# status.t | documentation

    #charset "us-ascii"

    /*
     *   Copyright (c) 2000, 2006 Michael J. Roberts.  All Rights Reserved.
     *
     *   TADS 3 Library - Status Line
     *
     *   This module defines the framework for displaying the status line,
     *   which is the area conventionally displayed at the top of the screen
     *   showing information such as the current location, score (if scoring is
     *   used at all), and number of turns.
     */

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

    /* ------------------------------------------------------------------------ */
    /*
     *   In case the 'score' module isn't included, make sure we can refer to
     *   totalScore as a property.  Likewise for the banner API and Web UI
     *   frame API.
     */
    property totalScore;
    property showBanner, setSize, sizeToContents;
    property flushWin, resize;

    /* ------------------------------------------------------------------------ */
    /*
     *   A special OutputStream for the <BANNER> tag contents.  This is really
     *   just part of the main output stream, but we use a separate output
     *   stream object so that we have our own separate stream state variables
     *   (for paragraph breaking and so forth).
     */
    transient statusTagOutputStream: OutputStream
        /*
         *   We're really part of the main window's output stream as far as the
         *   underlying interpreter I/O system is concerned, so we have to
         *   coordinate with the main game window's input manager.
         */
        myInputManager = inputManager

        /* we sit atop the system-level main console output stream */
        writeFromStream(txt)
        {
            /* write the text directly to the main output stream */
            tadsSay(txt);
        }
    ;

    /*
     *   A special OutputStream for the left half of the status line (the
     *   short description area) in text mode.  We use a separate stream for
     *   this because we must write the text using the output mode switching
     *   for the status line.
     *
     *   We only use this stream when we use the old-style text-mode status
     *   line interface, which explicitly separates the status line into a
     *   left part and a right part.  When we have the banner API available in
     *   the interpreter, we'll use banners instead, since banners give us
     *   much more flexibility.
     */
    transient statusLeftOutputStream: OutputStream
        /* we sit atop the system-level main console output stream */
        writeFromStream(txt)
        {
            /* write the text directly to the main output stream */
            tadsSay(txt);
        }
    ;

    /*
     *   A special OutputStream for the right half of the status line (the
     *   score/turn count area) in text mode.  We use a separate stream for
     *   this because we have to write this text with the special
     *   statusRight() intrinsic in text mode.
     *
     *   We only use this stream when we use the old-style text-mode status
     *   line interface, which explicitly separates the status line into a
     *   left part and a right part.  When we have the banner API available in
     *   the interpreter, we'll use banners instead, since banners give us
     *   much more flexibility.
     */
    transient statusRightOutputStream: OutputStream
        /*
         *   Write from the stream.  We simply buffer up text until we're
         *   asked to display the final data.
         */
        writeFromStream(txt)
        {
            /* buffer the text */
            buf_ += txt;
        }

        /*
         *   Flush the buffer.  This writes whatever we've buffered up to the
         *   right half of the text-mode status line.
         */
        flushStream()
        {
            /* write the text to the system console */
            statusRight(buf_);

            /* we no longer have anything buffered */
            buf_ = '';
        }

        /* our buffered text */
        buf_ = ''
    ;

    /* ------------------------------------------------------------------------ */
    /*
     *   Statusline modes.  We have three different ways to display the
     *   statusline, depending on the level of support in the interpreter.
     *
     *   StatusModeApi - use the banner API.  This is preferred method, because
     *   it gives us uniform capabilities on text and graphical interpreters,
     *   and provides an output stream for the statusline that is fully
     *   independent on the main game window's output stream.
     *
     *   StatusModeTag - use the <BANNER> tag.  This is the method we must use
     *   for HTML-enabled interpreters that don't support the banner API.  This
     *   gives us the full formatting capabilities of HTML, but isn't as good
     *   as StatusModeApi because we have to share our output stream with the
     *   main game window.
     *
     *   StatusModeText - use the old-style dedicated statusline in a text-only
     *   interpreter.  This is the least desirable method, because it gives us
     *   a rigid format for the statusline (exactly one line high, no control
     *   over colors, and with the strict left/right bifurcation).  We'll only
     *   use this method if we're on a text-only interpreter that doesn't
     *   support the banner API.
     *
     *   StatusModeBrowser - use the Web UI.  This is similar to API mode, but
     *   instead of using banner windows we use Web UI windows, which are
     *   implemented as IFRAMEs in the browser.
     */
    enum StatusModeApi, StatusModeTag, StatusModeText, StatusModeBrowser;

