Research how complex it is to mark changed lines (since last save, last - 1 save, - 2, etc.) using color on the gutter, as done by some text editors. For example, lines changed since last save (i.e. unsaved lines) are yellow, lines changed before last save but after last-but-one save are green, etc. These colors will be taken from INI, not customizable via Syntax Schema.
Indication is done by drawing border on the right edge of the gutter (for main line and wrapped sublines). Unmarked lines have standard gray border (matching bottom border of the main menu or toolbar, or top border of the statusbar).
Example from WinMerge (but it draws marks too close to text):
Research how complex it is to mark changed lines (since last save, last - 1 save, - 2, etc.) using color on the gutter, as done by some text editors. For example, lines changed since last save (i.e. unsaved lines) are yellow, lines changed before last save but after last-but-one save are green, etc. These colors will be taken from INI, not customizable via Syntax Schema.
Indication is done by drawing border on the right edge of the gutter (for main line and wrapped sublines). Unmarked lines have standard gray border (matching bottom border of the main menu or toolbar, or top border of the statusbar).
Example from WinMerge (but it draws marks too close to text):