Customize your RevealJS slides¶
One of the benefits of the convert command is the use of template files.
Currently, only the HTML export uses one. If not specified, the template
will be the one shipped with Manim Slides, see
manim_slides/templates/revealjs.html.
Because you can actually use your own template with the --use-template
option, possibilities are infinite!
Warning
Currently, the PresentationConfig class and its components
are not part of the public API. You can still use them, e.g.,
in the templates, but you may expect breaking changes between
releases.
Eventually, this will become part of the public API too, and we will document its usage.
Adding a clock to each slide¶
In this example, we show how to add a self-updating clock to the bottom left corner of every slide.
Note
This example is inspired from @gsong-math’s comment on Manim Slides’ repository.
What to add¶
Whenever you want to create a template, it is best practice to start from the default one (see link above).
Modifying it needs very basic HTML/JavaScript/CSS skills. To add a clock, you can simply add the following to the default template file:
<!doctype html>
<html>
<head>
<!-- Head stuff -->
</head>
<body>
<!-- Slides stuff -->
<script>
<!-- RevealJS stuff -->
</script>
<!-- Add a clock to each section dynamically using JavaScript -->
<script>
document.addEventListener('DOMContentLoaded', function () {
var revealContainer = document.querySelector('.reveal');
// Append dynamic content to each section
var sections = revealContainer.querySelectorAll('.slides > section');
sections.forEach(function (section) {
// Create a new clock container
var clockContainer = document.createElement('div');
clockContainer.className = 'clock';
// Append the new clock container to the section
section.appendChild(clockContainer);
});
// Function to update the clock content
function updateClock() {
var now = new Date();
var hours = now.getHours();
var minutes = now.getMinutes();
var seconds = now.getSeconds();
// Format the time as HH:MM:SS
var timeString = pad(hours) + ":" + pad(minutes) + ":" + pad(seconds);
// Update the content of all clock containers
var clockContainers = document.querySelectorAll('.clock');
clockContainers.forEach(function (container) {
container.innerText = timeString;
});
}
// Function to pad zero for single-digit numbers
function pad(number) {
return String(number).padStart(2, "0");
}
// Update the clock every second
setInterval(updateClock, 1000);
// Register a reveal.js event to update the clock on each slide change
Reveal.addEventListener('slidechanged', function (event) {
updateClock();
});
// Initial update
updateClock();
});
</script>
<!-- define the style of the clock -->
<style>
.clock {
position: fixed;
bottom: 10px;
left: 10px;
font-size: 24px;
font-family: "Arial", sans-serif;
color: #333;
}
/* control the relative position of the clock to the slides */
.reveal .slides > section.present, .reveal .slides > section > section.present {
min-height: 100% !important;
display: flex !important;
flex-direction: column !important;
justify-content: center !important;
position: absolute !important;
top: 0 !important;
}
section > h1 {
position: absolute !important;
top: 0 !important;
margin-left: auto !important;
margin-right: auto !important;
left: 0 !important;
right: 0 !important;
}
.print-pdf .reveal .slides > section.present, .print-pdf .reveal .slides > section > section.present {
min-height: 770px !important;
position: relative !important;
}
</style>
</body>
</html>
Tip
Because we use RevealJS to generate HTML slides, we recommend you to take a look at RevealJS’ documentation.
How it renders¶
Then, using the :template: <path/to/custom_template.html>
option, the basic example renders as follows:
Full code¶
Below, you can read the full content of the template file.
