a2d/MGTK.md

MouseGraphics ToolKit

This is a complex API library written by Apple circa 1985. It consists of:

• Graphics Primitives - screen management, lines, rects, polys, text, patterns, pens
  • Concepts
  • Commands
• Mouse Graphics - windows, menus, events, cursors
  • Concepts
  • Commands
  • More

For the purposes of DeskTop, the entry point is fixed at $4000 AUX, called MLI-style:

    JSR $4000
    .byte call
    .addr params

Result will be in A, with Z bit set, 0 indicating success (so BNE error works).

ca65 syntax is used for primitives: .byte, .word (interpreted as 16-bit signed integer), .addr (16-bit address), .res N (N byte buffer)

---

Graphics Primitives

Concepts

Point

.word       xcoord
.word       ycoord

Rect

.word       x1
.word       y1
.word       x2
.word       y2

Pattern

A simple repeating 8x8 pattern is defined by 8 bytes. All bits of each byte are used.

.byte       row0
.byte       row1
.byte       row2
.byte       row3
.byte       row4
.byte       row5
.byte       row6
.byte       row7

MapInfo

Used with GrafPorts to define offsets/clipping, and bitmaps for source data.

Point       viewloc
.addr       mapbits         $2000 for the screen, or bitmap bits
.byte       mapwidth        $80, or stride for bitmap
.byte       reserved
Rect        maprect         a.k.a. cliprect

GrafPort

There is always a current GrafPort (or "port" for short) that defines the destination and pen state of drawing operations.

MapInfo     portmap
Pattern     penpattern
.byte       colormask_and
.byte       colormask_or
Point       penloc
.byte       penwidth        horizontal pen thickness
.byte       penheight       vertical pen thickness
.byte       penmode
.byte       textback        text background
.addr       textfont

PolyList

.byte       count           number of vertices in this polygon
.byte       last            high bit set if there are more polygons
Point       vertex0
... repeats for each vertex
... repeats for each polygon

Font

This is a MousePaint-compatible font. Single- and double-width fonts are supported; max height is 16 pixels.

.byte       fonttype        0=regular, $80=double-width
.byte       lastchar        char code of last character (usually $7F)
.byte       height          pixels (1-16)
.res N      charwidth       pixels, for each char
.res N      row0            bits
.res N      row0right       bits (double-width only)
... repeats for each row

Commands

NoOp ($00)

No-op

No parameters.

Initialization

InitGraf ($01)

No parameters.

SetSwitches ($02)

Configure display switches

Parameters:

 .byte       flags           bit 0=hires, 1=page2, 2=mixed, 3=text

GrafPort - assign, update, query ports

InitPort ($03)

Initialize GrafPort to standard values

Parameters:

(input is address of GrafPort record)

SetPort ($04)

Set current port as specified

Parameters:

(input is address of GrafPort record)

GetPort ($05)

Get pointer to current port

Parameters:

.addr       port            (out)

SetPortBits ($06)

Set just the mapinfo (viewloc, mapbits) of the current grafport.

Parameters:

(input is address of MapInfo record)

SetPenMode ($07)

Set the pen mode of the current grafport.

Parameters:

.byte       mode            pen*/notpen*

SetPattern ($08)

Set the pattern of the current grafport.

Parameters:

.res 8      pattern         8x8 pixel pattern for PaintRect calls

SetColorMasks ($09)

Set the color masks of the current grafport.

Parameters:

.byte       and_mask
.byte       or_mask

SetPenSize ($0A)

Set the pen size of the current grafport.

Parameters:

.byte       penwidth        horizontal pen thickness
.byte       penheight       vertical pen thickness

SetFont ($0B)

Set the font of the current grafport.

Parameters:

.addr       textfont        font definition

SetTextBG ($0C)

Set the text background of the current grafport.

Parameters:

.byte       backcolor       0=black, $7F=white

Drawing - draw lines; frame, fill, and test rects and polys

Move ($0D)

Set pen location (relative) of the current grafport.

