# browser.t | documentation

    #charset "us-ascii"

    /*
     *   Copyright (c) 2000, 2006 Michael J. Roberts.  All Rights Reserved.
     *
     *   TADS 3 Library - browser (Web UI) input/output manager
     *
     *   This module defines the low-level functions for handling input and
     *   output via the Web UI.
     *
     *   The functions in this module are designed primarily for internal use
     *   within the library itself.  Games should use the higher level objects
     *   and functions defined in input.t and output.t instead of directly
     *   calling the functions defined here.  The reason for separating these
     *   functions is to make the UI selection pluggable, so that the same game
     *   can be compiled for either the traditional UI or the Web UI simply by
     *   plugging in the correct i/o module.
     */

    /* include the library header */
    #include "advlite.h"

    /* ------------------------------------------------------------------------ */
    /*
     *   Browser globals
     */
    transient browserGlobals: object
        /* the HTTPServer object for the browser UI session */
        httpServer = nil

        /*
         *   Log file handle.  For a LogTypeTranscript file, this is a
         *   LogConsole object; for other types, it's a regular file handle.
         */
        logFile = nil

        /* logging type (LogTypeXxx from tadsio.h, or nil if not logging) */
        logFileType = nil
    ;

    /* ------------------------------------------------------------------------ */
    /*
     *   Initialize the user interface.  The library calls this once at the
     *   start of the interpreter session to set up the UI.  For the Web UI, we
     *   create the HTTP server and send connection instructions to the client.
     */
    initUI()
    {
        /*
         *   Set up the HTTP server.  Listen on the launch address, which is
         *   the address that the client used to reach the external Web server
         *   that launched the interpreter.  For local stand-alone launches,
         *   the launch address is nil, so the HTTP server will listen on
         *   localhost, which is just what we need in order to connect to the
         *   local UI.
         */
        local srv = browserGlobals.httpServer = new HTTPServer(
            getLaunchHostAddr(), nil, 1024*1024);

        /* send connection instructions to the client */
        webSession.connectUI(srv);
    }

    /*
     *   Initialize the display.  We call this when we first enter the
     *   interpreter, and again at each RESTART, to set up the main game
     *   window's initial layout.  We set up the conventional IF screen layout,
     *   with the status line across the top and the transcript/command window
     *   filling the rest of the display.
     */
    initDisplay()
    {
        /* set up the command window and status line */
        webMainWin.createFrame(commandWin, 'command',
                               '0, statusline.bottom, 100%, 100%');
        webMainWin.createFrame(statuslineBanner, 'statusline',
                               '0, 0, 100%, content.height');

        /* capture the title string */
        local title = mainOutputStream.captureOutput(
            {: gameMain.setGameTitle() });

        /* parse out the contents of the <title> tag */
        if (rexSearch('<nocase>[<]title[>](.*)[<]/title[>]', title))
            title = rexGroup(1)[3];

        /* initialize the statusline window object */
        statuslineBanner.init();
        statusLine.statusDispMode = StatusModeBrowser;

        /* set the title */
        webMainWin.setTitle(title);

        /* get the session parameters from the arguments */
        local arg = libGlobal.getCommandSwitch('-gameid=');
        if (arg != nil && arg != '')
            webSession.launcherGameID = arg;

        arg = libGlobal.getCommandSwitch('-storagesid=');
        if (arg != nil && arg != '')
            webSession.storageSID = arg;

        arg = libGlobal.getCommandSwitch('-username=');
        if (arg != nil && arg != '')
            webSession.launcherUsername = arg;
    }

    /*
     *   Shut down the user interface.  The library calls this when the game is
     *   about to terminate.
     */
    terminateUI()
    {
        /* if we have an HTTP server, shut it down */
        if (browserGlobals.httpServer != nil)
        {
            /* flush our windows */
            webMainWin.flushWin();
            commandWin.sendWinEvent('<scrollToBottom/>');

            /* end any scripting */
            aioSetLogFile(nil, LogTypeTranscript);
            aioSetLogFile(nil, LogTypeCommand);

            /*
             *   keep running for a few more minutes, to give clients a chance
             *   to perform final tasks like downloading log files
             */
            ClientSession.shutdownWait(5*60*1000);

            /* send the shutdown message */
            eventPage.sendEvent('<shutdown/>');

