textbox.js

TextBox.prototype.scrollMessage = function(cb) {
    var self = this;
    function complete() {
        self.remove();
        cb();
    }
    this.textMetrics = TextBlotter.calculateMetrics({ text: this.text, maxWidth: TEXTBOX_MAX_WIDTH });
    if(this.text.trim() === '' || this.textMetrics.lines.length === 0 
        || this.textMetrics.lines[0].chars.length === 0) { // No message to show
        complete();
        return;
    }
    var scrollSpeed = calcScrollSpeed(this.text);
    var lineNumber = 0;
    var lineChar = 0;
    var lineChars = self.textMetrics.lines[lineNumber].chars.length;
    for(var nl = 1; nl < TEXTBOX_LINES_PER_PAGE; nl++) {
        var nextLine = self.textMetrics.lines[lineNumber + nl];
        if(nextLine) lineChars += nextLine.chars.length; else break;
    }
    //console.log(this.parent.username,'says:',this.text);
    var addLetter = function() {
        lineChar++;
        self.blotText({ 
            text: self.text, metrics: self.textMetrics, maxChars: lineChar,
            lineStart: lineNumber, lineCount: TEXTBOX_LINES_PER_PAGE
        });
        if(lineChar === lineChars) { // Line set finished?
            lineNumber += TEXTBOX_LINES_PER_PAGE;
            if(lineNumber >= self.textMetrics.lines.length) { // Last line complete?
                self.tickDelay(function() {
                    self.tickRepeat(function(progress) {
                        self.canvas = TextBlotter.transition({
                            bg: TEXTBOX_BG_COLOR, metrics: self.textMetrics, progress: 1 - progress.percent, 
                            lineCount : Math.min(self.textMetrics.lines.length, TEXTBOX_LINES_PER_PAGE)
                        });
                        self.updateScreen();
                        self.updateSprite();
                    }, TEXTBOX_CLOSE_TIME, complete);
                }, scrollSpeed * TEXTBOX_FINAL_DELAY);
            } else { // Still more lines
                lineChar = 0;
                lineChars = self.textMetrics.lines[lineNumber].chars.length;
                for(var nl = 1; nl < TEXTBOX_LINES_PER_PAGE; nl++) {
                    nextLine = self.textMetrics.lines[lineNumber + nl];
                    if(nextLine) lineChars += nextLine.chars.length; else break;
                }
                self.tickDelay(addLetter, scrollSpeed * TEXTBOX_PAGE_DELAY); // Begin next line
            }
        } else { // Line not finished, continue
            self.tickDelay(addLetter, scrollSpeed);
        }
    };
    this.tickRepeat(function(progress) {
        self.canvas = TextBlotter.transition({
            bg: TEXTBOX_BG_COLOR, metrics: self.textMetrics, progress: progress.percent,
            lineCount : Math.min(self.textMetrics.lines.length, TEXTBOX_LINES_PER_PAGE)
        });
        self.updateScreen();
        self.updateSprite();
    }, TEXTBOX_OPEN_TIME, function() {
        self.tickDelay(addLetter, scrollSpeed)
    });
};