STDWIN info

Guido van Rossum guido at cwi.nl
Sat Nov 5 22:04:44 AEST 1988


Well...  Posting this sounds like the only logical thing to do.  Some
remarks: (repeated below): STDWIN is currently available for X11,
Macintosh, Atari-ST, and ASCII terminals under Unix (termcap) or MS-DOS.
The ASCII versions are restricted to text output.  Unfortunately there
are no versions yet for the following popular machines/systems: Sun
(neither SunTools, SunView nor NeWS); MS-Windows; Presentation Manager;
Amiga.

Guido van Rossum, Centre for Mathematics and Computer Science (CWI), Amsterdam
guido at piring.cwi.nl or mcvax!piring!guido or guido%piring.cwi.nl at uunet.uu.net

[Last modified on Fri Nov  4 18:53:06 MET 1988 by guido]


1. Target systems

STDWIN is aimed at C programs.  It consists of a few header files (of
which only one is visible to the user) and a library.  In most cases
some system-provided libraries must also be used in the linking phase.

Currently, full STDWIN is available for the following environments:

(Note that in all cases the code is in beta test state; there may be
bugs, functionality may change slightly in the future and new
functionality may be added, but the basic framework isn't going to
change much.)

*       X version 11 release 2
*       Apple Macintosh using either LightspeedC (2.15) or MPW C (2.02)
*       Atari ST using Mark Williams C (2.1)
*       Whitechapel MG-1 running an old version of 4.2 BSD

You may volunteer to create a version for your favourite system, or to
port it to your favourite C compiler for one of the mentioned micros.

A subset emulating most of STDWIN's functionality on an alphanumeric
display (this excludes line drawing but includes windows, menus, text
editing etc.) is available for:

*       Any decent Unix that has termcap (tested with 4.{2,3} BSD)
*       MS-DOS using the Microsoft C compiler (4.0)


2. Getting the full scoop

I have written a paper about STDWIN which has been published as a
CWI report (Guido van Rossum: STDWIN -- A Standard Window System
Interface.  Centre for Mathematics and Computer Science, report
CS-R8817.  Amsterdam, 1988).  You might get a copy mailed to you by
politely asking our secretary, Marja Hegt <marja at cwi.nl>.

You can also get a source version for any or all of the above-mentioned
systems.  This is essentially a directory dump of my working version,
until I have the time or get some help to prepare a real distribution.
It is available through anonymous ftp access to gatekeeper.dec.com,
whose IP address is [128.45.9.52].  The directory is pub/stdwin; get
the file README for further instructions.  A version of the document
you're currently reading is in the file ABOUT.

Distribution outside the USA is solely by electronic mail.  Be prepared
to receive up to half a megabyte (in 50K pieces, tarred/ compressed/
uuencoded/ split).  If you're interested, write to:
  guido at cwi.nl.

3. Basic functionality

STDWIN allows multiple "full-function" windows, roughly in Macintosh
style (title bar, grow box, close box, scroll bars).  The appearance of
windows is determined by the default of the underlying window manager,
and so are other limitations (e.g., overlapping, maximum size, etc.).
Windows are dynamically created and destroyed by the application, never
directly by the user or the window manager.

STDWIN uses a coordinate system derived from the display's coordinate
system: (0, 0) is top left, with X pointing right and Y pointing down
(these are actually called h and v).  Pixel size is that of the display.
There are enquiry functions to ask for the display size in pixels and in
millimeters.

The application is responsible for redrawing the window contents when it
is exposed.  This is done by associating a "draw procedure" with each
window, which knows how to draw the entire window's contents.  It gets
passed a pointer to the window and the coordinates of the rectangle that
needs to be redrawn, so it can (although it needn't) restrict itself to
that area.  STDWIN guarantees that a window's redraw procedure is only
called while the application is waiting for an input event (most
implementations simply turn exposure events into calls to the draw
procedure).

If the application wants to change part of the graphics it is
displaying, this is usually done in a two-phase process: first, STDWIN
is told that a particular area of the screen must be changed; later,
when the application starts waiting for input events again, the draw
procedure is called to update the indicated area (and any other area
that was exposed or damaged in some way).

The application defines the width and height of the area it wants to
draw; this needn't bear any relation to the window or screen size.  This
area is called the "document" although you may also think of it as a
virtual window.  The actual window generally displays a sub-area of the
document; the window's scroll bars indicate the position of the window
with respect to the document.  The application always uses the
coordinates of its document; STDWIN performs the translation to window
or screen coordinates are required by the window manager, and ensures
clipping of all output to the window.

STDWIN is event-based.  An application is expected to have a main loop
containing a "get event" call followed by a switch on the event type.
There is no event mask; an application can simply ignore events it isn't
interested in.  The most important event types are:

ACTIVATE:       A window becomes active (keyboard attached and/or topmost)

CHAR:           ASCII character key pressed (except BS, TAB, CR)

COMMAND:        special key or function (CLOSE, TAB, RETURN, BS, CANCEL,
                arrow keys etc.)

