The following is the outcome of the investigation in T286564#7229226:
The undo panel is in the same place as the loading widget.
- Remove the current 'are you sure?' prompt;
- move loading widget to be //above// the edit box (below the 'Page body' label, if it's shown), so the text box is fully visible;
- after loading is complete and the text has been replaced, don't remove loading widget but instead change its text to '⎌ Undo transcription';
- on clicking 'undo', remove the text, have 100ms (or whatever) of blank, then insert the old text (to give a visual indication that something has changed, because the change might be quite small and/or off screen);
- then leave the undo panel open for a further 700ms or something (because we're not going to offer undoing the undo), and remove it.
- If 'undo' is not clicked, the widget stays open until the user types something in the text box, or clicks 'transcribe text' again.
This means that the text box will jump down a bit when the 'Transcribe text' button is clicked, so we'll add a 'slide down' to make it a bit less jarring. Only the top would move down, because the text box parent is already a flexbox.
Something like this:
| Loading: | Undo:
| {F34559466, size=full} | {F34559467, size=full}