termtosvg-template.md

termtosvg templates manual page

DESCRIPTION

templates are SVG files in which termtosvg embeds animations. Using templates makes it possible to:

• Have user defined terminal color themes and fonts
• Add a terminal UI or window frame to the animation
• Have interactive animations (for example play/pause buttons)

See here for a gallery of the templates included with termtosvg

TEMPLATE STRUCTURE

Here is the basic structure of a template:

<?xml version="1.0" encoding="utf-8"?>
<svg id="terminal" baseProfile="full" viewBox="0 0 656 325" width="656" version="1.1"
     xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
    <defs>
        <termtosvg:template_settings xmlns:termtosvg="https://github.com/nbedos/termtosvg">
            <termtosvg:screen_geometry columns="82" rows="19"/>
        </termtosvg:template_settings>
        <style type="text/css" id="generated-style">
            <!-- [snip!] -->
        </style>
        <style type="text/css" id="user-style">
            <!-- [snip!] -->
        </style>
    </defs>
    <svg id="screen" width="656" viewBox="0 0 656 323" preserveAspectRatio="xMidYMin meet">
        <!-- [snip!] -->
    </svg>
</svg>

Overall one can identify:

• An svg element with id "terminal"
• A defs element which includes:
  • A termtosvg specific template_settings element used to specify the terminal size (number of columns and rows) for which the template is made
  • A style element with id "generated-style" that will be overwritten by termtosvg
  • Another style element with id "user-style" that should contain at least the terminal color theme. This element is defined by the template creator and won't be overwritten by termtosvg
• An inner svg element with id "screen" which will contain the animation produced by termtosvg

TEMPLATE CUSTOMIZATION

The basic idea behind template customization is that termtosvg will preserve elements of the template that it does not modify. Hence it is possible to

• Customize the style of the animation by modifying the content of the style element with id "user-style"
• Add a new script element to embed JavaScript code in the animation
• Add other SVG elements, as long as they are not children of the svg element with id "screen"

I hope that the information provided here together with the code for the default templates is enough to get started with template customization, but feel free to open an issue if you need some help.

Custom color theme or font

Terminal color themes must be specified in the style element with id "user-style" and must define all the following classes: foreground, background, color0, color1, ..., color15. Font related attributes can also be specified together with the color theme. See below for an example.

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" id="terminal" baseProfile="full" viewBox="0 0 656 325" width="656" version="1.1">
    <defs>
        <termtosvg:template_settings xmlns:termtosvg="https://github.com/nbedos/termtosvg">
            <termtosvg:screen_geometry columns="82" rows="19"/>
        </termtosvg:template_settings>
        <style type="text/css" id="generated-style">
            /* ... Snip! ... */
        </style>
        <style type="text/css" id="user-style">
            .foreground {fill: #c5c5c5;}
            .background {fill: #1c1c1c;}
            .color0 {fill: #1c1c1c;}
            .color1 {fill: #ff005b;}
            /* ... Snip! ... */
            .color15 {fill: #e5e5e5;}

            font-family: Monaco, monospace;
        </style>
    </defs>
    <svg id="screen" width="656" viewBox="0 0 656 323" preserveAspectRatio="xMidYMin meet">
    </svg>
</svg>

Complete example here: gjm8.svg

Custom terminal UI

Complete example here: window_frame.svg

Embedding JavaScript

Just add your code in a new script element.

Complete example here: window_frame_js

termtosvg internal template usage

In order to produce the final animation, termtosvg will modify the template in a number of ways.

Template scaling

The first step is to scale the template to the right size based on the size of the terminal being recorded and the size of the template specified by the screen_geometry element. For this, termtosvg will update the viewBox, width and height attributes of the svg elements with ids "terminal" and "screen". The height and width attributes of these elements must use pixel units.

termtosvg will also update the columns and rows attributes of the screen_geometry to match the values of the current terminal session and keep things consistent.

Style update

Next, termtosvg will override the content of the style element with id "generated-style" with its own style sheet. This sheet exposes a CSS variable containing the duration of the animation in milliseconds, and specifies a few text related attributes. See example below.

<style type="text/css" id="generated-style"><![CDATA[
    :root {
        --animation-duration: 36544ms;
    }
    #screen {
        font-family: 'DejaVu Sans Mono', monospace;
        font-style: normal;
        font-size: 14px;
    }

    text {
        dominant-baseline: text-before-edge;
    }]]>
</style>

Animation update

Finally, termtosvg will overwrite the content of the element svg with id "screen" with the code produced by rendering the terminal session.

In the end, the animation produced by termtosvg has the same structure as the initial template which make it possible to use an animation as a template (provided the animation was created with termtosvg >= 0.5.0).