# MEP29: Text light markup¶

Discussion

## Branches and Pull requests¶

None at the moment, proof of concept only.

## Abstract¶

This MEP proposes to add lightweight markup to the text artist.

## Detailed description¶

Using different size/color/family in a text annotation is difficult because the text method accepts argument for size/color/family/weight/etc. that are used for the whole text. But, if one wants, for example, to have different colors, one has to look at the gallery where one such example is provided: http://matplotlib.org/examples/text_labels_and_annotations/rainbow_text.html

This example takes a list of strings as well as a list of colors which makes it cumbersome to use. An alternative would be to use a restricted set of pango-like markup and to interpret this markup.

Some markup examples:

Hello <b>world!</b>`
Hello <span color="blue">world!</span>

## Implementation¶

A proof of concept is provided in markup_example.py but it currently only handles the horizontal direction.

### Improvements¶

• This proof of concept uses regex to parse the text but it may be better to use the html.parser from the standard library.
• Computation of text fragment positions could benefit from the OffsetFrom class. See for example item 5 in Using Complex Coordinates with Annotations

### Problems¶

• One serious problem is how to deal with text having both latex and html-like tags. For example, consider the following:

$<b>Bold$</b>

Recommendation would be to have mutual exclusion.

## Backward compatibility¶

None at the moment since it is only a proof of concept

## Alternatives¶

As proposed by @anntzer, this could be also implemented as improvements to mathtext. For example:

r"$\text{Hello \textbf{world}}$"
r"$\text{Hello \textcolor{blue}{world}}$"
r"$\text{Hello \textsf{\small world}}$"