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why-cant-we-deploy-today/js/controllers/slidenumber.js

124 lines
3.5 KiB
JavaScript

/**
* Handles the display of reveal.js' optional slide number.
*/
export default class SlideNumber {
constructor(Reveal) {
this.Reveal = Reveal;
}
render() {
this.element = document.createElement("div");
this.element.className = "slide-number";
this.Reveal.getRevealElement().appendChild(this.element);
}
/**
* Called when the reveal.js config is updated.
*/
configure(config, oldConfig) {
let slideNumberDisplay = "none";
if (config.slideNumber && !this.Reveal.isPrintingPDF()) {
if (config.showSlideNumber === "all") {
slideNumberDisplay = "block";
} else if (
config.showSlideNumber === "speaker" &&
this.Reveal.isSpeakerNotes()
) {
slideNumberDisplay = "block";
}
}
this.element.style.display = slideNumberDisplay;
}
/**
* Updates the slide number to match the current slide.
*/
update() {
// Update slide number if enabled
if (this.Reveal.getConfig().slideNumber && this.element) {
this.element.innerHTML = this.getSlideNumber();
}
}
/**
* Returns the HTML string corresponding to the current slide
* number, including formatting.
*/
getSlideNumber(slide = this.Reveal.getCurrentSlide()) {
let config = this.Reveal.getConfig();
let value;
let format = "h.v";
if (typeof config.slideNumber === "function") {
value = config.slideNumber(slide);
} else {
// Check if a custom number format is available
if (typeof config.slideNumber === "string") {
format = config.slideNumber;
}
// If there are ONLY vertical slides in this deck, always use
// a flattened slide number
if (!/c/.test(format) && this.Reveal.getHorizontalSlides().length === 1) {
format = "c";
}
// Offset the current slide number by 1 to make it 1-indexed
let horizontalOffset =
slide && slide.dataset.visibility === "uncounted" ? 0 : 1;
value = [];
switch (format) {
case "c":
value.push(this.Reveal.getSlidePastCount(slide) + horizontalOffset);
break;
case "c/t":
value.push(
this.Reveal.getSlidePastCount(slide) + horizontalOffset,
"/",
this.Reveal.getTotalSlides()
);
break;
default:
let indices = this.Reveal.getIndices(slide);
value.push(indices.h + horizontalOffset);
let sep = format === "h/v" ? "/" : ".";
if (this.Reveal.isVerticalSlide(slide))
value.push(sep, indices.v + 1);
}
}
let url = "#" + this.Reveal.location.getHash(slide);
return this.formatNumber(value[0], value[1], value[2], url);
}
/**
* Applies HTML formatting to a slide number before it's
* written to the DOM.
*
* @param {number} a Current slide
* @param {string} delimiter Character to separate slide numbers
* @param {(number|*)} b Total slides
* @param {HTMLElement} [url='#'+locationHash()] The url to link to
* @return {string} HTML string fragment
*/
formatNumber(a, delimiter, b, url = "#" + this.Reveal.location.getHash()) {
if (typeof b === "number" && !isNaN(b)) {
return `<a href="${url}">
<span class="slide-number-a">${a}</span>
<span class="slide-number-delimiter">${delimiter}</span>
<span class="slide-number-b">${b}</span>
</a>`;
} else {
return `<a href="${url}">
<span class="slide-number-a">${a}</span>
</a>`;
}
}
destroy() {
this.element.remove();
}
}