    /* ------------------------------------------------------------------------ */
    /*
     *   Status line - this is an abstract object that controls the status line
     *   display.
     *
     *   We provide two main methods: showStatusHtml, which shows the status
     *   line in HTML format, and showStatusText, which shows the status line
     *   in plain text mode.  To display the status line, we invoke one or the
     *   other of these methods, according to the current mode, to display the
     *   statusline.  The default implementations of these methods generate the
     *   appropriate formatting codes for a statusline with a left part and a
     *   right part, calling showStatusLeft and showStatusRight, respectively,
     *   to display the text for the parts.
     *
     *   Games can customize the statusline at two levels.  At the simpler
     *   level, a game can modify showStatusLeft and/or showStatusRight to
     *   change the text displayed on the left and/or right of the statusline.
     *   Since these two methods are used regardless of the statusline style of
     *   the underlying interpreter, games don't have to worry about the
     *   different modes when overriding these.
     *
     *   At the more complex level, a game can modify showStatusHtml and/or
     *   showStatusText.  Modifying these routines provides complete control
     *   over the formatting of the entir status line.  If a game wants to use
     *   something other than the traditional left/right display, it must
     *   modify these methods.
     *
     *   This object is transient, because the statusline style is a function
     *   of the interpreter we're currently running on, and thus isn't suitable
     *   for saving persistently.
     */
    transient statusLine: object
        /*
         *   Show the status line, in HTML or text mode, as appropriate.  By
         *   default, the library sets this up as a "prompt daemon," which
         *   means that this will be called automatically just before each
         *   command line is read.
         */
        showStatusLine()
        {
            local oldStr;

            /* if the status line isn't active, or there's no PC, skip this */
            if (statusDispMode == nil || gPlayerChar == nil)
                return;

            /*
             *   Enter status-line mode.  This will do whatever is required for
             *   our current status-line display style to prepare the output
             *   manager so that any text we display to the default output
             *   stream is displayed on the status line.
             */
            oldStr = beginStatusLine();

            /* make sure we restore statusline mode before we're done */
            try
            {
                /*
                 *   Generate a text or HTML status line, as appropriate.  If
                 *   we're in <BANNER> tag mode or banner API mode, use HTML to
                 *   format the contents of the status line; if we're using the
                 *   old-style text mode, use plain text, since the formatting
                 *   is rigidly defined in this mode.
                 */
                switch (statusDispMode)
                {
                case StatusModeTag:
                case StatusModeApi:
                case StatusModeBrowser:
                    /* show the HTML status line */
                    showStatusHtml();
                    break;

                case StatusModeText:
                    /* show the status line in plain text mode */
                    showStatusText();
                    break;
                }
            }
            finally
            {
                /* end status-line mode */
                endStatusLine(oldStr);

            }
        }

        /* prompt-daemon showing the status line */
        showStatusLineDaemon()
        {
            /* show the status line as normal */
            showStatusLine();

            /*
             *   Explicitly flush the status line if it's in a banner window.
             *   This will ensure that we'll redraw the status line on each
             *   turn if we're reading an input script, which is nice because
             *   it provides a visual indication that something's happening.
             */
            if (statusDispMode is in (StatusModeApi, StatusModeBrowser))
                statuslineBanner.flushBanner();
        }

        /*
         *   Show the status line in HTML format.  Our default implementation
         *   shows the traditional two-part (left/right) status line, using
         *   showStatusLeft() and showStatusRight() to display the parts.
         */
        showStatusHtml()
        {
            /*
             *   start the left half, and write the <A HREF> to hyperlink the
             *   location name to a "look around" command
             */
            "<<statusHTML(0)>><<
              aHref(BMsg(command look around, 'look around'),
                    nil, nil, AHREF_Plain)>>";