            /* wait a short time for clients to process the shutdown event */
            ClientSession.shutdownWait(5*1000);

            /* shut down the http server */
            browserGlobals.httpServer.shutdown(true);
        }
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Check to see if we're in HTML mode
     */
    checkHtmlMode()
    {
        /*
         *   The web UI is always in HTML mode.  This is regardless of the
         *   interpreter class, because that only tells us about the
         *   interpreter's own native UI.  The actual user interface in Web UI
         *   mode runs in a separate Web browser app, which is inherently HTML
         *   capable.
         */
        return true;
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Write text to the main game window
     */
    aioSay(txt)
    {
        /* write the text to the main command window */
        commandWin.write(txt);

        /* if we're logging a full transcript, write the text */
        if (browserGlobals.logFileType == LogTypeTranscript)
            browserGlobals.logFile.writeToStream(txt);
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Is a script file active?
     */
    readingScript()
    {
        return setScriptFile(ScriptReqGetStatus) != nil;
    }

    /*
     *   Is an event script active?
     */
    readingEventScript()
    {
        local s = setScriptFile(ScriptReqGetStatus);
        return (s != nil && (s & ScriptFileEvent) != 0);
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Get a line of input from the keyboard, with timeout
     */
    aioInputLineTimeout(timeout)
    {
        /* check for script input */
        local scriptMode = setScriptFile(ScriptReqGetStatus);
        if (scriptMode != nil)
        {
            /* we're in a script, so use the regular input line reader */
            local e = inputLineTimeout(timeout);

            /*
             *   If it's not an end-of-file indication, return the event.  An
             *   EOF means that there are no more events in the script, so
             *   return to reading from the live client UI.
             */
            if (e[1] != InEvtEof)
            {
                /* echo the input if we're not in quiet mode */
                if (e[1] == InEvtLine && !(scriptMode & ScriptFileQuiet))
                    aioSay(e[2].htmlify() + '\n');

                /* log and return the event */
                return aioLogInputEvent(e);
            }
        }

        /*
         *   read an input line event from the main command window, log it, and
         *   return it
         */
        return aioLogInputEvent(commandWin.getInputLine(timeout));
    }

    /*
     *   Cancel a suspended input line
     */
    aioInputLineCancel(reset)
    {
        /* cancel the input line in the command window */
        commandWin.cancelInputLine(reset);
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Read an input event
     */
    aioInputEvent(timeout)
    {
        /* check for script input */
        if (readingEventScript())
        {
            /* we're in a script, so use the regular input line reader */
            local e = inputEvent(timeout);

            /*
             *   If it's not an end-of-file indication, return the event.  An
             *   EOF means that there are no more events in the script, so
             *   return to reading from the live client UI.
             */
            if (e[1] != InEvtEof)
                return aioLogInputEvent(e);
        }

        /* read an event from the main command window, log it, and return it */
        return aioLogInputEvent(webMainWin.getInputEvent(timeout));
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Show a "More" prompt
     */
    aioMorePrompt()
    {
        /* show a More prompt in the main command window */
        commandWin.showMorePrompt();
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Clear the screen
     */
    aioClearScreen()
    {
        /* clear the main transcript window */
        commandWin.clearWindow();
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Show a file selector dialog
     */
    aioInputFile(prompt, dialogType, fileType, flags)
    {
        /*
         *   First, try reading from the local console.  Even though we're
         *   using the Web UI, there are two special cases where the input will
         *   come from the local (server-side) console instead of from the
         *   browser UI:
         *
         *   1. We're reading from an event script.  In this case, regardless
         *   of the UI mode, the interpreter reads from a server-side file and
         *   parses the results into an inputFile() result, bypassing any UI
         *   interaction.
         *
         *   2. We're running in the Web UI's local stand-alone configuration,
         *   where the browser is actually an integrated window within the
         *   interpreter.  This configuration simulates the traditional UI by
         *   running everything locally - the client and server are running on
         *   the same machine, so there's really no distinction between
         *   client-side and server-side.  Because everything's local, files
         *   are local, so we want to display traditional local file selector
         *   dialogs.  The stand-alone interpreter does this for us via the
         *   standard inputFile() function when it detects this configuration.
         *
         *   If neither of these special cases apply, inputFile() will return
         *   an error to let us know that it can't show a file dialog in the
         *   current configuration, so we'll continue on to showing the dialog
         *   on the client side via the Web UI.
         */
        local f = inputFile(prompt, dialogType, fileType, flags);

