LineBreakMeasurer.js

/**
 * Word wrapping
 *
 * @author (Javascript) Dmitry Farafonov
 */

var AttributedStringIterator = function (text) {
    //this.text = this.rtrim(this.ltrim(text));
    text = text.replace(/(\s)+/, " ");
    this.text = this.rtrim(text);
    /*
    if (beginIndex < 0 || beginIndex > endIndex || endIndex > length()) {
        throw new IllegalArgumentException("Invalid substring range");
    }
    */
    this.beginIndex = 0;
    this.endIndex = this.text.length;
    this.currentIndex = this.beginIndex;

    //console.group("[AttributedStringIterator]");
    var i = 0;
    var string = this.text;
    var fullPos = 0;

    //console.log("string: \"" + string + "\", length: " + string.length);
    this.startWordOffsets = [];
    this.startWordOffsets.push(fullPos);

    // TODO: remove i 1000
    while (i < 1000) {
        var pos = string.search(/[ \t\n\f-\.\,]/);
        if (pos == -1)
            break;

        // whitespace start
        fullPos += pos;
        string = string.substr(pos);
        ////console.log("fullPos: " + fullPos + ", pos: " + pos +  ", string: ", string);

        // remove whitespaces
        var pos = string.search(/[^ \t\n\f-\.\,]/);
        if (pos == -1)
            break;

        // whitespace end
        fullPos += pos;
        string = string.substr(pos);

        ////console.log("fullPos: " + fullPos);
        this.startWordOffsets.push(fullPos);

        i++;
    }
    //console.log("startWordOffsets: ", this.startWordOffsets);
    //console.groupEnd();
};
AttributedStringIterator.prototype = {
    getEndIndex: function (pos) {
        if (typeof (pos) == "undefined")
            return this.endIndex;

        var string = this.text.substr(pos, this.endIndex - pos);

        var posEndOfLine = string.search(/[\n]/);
        if (posEndOfLine == -1)
            return this.endIndex;
        else
            return pos + posEndOfLine;
    },
    getBeginIndex: function () {
        return this.beginIndex;
    },
    isWhitespace: function (pos) {
        var str = this.text[pos];
        var whitespaceChars = " \t\n\f";

        return (whitespaceChars.indexOf(str) != -1);
    },
    isNewLine: function (pos) {
        var str = this.text[pos];
        var whitespaceChars = "\n";

        return (whitespaceChars.indexOf(str) != -1);
    },
    preceding: function (pos) {
        //console.group("[AttributedStringIterator.preceding]");
        for (var i in this.startWordOffsets) {
            var startWordOffset = this.startWordOffsets[i];
            if (pos < startWordOffset && i > 0) {
                //console.log("startWordOffset: " + this.startWordOffsets[i-1]);
                //console.groupEnd();
                return this.startWordOffsets[i - 1];
            }
        }
        //console.log("pos: " + pos);
        //console.groupEnd();
        return this.startWordOffsets[i];
    },
    following: function (pos) {
        //console.group("[AttributedStringIterator.following]");
        for (var i in this.startWordOffsets) {
            var startWordOffset = this.startWordOffsets[i];
            if (pos < startWordOffset && i > 0) {
                //console.log("startWordOffset: " + this.startWordOffsets[i]);
                //console.groupEnd();
                return this.startWordOffsets[i];
            }
        }
        //console.log("pos: " + pos);
        //console.groupEnd();
        return this.startWordOffsets[i];
    },
    ltrim: function (str) {
        var patt2 = /^\s+/g;
        return str.replace(patt2, "");
    },
    rtrim: function (str) {
        var patt2 = /\s+$/g;
        return str.replace(patt2, "");
    },
    getLayout: function (start, limit) {
        return this.text.substr(start, limit - start);
    },
    getCharAtPos: function (pos) {
        return this.text[pos];
    }
};

var LineBreakMeasurer = function (paper, x, y, text, fontAttrs) {
    this.paper = paper;
    this.text = new AttributedStringIterator(text);
    this.fontAttrs = fontAttrs;

    if (this.text.getEndIndex() - this.text.getBeginIndex() < 1) {
        throw {message: "Text must contain at least one character.", code: "IllegalArgumentException"};
    }