            /* show the left part of the status line */
            showStatusLeft();

            /*
             *   end the left portion and start the right portion, then
             *   generate the <A HREF> to link the score to a FULL SCORE
             *   command
             */
            "<./a></a><<statusHTML(1)>><<
              aHref(BMsg(command full score, 'full score'), nil, nil, AHREF_Plain)>>";

            /* show the right part of the status line */
            showStatusRight();

            /* end the score link, and end the right half wrapper */
            "<./a></a><<statusHTML(2)>>";

            /* add the status-line exit list, if desired */
            if (gPlayerChar.location!= nil)
                gPlayerChar.location.showStatuslineExits();
        }

        /*
         *   Get the estimated HTML-style banner height, in lines of text.
         *   This is used to set the status line banner size for platforms
         *   where sizing to the exact height of the rendered contents isn't
         *   supported.
         *
         *   If showStatusHtml() is overridden to display more or fewer lines
         *   of text than the basic implementation here, then this routine must
         *   be overridden as well to reflect the new height.
         */
        getEstimatedHeightHtml()
        {
            local ht;

            /*
             *   we need one line for the basic display (the location name and
             *   score/turn count)
             */
            ht = 1;

            /* add in the estimated height of the exits display, if appropriate */
            if (gPlayerChar.location != nil)
                ht += gPlayerChar.location.getStatuslineExitsHeight();

            /* return the result */
            return ht;
        }

        /*
         *   Show the statusline in text mode.  Our default implementation
         *   shows the traditional two-part (left/right) status line, using
         *   showStatusLeft() and showStatusRight() to display the parts.
         */
        showStatusText()
        {
            /* show the left part of the display */
            showStatusLeft();

            /* switch to the right-side status stream */
            outputManager.setOutputStream(statusRightOutputStream);

            /* show the right-half text */
            showStatusRight();

            /* flush the right-side stream */
            statusRightOutputStream.flushStream();
        }

        /*
         *   Show the left part of a standard left/right statusline.  By
         *   default, we'll show the player character's location, by calling
         *   statusName() on the PC's immediate container.
         */
        showStatusLeft()
        {
            local actor;

            /* get the player character actor */
            actor = gPlayerChar;

            "<.statusroom>";

            /* show the actor's location's status name */
            if (actor != nil && actor.location != nil)
                actor.location.statusName(actor);

            "<./statusroom>";
        }

        /*
         *   Show the right part of a standard left/right statusline.  By
         *   default, we'll show the current score, a slash, and the number of
         *   turns.
         */
        showStatusRight()
        {
            local s;

            /* if there's a score object, show the score */
            if ((s = libGlobal.scoreObj) != nil)
            {
                /* show the score and the number of turns so far */
                "<.statusscore><<s.totalScore>>/<<
                libGlobal.totalTurns>><./statusscore>";
            }
            /* Just show the number of turns */
            else
                "<.statusscore><<
                libGlobal.totalTurns>><./statusscore>";
        }

        /*
         *   Set up the status line's color scheme.  This is called each time
         *   we redraw the status line to set the background and text colors.
         *   We call the statusline banner window to do the work, since the
         *   mechanism is different between the traditional and Web UIs.
         */
        setColorScheme()
        {
            /* call the banner window to do the work */
            statuslineBanner.setColorScheme();
        }

        /*
         *   Begin status-line mode.  This sets up the output manager so that
         *   text written to the default output stream is displayed on the
         *   status line.  Returns the original output stream.
         */
        beginStatusLine()
        {
            local oldStr;

            /* check what kind of statusline display we're using */
            switch(statusDispMode)
            {
            case StatusModeApi:
                /*
                 *   We have a banner API window.  Start by clearing the
                 *   window, so we can completely replace everything in it.
                 */
                statuslineBanner.clearWindow();

                /*
                 *   If the platform doesn't support size-to-contents, then set
                 *   the height to our best estimate for the size.
                 *
                 *   If we do support size-to-contents, we'll set the height to
                 *   the exact rendered size when we're done, so we don't need
                 *   to worry about setting an estimate; indicate this to the
                 *   interpreter by setting the is-advisory flag to true.
                 */
                statuslineBanner.setSize(getEstimatedHeightHtml(),
                                         BannerSizeAbsolute, true);