MOUSE:          MOUSE DOWN, MOUSE MOVE (only while down), MOUSE UP;
                fields in the event record indicate the h, v position,
                the number of the button, and the "click number" if the
                event is potentially part of a multiple-click sequence

MENU:           menu id and item number of a menu selection

SIZE:           user has resized the window

TIMER:          the window's timer went off; each window has one
                programmable timer which can be set to go off at N/10
                seconds in the future.  When the timer goes off a TIMER
                event is returned.

Currently, STDWIN draws text in a single font.  The actual font used
depends on the underlying window manager (and can sometimes be
influenced by the application programmer and/or the end user in a
system-dependent manner).  The font may be proportionally spaced, and
there are enquiry functions to find out the dimensions of characters and
strings.

There are functions to draw text and simple lines, rectangles and
circles, and ways to erase, shade or invert rectangular areas.  There is
no way (yet) to do general bitblt operations, or to influence the pen
shape.


4. Higher level functionality

STDWIN provides a blinking vertical bar which can be used to indicate
the text insertion point, so the application needn't use TIMER events to
do the blinking.

STDWIN provides Macintosh-style menus.  Each window has its own set of
menus, although by default all menus apply to all windows.  A reasonably
number of menus per window is allowed, each with a reasonable number of
(textual) menu items.  Menus can be changed dynamically.  Items can be
enabled or disabled, and a 'tick mark' can be placed in front of an
item.  Each menu item may have a shortcut character, which, when typed
in combination with some system-defined meta key (e.g., ALT or an ESC-
prefix) selects the menu item (if enabled).  Menu selection is done
completely "underwater"; all the application notices are MENU events.

STDWIN has a few simple routines to display Mac-style "dialog boxes",
e.g., to show an error message, or to ask a yes/no question or to ask
for a string to be typed.  There is also a predefined function to ask
for a file name, which may allow the user to browse the file system in
some implementations.

STDWIN comes with a package built on top of the basic functionality, to
edit arbitrary blocks of text (cf. Macintosh TEXTEDIT).  In the future,
more packages will be provided, e.g., a package to provide a simple file
editor (available now!), a package to display a scrolling list of items,
a package to define a list of arbitrary labeled "buttons", and a package
to simplify the binding of menus to functions somewhat, and a VT100
emulator (available now!).


5. Function definitions

Here follows a slightly edited listing of the <stdwin.h> header file,
which more or less documents all available functions and data
structures.  Note that the argument lists are given here as ANSI C
prototypes (untested).

#define bool int

void winit();
void wdone();

void wsetdefwinsize(int width, int height);
void wsetdefwinpos(int h, int v);

#define MENU struct menu

/* The contents of a text attributes struct are disclosed here because
   the interface allows the programmer to declare objects of this type.
   (I'm not so sure anymore that this is the right thing to do!) */

struct textattr {
        short font;
        unsigned char size;
        unsigned char style;
};

#define TEXTATTR struct textattr

#ifndef WINDOW

struct window {
        short tag;
};

#define WINDOW struct window

#endif

WINDOW *wopen(char *title, void drawproc();
void wclose(WINDOW *win);
#define wgettag(win) ((win)->tag)
#define wsettag(win, newtag) ((win)->tag= newtag)
void wsetactive(WINDOW *win);
WINDOW *wgetactive();
void wgetwinsize(WINDOW *win, int *width, int *height);
void wsetdocsize(WINDOW *win, int width, int height);
void wsettitle(WINDOW *win, char *title);

void wsetorigin(WINDOW *win, int h, int v);
void wshow(WINDOW *win, int left, int top, int right, int bottom);
void wchange(WINDOW *win, int left, int top, int right, int bottom);
void wscroll(WINDOW *win, int left, int top, int right, int bottom,
        int dh, int dv);

void wfleep();
void wmessage(char *str);
void wperror(char *name);
bool waskstr(char *prompt, char *buf, int buflen);
int waskync(char *question, int dflt);
bool waskfile(char *prompt, char *buf, int buflen, bool new);

void wsetcaret(WINDOW *win, int h, int v);
void wnocaret(WINDOW *win);

void wsettimer(WINDOW *win, int deciseconds);

MENU *wmenucreate(int id, char *title);
void wmenudelete(MENU *mp);
int wmenuadditem(MENU *mp, char *text, char shortcut);
void wmenusetitem(MENU *mp, int i, char *text);
void wmenusetdeflocal(bool local);
void wmenuattach(WINDOW *win, MENU *mp);
void wmenudetach(WINDOW *win, MENU *mp);

/* EVENT STRUCT DEFINITION */

struct event {
        int type;
        WINDOW *window;
        union {
        /* case WE_CHAR: */
                int character;
        /* case WE_COMMAND: */
                int command;
        /* case WE_MENU: */
                struct { int id; int item; } m;
        /* case WE_DRAW: */
                struct { int left, top, right, bottom; } area;
        /* case WE_MOUSE_DOWN, WE_MOUSE_MOVE, WE_MOUSE_UP: */
                struct {
                        int v;
                        int h;
                        int clicks;
                        int button;
                        int mask;
                } where;
        } u;
};

