Pull Request resolves #48199 .

• I read the Generative AI policy and my contribution is either not created with the help of AI or is compatible with the policy and GNU/GPL 2 or later.

Summary of Changes

with the recent pr from @bembelimen connecting the media manager to the tinymce media button there is less need to display the ugly xtd-editor buttons. This adds a native tinymce plugin to add a readmore button to the toolbar.

Note It works the same as the existing xtd-editor with one exception. Instead of a warning that you already have a readmore in the article the button is disabled. To me that makes more sense

Important I have not added an update sql so that we don't touch an already configured toolbar. Users upgrading will either need to drag and drop the icon to their toolbar or reload a preset

Testing Instructions

This requires the js scripts to be rebuilt so either use a prebuilt update package OR checkout and then npm ci

Then go to the tinymce plugin and either drag the new icon to your existing toolbar OR click on use Advanced preset or medium prest or simple preset. This will replace your current toolbar with the preset

I have deliberately place the button near the beginning so that it will always be displayed without being hidden when the toolbar wraps

Simple Preset

Medium Preset

Advanced Preset

Actual result BEFORE applying this Pull Request

no readmore button on the toolbar

Expected result AFTER applying this Pull Request

new readmore button on the tolbar

Link to documentations

Please select:

• Documentation link for guide.joomla.org:

• No documentation changes for guide.joomla.org needed

• Pull Request link for manual.joomla.org:

• No documentation changes for manual.joomla.org needed