Parameters:

.word       xdelta
.word       ydelta

MoveTo ($0E)

Set pen location (absolute) of the current grafport.

Parameters:

Point        pos

Line ($0F)

Draw line from pen location (relative) of the current grafport.

Parameters:

.word       xdelta
.word       ydelta

LineTo ($10)

Draw line from pen location (absolute) of the current grafport.

Parameters:

Point       pos

PaintRect ($11)

Fill rectangle with pattern of the current grafport.

Parameters:

Rect        rect

FrameRect ($12)

Draw rectangle with pen mode/size of the current grafport.

Parameters:

Rect        rect

InRect ($13)

Is current position in bounds? A=$80 true, 0 false

Parameters:

Rect        rect

PaintBits ($14)

Draw bitmap.

Parameters:

(input is address of MapInfo record)

PaintPoly ($15)

Fill multiple closed polygons with the pattern of the current grafport.

Parameters:

(input is address of PolyList record)

FramePoly ($16)

Draw multiple closed polygons with the pen mode/size of the current grafport.

Parameters:

(input is address of PolyList record)

InPoly ($17)

Is pen location of the current grafport within the polygon? A=$80 true, 0 false

Parameters:

(input is address of PolyList record)

Text - draw and measure text

TextWidth ($18)

Measure the width of a string in pixels

Parameters:

.addr       data
.byte       length
.word       width           (out) result in pixels

DrawText ($19)

Draw string at the pen location of the current graphport (as left, baseline)

Parameters:

.addr       data
.byte       length

Utility - configuration and version

SetZP1 ($1A)

Configure lower half of ZP usage by API (speed vs. convenience)

Parameters:

.byte       preserve        0=stash/no auto restore; 1=restore now and onward

SetZP2 ($1B)

Configure upper half ZP usage by API (speed vs. convenience)

Parameters:

.byte       preserve        0=stash/no auto restore; 1=restore now and onward

---

Mouse Graphics

Concepts

Cursor

.res 24     bitmap          2x12 byte bitmap (XOR'd after mask)
.res 24     mask            2x12 byte mask (OR'd with screen)
.byte       hotx            hotspot coords (pixels)
.byte       hoty

Event

.byte       kind            event_kind_*
.res 4

if kind is event_kind_key_down:

.byte       kind            event_kind_*
.byte       key             (ASCII code; high bit clear)
.byte       modifiers       (0=none, 1=open-apple, 2=solid-apple, 3=both)
.res 2      reserved

if kind is event_kind_update:

.byte       kind            event_kind_*
.byte       window_id
.res 3      reserved

otherwise:

.byte       kind            event_kind_*
.word       mousex
.word       mousey

event_kind_no_event        := 0    ; No mouse or keypress
event_kind_button_down     := 1    ; Mouse button was depressed
event_kind_button_up       := 2    ; Mouse button was released
event_kind_key_down        := 3    ; Key was pressed
event_kind_drag            := 4    ; Mouse button still down
event_kind_apple_key       := 5    ; Mouse button was depressed, modifier key down
event_kind_update          := 6    ; Window update needed

event_modifier_open_apple  := 1 << 0
event_modifier_solid_apple := 1 << 1

Menu

Menu Bar record:

.word       count           Number of menu bar items

.byte       menu_id         Menu identifier
.byte       disabled        Flag
.addr       title           Address of length-prefixed string
.addr       menu            Address of Menu record
.res 6      reserved        Reserved
... repeats for each menu

Menu record:

.word       count           Number of items in menu

.res  5     reserved        Reserved
.byte       options         bit 0=OA, 1=SA, 2=mark, 5=check, 6=filler, 7=disabled
.byte       mark_char       Custom mark character if mark option set
.byte       char1           ASCII code of shortcut #1 (e.g. uppercase B); or 0
.byte       char2           ASCII code of shortcut #2 (e.g. lowercase b, or same); or 0
.addr       name            Address of length-prefixed string
... repeats for each menu item

Window "winfo"

