% ***************************************************************** % * * % * This module is a part of the SAO VAX/VMS * % * RED full-screen text editor * % * * % * It was created by * % * Roger Hauck * % * Smithsonian Institution * % * Astrophysical Observatory * % * Cambridge, Massachusetts 02138 * % * (617)495-7151 (FTS 830-7151) * % * * % * This module may be reproduced * % * provided that this header is retained. * % * * % ***************************************************************** % Define Window-related Variables 0 'PNTR VARIABLE 0 'TOPWINDOW VARIABLE % # of bytes before cursor in window 0 'BOTWINDOW VARIABLE % # of bytes after cursor in window 0 'BLANK_LINES VARIABLE % # of blank lines in window 'TOPOWINDOW@ : % TOPOWINDOW@, address of first byte of window BOTOTOP @ TOPWINDOW @ - ; 'TOPOWINDOW! : % address, TOPWINDOW! (establishes top of window) BOTOTOP @ - MINUS TOPWINDOW ! ; 'BOTOWINDOW@ : TOPOBOT @ BOTWINDOW @ + ; 'BOTOWINDOW! : TOPOBOT @ - BOTWINDOW ! ; 'TOP_WINDOW_STRING : % TOP_WINDOW_STRING, descriptor % of string from top of window to cursor TOPWINDOW @ BOTOTOP @ OVER - SWAP ; 'BOT_WINDOW_STRING : % BOT_WINDOW_STRING, descriptor % of string from cursor to bottom of window TOPOBOT @ BOTWINDOW @ ; % Operations relating to window management. 'S.CUP : % S.CUP (puts cursor at preselected position) SROW D@ CUP ; 'E.CR_TYO : CRET TYO % output CR ; 'E.TAB_TYO : TAB_MODE @ IF % hard tabs? 09 TYO ELSE % output hard tab BOLD ASCII I TYO STEADY THEN % output bold I ; 'E.TYO : DISPATCH 0D E.CR_TYO DISPATCH 09 E.TAB_TYO DUP 80 LE_IF % is mark bit set? 7F AND 4 ELSE % yes, reset bit, request underscore 0 THEN SWAP % no DUP 20 GT_IF % is it a control character? 40 + SWAP 1 OR ELSE % yes, make upper case and request bold SWAP THEN % no OVER 7F EQ_IF % is it a DEL? UNDER 18 SWAP THEN % yes, display as checkerboard NEZ_IF % any attribute requests? UNDROP DUP 1 AND NEZ_IF BOLD THEN % control character 4 AND NEZ_IF UNDERSCORE THEN % parity bit on TYO 0 SGR ELSE % output byte with attributes TYO THEN % no, normal ; 'PLINE : BEGIN DUP 1+ SWAP B@ % get next character DUP CRET NE IF E.TYO REPEAT % output it DROP CR % drop CR, output NL 8 IDLES % idle ; 'TW_COUNT : % TW_COUNT, descriptor of top of window TOPOWINDOW@ TOPWINDOW @ ; 'BW_COUNT : % BW_COUNT, descriptor of bottom of window TOPOBOT @ BOTWINDOW @ ; 'E.TYPE : NEZ_IF UNDROP ERASE_REST_OF_LINE ( DUP I + B@ DUP E.TYO CRET EQ_IF 0A TYO ERASE_THIS_LINE THEN ) THEN DROP ; 'SBB_COUNT : GTZ_IF UNDROP ( SBB DUP LEZ_IF EXIT THEN ) THEN LAST_I ; 09 'TAB CONSTANT ASSEMBLER< 'D.TAB : % current column #, D.TAB, new column # TAB_MODE @ IF % hard tabs? DECL (P) BICL2 S^ 7 (P) ADDL2 S^ 9 (P) ELSE % yes 1+ THEN % no ; > 'FIND_CURSOR_COLUMN : CRET TOP_COUNT SBB GEZ_IF % search backwards for carriage return, found? UNDROP + 1+ THEN % yes, calculate location BOTOTOP @ OVER - % descriptor of string passed over 1 SWAP % initialize