        /* if that failed, forget the result */
        if (f[1] == InFileFailure)
            f = nil;

        /* if we got a file, check for warnings */
        if (f != nil && f.length() >= 4 && f[4] != nil)
        {
            /* keep going until we get a definitive answer */
            for (local done = nil ; !done ; )
            {
                /* show the warning dialog */
                local d = webMainWin.getInputDialog(
                    InDlgIconWarning,
                    libMessages.inputFileScriptWarning(f[4], f[2]),
                    libMessages.inputFileScriptWarningButtons, 1, 3);

                /* check the result */
                switch (d)
                {
                case 0:
                case 3:
                    /* dialog error or Cancel Script - stop the script */
                    setScriptFile(nil);

                    /* return a Cancel result */
                    return [InFileCancel];

                case 1:
                    /* "Yes" - proceed */
                    done = true;
                    break;

                case 2:
                    /* Choose New File button - show a file dialog */
                    local fNew = webMainWin.getInputFile(
                        prompt, dialogType, fileType, flags);

                    switch (fNew[1])
                    {
                    case InFileSuccess:
                        /* success - use the new file, and we're done */
                        f = fNew;
                        done = true;
                        break;

                    case InFileCancel:
                        /* cancel - repeat the prompt */
                        break;

                    case InFileFailure:
                        /* dialog error - cancel the script */
                        setScriptFile(nil);
                        return [InFileCancel];
                    }
                }
            }
        }

        /*
         *   if we didn't get a result from a script or from the local console,
         *   tell the client UI to display its file dialog
         */
        if (f == nil)
            f = webMainWin.getInputFile(prompt, dialogType, fileType, flags);

        /* log a synthetic <file> event, if applicable */
        aioLogInputEvent(
            ['<file>',
             f[1] != InFileSuccess ? '' :
             dataType(f[2]) == TypeObject && !f[2].ofKind(FileName) ? 't' :
             f[2]]);

        /* return the file information */
        return f;
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Show an input dialog
     */
    aioInputDialog(icon, prompt, buttons, defaultButton, cancelButton)
    {
        /* check for script input */
        local d = nil;
        if (readingEventScript())
        {
            /* we're in a script, so use the regular dialog event reader */
            d = inputDialog(icon, prompt, buttons, defaultButton, cancelButton);

            /* if it failed, forget the result */
            if (d == 0)
                d = nil;
        }

        /* if we didn't get script input, show the dialog via the client UI */
        if (d == nil)
            d = webMainWin.getInputDialog(icon, prompt, buttons,
                                          defaultButton, cancelButton);

        /* log a synthetic <dialog> event, if applicable */
        aioLogInputEvent(['<dialog>', d]);

        /* return the result */
        return d;
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Set/remove the output logging file
     */
    aioSetLogFile(fname, typ = LogTypeTranscript)
    {
        /* if there's currently a log file open, close it */
        local log = browserGlobals.logFile;
        if (log != nil)
        {
            switch (browserGlobals.logFileType)
            {
            case LogTypeTranscript:
                /* for a transcript, we have a log console as the handle */
                log.closeConsole();
                break;

            default:
                /* for other types, we have a regular file handle */
                try
                {
                    log.closeFile();
                }
                catch (Exception exc)
                {
                    /* ignore errors, as we have no way to return them */
                }
                break;
            }

            /* we've closed the handle, so forget it */
            log = nil;
        }

        /* presume success */
        local ok = true;

        /* if there's a filename, create a new console for this file */
        if (fname != nil)
        {
            /* create the output handle according to the type */
            switch (typ)
            {
            case LogTypeTranscript:
                /*
                 *   full transcript - create a log console, which will do the
                 *   standard output formatting for us
                 */
                log = new LogConsole(fname, nil, 80);
                break;

            case LogTypeCommand:
            case LogTypeScript:
                /* for other types, create an ordinary text file */
                try
                {
                    /* open the log file */
                    log = File.openTextFile(fname, FileAccessWrite, nil);