.byte       id
.byte       options         option_*
.addr       title
.byte       hscroll         scroll_option_*
.byte       vscroll         scroll_option_*
.byte       hthumbmax
.byte       hthumbpos
.byte       vthumbmax
.byte       vthumbpos
.byte       status
.byte       reserved
.word       mincontwidth    minimum content size (horizontal)
.word       maxcontwidth    maximum content size (horizontal)
.word       mincontlength   minimum content size (vertical)
.word       maxcontlength   maximum content size (vertical)
GrafPort    windowport      GrafPort record
.addr       nextwinfo       address of next lower window in stack

Windows have a content area which has the requested dimensions. Above this is an optional title bar which in turn has an optional close box. Within the content area are an optional resize box and optional scroll bars.

option_dialog_box       := 1 << 0
option_go_away_box      := 1 << 1
option_grow_box         := 1 << 2

scroll_option_none      := 0
scroll_option_present   := 1 << 7
scroll_option_thumb     := 1 << 6
scroll_option_active    := 1 << 0
scroll_option_normal    := scroll_option_present | scroll_option_thumb | scroll_option_active

Commands

Initialization

Version ($1C)

Get toolkit version

Parameters:

.byte       (out) major
.byte       (out) minor
.byte       (out) patch
.byte       (out) status
.word       (out) number

StartDeskTop ($1D)

Inits state, registers interrupt handler, draws desktop

Parameters:

.byte       machine         ROM FBB3 ($06 = IIe or later)
.byte       subid           ROM FBC0 ($EA = IIe, $E0 = IIe enh/IIgs, $00 = IIc/IIc+)
.byte       op_sys          0=ProDOS, 1=Pascal
.byte       slot_num:       Mouse slot, 0 = search (will be filled in)
.byte       use_interrupts  0=passive, 1=interrupt
.addr       sysfontptr
.addr       savearea        buffer for saving screen data (e.g. behind menus)
.word       savesize        bytes

StopDeskTop ($1E)

Deallocates interrupt, hides cursor

No parameters.

SetUserHook ($1F)

Parameters:

.byte       hook_id         0=before, 1=after event checking
.addr       routine_ptr     0=remove hook_id

AttachDriver ($20)

Install pointer driver; A=0 on success, $95 if mouse disabled

Parameters:

.addr       hook            Mouse hook routine to install
.addr       mouse_state     (out) Address of mouse state (.word x, y; .byte status)

ScaleMouse ($21)

Set mouse/screen scaling

Parameters:

.byte       x_exponent      x-scale factor for mouse, 0...3
.byte       y_exponent      y-scale factor for mouse, 0...3

KeyboardMouse ($22)

Next operation will be performed by keyboard

No parameters.

GetIntHandler ($23)

Get address of interrupt handler

Parameters:

.addr       handler         (out) Address of interrupt handler (after cld)

Cursor Manager - set, show, hide

SetCursor ($24)

Set cursor definition

Parameters:

(input is address of Cursor record)

ShowCursor ($25)

Return cursor to visibility

No parameters.

HideCursor ($26)

Cursor hidden until ShowCursor call

No parameters.

ObscureCursor ($27)

Cursor hidden until moved

No parameters.

GetCursorAddr ($28)

Get cursor definition

Parameters:

.addr definition            (out) Address of cursor record

Event Manager - get, peek, post

CheckEvents ($29)

Process mouse/kbd if GetEvent will be delayed.

No parameters.

GetEvent ($2A)

Parameters:

(parameter is address of Event record)

FlushEvents ($2B)

No parameters.

PeekEvent ($2C)

Parameters:

(parameter is address of Event record)

PostEvent ($2D)

Post event to queue

Parameters:

(parameter is address of Event record)

SetKeyEvent ($2E)

If set, keypresses are ignored by Tool Kit

Parameters:

.byte       handle_keys     high bit set = ignore keyboard, otherwise check

Menu Manager - configure, enable, disable, select

InitMenu ($2F)

Configure characters used for menu glyphs. Optional. The defaults are solid=$1E, open=$1F, check=$1D, control=$01.

