; --------------------------------------------------------------------- ; Paul Overaa's Amiga Computing Assembler Series - code for instalment 5 ; --------------------------------------------------------------------- NULL EQU 0 TRUE EQU 1 NM_TITLE EQU 1 NM_ITEM EQU 2 NM_END EQU 0 IDCMP_MENUPICK EQU $00000100 IDCMP_RAWKEY EQU $00000400 MENUNULL EQU $FFFFFFFF im_Class EQU $14 im_Code EQU $18 wd_UserPort EQU $56 TAG_DONE EQU 0 TAG_END EQU 0 WA_BASE EQU $80000063 WA_Left EQU WA_BASE+$01 WA_Top EQU WA_BASE+$02 WA_Width EQU WA_BASE+$03 WA_Height EQU WA_BASE+$04 WA_IDCMP EQU WA_BASE+$07 WA_Title EQU WA_BASE+$0B WA_DragBar EQU WA_BASE+$1F WA_PubScreen EQU WA_BASE+$16 MODE_OLDFILE EQU 1005 MEMF_ANY EQU 0 DOS_FIB EQU 2 fib_Size EQU 124 rf_File EQU 4 rf_Dir EQU 8 IOSTD_SIZE EQU $30 io_Data EQU $28 io_Length EQU $24 io_Command EQU $1c CONFLAG_DEFAULT EQU 0 window_SIZEOF EQU $88 CMD_WRITE EQU $3 LINEFEED EQU $A PAGELENGTH EQU 22 CURSORUP EQU $4C CURSORDOWN EQU $4D _AbsExecBase EQU 4 _LVOOpenLibrary EQU -552 _LVOCloseLibrary EQU -414 _LVODisplayBeep EQU -96 _LVOLockPubScreen EQU -510 _LVOUnlockPubScreen EQU -516 _LVOOpenWindowTagList EQU -606 _LVOCloseWindow EQU -72 _LVOGetVisualInfoA EQU -126 _LVOFreeVisualInfo EQU -132 _LVOCreateMenusA EQU -48 _LVOFreeMenus EQU -54 _LVOLayoutMenusA EQU -66 _LVOSetMenuStrip EQU -264 _LVOClearMenuStrip EQU -54 _LVOWaitPort EQU -384 _LVOGetMsg EQU -372 _LVOReplyMsg EQU -378 _LVOAllocFileRequest EQU -30 _LVOFreeFileRequest EQU -36 _LVOAslRequest EQU -60 _LVOExamineFH EQU -390 _LVOAllocMem EQU -198 _LVOFreeMem EQU -210 _LVOOpen EQU -30 _LVOClose EQU -36 _LVOAllocDosObject EQU -228 _LVOFreeDosObject EQU -234 _LVORead EQU -42 _LVOAddPart EQU -882 _LVOCreateMsgPort EQU -666 _LVODeleteMsgPort EQU -672 _LVOCreateIORequest EQU -654 _LVODeleteIORequest EQU -660 _LVOOpenDevice EQU -444 _LVOCloseDevice EQU -450 _LVODoIO EQU -456 ; --------------------------------------------------------------------- LINKLIB MACRO move.l a6,-(a7) movea.l \2,a6 jsr \1(a6) move.l (a7)+,a6 ENDM CALLSYS MACRO LINKLIB _LVO\1,\2 ENDM ; --------------------------------------------------------------------- _main lea function_stack,a5 for alloc/dealloc operations lea lib_names,a2 lea _DOSBase,a3 move.w #(5-1),d3 loop counter .loop movea.l (a2)+,a1 library name pointer moveq #0,d0 any version will do CALLSYS OpenLibrary,_AbsExecBase move.l d0,(a3)+ store returned base dbeq d3,.loop beq.s lib_error_exit ; all libraries are open and available for use. jsr LockScreen beq.s closedown jsr GetVisInfo beq.s closedown jsr OpenWindow beq.s closedown jsr CreateMenu beq.s closedown jsr LayoutMenu beq.s closedown jsr InstallMenu beq.s closedown jsr AllocFileReq beq.s closedown jsr SetupMsgPort beq.s closedown jsr SetupIOReq beq.s closedown jsr OpenDev beq.s closedown ; now everything is set up we can call the event handler! movea.l window_p,a1 movea.l wd_UserPort(a1),a2 user port address jsr EventHandler handle user actions closedown move.l (a5)+,d0 retrieve function pointer beq.s lib_normal_exit move.l d0,a0 jsr (a0) and execute routine if it exists! bra.s closedown lib_normal_exit lea lib_base_end,a3 revised label - see text moveq #5,d2 library count jsr CloseLibs close libraries moveq #0,d0 clear d0 for O/S rts and terminate program lib_error_exit moveq #(5-1),d2 see part 1 mag text sub d3,d2 jsr CloseLibs close libraries moveq #0,d0 clear d0 for O/S rts and terminate program ; --------------------------------------------------------------------- ; CloseLibs() On entry... ; a3 should hold address of the longword location just past ; that of the first library to close (this is because the ; routine uses a backward reading loop). ; d2 should hold count of the number of libraries to close CloseLibs tst.b d2 test counter beq.s loop_end movea.l -(a3),a1 get library base CALLSYS CloseLibrary,_AbsExecBase subq.b #1,d2 bra.s CloseLibs loop_end rts ; --------------------------------------------------------------------- ; LockScreen() and UnlkScreen() on entry... need no register parameters! LockScreen movem.l a0-a1/d0-d1,-(a7) preserve regs lea workbench_name,a0 pointer to screen name CALLSYS LockPubScreen,_IntuitionBase move.l d0,workbench_p save returned pointer beq.s .error move.l #UnlkScreen,-(a5) push deallocation routine address .error movem.l (a7)+,a0-a1/d0-d1 restore regs rts UnlkScreen movem.l a0-a1/d0-d1,-(a7) preserve regs movea.w #NULL,a0 screen name not needed movea.l workbench_p,a1 screen to unlock CALLSYS UnlockPubScreen,_IntuitionBase movem.l (a7)+,a0-a1/d0-d1 restore regs rts ; --------------------------------------------------------------------- ; OpenWindow() and ShutWindow() on entry... need no register parameters! OpenWindow movem.l a0-a1/d0-d1,-(a7) preserve regs movea.w #NULL,a0 lea tags,a1 start of tag list CALLSYS OpenWindowTagList,_IntuitionBase move.l d0,window_p save returned pointer beq.s .error move.l #ShutWindow,-(a5) push deallocation routine address .error movem.l (a7)+,a0-a1/d0-d1 restore regs rts ShutWindow movem.l a0-a1/d0-d1,-(a7) preserve regs movea.l window_p,a0 window to close CALLSYS CloseWindow,_IntuitionBase movem.l (a7)+,a0-a1/d0-d1 restore regs rts ; --------------------------------------------------------------------- ; GetVisInfo() and FreeVisInfo() on entry... need no register parameters! GetVisInfo movem.l a0-a1/d0-d1,-(a7) preserve regs movea.l workbench_p,a0 movea.w #TAG_END,a1 no tags CALLSYS GetVisualInfoA,_GadToolsBase move.l d0,visual_info_p save returned pointer beq.s .error move.l #FreeVisInfo,-(a5) push deallocation routine address .error movem.l (a7)+,a0-a1/d0-d1 restore regs rts FreeVisInfo movem.l a0-a1/d0-d1,-(a7) preserve regs movea.l visual_info_p,a0 CALLSYS FreeVisualInfo,_GadToolsBase movem.l (a7)+,a0-a1/d0-d1 restore regs rts ; --------------------------------------------------------------------- ; CreateMenu() and FreeMenu() on entry... need no register parameters! CreateMenu movem.l a0-a1/d0-d1,-(a7) preserve regs lea menu,a0 movea.w #TAG_END,a1 no tags CALLSYS CreateMenusA,_GadToolsBase move.l d0,menu_p save returned pointer beq.s .error move.l #FreeMenu,-(a5) push deallocation routine address .error movem.l (a7)+,a0-a1/d0-d1 restore regs rts FreeMenu movem.l a0-a1/d0-d1,-(a7) preserve regs movea.l menu_p,a0 menu to free CALLSYS FreeMenus,_GadToolsBase movem.l (a7)+,a0-a1/d0-d1 restore regs rts ; --------------------------------------------------------------------- ; LayoutMenu() on entry... needs no register parameters! LayoutMenu movem.l a0-a1/d0-d1,-(a7) preserve regs movea.l menu_p,a0 movea.l visual_info_p,a1 movea.w #TAG_END,a2 no tags CALLSYS LayoutMenusA,_GadToolsBase tst.l d0 nothing to deallocate movem.l (a7)+,a0-a1/d0-d1 restore regs rts ; --------------------------------------------------------------------- ; InstallMenu() and RemoveMenu() on entry... need no register parameters! InstallMenu movem.l a0-a1/d0-d1,-(a7) preserve regs movea.l window_p,a0 movea.l menu_p,a1 CALLSYS SetMenuStrip,_IntuitionBase tst.l d0 beq.s .error move.l #RemoveMenu,-(a5) push deallocation routine address .error movem.l (a7)+,a0-a1/d0-d1 restore regs rts RemoveMenu movem.l a0-a1/d0-d1,-(a7) preserve regs movea.l window_p,a0 target window CALLSYS ClearMenuStrip,_IntuitionBase movem.l (a7)+,a0-a1/d0-d1 