                    /* for an event script, write the <eventscript> opener */
                    if (typ == LogTypeScript)
                        log.writeFile('<eventscript>\n');
                }
                catch (Exception exc)
                {
                    /* if anything went wrong, we have no log file */
                    log = nil;
                }
                break;

            default:
                throw RuntimeError.newRuntimeError(2306, 'bad log file type');
            }

            /* we failed if the log handle is nil */
            if (log == nil)
            {
                ok = nil;
                typ = nil;
            }
        }
        else
        {
            /* no longer logging */
            typ = nil;
        }

        /* remember the new handle and log type */
        browserGlobals.logFile = log;
        browserGlobals.logFileType = typ;

        /* return the success/failure indicator */
        return ok;
    }

    /*
     *   Log an input event.  We call this internally from each of the event
     *   input routines to add the event to any event or command log we're
     *   creating.
     */
    aioLogInputEvent(evt)
    {
        /* if the system is maintaining its own input log, write it there */
        logInputEvent(evt);

        /* get the script globals */
        local ltyp = browserGlobals.logFileType;
        local log = browserGlobals.logFile;

        /* get the basic event parameters */
        local evtType = evt[1];
        local param = (evt.length() > 1 ? evt[2] : nil);

        /* format the event based on the event type */
        switch (ltyp)
        {
        case LogTypeTranscript:
            /* transcript - echo command line input */
            if (evt[1] == InEvtLine)
                log.writeToStream(evt[2].htmlify() + '\n');
            break;

        case LogTypeCommand:
            /* command script - write command inputs only */
            if (evt[1] == InEvtLine)
                log.writeFile('>' + evt[2] + '\n');
            break;

        case LogTypeScript:
            /* event script - write all event types */
            switch (evtType)
            {
            case InEvtKey:
                log.writeFile('<key>' + evtCharForScript(param));
                break;

            case InEvtTimeout:
                log.writeFile('<timeout>' + param);
                break;

            case InEvtHref:
                log.writeFile('<href>' + param);
                break;

            case InEvtNoTimeout:
                log.writeFile('<notimeout>');
                break;

            case InEvtEof:
                log.writeFile('<eof>');
                break;

            case InEvtLine:
                log.writeFile('<line>' + param);
                break;

            case InEvtSysCommand:
                log.writeFile('<command>' + param);
                break;

            case InEvtEndQuietScript:
                log.writeFile('<endqs>');
                break;

            default:
                /* if it's a string value, it's the literal event tag */
                if (dataType(evtType) == TypeSString)
                    log.writeFile(evtType + param);
                break;
            }

            /* add a newline at the end of the event line */
            log.writeFile('\n');
            break;
        }

        /*
         *   return the event, so that the caller can conveniently return it
         *   after logging it
         */
        return evt;
    }

    /*
     *   Get an InEvtKey event parameter in suitable format for script file
     *   output.  This returns the key as it appears in the event, except that
     *   ASCII control characters are translated to '[ctrl-X]'.
     */
    evtCharForScript(c)
    {
        if (c.toUnicode(1) < 32)
        {
            /* it's a control character - return the [ctrl-X] sequence */
            return '[ctrl-<<makeString(c.toUnicode(1) + 64)>>]';
        }
        else
        {
            /* return everything else as it appears in the event descriptor */
            return c;
        }
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Generate a string to show hyperlinked text.  The browser UI is always
     *   in HTML mode, so we unconditionally generate the hyperlink.
     *
     *   If the display text is included, we'll generate the entire link,
     *   including the <A HREF> tag, the hyperlinked text contents, and the
     *   </A> end tag.  If the text is omitted, we'll simply generate the <A
     *   HREF> tag itself, leaving it to the caller to display the text and the
     *   </A>.
     *
     *   The optional 'flags' is a combination of AHREF_xxx flags indicating
     *   any special properties of the hyperlink.
     */
    aHref(href, txt?, title?, flags = 0)
    {
        /* figure extra properties, based on the flags */
        local props = '';
        if (flags & AHREF_Plain)
            props += 'class="plain" ';

