Module drawing 

The closed drawing command set a Canvas node carries.

The Renderer is compiled ahead of time, so drawing code cannot cross the boundary. A fixed vocabulary of commands does instead. Every command is the same 36 bytes, which is what lets a reader skip a command it does not know and what keeps the list free of pointers: a path with many points is registered once as an asset and referenced by id.

Colour is a Paint, never a raw colour, so a canvas can draw in a ColorRole and the design system still decides what that role looks like.

Structs

DrawCommandSchema

DrawFieldSchema

DrawList

An encoded drawing command list, ready to go on the wire as one property value.

DrawListBuilder

Builds a command list. Each call appends one fixed-size record; TextAt also appends its bytes to the text region, which is written after every record.

Enums

DrawCommand

One drawing command. Coordinates are dp from the widget’s top-left corner.

DrawFieldType

How one of the six words of a command is read back.

Constants

COMMAND_LEN

Bytes of one command record: tag, length, paint, then six 32-bit words.

DRAW_COMMAND_SCHEMA

Every command in wire order. Appending is the only allowed edit.

TAG_ARC

TAG_CIRCLE

TAG_LINE

TAG_POLYLINE_REF

TAG_RECT

TAG_ROUND_RECT

TAG_TEXT_AT

Functions

decode_commands

Decodes a command list: n fixed-size records followed by the TextAt strings.