Parameters:

.byte       solid_char      char code to use for solid apple glyph
.byte       open_char       char code to use for open apple glyph
.byte       check_char      char code to use for checkmark glyph
.byte       control_char    char code to use for control key glyph

SetMenu ($30)

Configure (and draw) menu

Parameters:

(input is address of Menu Bar record)

MenuSelect ($31)

Enter modal loop for handling mouse-down on menu bar

Parameters:

.byte       menu_id         (out) Top level menu identifier, or 0 if none
.byte       menu_item       (out) Index (1-based) of item in menu, or 0 if none

MenuKey ($32)

Find menu item corresponding to keypress

Parameters:

.byte       menu_id         (out)
.byte       menu_item       (out)
.byte       which_key
.byte       key_mods        bit 0=OA, bit 1=SA

HiliteMenu ($33)

Toggle highlight state of menu

Parameters:

.byte       menu_id

DisableMenu ($34)

Disable/enable a menu. Effectively disables all items, but individual disable/enable states are restored when re-enabled.

Parameters:

.byte       menu_id
.byte       disable         0=enable, 1=disable

DisableItem ($35)

Disable/enable a specific item in a menu.

Parameters:

.byte       menu_id
.byte       menu_item
.byte       disable         0=enable, 1=disable

CheckItem ($36)

Sets a specific menu item as checked.

Parameters:

.byte       menu_id
.byte       menu_item
.byte       check           0=unchecked, 1=checked

SetMark ($37)

Sets a specific menu item as using a distinct mark character when checked.

Parameters:

.byte       menu_id
.byte       menu_item
.byte       set_char        0=use checkmark, 1=use mark_char
.byte       mark_char       char code to use for mark

Window Manager - open, close, drag, grow, update

OpenWindow ($38)

Parameters:

(input is address of WInfo record)

CloseWindow ($39)

Parameters:

.byte window_id

CloseAll ($3A)

No parameters.

GetWinPtr ($3B)

Get pointer to window params by id; A=0 on success

Parameters:

.byte       window_id
.addr       window_ptr      (out) winfo address

GetWinPort ($3C)

Get drawing state of window

Parameters:

.byte       window_id
.addr       port            (out) grafport address

SetWinPort ($3D)

Update port of window

Parameters:

.byte       window_id
.addr       port            GrafPort to copy from

BeginUpdate ($3E)

Respond to update event for window

Parameters:

.byte       window_id

EndUpdate ($3F)

No parameters.

FindWindow ($40)

Parameters:

.word       mousex          screen coordinates
.word       mousey
.byte       which_area      (out) area_*
.byte       window_id       (out) of window

FrontWindow ($41)

Get id of top window

Parameters:

.byte       window_id       (out) window, or 0 if none

SelectWindow ($42)

Make window topmost

Parameters:

.byte       window_id

TrackGoAway ($43)

Parameters:

.byte       clicked         (out) 0 = cancelled, 1 = close
.byte       ??              (out)
.byte       ??              (out)

DragWindow ($44)

Parameters:

.byte       window_id
.word       dragx           mouse coords
.word       dragy
.byte       moved           (out) high bit set if moved, clear if not

GrowWindow ($45)

Parameters:

.byte       window_id
.word       mousex
.word       mousey
.byte       itgrew          (out) 0 = no change, 1 = moved

ScreenToWindow ($46)

Map screen coords to content coords

Parameters:

.byte       window_id
.word       screenx
.word       screeny
.word       windowx         (out)
.word       windowy         (out)

WindowToScreen ($47)

Map content coords to screen coords

Parameters:

.byte       window_id
.word       windowx
.word       windowy
.word       screenx         (out)
.word       screeny         (out)

Control Manager - scrollbars

FindControl ($48)

Parameters:

.word       mousex
.word       mousey
.byte       which_ctl       ctl_*
.byte       which_part      part_*

SetCtlMax ($49)

Parameters:

.byte       which_ctl       ctl_*_scroll_bar
.byte       ctlmax          maximum value

TrackThumb ($4A)

Parameters:

.byte       which_ctl       ctl_*_scroll_bar
.word       mousex
.word       mousey
.byte       thumbpos        (out) 0...255
.byte       thumbmobed      (out) 0 = no change, 1 = moved

UpdateThumb ($4B)

Parameters:

.byte       which_ctl       ctl_*_scroll_bar
.byte       thumbpos        new position 0...250

ActivateCtl ($4C)

Activate/deactivate scroll bar

Parameters:

.byte       which_ctl       ctl_*_scroll_bar
.byte       activate        0=deactivate, 1=activate

More

NOTE: Movable DA windows must maintain an offscreen_flag. If a window is moved so that the content area is entirely offscreen then various operations should be skipped because the window's box coordinates will not be set correctly. TODO: Figure out if this is just a bug in the DAs.

Application Use

Initialization

• StartDeskTop
• InitMenu (if necessary; the defaults are sensible)
• SetMenu
• Run main loop until quit
• StopDeskTop

Main Loop

• GetEvent
• If event_kind_button_down or event_kind_apple_key:
  • FindWindow to figure out what was clicked
  • If area_desktop - ignore
  • If area_menubar - handle menu
  • If area_dragbar - handle window drag
  • If area_grow_box - handle window resize
  • If area_close_box - handle window close
  • If area_content:
    • FindControl
    • If ctl_*_scroll_bar - handle scrolling
    • If ctl_dead_zone - ignore
    • If ctl_not_a_control:
      • If not topmost:
        • SelectWindow
      • Otherwise, handle content click per app
• If event_kind_key_down - handle key
• If event_kind_drag:
  • TODO
• If event_kind_update:
  • Redraw contents of window_id

Redraw window

• GetWinPort - get pointer to window's port
• SetPort - make it current
• HideCursor - if multiple drawing calls will be made
• ... draw ...
• ShowCursor - if needed
• SetWinPort - save attributes if desired

Handle Key

• MenuKey
• If menu_id is not 0:
  • Dispatch for menu_id and menu_item
  • HiliteMenu to toggle state back off when done
• Otherwise:
  • handle key press per app

Handle Menu

• MenuSelect to initiate menu modal loop
• If menu_id is 0, done
• Dispatch for menu_id and menu_item
• HiliteMenu to toggle state back off when done

Handle Window Drag

• SelectWindow to make topmost if necessary
• DragWindow to initiate drag modal loop
• Handle update events
• Redraw window content if not moved and was made topmost
• If canceled - done
• For DeskTop DAs:
  • Call JUMP_TABLE_REDRAW_ALL.
  • If offscreen flag was not set, redraw desktop icons (DESKTOP_REDRAW_ICONS).
  • Set offscreen flag if window's top is greater than or equal to the screen bottom (191), clear otherwise.
  • If offscreen flag is not set, redraw window.

Handle Window Close

• TrackGoAway to initiate modal close loop
• If canceled - done
• CloseWindow

Handle Scrolling

• If part_thumb:
  • TrackThumb to initiate modal scroll loop
  • If thumb did not move - done
  • Redraw window content
  • UpdateThumb
• If part_page_*:
  • Scroll by a "page"
  • Redraw window content
  • UpdateThumb
• If part_*_arrow:
  • Scroll by a "line"
  • Redraw window content
  • UpdateThumb

Handle Window Resize

• GrowWindow to initiate modal resize loop
• If canceled - done
• UpdateThumb if needed to adjust scroll bars
• Redraw window content
• For DeskTop DAs:
  • Call JUMP_TABLE_REDRAW_ALL.
  • Call DESKTOP_REDRAW_ICONS.

Handle Update Events

• Repeat:
  • PeekEvent
  • If not event_kind_update - exit these steps
  • Otherwise:
    • GetEvent
    • BeginUpdate
    • If error, continue
    • Otherwise:
      • Redraw window_id's content
      • EndUpdate