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
<title>{{ title }}</title>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/reveal.js/{{ reveal_version }}/reveal.min.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/reveal.js/{{ reveal_version }}/theme/{{ reveal_theme }}.min.css">
<!-- Theme used for syntax highlighting of code -->
<!-- <link rel="stylesheet" href="lib/css/zenburn.css"> -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.13.1/styles/zenburn.min.css">
<!-- <link rel="stylesheet" href="index.css"> -->
</head>
<body>
<div class="reveal">
<div class="slides">
{%- for presentation_config in presentation_configs -%}
{% set outer_loop = loop %}
{%- for slide_config in presentation_config.slides -%}
{%- if data_uri -%}
{% set file = file_to_data_uri(slide_config.file) %}
{%- else -%}
{% set file = assets_dir / slide_config.file.name %}
{%- endif -%}
<section
data-background-size={{ background_size }}
data-background-color="{{ presentation_config.background_color }}"
data-background-video="{{ file }}"
{% if loop.index == 1 and outer_loop.index == 1 -%}
data-background-video-muted
{%- endif -%}
{% if slide_config.loop -%}
data-background-video-loop
{%- endif -%}
{% if slide_config.auto_next -%}
data-autoslide="{{ get_duration_ms(slide_config.file) }}"
{%- endif -%}>
{% if slide_config.notes != "" -%}
<aside class="notes" data-markdown>{{ slide_config.notes }}</aside>
{%- endif %}
</section>
{%- endfor -%}
{%- endfor -%}
</div>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/reveal.js/{{ reveal_version }}/reveal.min.js"></script>
<!-- To include plugins, see: https://revealjs.com/plugins/ -->
{% if has_notes -%}
<script src="https://cdnjs.cloudflare.com/ajax/libs/reveal.js/{{ reveal_version }}/plugin/markdown/markdown.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/reveal.js/{{ reveal_version }}/plugin/notes/notes.min.js"></script>
{%- endif -%}
<!-- <script src="index.js"></script> -->
<script>
Reveal.initialize({
{% if has_notes -%}
plugins: [ RevealMarkdown, RevealNotes ],
{%- endif %}
// The "normal" size of the presentation, aspect ratio will
// be preserved when the presentation is scaled to fit different
// resolutions. Can be specified using percentage units.
width: {{ width }},
height: {{ height }},
// Factor of the display size that should remain empty around
// the content
margin: {{ margin }},
// Bounds for smallest/largest possible scale to apply to content
minScale: {{ min_scale }},
maxScale: {{ max_scale }},
// Display presentation control arrows
controls: {{ controls }},
// Help the user learn the controls by providing hints, for example by
// bouncing the down arrow when they first encounter a vertical slide
controlsTutorial: {{ controls_tutorial }},
// Determines where controls appear, "edges" or "bottom-right"
controlsLayout: {{ controls_layout }},
// Visibility rule for backwards navigation arrows; "faded", "hidden"
// or "visible"
controlsBackArrows: {{ controls_back_arrows }},
// Display a presentation progress bar
progress: {{ progress }},
// Display the page number of the current slide
// - true: Show slide number
// - false: Hide slide number
//
// Can optionally be set as a string that specifies the number formatting:
// - "h.v": Horizontal . vertical slide number (default)
// - "h/v": Horizontal / vertical slide number
// - "c": Flattened slide number
// - "c/t": Flattened slide number / total slides
//
// Alternatively, you can provide a function that returns the slide
// number for the current slide. The function should take in a slide
// object and return an array with one string [slideNumber] or
// three strings [n1,delimiter,n2]. See #formatSlideNumber().
slideNumber: {{ slide_number }},
// Can be used to limit the contexts in which the slide number appears
// - "all": Always show the slide number
// - "print": Only when printing to PDF
// - "speaker": Only in the speaker view
showSlideNumber: {{ show_slide_number }},
// Use 1 based indexing for # links to match slide number (default is zero
// based)
hashOneBasedIndex: {{ hash_one_based_index }},
// Add the current slide number to the URL hash so that reloading the
// page/copying the URL will return you to the same slide
hash: {{ hash }},
// Flags if we should monitor the hash and change slides accordingly
respondToHashChanges: {{ respond_to_hash_changes }},
// Push each slide change to the browser history. Implies `hash: true`
history: {{ history }},
// Enable keyboard shortcuts for navigation
keyboard: {{ keyboard }},
// Optional function that blocks keyboard events when retuning false
//
// If you set this to 'focused', we will only capture keyboard events
// for embedded decks when they are in focus
keyboardCondition: {{ keyboard_condition }},
// Disables the default reveal.js slide layout (scaling and centering)
// so that you can use custom CSS layout
disableLayout: {{ disable_layout }},
// Enable the slide overview mode
overview: {{ overview }},
// Vertical centering of slides
center: {{ center }},
// Enables touch navigation on devices with touch input
touch: {{ touch }},
// Loop the presentation
loop: {{ loop }},
// Change the presentation direction to be RTL
rtl: {{ rtl }},
// Changes the behavior of our navigation directions.
