omi/asset/hll/hll.js

/*!
 * reveal-code-focus 1.0.0
 * Copyright 2015-2017 Benjamin Tan <https://demoneaux.github.io/>
 * Available under MIT license <https://github.com/demoneaux/reveal-code-focus/blob/master/LICENSE>
 */
;(function(window, Reveal, hljs) {
    if (typeof window.RevealCodeFocus == 'function') {
        return;
    }

    var currentSlide, currentFragments, scrollToFocused = true, prevSlideData = null;

    // Iterates through `array`, running `callback` for each `array` element.
    function forEach(array, callback) {
        var i = -1, length = array ? array.length : 0;
        while (++i < length) {
            callback(array[i]);
        }
    }

    function indexOf(array, elem) {
        var i = -1, length = array ? array.length : 0;
        while (++i < length) {
            if (array[i] === elem) {
                return i;
            }
        }
    }

    function initialize(e) {
        // Initialize code only once.
        // TODO: figure out why `initialize` is being called twice.
        if (initialize.ran) {
            return;
        }
        initialize.ran = true;

        // TODO: mark as parsed.
        forEach(document.querySelectorAll('pre code'), function(element) {
            // Trim whitespace if the `data-trim` attribute is present.
            if (element.hasAttribute('data-trim') && typeof element.innerHTML.trim == 'function') {
                element.innerHTML = element.innerHTML.trim();
            }

            // Highlight code using highlight.js.
            hljs.highlightBlock(element);

            // Split highlighted code into lines.
            var openTags = [], reHtmlTag = /<(\/?)span(?:\s+(?:class=(['"])hljs-.*?\2)?\s*|\s*)>/g;
            element.innerHTML = element.innerHTML.replace(/(.*?)\r?\n/g, function(_, string) {
                if (!string) {
                    return '<span class=line>&nbsp;</span>';
                }
                var openTag, stringPrepend;
                // Re-open all tags that were previously closed.
                if (openTags.length) {
                    stringPrepend = openTags.join('');
                }
                // Match all HTML `<span>` tags.
                reHtmlTag.lastIndex = 0;
                while (openTag = reHtmlTag.exec(string)) {
                    // If it is a closing tag, remove the opening tag from the list.
                    if (openTag[1]) {
                        openTags.pop();
                    }
                    // Otherwise if it is an opening tag, push it to the list.
                    else {
                        openTags.push(openTag[0]);
                    }
                }
                // Close all opened tags, so that strings can be wrapped with `span.line`.
                if (openTags.length) {
                    string += Array(openTags.length + 1).join('</span>');
                }
                if (stringPrepend) {
                    string = stringPrepend + string;
                }
                return '<span class=line>' + string + '</span>';
            });
        });

        Reveal.addEventListener('slidechanged', updateCurrentSlide);

        Reveal.addEventListener('fragmentshown', function(e) {
            focusFragment(e.fragment);
        });

        // TODO: make this configurable.
        // When a fragment is hidden, clear the current focused fragment,
        // and focus on the previous fragment.
        Reveal.addEventListener('fragmenthidden', function(e) {
            var index = indexOf(currentFragments, e.fragment);
            focusFragment(currentFragments[index - 1]);
        });

        updateCurrentSlide(e);
    }
    initialize.ran = false;

    function updateCurrentSlide(e) {
        currentSlide = e.currentSlide;
        currentFragments = currentSlide.getElementsByClassName('fragment');
        clearPreviousFocus();

        // If moving back to a previous slide<64><65>
        if (
            currentFragments.length &&
            prevSlideData &&
            (
                prevSlideData.indexh > e.indexh ||
                (prevSlideData.indexh == e.indexh && prevSlideData.indexv > e.indexv)
            )
        ) {
            // <20><>return to the last fragment and highlight the code.
            while (Reveal.nextFragment()) {}
            var currentFragment = currentFragments[currentFragments.length - 1];
            currentFragment.classList.add('current-fragment');
            focusFragment(currentFragment);
        }

        // Update previous slide information.
        prevSlideData = {
            'indexh': e.indexh,
            'indexv': e.indexv
        };
    }

    // Removes any previously focused lines.
    function clearPreviousFocus() {
        forEach(currentSlide.querySelectorAll('pre code .line.focus'), function(line) {
            line.classList.remove('focus');
        });
    }

    function focusFragment(fragment) {
        clearPreviousFocus();
        if (!fragment) {
            return;
        }

        var lines = fragment.getAttribute('data-code-focus');
        if (!lines) {
            return;
        }

        var codeBlock = parseInt(fragment.getAttribute('data-code-block'));
        if (isNaN(codeBlock)) {
            codeBlock = 1;
        }

        var code = currentSlide.querySelectorAll('pre:nth-of-type(' + codeBlock + ') code .line');
        if (!code) {
            return;
        }

        var topLineNumber, bottomLineNumber;

        forEach(lines.split(','), function(line) {
            lines = line.split('-');
            if (lines.length == 1) {
                focusLine(lines[0]);
            } else {
                var i = lines[0] - 1, j = lines[1];

                while (++i <= j) {
                    focusLine(i);
                }
            }
        });

        function focusLine(lineNumber) {
            // Convert from 1-based index to 0-based index.
            lineNumber -= 1;

            var line = code[lineNumber];
            if (!line) {
                return;
            }

            line.classList.add('focus');

            if (scrollToFocused) {
                if (topLineNumber == null) {
                    topLineNumber = bottomLineNumber = lineNumber;
                } else {
                    if (lineNumber < topLineNumber) {
                        topLineNumber = lineNumber;
                    }
                    if (lineNumber > bottomLineNumber) {
                        bottomLineNumber = lineNumber;
                    }
                }
            }
        }

        if (scrollToFocused && topLineNumber != null) {
            var topLine =  code[topLineNumber];
            var bottomLine = code[bottomLineNumber];
            var codeParent = topLine.parentNode;
            var scrollTop = topLine.offsetTop;
            var scrollBottom = bottomLine.offsetTop + bottomLine.clientHeight;
            codeParent.scrollTop = scrollTop - (codeParent.clientHeight - (scrollBottom - scrollTop)) / 2;
        }
    }

    function RevealCodeFocus(options) {
        options || (options = {
            'scrollToFocused': true
        });

        if (options.scrollToFocused != null) {
            scrollToFocused = options.scrollToFocused;
        }

        if (Reveal.isReady()) {
            initialize({ 'currentSlide': Reveal.getCurrentSlide() });
        } else {
            Reveal.addEventListener('ready', initialize);
        }
    }

    window.RevealCodeFocus = RevealCodeFocus;
}(this, this.Reveal, this.hljs));