restore regs rts ; --------------------------------------------------------------------- ; AllocFileReq() and FreeFileReq() on entry... need no register parameters! AllocFileReq movem.l a0-a1/d0-d1,-(a7) preserve regs CALLSYS AllocFileRequest,_AslBase move.l d0,file_request_p save returned pointer beq.s .error move.l #FreeFileReq,-(a5) push deallocation routine address .error movem.l (a7)+,a0-a1/d0-d1 restore regs rts FreeFileReq movem.l a0-a1/d0-d1,-(a7) preserve regs movea.l file_request_p,a0 requester to close CALLSYS FreeFileRequest,_AslBase movem.l (a7)+,a0-a1/d0-d1 restore regs rts ; --------------------------------------------------------------------- ; SetupMsgPort() and RemoveMsgPort() on entry... need no register parameters! SetupMsgPort movem.l a0-a1/d0-d1,-(a7) preserve regs CALLSYS CreateMsgPort,_AbsExecBase move.l d0,io_port_p save returned pointer beq.s .error move.l #RemoveMsgPort,-(a5) push deallocation routine address .error movem.l (a7)+,a0-a1/d0-d1 restore regs rts RemoveMsgPort movem.l a0-a1/d0-d1,-(a7) preserve regs movea.l io_port_p,a0 message port address CALLSYS DeleteMsgPort,_AbsExecBase movem.l (a7)+,a0-a1/d0-d1 restore regs rts ; --------------------------------------------------------------------- ; SetupIOReq() and RemoveIOReq() on entry... need no register parameters! SetupIOReq movem.l a0-a1/d0-d1,-(a7) preserve regs moveq #IOSTD_SIZE,d0 size of std i/o structure movea.l io_port_p,a0 reply port for messages CALLSYS CreateIORequest,_AbsExecBase move.l d0,io_request_p save returned pointer beq.s .error move.l #RemoveIOReq,-(a5) push deallocation routine address movea.l d0,a0 io_request_p move.l window_p,io_Data(a0) store window pointer in request move.l #window_SIZEOF,io_Length(a0) .error movem.l (a7)+,a0-a1/d0-d1 restore regs rts RemoveIOReq movem.l a0-a1/d0-d1,-(a7) preserve regs movea.l io_request_p,a0 I/O request address CALLSYS DeleteIORequest,_AbsExecBase movem.l (a7)+,a0-a1/d0-d1 restore regs rts ; --------------------------------------------------------------------- ; OpenDev() and CloseDev() on entry... need no register parameters! ; The Exec OpenDevice() function returns ZERO if successful. Because of ; this it is necessary to invert the state of the zero flag after testing ; d0 in order to comply with our (self-imposed) allocation routine return ; conditions (zero flag set is used to indicate an error)! OpenDev movem.l a0-a1/d0-d1,-(a7) preserve regs moveq #0,d0 unit number 0 moveq #CONFLAG_DEFAULT,d1 default flags lea con_name,a0 device name movea.l io_request_p,a1 i/o request pointer move.w #CMD_WRITE,io_Command(a1) ALL commands will be writes! CALLSYS OpenDevice,_AbsExecBase tst.l d0 test for success bne.s .error move.l #CloseDev,-(a5) push deallocation routine address lea AutoWrapOff,a0 jsr ConsoleCommand lea TurnCursorOff,a0 jsr ConsoleCommand lea SetColours,a0 jsr ConsoleCommand lea ClearConsole,a0 jsr ConsoleCommand moveq #1,d0 clear zero flag movem.l (a7)+,a0-a1/d0-d1 restore regs rts .error moveq #0,d0 set zero flag movem.l (a7)+,a0-a1/d0-d1 restore regs rts CloseDev movem.l a0-a1/d0-d1,-(a7) preserve regs movea.l io_request_p,a1 I/O request address CALLSYS CloseDevice,_AbsExecBase movem.l (a7)+,a0-a1/d0-d1 restore regs rts ; --------------------------------------------------------------------- ; --------------------------------------------------------------------- ; Function name: EventHandler() ; Purpose: Handles window menu and raw keycode events ; Input Parameters: Address of IDCMP user-port should be in a2. ; Output parameters: None ; Register Usage: a0: Used by WaitPort() and GetMsg() ; a1: Used by ReplyMsg() ; a2: Holds user-port address ; d0: Used by WaitPort() and GetMsg() ; d1: Unused but possibly altered by system functions ; d2: Used as an exit flag (quit when non-zero) ; d3: Used to hold message class field ; d4: Used to hold message code field ; d5: Loop counter in ShowFirstPage() ; d6: Used to hold line number in KeyHandler() ; and ShowFirstPage() routines ; d7: Used to hold copy of line number in DisplayLine() ; Other Notes: Within EventHandler() all registers are preserved ; --------------------------------------------------------------------- EventHandler movem.l d0-d7/a0-a2,-(a7) preserve registers clr.l d2 clear exit flag EventHandler2 movea.l a2,a0 port address CALLSYS WaitPort,_AbsExecBase jsr GetMessage cmpi.l #TRUE,d2 exit flag set? bne.s EventHandler2 tst.l buffer_p beq.s .no_buffers are buffers still allocated? movea.l buffer_p,a1 move.l buffer_size,d0 CALLSYS FreeMem,_AbsExecBase free main buffer memory movea.l lp_buffer_p,a1 move.l lp_size,d0 CALLSYS FreeMem,_AbsExecBase free line pointer buffer .no_buffers movem.l (a7)+,d0-d7/a0-a2 restore registers rts logical end of routine ; --------------------------------------------------------------------- GetMessage movea.l a2,a0 get port address in a0 CALLSYS GetMsg,_AbsExecBase get the message tst.l d0 beq.s GetMessageExit did it exist? movea.l d0,a1 copy pointer to a1 move.l im_Class(a1),d3 copy message class move.w im_Code(a1),d4 copy message code CALLSYS ReplyMsg,_AbsExecBase then send message back cmpi.l #IDCMP_MENUPICK,d3 check message class beq.s MenuMessage handle menu messages cmpi.l #IDCMP_RAWKEY,d3 check message class bne.s GetMessage ignore anything else jsr KeyHandler use raw keypress data bra.s GetMessage MenuMessage cmpi.w #MENUNULL,d4 beq.s GetMessage also skip if MENUNULL lsr.w #5,d4 extract menu item number andi.b #$3F,d4 (will be either 0 or 1) beq.s GetFile moveq #TRUE,d2 set QUIT signal to exit routine bra.s GetMessage GetFile jsr FileHandler tst.l buffer_p beq.s GetMessage is there a valid buffer? jsr ShowFirstPage bra.s GetMessage check for more messages! GetMessageExit rts d2 holds exit flag ; --------------------------------------------------------------------- ; Routine to distinguish between cursor up and cursor down events ; register d4 holds key code as routine is entered KeyHandler tst.l buffer_p beq .error .keycheck1 cmpi.w #CURSORUP,d4 has user hit cursor up key? bne.s .keycheck2 tst.l current_topline yes but are we at top? beq .error lea GoToBottom,a0 no, so adjust display jsr ConsoleCommand lea DeleteLine,a0 jsr ConsoleCommand lea GoToTop,a0 jsr ConsoleCommand lea InsertLine,a0 jsr ConsoleCommand subq.l #1,current_topline adjust line variables subq.l #1,current_bottomline move.l current_topline,d6 bra.s .displayline .keycheck2 cmpi.w #CURSORDOWN,d4 has user hit cursor down key? bne.s .quietexit move.l line_count,d6 yes, but are we at bottom? subq.l #1,d6 cmp.l current_bottomline,d6 beq.s .error lea GoToBottom,a0 no, so adjust display jsr ConsoleCommand lea NextLine,a0 jsr ConsoleCommand addq.l #1,current_topline adjust line variables addq.l #1,current_bottomline move.l current_bottomline,d6 .displayline jsr DisplayLine .quietexit rts .error movea.w #NULL,a0 flash screen to show error! CALLSYS DisplayBeep,_IntuitionBase rts ; --------------------------------------------------------------------- ; routine to display first 'screen page' of the file ShowFirstPage lea ClearConsole,a0 jsr ConsoleCommand move.l #0,current_topline set initial topline move.l line_count,d5 cmpi.l #PAGELENGTH,d5 is count2',$6D END ; ---------------------------------------------------------------------