column count ( OVER I + B@ TAB EQ_IF D.TAB ELSE % yes, calculate new column 1+ THEN ) % no, increment column # SCOL ! % record it 2DROP % drop search byte, pointer to beginning of line ; 'DEFINE_TOP_OF_WINDOW : CRET TOP_COUNT TF @ 1+ % setup to search DUP 1+ SROW ! % set cursor row to center of window SBB_COUNT % do search TF @ - MINUS 0 MAX BLANK_LINES ! % calculate & store # of blank lines + 1+ TOPOWINDOW! % find top of window DROP % drop search byte FIND_CURSOR_COLUMN ; 'FILL_BOTTOM_WINDOW : % (cursor must be correctly positioned first) TOPOBOT @ % save pointer TF @ 1+ ( % loop through bottom lines ERASE_REST_OF_LINE BEGIN BOPOP IF % anything left? DUP CRET NE ELSE % yes, indicate whether it's a carriage return CRET 0 THEN % no, simulate carriage return IF % was it a carriage return? E.TYO REPEAT % no, output character TYO I' NEZ_IF % yes, output carriage return, last line? LFEED TYO THEN % no, output line feed ) TOPOBOT @ SWAP TOPOBOT ! BOTOWINDOW! % record pointers ; 'ADD_LINE_AT_BOTTOM : TOPOBOT @ BOTOWINDOW@ TOPOBOT ! % temporarily redefine bottom buffer BEGIN BOPOP IF % anything left? DUP E.TYO % yes, output it CRET EQ ELSE % stop if CR -1 THEN % EOF, stop END TOPOBOT @ % new bottom of window SWAP TOPOBOT ! % restore bottom buffer BOTOWINDOW! % store bottom of window ; 'FIND_CURSOR : SCOL 1<- SROW 1<- TW_COUNT ( % scan through bottom of window DUP I + B@ % next byte CRET EQ_IF % is it a CR SCOL 1<- SROW 1+<- ELSE % yes, reset column, increment row UNDROP TAB EQ_IF % is it a tab? SCOL @ D.TAB SCOL ! ELSE % yes, get column # SCOL 1+! THEN THEN % no, increment column ) DROP SROW BLANK_LINES @ 1+ +<- % get real row # ; 'SETSCREEN : DISP_FLAG 2 <- ; 'DISP : DISP_FLAG @ 1 OR DISP_FLAG ! ; %**************** TEMPORARY DEFINITIONS *************** 'NSCROLL : DROP DISP ; '-NSCROLL : DROP DISP ; %******************************************************** 'REVISE_WINDOW : % (scrolls if necessary and redraws cursor) 1 SROW @ - DUP GEZ IF % cursor above window? 1+ -NSCROLL ELSE % yes, scroll down WINDOW_SIZE + MINUS DUP GTZ IF % cursor below window? NSCROLL ELSE DROP THEN THEN % yes, scroll up S.CUP ; 'SCROLL_DOWN_1 : % screen must be set up first RI % scroll down TOPOWINDOW@ DUP 1- TOPOTOP @ MAX DUP TOPOWINDOW! % reduce at least one BEGIN % loop till top of file or CR 1- DUP TOPOTOP @ GT IF % past the beginning? -1 ELSE % yes, signal exit DUP B@ CRET EQ THEN % signal exit if CR END 1+ % new value for TOPOWINDOW SWAP OVER - GTZ_IF UNDROP ( DUP I + B@ E.TYO ) ELSE % draw the line BLANK_LINES 1+! THEN % store new value TOPOWINDOW! ; 'FIND_BOTOWINDOW : % stores position of first char. below screen in BOTOWINDOW TOPOBOT @ % save TOPOBOT WINDOW_SIZE 2+ SROW @ - ( BEGIN BOPOP IF % any more bytes? CRET EQ ELSE % signal end if CR -1 THEN % EOF, signal end END ) % got it TOPOBOT @ % new bottom of window SWAP TOPOBOT ! % restore bottom buffer BOTOWINDOW! % store bottom of window ;