Hover Text Sign

// =====================================================================
//  Hover Text Sign
//  skimi3d script library
//  https://grid.skimi3d.com/scripts/hover-text-sign
//
//  Floating words above a prim. The label on a door, the name of a
//  shop, the price on a stall, the arrow that says which way the
//  landing point is.
//
//  It can also read its words out of the object's Description, which is
//  the trick worth knowing: one script, twenty signs, and you change
//  each one from the build tool without ever opening the code.
//
//  Plain LSL.
// =====================================================================


// ---------------------------------------------------------------------
//  Settings
// ---------------------------------------------------------------------

// The words, one line per entry. Keep it short: hover text is read at a
// glance and there is a hard limit of about 254 characters in total.
list LINES = [
    "The Old Forge",
    "open to visitors"
];

// Take the words from the object's Description instead of from the list
// above. Use a vertical bar to separate lines: Ferry|leaves on the hour
//
// This is how you run twenty signs off one script. Drop the same script
// into all of them and give each one a different Description.
integer READ_FROM_DESCRIPTION = FALSE;

// Colour of the text, and how solid it is.
vector COLOUR = <1.0, 1.0, 1.0>;
float  ALPHA  = 1.0;

// Make the prim itself invisible, so the words hang in the air on their
// own. The prim is still there and can still be clicked.
integer HIDE_THE_PRIM = FALSE;


// ---------------------------------------------------------------------
//  Everything below here is the machinery
// ---------------------------------------------------------------------

// Hover text is cut off past roughly this many characters, and the cut
// is silent. Better to say so than to let somebody wonder where the
// last line went.
integer LIMIT = 254;


write()
{
    string text = "";

    if (READ_FROM_DESCRIPTION)
    {
        string d = llGetObjectDesc();

        // A brand new prim says "(No Description)" in some viewers and
        // nothing in others. Neither is a sign.
        if (d == "" || d == "(No Description)")
        {
            llSetText("", COLOUR, ALPHA);
            llOwnerSay("My Description is empty, so I have nothing to say. Put the words in the Description, and use | between lines.");
            return;
        }

        text = llDumpList2String(llParseString2List(d, ["|"], []), "\n");
    }
    else
    {
        text = llDumpList2String(LINES, "\n");
    }

    if (llStringLength(text) > LIMIT)
    {
        llOwnerSay("My text is longer than a sign can hold, so the end of it will not show. Around " + (string)LIMIT + " characters is the whole budget, newlines included.");
    }

    llSetText(text, COLOUR, ALPHA);
}


default
{
    state_entry()
    {
        if (HIDE_THE_PRIM) llSetAlpha(0.0, ALL_SIDES);
        write();
    }

    changed(integer what)
    {
        // A sign that changes hands should read itself again, because
        // the new owner's Description is the one that counts.
        if (what & CHANGED_OWNER) write();
    }

    touch_start(integer total)
    {
        // THERE IS NO EVENT FOR A CHANGED DESCRIPTION. Editing it in
        // the build tool tells the script nothing at all, and a sign
        // that polled its own Description every few seconds would be
        // twenty signs polling for ever to catch an edit that happens
        // twice a year. So: change the Description, then touch the
        // sign. Owner only, because a visitor touching a sign should
        // not be able to set it working.
        if (llDetectedKey(0) != llGetOwner()) return;
        write();
    }

    on_rez(integer start)
    {
        llResetScript();
    }
}