%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Virtual-Screen.SL
%
% Author: Alan Snyder
% Hewlett-Packard/CRC
% Date: 18 August 1982
% Revised: 22 February 1983
%
% Inspired by Will Galway's EMODE Virtual Screen package.
%
% A virtual screen is an object that can be used as independent rectangular
% character display, but in fact shares a physical screen with other objects. A
% virtual screen object maintains a stored representation of the image on the
% virtual screen, which is used to update the physical screen when new areas of
% the virtual screen become "exposed". A virtual screen does not itself
% maintain any information about changes to its contents. It sends all changes
% directly to the physical screen as they are made, and sends the entire screen
% contents to the physical screen upon its request.
%
% A virtual screen is a legitimate "owner" for a shared physical screen, in that
% it satisfies the required interface.
%
% 22-Feb-83 Alan Snyder
% Declare -> Declare-Flavor.
% 28-Dec-82 Alan Snyder
% Avoid writing to shared screen when virtual screen is not exposed. Add
% WRITE-STRING and WRITE-VECTOR methods. Improve efficiency of CLEAR-TO-EOL
% method. Remove patch that avoided old compiler bug. Reformat.
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
(BothTimes (load objects))
(CompileTime (load fast-int fast-vectors display-char))
(de create-virtual-screen (shared-physical-screen)
(make-instance 'virtual-screen 'screen shared-physical-screen))
(defflavor virtual-screen
((height (=> screen height)) % number of rows (0 indexed)
maxrow % highest numbered row
(width (=> screen width)) % number of columns (0 indexed)
maxcol % highest numbered column
(row-origin 0) % position of upper left on the shared screen
(column-origin 0) % position of upper left on the shared screen
(default-enhancement (=> screen normal-enhancement))
(cursor-row 0) % the virtual cursor position
(cursor-column 0) % the virtual cursor position
(exposed? NIL)
image % the virtual image
screen % the shared-physical-screen
)
()
(gettable-instance-variables height width row-origin column-origin screen
exposed?)
(settable-instance-variables default-enhancement)
(initable-instance-variables height width row-origin column-origin screen
default-enhancement)
)
(declare-flavor shared-physical-screen screen)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Private Macros:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
(defmacro image-fetch (image row col)
`(vector-fetch (vector-fetch ,image ,row) ,col))
(defmacro image-store (image row col value)
`(vector-store (vector-fetch ,image ,row) ,col ,value))
(dm for-all-positions (form)
% Executes the body repeatedly with the following variables
% bound: ROW, COL, SCREEN-ROW, SCREEN-COL.
`(for (from row 0 maxrow)
(with screen-row)
(do (setf screen-row (+ row-origin row))
(for (from col 0 maxcol)
(with screen-col ch)
(do (setf screen-col (+ column-origin col))
,@(cdr form)
)))))
(dm for-all-columns (form)
% Executes the body repeatedly with the following variables
% bound: COL, SCREEN-COL.
`(for (from col 0 maxcol)
(with screen-col ch)
(do (setf screen-col (+ column-origin col))
,@(cdr form)
)))
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Public methods:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
(defmethod (virtual-screen set-size) (new-height new-width)
% Change the size of the screen. The screen is first DeExposed. The contents
% are cleared. You must Expose the screen yourself if you want it to be
% displayed.
(=> self deexpose)
(setf height new-height)
(setf width new-width)
(=> self &new-size)
)
(defmethod (virtual-screen set-origin) (new-row new-column)
% Change the location of the screen. The screen is first DeExposed. You must
% Expose the screen yourself if you want it to be displayed.
(=> self deexpose)
(setf row-origin new-row)
(setf column-origin new-column)
)
(defmethod (virtual-screen set-cursor-position) (row column)
(cond ((< row 0) (setf row 0))
((> row maxrow) (setf row maxrow)))
(cond ((< column 0) (setf column 0))
((> column maxcol) (setf column maxcol)))
(setf cursor-row row)
(setf cursor-column column)
)
(defmethod (virtual-screen write) (ch row column)
% Write one character using the default enhancement.
(if (and (>= row 0) (<= row maxrow) (>= column 0) (<= column maxcol))
(let ((dc (display-character-cons default-enhancement 0 (& ch 16#FF)))
(screen-row (+ row row-origin))
)
(setq dc (=> screen convert-character dc))
(image-store image row column dc)
(if exposed?
(=> screen write dc screen-row (+ column column-origin) self))
)))
(defmethod (virtual-screen write-range) (ch row left-column right-column)
% Write repeatedly.
(when (and (>= row 0)
(<= row maxrow)
(<= left-column maxcol)
(>= right-column 0)
)
(if (< left-column 0) (setf left-column 0))
(if (> right-column maxcol) (setf right-column maxcol))
(let ((dc (display-character-cons default-enhancement 0 (& ch 16#FF)))
(screen-row (+ row row-origin))
)
(setq dc (=> screen convert-character dc))
(for (from col left-column right-column)
(do (image-store image row col dc)
(if exposed?
(=> screen write dc screen-row (+ col column-origin) self))
)))))
(defmethod (virtual-screen write-display-character) (dc row column)
% Write one character (explicit enhancement)
(when (and (>= row 0) (<= row maxrow) (>= column 0) (<= column maxcol))
(setq dc (=> screen convert-character dc))
(image-store image row column dc)
(if exposed?
