Squiggles

Squiggles are used to underline miss-spelled words. Instead of simply erasing all squiggles and rechecking all words in a block when the block is changed, the squiggles are handled much like the words they underline.

The word currently being edited is the pending word. When the cursor does not touch the pending word anymore (due to being moved away or the user typing a word separator), the word is spell-checked. If it is miss-spelled, it will be squiggled.

When text is added to the block, fl_Squiggles::textInserted is called with information of where in the block the text was added, and how much. It will then remove any squiggle located at that offset, move all following squiggles (so they end up aligned with the words they should underline) and spell-checks words in the added text (via fl_BlockLayout::_recalcPendingWord).

When text is deleted from the block, fl_Squiggles::textDeleted is called with information of where in the block text was deleted, and how much. It removes squiggles intersecting with that area, moves all following squiggles and makes pending the word at the deletion point since two words may have been joined, or a word lost part of its letters.

When a block is split in two, fl_Squiggles::split is called with information of where the block was split, and a pointer to the new block. The squiggles from the old block are split between it and the new block. The word at the end of the old block (which may have been broken), is spell-checked, and the first word of the new block is made the pending word.

When two blocks are merged into one, fl_Squiggles::join is called with information of the offset where squiggles from the second block should be joined onto the first block. The word at the merge point is made the pending word.

There's one known buglet: typing "gref' " correctly squiggles the word when typing ' since it's a word separator. However, deleting the s in "gref's" leaves gref unsquiggled because the word gref was not pending when the ' changed from a word character to a word delimiter. (hard to explain - just try it)