<!-- Copyright 2002 Adam Megacz, see the COPYING file for licensing [LGPL] -->
<xwt>

    A text edit box.

        multiline : boolean       -- if true, lines will be broken at newline characters
        editable  : boolean       -- if false, the text cannot be changed, although it can be copied

    <redirect target="self"/>

    <static>
        var boxen = [];
        var cr_regexp = /[\n\r]/g;
        var nonwhitespace = /\S/;
    </static>

    <template textcolor="black" orient="vertical" vpad="2" editable="true" multiline="false" text="" cursor="text">

        // Structural Stuff //////////////////////////////////////////////////////////////////////

        // Cursor1 is the cursor -- when there is no selection, its width is
        // 1, and its height is the height of one line. When the user selects
        // a one-line region, Cursor1 is expanded to cover that region (but
        // placed behind the text on the z-axis). When the user selects more
        // than one line, Cursor1 covers the background of the first line of
        // the selection, Cursor3 covers the last line, and the intermediate
        // lines get their color set to "blue".

        var curs = $curs;                      // the main cursor
        var curs2 = $curs2;                    // the "backup" cursor for multiline selections
        var numcursors = 2;                    // the number of non-textline children of this box
        var master = 0;

        <box text="" align="topleft"/>
        <box id="curs" absolute="true" textcolor="white" color="blue" width="1" y="0" x="1" invisible="true"/>
        <box id="curs2" absolute="true" textcolor="white" color="blue" width="1" y="0" x="1" invisible="true"/>

        // Cursor Manipulation //////////////////////////////////////////////////////////////////////

        // cx1, cy1 is the coordinates (in characters, not pixels) of the start of the selection
        // cx2, cy2 is the coordinates (in characters, not pixels) of the end   of the selection
        cx2 = cx1 = cy2 = cy1 = 0;

        // the x-coordinate of the beginning of the selection, in characters
        _cx1 = function(a) {
            a = xwt.math.floor(a);
            if (0 > a) { if (cy1 > 0) cy1--; a = thisbox[cy1].text.length; }
            if (numchildren - numcursors > cy1 and a > thisbox[cy1].text.length) { cy1++; a = 0; }
            curs.x = xwt.textwidth(font, thisbox[cy1].text.substring(0, a));
            arguments.cascade(a);
            sync();
        }

        // the x-coordinate of the end of the selection, in characters
        _cx2 = function(a) {
            a = xwt.math.floor(a);
            if (0 > a) { cy2--; a = thisbox[cy2].text.length; }
            if (numchildren - numcursors > cy2 and a > thisbox[cy2].text.length) { cy2++; a = 0; }
            arguments.cascade(a);
            sync();
        }

        // the y-coordinate of the beginning of the selection, in characters
        _cy1 = function(a) {
            a = xwt.math.floor(a);
            if (0 > a) { a = 0; cx1 = 0; }
            arguments.cascade(a);
            if (cx1 > thisbox[a].text.length) cx1 = thisbox[a].text.length;
            sync();
        }

        // the y-coordinate of the end of the selection, in characters
        _cy2 = function(a) {
            a = xwt.math.floor(a);
            arguments.cascade(a);
            while (a >= numchildren - numcursors) {
                var b = getbox();
                b.text = "";
                thisbox[numchildren - numcursors] = b;
            }
            if (cx2 > thisbox[a].text.length) cx2 = thisbox[a].text.length;
            sync();
        }

        // the x-coordinate of the beginning of the selection, measured in _pixels_
        __px1 = function() {
            if (cy1 > numchildren || thisbox[cy1].text == null) return 0;
            return xwt.textwidth(font, thisbox[cy1].text.substring(0, cx1));
        }

        // the x-coordinate of the end of the selection, measured in _pixels_
        __px2 = function() {
            if (cy2 > numchildren || thisbox[cy2].text == null) return 0;
            return xwt.textwidth(font, thisbox[cy2].text.substring(0, cx2));
        }

        // on the r-th row, this will determine how many characters are to the left of a
        // point b pixels from the left edge of the edit  Algorithm is a binary search,
        // making educated guesses based on the average width of a character on that line.
        getboundary = function(r, b) {

            if (o >= b) return 0;
            var s = thisbox[r].text;

            var left = 0;                                 // the left boundary of the search region, in characters
            var right = s.length;                         // the right boundary of the search region, in characters
            var start = 0;                                // the left boundary of the search region, in pixels
            // the right boundary of the search region, in pixels
            var end = xwt.textwidth(font, s);
            if (b >= end) return right;                            // short circuit if we're off the end

            var avgwidth = end / right;                            // average width of one character

            while(true) {
                var middle = left + (b - start) / avgwidth;        // make a guess at where we should look

