Doubtful
Try: Overlapping textboxes
- top one has the highlighted colour
- fixed width font same in both so spaces and chars align
- option: bold in the "edit char text box", but that may cause spaces to be wider and mess up spacing
Try: single char edit box, with origin moved to position it over the "edit char"
- easier with fixed width font in main text box (theoretically could support variable width font if you make a table of "char widths" to calculate origin)
- Bonus: Can use bold and colour for edit char as don't depend on width of spaces
- Bonus: Can also use reverse font (black on grey instead of white on black), can even alternate the reverse normal font for blinking edit char effect.
- Bonus: Text box doesn't need to be transparent since doesn't rely on transparent spaces to show text behind
Try: Overlapping rectangle that hovers over "edit character", no change to text box, just highlights or blinks on the selected edit char
- easier if fixed width font
Paul