                /* switch to the banner's output stream */
                oldStr = statuslineBanner.setOutputStream();

                /* set up the statusline color in the window */
                setColorScheme();

                /* done */
                break;

            case StatusModeBrowser:
                /* browser UI - clear the window */
                statuslineBanner.clearWindow();

                /* switch to its output stream */
                oldStr = statuslineBanner.setOutputStream();
                break;

            case StatusModeTag:
                /*
                 *   We're using <BANNER> tags.  Switch to our statusline
                 *   output stream.
                 */
                oldStr = outputManager.setOutputStream(statusTagOutputStream);

                /* set up the <BANNER> tag */
                "<banner id=StatusLine height=previous border>";

                /* set up the color scheme */
                setColorScheme();

                /* done */
                break;

            case StatusModeText:
                /* flush the main window */
                flushOutput();

                /* plain text mode - enter text status mode */
                statusMode(StatModeStatus);

                /* switch to the status-left output stream */
                oldStr = outputManager.setOutputStream(statusLeftOutputStream);

                /* done */
                break;
            }

            /* return the original output stream */
            return oldStr;
        }

        /* end statusline display */
        endStatusLine(oldStr)
        {
            /* restore the old default output stream */
            outputManager.setOutputStream(oldStr);

            /* check the type of statusline we're generating */
            switch (statusDispMode)
            {
            case StatusModeApi:
                /* banner API mode - end the last line */
                statuslineBanner.writeToBanner('\n');

                /*
                 *   Size the window to its current contents.  This doesn't
                 *   work everywhere - on a few platforms, it does nothing -
                 *   but this will give us the optimal size where it's
                 *   supported.  On platforms that don't support this, it'll do
                 *   nothing, which means we'll simply be left with the
                 *   "advisory" size we established earlier.
                 */
                statuslineBanner.sizeToContents();
                break;

            case StatusModeBrowser:
                /* browser mode - flush the window and update the content size */
                statuslineBanner.flushWin();
                break;

            case StatusModeTag:
                /* HTML <BANNER> mode - end the <BANNER> tag */
                statusTagOutputStream.writeToStream('</banner>');
                break;

            case StatusModeText:
                /* plain text statusline - end status mode */
                statusMode(StatModeNormal);
            }
        }

        /*
         *   Initialize the banner window, given the BannerWindow object
         *   representing the status line banner API window.
         */
        initBannerWindow(win)
        {
            /*
             *   Try showing the banner API window.  If that succeeds, use the
             *   banner API window, since it's the most portable and flexible
             *   way to show the status line.  If we can't create the banner
             *   API window, it means we're on an interpreter that doesn't
             *   support the banner API, so fall back on one of the older, less
             *   flexible mechanisms; which older mechanism we choose depends
             *   on what kind of interpreter we're on.
             *
             *   Since we create the status line banner during initialization
             *   and normally leave it as the first item in the display list at
             *   all times, we can attach to an existing status line banner
             *   window if there is one.  This will avoid unnecessary redrawing
             *   on RESTART.
             */
            if (win.showBanner(nil, BannerFirst, nil, BannerTypeText,
                               BannerAlignTop, nil, nil,
                               BannerStyleBorder | BannerStyleTabAlign))
            {
                /*
                 *   we successfully created the banner window - use the banner
                 *   API to show the status line
                 */
                statusDispMode = StatusModeApi;
            }
            else if (outputManager.htmlMode)
            {
                /*
                 *   We failed to create a banner API window, and we're running
                 *   on a full HTML interpreter, so use <BANNER> tags to
                 *   produce the status line.
                 */
                statusDispMode = StatusModeTag;
            }
            else
            {
                /*
                 *   We failed to create a banner API window, and we're running
                 *   on a text-only interpreter - use the old-style
                 *   fixed-format status line mechanism.
                 */
                statusDispMode = StatusModeText;
            }
        }

        /*
         *   The status mode we're using.  If this is nil, it means we haven't
         *   chosen a mode yet.
         */
        statusDispMode = nil
    ;

Adv3Lite Library Reference Manual
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