        /* generate the <A HREF>, text, and </A>, as applicable */
        return '<a <<props>> href="<<href.findReplace('"', '%22')>>"<<
               (title != nil
                ? ' title="' + title.findReplace('"', '&#34;') + '"'
                : '')
               >> onclick="javascript:return gamehref(event,\'<<
               href.findReplace(['\'', '"'],
                                ['\\\'', '\'+String.fromCharCode(34)+\''])
               >>\', \'main.command\', this);"><.a><<
               (txt != nil ? txt + '<./a></a>' : '')>>';
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Generate a string to show hyperlinked text, with alternate text if
     *   we're not in HTML mode.  The browser UI is always in HTML mode, so we
     *   unconditionally generate the hyperlink.
     */
    aHrefAlt(href, linkedText, altText, title?)
    {
        return aHref(href, linkedText, title);
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   The standard main command window.
     */
    transient commandWin: WebCommandWin
    ;

    /* ------------------------------------------------------------------------ */
    /*
     *   Generate HTML to wrap the left/right portions of the status line.  The
     *   basic status line has three stages: stage 0 precedes the left portion,
     *   stage 1 comes between the left and right portions, and stage 2 follows
     *   the right portion.  If we're listing exits, we get two more stages:
     *   stage 3 precedes the exit listing, stage 4 follows it.
     */
    statusHTML(stage)
    {
        switch(stage)
        {
        case 0:
            /* start the left-aligned portion */
            return '<div class="statusleft">';

        case 1:
            /* close the left portion, and start the right-aligned portion */
            return '</div><div class="statusright">';

        case 2:
            /*
             *   Close the right portion, and break clear of the floating
             *   sections.  The break is necessary to make sure that the
             *   contents of the two sections count in the window height; some
             *   browsers don't include floating boxes in the content height,
             *   so we need to manually extend the main vertical box's height
             *   past the floating sections.
             */
            return '</div><div class="statusStrut"></div>';

        case 3:
        case 4:
            /* before/after exit listing - we have nothing to add here */
            return '';

        default:
            return '';
        }
    }

    /* ------------------------------------------------------------------------ */
    /*
     *   Web Banner Window.  This is designed as a *partial* drop-in
     *   replacement for the BannerWindow class, using Web UI windows as
     *   implemented in the core TADS javascript client.
     *
     *   This class is designed to be mixed with a WebWindow subclass.
     *
     *   This isn't a complete replacement for BannerWindow, because the layout
     *   model for the Web UI is different from the banner window model (the
     *   Web UI model is better and more flexible).  This class implements the
     *   parts of the BannerWindow API related to the stream-oriented output to
     *   the window, so you shouldn't have to change anything that writes HTML
     *   text to the window.  However, you will have to rework code that sets
     *   up the window's layout to use the Web UI model.
     */
    class WebBannerWin: OutputStreamWindow
        /*
         *   Initialize.  Call this when first displaying the window in the UI.
         */
        init()
        {
            /* set up our output stream */
            createOutputStream();
        }

        /* create our output stream subclass */
        createOutputStreamObj()
        {
            return new transient WebWinOutputStream(self);
        }

        /* flush output */
        flushBanner()
        {
            flushWin();
        }

        /* write text */
        writeToBanner(txt)
        {
            outputStream_.writeToStream(txt);
        }

        /*
         *   Banner window size settings.  We simply ignore these; callers must
         *   rework their layout logic for the Web UI, since the javascript
         *   layout system is so different.
         */
        setSize(siz, units, advisory) { }
        sizeToContents() { }
    ;

    /*
     *   Output stream for web banner windows
     */
    class WebWinOutputStream: OutputStream
        /* construct */
        construct(win)
        {
            /* do the base class construction */
            inherited();

            /* save our window */
            win_ = win;
        }

        /* ignore preinit - we're always created dynamically */
        execute() { }

        /* write to the underlying window */
        writeFromStream(txt)
        {
            /* add the text to the window */
            win_.write(txt);
        }

        /* our status line window */
        win_ = nil
    ;

    /* ------------------------------------------------------------------------ */
    /*
     *   The basic status line window.  The "banner" in the name is historical,
     *   because the traditional console UI implements the status line as a
     *   banner window.  We don't actually have banner windows in the Web UI;
     *   we use iframes instead.  But we keep the name to make it easier to
     *   port games written for the traditional UI to the Web UI.
     */
    transient statuslineBanner: WebStatusWin, WebBannerWin
    ;

Adv3Lite Library Reference Manual
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