//
// "default"
// Left/right arrow keys step between horizontal slides, up/down
// arrow keys step between vertical slides. Space key steps through
// all slides (both horizontal and vertical).
//
// "linear"
// Removes the up/down arrows. Left/right arrows step through all
// slides (both horizontal and vertical).
//
// "grid"
// When this is enabled, stepping left/right from a vertical stack
// to an adjacent vertical stack will land you at the same vertical
// index.
//
// Consider a deck with six slides ordered in two vertical stacks:
// 1.1 2.1
// 1.2 2.2
// 1.3 2.3
//
// If you're on slide 1.3 and navigate right, you will normally move
// from 1.3 -> 2.1. If "grid" is used, the same navigation takes you
// from 1.3 -> 2.3.
navigationMode: {{ navigation_mode }},
// Randomizes the order of slides each time the presentation loads
shuffle: {{ shuffle }},
// Turns fragments on and off globally
fragments: {{ fragments }},
// Flags whether to include the current fragment in the URL,
// so that reloading brings you to the same fragment position
fragmentInURL: {{ fragment_in_url }},
// Flags if the presentation is running in an embedded mode,
// i.e. contained within a limited portion of the screen
embedded: {{ embedded }},
// Flags if we should show a help overlay when the question-mark
// key is pressed
help: {{ help }},
// Flags if it should be possible to pause the presentation (blackout)
pause: {{ pause }},
// Flags if speaker notes should be visible to all viewers
showNotes: {{ show_notes }},
// Global override for autolaying embedded media (video/audio/iframe)
// - null: Media will only autoplay if data-autoplay is present
// - true: All media will autoplay, regardless of individual setting
// - false: No media will autoplay, regardless of individual setting
autoPlayMedia: {{ auto_play_media }},
// Global override for preloading lazy-loaded iframes
// - null: Iframes with data-src AND data-preload will be loaded when within
// the viewDistance, iframes with only data-src will be loaded when visible
// - true: All iframes with data-src will be loaded when within the viewDistance
// - false: All iframes with data-src will be loaded only when visible
preloadIframes: {{ preload_iframes }},
// Can be used to globally disable auto-animation
autoAnimate: {{ auto_animate }},
// Optionally provide a custom element matcher that will be
// used to dictate which elements we can animate between.
autoAnimateMatcher: {{ auto_animate_matcher }},
// Default settings for our auto-animate transitions, can be
// overridden per-slide or per-element via data arguments
autoAnimateEasing: {{ auto_animate_easing }},
autoAnimateDuration: {{ auto_animate_duration }},
autoAnimateUnmatched: {{ auto_animate_unmatched }},
// CSS properties that can be auto-animated. Position & scale
// is matched separately so there's no need to include styles
// like top/right/bottom/left, width/height or margin.
autoAnimateStyles: {{ auto_animate_styles }},
// Controls automatic progression to the next slide
// - 0: Auto-sliding only happens if the data-autoslide HTML attribute
// is present on the current slide or fragment
// - 1+: All slides will progress automatically at the given interval
// - false: No auto-sliding, even if data-autoslide is present
autoSlide: {{ auto_slide }},
// Stop auto-sliding after user input
autoSlideStoppable: {{ auto_slide_stoppable }},
// Use this method for navigation when auto-sliding (defaults to navigateNext)
autoSlideMethod: {{ auto_slide_method }},
// Specify the average time in seconds that you think you will spend
// presenting each slide. This is used to show a pacing timer in the
// speaker view
defaultTiming: {{ default_timing }},
// Enable slide navigation via mouse wheel
mouseWheel: {{ mouse_wheel }},
// Opens links in an iframe preview overlay
// Add `data-preview-link` and `data-preview-link="false"` to customize each link
// individually
previewLinks: {{ preview_links }},
// Exposes the reveal.js API through window.postMessage
postMessage: {{ post_message }},
// Dispatches all reveal.js events to the parent window through postMessage
postMessageEvents: {{ post_message_events }},
// Focuses body when page changes visibility to ensure keyboard shortcuts work
focusBodyOnPageVisibilityChange: {{ focus_body_on_page_visibility_change }},
// Transition style
transition: {{ transition }}, // none/fade/slide/convex/concave/zoom
// Transition speed
transitionSpeed: {{ transition_speed }}, // default/fast/slow
// Transition style for full page slide backgrounds
backgroundTransition: {{ background_transition }}, // none/fade/slide/convex/concave/zoom
// The maximum number of pages a single slide can expand onto when printing
// to PDF, unlimited by default
pdfMaxPagesPerSlide: {{ pdf_max_pages_per_slide }},
// Prints each fragment on a separate slide
pdfSeparateFragments: {{ pdf_separate_fragments }},
// Offset used to reduce the height of content within exported PDF pages.