#define EVENT struct event

/* Event types */

#define WE_NULL         0       /* (Used internally) */
#define WE_ACTIVATE     1       /* Window became active */
#define WE_CHAR         2       /* Character typed at keyboard */
#define WE_COMMAND      3       /* Special command, function key etc. */
#define WE_MOUSE_DOWN   4       /* Mouse button pressed */
#define WE_MOUSE_MOVE   5       /* Mouse moved with button down */
#define WE_MOUSE_UP     6       /* Mouse button released */
#define WE_MENU         7       /* Menu item selected */
#define WE_SIZE         8       /* Window size changed */
#define WE_MOVE         9       /* (Reserved) */
#define WE_DRAW         10      /* Request to redraw part of window */
#define WE_TIMER        11      /* Window's timer went off */
#define WE_DEACTIVATE   12      /* Window became inactive */

/* Command codes for WE_COMMAND.
   Special ways of entering these are usually available,
   such as clicking icons, standard menu items or special keys.
   Some ASCII keys are also passed back as commands since they
   more often than not need special processing. */

#define WC_CLOSE        1       /* Should become a separate event! */
/* The following four are arrow keys */
#define WC_LEFT         2
#define WC_RIGHT        3
#define WC_UP           4
#define WC_DOWN         5
/* ASCII keys */
#define WC_CANCEL       6
#define WC_BACKSPACE    7
#define WC_TAB          8
#define WC_RETURN       9

void wgetevent(EVENT *ep);
void wungetevent(EVENT *ep);
void wupdate(WINDOW *win);
void wbegindrawing(WINDOW *win);
void wenddrawing(WINDOW *win);
void wflush();

void wdrawline(int h1, int v1, int h2, int v2);
void wxorline(int h1, int v1, int h2, int v2);
void wdrawcircle(int h, int v, int radius);
void wdrawelarc(int h, int v, int radh, int radv, int angle1, int angle2);
void wdrawbox(int left, int top, int right, int bottom);
void werase(int left, int top, int right, int bottom);
void wpaint(int left, int top, int right, int bottom);
void winvert(int left, int top, int right, int bottom);
void wshade(int left, int top, int right, int bottom, int percent);

int wdrawtext(int h, int v, char *str, int len);
int wdrawchar(int h, int v, char c);
int wlineheight();
int wtextwidth(char *str, int len);
int wcharwidth(char c);
int wtextbreak(char *str, int len, int width);

void wgettextattr(TEXTATTR *attr);
void wsettextattr(TEXTATTR *attr);
void wgetwintextattr(WINDOW *win, TEXTATTR *attr);
void wsetwintextattr(WINDOW *win, TEXTATTR *attr);

void wsetplain();
void wsethilite();
void wsetinverse();
void wsetitalic();
void wsetbold();
void wsetbolditalic();
void wsetunderline();

/* TEXTEDIT PACKAGE DEFINITIONS */

#define TEXTEDIT struct _textedit

TEXTEDIT *tealloc(WINDOW *win, int left, int top, int width);
TEXTEDIT *tecreate(WINDOW *win,
        int left, int top, int right, int bottom);
void tefree(TEXTEDIT *tp);
void tedestroy(TEXTEDIT *tp);

void tedraw(TEXTEDIT *tp);
void tedrawnew(TEXTEDIT *tp, int left, int top, int right, int bottom);
void temove(TEXTEDIT *tp, int left, int top, int width);
void temovenew(TEXTEDIT *tp,
        int left, int top, int right, int bottom);

void tesetfocus(TEXTEDIT *tp, int foc1, int foc2);
void tereplace(TEXTEDIT *tp, char *str);
void tesetbuf(TEXTEDIT *tp, char *buf, int buflen);

void tearrow(TEXTEDIT *tp, int code);
void tebackspace(TEXTEDIT *tp);
bool teclicknew(TEXTEDIT *tp, int h, int v, bool extend);
bool tedoubleclick(TEXTEDIT *tp, int h, int v);
bool teevent(TEXTEDIT *tp, EVENT *ep);

#define teclick(tp, h, v) teclicknew(tp, h, v, FALSE)
#define teclickextend(tp, h, v) teclicknew(tp, h, v, TRUE)

char *tegettext(TEXTEDIT *tp);
int tegetlen(TEXTEDIT *tp);
int tegetnlines(TEXTEDIT *tp);
int tegetfoc1(TEXTEDIT *tp);
int tegetfoc2(TEXTEDIT *tp);
int tegetleft(TEXTEDIT *tp);
int tegettop(TEXTEDIT *tp);
int tegetright(TEXTEDIT *tp);
int tegetbottom(TEXTEDIT *tp);

/* Text paragraph drawing functions: */

int wdrawpar(int h, int v, char *text, int width);
        /* Returns new v coord. */
int wparheight(char *text, int width);
        /* Returns height */



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