Flutter Quill - Document Model
Documents are represented as a tree of nodes. There are 3 main types of nodes:
Leaf - a leaf node which represents a segment of styled text within a document. There are two kinds of leaf nodes - text and embeds.
Line - represents an individual line of text within a document. Line nodes are containers for leaf nodes.
Block - represents a group of adjacent lines which share the same style. Examples of blocks include lists, quotes or code blocks.