| ========================= |
| MEP29: Text light markup |
| ========================= |
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| .. contents:: |
| :local: |
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| Status |
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| Discussion |
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| Branches and Pull requests |
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| None at the moment, proof of concept only. |
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| Abstract |
| ======== |
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| This MEP proposes to add lightweight markup to the text artist. |
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| Detailed description |
| ==================== |
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| Using different size/color/family in a text annotation is difficult because the |
| `~.Axes.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: |
| :doc:`/gallery/text_labels_and_annotations/rainbow_text` |
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| 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. |
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| .. _pango: https://docs.gtk.org/Pango/pango_markup.html#pango-markup |
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| Some markup examples:: |
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| Hello <b>world!</b>` |
| Hello <span color="blue">world!</span> |
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| Implementation |
| ============== |
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| A proof of concept is provided in `markup_example.py <https://github.com/rougier/matplotlib/blob/markup/examples/text_labels_and_annotations/markup.py>`_ but it currently only handles the horizontal direction. |
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| Improvements |
| ------------ |
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| * This proof of concept uses regex to parse the text but it may be better |
| to use the html.parser from the standard library. |
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| * Computation of text fragment positions could benefit from the OffsetFrom |
| class. See for example item 5 in `Using Complex Coordinates with Annotations <https://matplotlib.org/devdocs/users/explain/text/annotations.html#using-complex-coordinates-with-annotations>`_ |
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| Problems |
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| * One serious problem is how to deal with text having both LaTeX and |
| HTML-like tags. For example, consider the following:: |
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| $<b>Bold$</b> |
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| Recommendation would be to have mutual exclusion. |
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| Backward compatibility |
| ====================== |
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| None at the moment since it is only a proof of concept |
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| Alternatives |
| ============ |
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| As proposed by @anntzer, this could be also implemented as improvements to |
| mathtext. For example:: |
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| r"$\text{Hello \textbf{world}}$" |
| r"$\text{Hello \textcolor{blue}{world}}$" |
| r"$\text{Hello \textsf{\small world}}$" |
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