// This exists to account for environment differences based on how you
// print to PDF. CLI printing options, like phantomjs and wkpdf, can end
// on precisely the total height of the document whereas in-browser
// printing has to end one pixel before.
pdfPageHeightOffset: {{ pdf_page_height_offset }},
// Number of slides away from the current that are visible
viewDistance: {{ view_distance }},
// Number of slides away from the current that are visible on mobile
// devices. It is advisable to set this to a lower number than
// viewDistance in order to save resources.
mobileViewDistance: {{ mobile_view_distance }},
// The display mode that will be used to show slides
display: {{ display }},
// Hide cursor if inactive
hideInactiveCursor: {{ hide_inactive_cursor }},
// Time before the cursor is hidden (in ms)
hideCursorTime: {{ hide_cursor_time }}
});
{% if data_uri %}
// Fix found by @t-fritsch on GitHub
// see: https://github.com/hakimel/reveal.js/discussions/3362#discussioncomment-6651475.
function fixBase64VideoBackground(event) {
// event.previousSlide, event.currentSlide, event.indexh, event.indexv
if (event.currentSlide.getAttribute('data-background-video')) {
const background = Reveal.getSlideBackground(event.indexh, event.indexv),
video = background.querySelector('video'),
sources = video.querySelectorAll('source');
sources.forEach((source, i) => {
const src = source.getAttribute('src');
if(src.match(/^data:video.*;base64$/)) {
const nextSrc = sources[i+1]?.getAttribute('src');
video.setAttribute('src', `${src},${nextSrc}`);
}
});
}
}
Reveal.on( 'ready', fixBase64VideoBackground );
Reveal.on( 'slidechanged', fixBase64VideoBackground );
{% endif %}
</script>
<!-- Add a clock to each section dynamically using JavaScript -->
<script>
document.addEventListener('DOMContentLoaded', function () {
var revealContainer = document.querySelector('.reveal');
// Append dynamic content to each section
var sections = revealContainer.querySelectorAll('.slides > section');
sections.forEach(function (section) {
// Create a new clock container
var clockContainer = document.createElement('div');
clockContainer.className = 'clock';
// Append the new clock container to the section
section.appendChild(clockContainer);
});
// Function to update the clock content
function updateClock() {
var now = new Date();
var hours = now.getHours();
var minutes = now.getMinutes();
var seconds = now.getSeconds();
// Format the time as HH:MM:SS
var timeString = pad(hours) + ":" + pad(minutes) + ":" + pad(seconds);
// Update the content of all clock containers
var clockContainers = document.querySelectorAll('.clock');
clockContainers.forEach(function (container) {
container.innerText = timeString;
});
}
// Function to pad zero for single-digit numbers
function pad(number) {
return String(number).padStart(2, "0");
}
// Update the clock every second
setInterval(updateClock, 1000);
// Register a reveal.js event to update the clock on each slide change
Reveal.addEventListener('slidechanged', function (event) {
updateClock();
});
// Initial update
updateClock();
});
</script>
<!-- define the style of the clock -->
<style>
.clock {
position: fixed;
bottom: 10px;
left: 10px;
font-size: 24px;
font-family: "Arial", sans-serif;
color: #333;
}
/* control the relative position of the clock to the slides */
.reveal .slides > section.present, .reveal .slides > section > section.present {
min-height: 100% !important;
display: flex !important;
flex-direction: column !important;
justify-content: center !important;
position: absolute !important;
top: 0 !important;
}
section > h1 {
position: absolute !important;
top: 0 !important;
margin-left: auto !important;
margin-right: auto !important;
left: 0 !important;
right: 0 !important;
}
.print-pdf .reveal .slides > section.present, .print-pdf .reveal .slides > section > section.present {
min-height: 770px !important;
position: relative !important;
}
</style>
</body>
</html>