_ok:
	pop	edi
	or	ebx,ebx
	jz	overwrite_done
	push	esi
	mov	esi,[edi]
	btr	esi,0
	jc	overwrite_existing_segment
	call	allocate_segment
	jc	memory_shortage
	call	store_free_segment_for_undo
	mov	edx,eax
	or	edx,1
	mov	[edi],edx
	mov	[eax],esi
	or	edi,1
	mov	[eax+4],edi
	mov	edi,eax
	pop	esi
	xor	edx,edx
	cmp	ebx,SEGMENT_DATA_LENGTH