                // extra safety guard against infinite loops
                if (left == right) return left;
                if (left >= middle) middle = left + 1;
                if (middle >= right) middle = left - 1;

                start = xwt.textwidth(font, s.substring(0, middle));
                if (start > b) {
                    right = middle;
                } else if (b >= start + xwt.textwidth(font, s.charAt(middle))) {
                    left = middle;
                } else {
                    return middle;
                }
            }
        }

        // returns the row containing the point yp pixels from the top of the widget
        getrow = function(yp) { return xwt.math.min(numchildren - numcursors - 1, xwt.math.floor(yp / lineheight)); }

        sync = function() {
            curs.x = px1;
            curs.y = thisbox[cy1].y; //lineheight * cy1 + thisbox[0].y;
            curs.width = px2 - px1;
            if (1 > curs.width) { curs.width = 1; curs.text = ""; }
            curs2.invisible = true;

            if (cy1 != cy2) {
                curs.width = width - curs.x;
                curs2.invisible = false;
                curs2.x = 0;
                curs2.y = thisbox[cy2].y; //lineheight * cy2;
                curs2.height = lineheight;
                curs2.width = px2;
            }

            for(var i=0; numchildren - numcursors>i; i++) {
                if (i>cy1 and cy2>i) { 
                    thisbox[i].textcolor = "white";
                    thisbox[i].color = "blue";
                } else {
                    thisbox[i].textcolor = "black";
                    thisbox[i].color = null;
                }
            }

            curs.text = (thisbox[cy1] == null || thisbox[cy1].text == null) ? null :
                            thisbox[cy1].text.substring(getboundary(cy1, curs.x),
                                                     getboundary(cy1, curs.x + curs.width));

            curs2.text = (thisbox[cy2] == null || thisbox[cy2].text == null) ? null :
                            thisbox[cy2].text.substring(getboundary(cy2, curs2.x),
                                                     getboundary(cy2, curs2.x + curs2.width));
        }


        // Externally Visible Traps //////////////////////////////////////////////////////////

        _focused = function(f) {
            if (!f) {
                if (curs.width == 1) curs.invisible = true;
            } else {
                curs.invisible = false;
            }
        }

        // returns the currently-selected text
        __selection = function() {
            var ret = "";
            if (cy1 == cy2) {
                ret += thisbox[cy1].text.substring(cx1, cx2);
            } else {
                ret += thisbox[cy1].text.substring(cx1) + "\n";
                for(var i=cy1 + 1; cy2 > i; i++) ret += thisbox[i].text + "\n";
                ret += thisbox[cy2].text.substring(0, cx2);
            }
            return ret;
        }

        _font = function(f) {
            curs.height = curs2.height = lineheight = f == null ? xwt.textheight() : xwt.textheight(f);
            for(var i=0; numchildren>i; i++) {
                thisbox[i].font = f;
                if (numchildren - numcursors > i) thisbox[i].minheight = lineheight;
            }
        }
        font = null;

        _editable = function(e) {
            if (e) {
                auto_focus = true;
                color = "white";
            } else {
                auto_focus = false;
                focused = false;
                curs.invisible = true;
                curs2.invisible = true;
            }
        }

        _multiline = function(m) {
            if (m and m != "false") {
                while(numchildren > numcursors + 1) thisbox[1].thisbox = null;
                arguments.cascade(true);
            } else {
                arguments.cascade(false);
            }
        }

        __text = function(t) {
            if (arguments.length == 0) {
                var ret = "";
                for(var i=0; numchildren - numcursors>i; i++) ret = ret + thisbox[i].text + "\n";
                return ret.substring(0, ret.length - 1); // chop off trailing CR
            }
            var me = this;
            for(var i = numchildren - numcursors - 1; i >= 0; i--) {
                static.boxen[static.boxen.length] = me[i];
                me[i].thisbox = null;
            }
            cy1 = 0; cy2 = 0; cx1 = 0; cx2 = 0;
            xwt.thread = function() {
                try { insert_text(t); } catch (e) { xwt.println(e); }
            }
        }

        last_was_a_kill = false;               // indicates if the last "action" was a kill -- lets us know if we
                                               // we should append newly killed text to the kill buffer or clear it


        // Text Manipulation /////////////////////////////////////////////////////////////