    //this.measurer = new TextMeasurer(paper, this.text, this.fontAttrs);
    this.limit = this.text.getEndIndex();
    this.pos = this.start = this.text.getBeginIndex();

    this.rafaelTextObject = this.paper.text(x, y, this.text.text).attr(fontAttrs).attr("text-anchor", "start");
    this.svgTextObject = this.rafaelTextObject[0];
};
LineBreakMeasurer.prototype = {
    nextOffset: function (wrappingWidth, offsetLimit, requireNextWord) {
        //console.group("[nextOffset]");
        var nextOffset = this.pos;
        if (this.pos < this.limit) {
            if (offsetLimit <= this.pos) {
                throw {message: "offsetLimit must be after current position", code: "IllegalArgumentException"};
            }

            var charAtMaxAdvance = this.getLineBreakIndex(this.pos, wrappingWidth);
            //charAtMaxAdvance --;
            //console.log("charAtMaxAdvance:", charAtMaxAdvance, ", [" + this.text.getCharAtPos(charAtMaxAdvance) + "]");

            if (charAtMaxAdvance == this.limit) {
                nextOffset = this.limit;
                //console.log("charAtMaxAdvance == this.limit");
            } else if (this.text.isNewLine(charAtMaxAdvance)) {
                //console.log("isNewLine");
                nextOffset = charAtMaxAdvance + 1;
            } else if (this.text.isWhitespace(charAtMaxAdvance)) {
                // TODO: find next noSpaceChar
                //return nextOffset;
                nextOffset = this.text.following(charAtMaxAdvance);
            } else {
                // Break is in a word;  back up to previous break.
                /*
                var testPos = charAtMaxAdvance + 1;
                if (testPos == this.limit) {
                    console.error("hbz...");
                } else {
                    nextOffset = this.text.preceding(charAtMaxAdvance);
                }
                */
                nextOffset = this.text.preceding(charAtMaxAdvance);

                if (nextOffset <= this.pos) {
                    nextOffset = Math.max(this.pos + 1, charAtMaxAdvance);
                }
            }
        }
        if (nextOffset > offsetLimit) {
            nextOffset = offsetLimit;
        }
        //console.log("nextOffset: " + nextOffset);
        //console.groupEnd();
        return nextOffset;
    },
    nextLayout: function (wrappingWidth) {
        //console.groupCollapsed("[nextLayout]");
        if (this.pos < this.limit) {
            var requireNextWord = false;
            var layoutLimit = this.nextOffset(wrappingWidth, this.limit, requireNextWord);
            //console.log("layoutLimit:", layoutLimit);
            if (layoutLimit == this.pos) {
                //console.groupEnd();
                return null;
            }
            var result = this.text.getLayout(this.pos, layoutLimit);
            //console.log("layout: \"" + result + "\"");

            // remove end of line

            //var posEndOfLine = this.text.getEndIndex(this.pos);
            //if (posEndOfLine < result.length)
            //	result = result.substr(0, posEndOfLine);

            this.pos = layoutLimit;

            //console.groupEnd();
            return result;
        } else {
            //console.groupEnd();
            return null;
        }
    },
    getLineBreakIndex: function (pos, wrappingWidth) {
        //console.group("[getLineBreakIndex]");
        //console.log("pos:"+pos + ", text: \""+ this.text.text.replace(/\n/g, "_").substr(pos, 1) + "\"");

        var bb = this.rafaelTextObject.getBBox();

        var charNum = -1;
        try {
            var svgPoint = this.svgTextObject.getStartPositionOfChar(pos);
            //var dot = this.paper.ellipse(svgPoint.x, svgPoint.y, 1, 1).attr({"stroke-width": 0, fill: Color.blue});
            svgPoint.x = svgPoint.x + wrappingWidth;
            //svgPoint.y = bb.y;
            //console.log("svgPoint:", svgPoint);

            //var dot = this.paper.ellipse(svgPoint.x, svgPoint.y, 1, 1).attr({"stroke-width": 0, fill: Color.red});

            charNum = this.svgTextObject.getCharNumAtPosition(svgPoint);
        } catch (e) {
            console.warn("getStartPositionOfChar error, pos:" + pos);
            /*
            var testPos = pos + 1;
            if (testPos < this.limit) {
                return testPos
            }
            */
        }
        //console.log("charNum:", charNum);
        if (charNum == -1) {
            //console.groupEnd();
            return this.text.getEndIndex(pos);
        } else {
            // When case there is new line between pos and charnum then use this new line
            var newLineIndex = this.text.getEndIndex(pos);
            if (newLineIndex < charNum) {
                console.log("newLineIndex <= charNum, newLineIndex:" + newLineIndex + ", charNum:" + charNum, "\"" + this.text.text.substr(newLineIndex + 1).replace(/\n/g, "?") + "\"");
                //console.groupEnd();

                return newLineIndex;
            }

            //var charAtMaxAdvance  = this.text.text.substring(charNum, charNum + 1);
            var charAtMaxAdvance = this.text.getCharAtPos(charNum);
            //console.log("!!charAtMaxAdvance: " + charAtMaxAdvance);
            //console.groupEnd();
            return charNum;
        }
    },
    getPosition: function () {
        return this.pos;
    }
};