(=> screen write dc (+ row row-origin) (+ column column-origin) self))
))
(defmethod (virtual-screen write-string) (row left-column s count)
% S is a string of characters. Write S[0..COUNT-1] using the default
% enhancement to the specified row, starting at the specified column.
(when (and (> count 0)
(>= row 0)
(<= row maxrow)
(<= left-column maxcol)
(> (+ left-column count) 0)
)
(let ((smax (- count 1))
(image-row (vector-fetch image row))
(screen-row (+ row row-origin))
)
(if (< left-column 0) (setf left-column 0))
(if (> (+ left-column smax) maxcol)
(setf smax (- maxcol left-column)))
(for (from i 0 smax)
(for col left-column (+ col 1))
(for screen-col (+ left-column column-origin) (+ screen-col 1))
(do
(let ((ch (string-fetch s i)))
(setf ch (display-character-cons default-enhancement 0 ch))
(setf ch (=> screen convert-character ch))
(vector-store image-row col ch)
(if exposed?
(=> screen write ch screen-row screen-col self))
))))))
(defmethod (virtual-screen write-vector) (row left-column v count)
% V is a vector of display-characters. Write V[0..COUNT-1] to the specified
% row, starting at the specified column.
(when (and (> count 0)
(>= row 0)
(<= row maxrow)
(<= left-column maxcol)
(> (+ left-column count) 0)
)
(let ((vmax (- count 1))
(image-row (vector-fetch image row))
(screen-row (+ row row-origin))
)
(if (< left-column 0) (setf left-column 0))
(if (> (+ left-column vmax) maxcol)
(setf vmax (- maxcol left-column)))
(for (from i 0 vmax)
(for col left-column (+ col 1))
(for screen-col (+ left-column column-origin) (+ screen-col 1))
(do
(let ((ch (vector-fetch v i)))
(vector-store image-row col ch)
(if exposed?
(=> screen write ch screen-row screen-col self))
))))))
(defmethod (virtual-screen clear) ()
(let ((dc (display-character-cons default-enhancement 0 #\space)))
(setq dc (=> screen convert-character dc))
(for-all-positions
(image-store image row col dc)
)
(if exposed?
(for-all-positions
(=> screen write dc screen-row screen-col self)
))
))
(defmethod (virtual-screen clear-to-end) (first-row)
(if (< first-row 0) (setf first-row 0))
(let ((dc (display-character-cons default-enhancement 0 #\space)))
(setq dc (=> screen convert-character dc))
(for (from row first-row maxrow)
(with screen-row)
(do (setf screen-row (+ row-origin row))
(for-all-columns
(image-store image row col dc)
)
(if exposed?
(for-all-columns
(=> screen write dc screen-row screen-col self)
))
))))
(defmethod (virtual-screen clear-to-eol) (row first-column)
(when (and (>= row 0) (<= row maxrow))
(if (< first-column 0) (setf first-column 0))
(let ((dc (display-character-cons default-enhancement 0 #\space))
(image-row (vector-fetch image row))
)
(setq dc (=> screen convert-character dc))
(for (from col first-column maxcol)
(do (vector-store image-row col dc)))
(if exposed?
(let ((screen-row (+ row row-origin)))
(for
(from col (+ first-column column-origin) (+ maxcol column-origin))
(do (=> screen write dc screen-row col self)))))
)))
(defmethod (virtual-screen expose) ()
% Expose the screen. Make it overlap all other screens.
(=> screen select-primary-owner self)
(setf exposed? T)
)
(defmethod (virtual-screen deexpose) ()
% Remove the screen from the display.
(when exposed?
(=> screen remove-owner self)
(setf exposed? NIL)
))
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Semi-Private methods:
% The following methods are for use ONLY by the shared physical screen.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
(defmethod (virtual-screen send-changes) (breakout-allowed)
% This method is invoked by the shared physical screen to obtain any buffered
% changes to the virtual screen image. Since the virtual screen does not
% buffer any changes, this method does nothing.
)
(defmethod (virtual-screen send-contents) (breakout-allowed)
% This method is invoked by the shared physical screen to obtain the entire
% virtual screen image.
(for-all-positions
(let ((ch (image-fetch image row col)))
(=> screen write ch screen-row screen-col self)
)))
(defmethod (virtual-screen assert-ownership) ()
% This method is invoked by the shared physical screen to obtain the desired
% area for the virtual screen.
(=> screen set-owner-region row-origin column-origin height width self)
)
(defmethod (virtual-screen screen-cursor-position) ()
% This method is invoked by the shared physical screen to obtain the desired
% cursor position for the virtual screen.
(cons
(+ cursor-row row-origin)
(+ cursor-column column-origin)
))
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Private methods:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
(defmethod (virtual-screen init) (init-plist)
(=> self &new-size)
)
(defmethod (virtual-screen &new-size) ()
(if (< height 0) (setf height 0))
(if (< width 0) (setf width 0))
(setf maxrow (- height 1))
(setf maxcol (- width 1))
(setf image (make-vector maxrow NIL))
(let ((line (make-vector maxcol #\space)))
(for (from row 0 maxrow)
(do (vector-store image row (copyvector line))))
)
)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
(undeclare-flavor screen)