        // deletes the region between the start and end of the selection
        var nuke_selection = function() {
            if (cy1 != cy2 and thisbox[cy1].text != null and thisbox[cy2].text != null) {
                thisbox[cy1].text = thisbox[cy1].text.substring(0, cx1) + thisbox[cy2].text.substring(cx2);
                for(var i=cy1 + 1; cy2 >= i; i++) thisbox[cy1 + 1].thisbox = null;
                cy2 = cy1;
                cx2 = cx1;
            } else {
                thisbox[cy1].text = thisbox[cy1].text.substring(0, cx1) +  thisbox[cy1].text.substring(cx2);
                cx2 = cx1;
            }
        }

        var getbox = function() {
            if (static.boxen.length == 0) static.boxen[0] = xwt.newBox();
            var ret = static.boxen[static.boxen.length - 1];
            static.boxen.length--;
            ret.minheight = lineheight;
            ret.vshrink = true;
            ret.textcolor = "black";
            ret.font = font;
            ret.align = "topleft";
            ret.invisible = false;
            ret.absolute = false;
            return ret;
        }

        // nukes the selected region and inserts arg in its place
        var insert_text = function(arg) {
            var mine = master = xwt.math.random();
            if (!multiline) arg = (arg + "").replace(static.cr_regexp, "");
            if (curs.width > 1) nuke_selection();
            while(!(arg == null || arg == "" || arg.replace == null)) {
                cy2 = cy1; cx2 = cx1;
                // insert a new line if necessary
                if (arg.charAt(0) == '\n') {
                    var n = getbox();
                    thisbox[cy1 + 1] = n;
                    n.text = thisbox[cy1].text.substring(cx1); 
                    thisbox[cy1].text = thisbox[cy1].text.substring(0, cx1); 
                    cy1++; cy2 = cy1; cx1 = 0; cx2 = 0;
                    arg = arg.substring(1);
                    xwt.yield();
                    if (master != mine) return;
                }
                var upto = arg.indexOf('\n') == -1 ? arg.length : arg.indexOf('\n');
                var itext = arg.substring(0, upto);
                thisbox[cy1].text = thisbox[cy1].text.substring(0, cx1) + itext + thisbox[cy1].text.substring(cx1);
                cx1 += itext.length;
                arg = arg.substring(upto);
            }   
            cy2 = cy1;
            cx2 = cx1;
            master = 0;
        }

            
        // XWT Event Handlers //////////////////////////////////////////////////////////////

_Press2 = function() {
xwt.println("curs.x = " + curs.x);
xwt.println("curs.y = " + curs.y);
xwt.println("curs.w = " + curs.width);
xwt.println("curs.h = " + curs.height);
xwt.println("curs.i = " + curs.invisible);
xwt.println("curs[] = " + indexof(curs));
xwt.println("numchi = " + numchildren);
}

        _Press1 = function() {
            focused = true;
            if (master != 0) return;
            last_was_a_kill = false;

            root._Move = function() {
                curs.invisible = false;
                var mousey_row = getrow(mousey);
                var pressy_row = getrow(pressy);

                if (pressy_row > mousey_row || (mousey_row == pressy_row and pressx > mousex)) {
                    cy1 = mousey_row;
                    cy2 = pressy_row;
                    cx1 = getboundary(cy1, mousex);
                    cx2 = getboundary(cy2, pressx);

                } else {
                    var newcy2 = mousey_row;
                    if (newcy2 > numchildren - numcursors - 1) newcy2 = numchildren - numcursors - 1;
                    cy2 = newcy2;
                    cy1 = pressy_row;
                    cx2 = xwt.math.min(getboundary(cy2, mousex), thisbox[cy2].text.length);
                    cx1 = getboundary(cy1, pressx);
                }
            }

            root.__Release1 = function() {
                root._Move = null;
                root._Release1 = null;
                if (cx1 != cx2 || cy1 != cy2) xwt.clipboard = selection;
            }

            pressx = mousex;
            pressy = mousey;
            cy1 = getrow(mousey);
            cy2 = getrow(mousey);
            cx2 = xwt.math.min(getboundary(cy1, mousex), thisbox[cy1].text.length);
            cx1 = xwt.math.min(getboundary(cy1, mousex), thisbox[cy1].text.length);
        }

        __Press3 = function() {
            last_was_a_kill = false;
            cy1 = cy2 = getrow(mousey);
            cx2 = cx1 = xwt.math.min(getboundary(cy1, mousex), thisbox[cy1].text.length);
            if (xwt.clipboard != null and editable) insert_text(xwt.clipboard);
        }

        _DoubleClick1 = function() {
            cy1 = cy2 = getrow(mousey);
            cx1 = 0; cx2 = thisbox[cy1].text.length;
            xwt.clipboard = selection;
        }

        var key_C_Q = function() {

            // C-q => fill
            var start = cy1;
            var stop = cy2;

            // if a region wasn't selected, fill this paragraph alone
            if (cy1 == cy2) {
                while (start > 0 and thisbox[start].text.match(static.nonwhitespace)) start--;
                while (numchildren - numcursors > stop and thisbox[stop].text.match(static.nonwhitespace)) stop++;
            }

            // pull out the text-to-be filled
            var filltext = "";
            for(var i=start; stop >= i; i++) {
                filltext += thisbox[start].text + "\n";
                if (numchildren > numcursors) {
                    static.boxen[static.boxen.length] = thisbox[start];
                    thisbox[start].thisbox = null;
                } else {
                    thisbox[start].text = "";
                }
            }

            xwt.println("prefill text:\n" + filltext);            

            filltext = filltext.replace(/^\\s+/);

            var quoted = false;
            if (filltext.substring(0, 2) == "> ") {
                filltext = filltext.substring(2).replace(/\n> /g, "\n");
                quoted = true;
            }

            filltext = filltext.replace(/\s+/g, " ");

            var newfilltext = "";

            while (filltext.length > 0) {
                var tmp = filltext.substring(0, 78);
                var tmp2;
                if (tmp.lastIndexOf(' ') != -1) {
                    filltext = tmp.substring(tmp.lastIndexOf(' ') + 1) + filltext.substring(78);
                    tmp2 = tmp.substring(0, tmp.lastIndexOf(' '));
                } else {
                    tmp2 = filltext;
                    filltext = "";
                }
                newfilltext += (quoted ? "> " : "") + tmp2 + "\n";  
            }

            cy1 = start; cy2 = start;
            cx1 = 0; cx2 = 0;

            xwt.println("newfilltext:\n" + newfilltext);

            insert_text("\n" + newfilltext + "\n");
         }

        var key_C_W = function() { if (xwt.clipboard != null) xwt.clipboard = selection;
                                   if (editable) nuke_selection();
                                 }
        var key_C_K = function() { if (!editable) return;
                                   if (1 >= curs.width and cx1 == thisbox[cy1].text.length) cx2++;
                                   else if (1 >= curs.width) cx2 = thisbox[cy2].text.length;
                                   if (!last_was_a_kill and xwt.clipboard != null) xwt.clipboard = "";
                                   if (xwt.clipboard != null) xwt.clipboard += selection;
                                   else xwt.clipboard = selection;
                                   nuke_selection();
                                 }

        _KeyPressed = function(key) {
            if (master != 0) return;
            if (!focused) return;
            var kill = false;
            if (key == "C-a") { cx1 = 0; cx2 = 0; }
            else if (key == "C-e") { cx1 = thisbox[cy2].text.length; cx2 = cx1; cy2 = cy1; }
            else if (key == "C-d" || key == "delete") { if (!editable) return; if (1 >= curs.width) cx2++; nuke_selection(); }
            else if (key == "C-y") { if (xwt.clipboard != null and editable) insert_text(xwt.clipboard); }
            else if (key == "C-k") key_C_K();
            else if (key == "C-w") key_C_W();
            else if (key == "C-h" || key == "back_space") {
                if (!editable) return;
                if (cx1 == 0 and cx2 == 0 and cy1 == 0 and cy2 == 0) return;
                if (1 >= curs.width) cx1--;
                nuke_selection();
            }
            else if (key == "C-b" || key == "left") { cx1--; cy2 = cy1; cx2 = cx1; }
            else if (key == "C-p" || key == "up") { cy1--; cy2 = cy1; cx2 = cx1; }
            else if (key == "C-f" || key == "right") { cx2++; cy1 = cy2; cx1 = cx2; }
            else if (key == "C-m" || key == "C-o" || key == "enter" || key == "C-j") { if (editable) insert_text("\n"); }
            else if (key == "C-n" || key == "down") { cy2++; cy1 = cy2; cx1 = cx2; }
            else if (key == "C-q") key_C_Q();
            else if (key.length == 1) {
                if (!editable) return;
                if (curs.width > 1) nuke_selection();
                thisbox[cy1].text = thisbox[cy1].text.substring(0, cx1) +
                                 key +
                                 thisbox[cy1].text.substring(cx1);
                cx2 = cx1 + 1; cx1 = cx2;
            }
        
            last_was_a_kill = key == "C-k";
        }
    
    </template>
</xwt>