2.8 KiB
Racket Wiki CMap component
This directory contains the complete browser-side CMap component.
cmap.js is the drawing and hit-testing engine. It is based on the
MIT-licensed ionstage/cmap 0.1.3 source and is now maintained as part of
racket-wiki. Its public additions include onSelection on a map and
onActivation and onRendered callbacks. Activation is recognized inside the
same hit-test and drag lifecycle as selection, so it does not depend on a DOM
dblclick event that may be suppressed by dragging.
cmap-racket-wiki.js contains the wiki-specific editor model, selection state,
content-based initial sizing, resize and relation controls, page concepts and
submap concepts. Automatic sizing remains active while text is edited and is
disabled when the user resizes a concept manually.
Selected concepts expose an edit handle. The host opens a modal editor for
their independent display label, synopsis, background colour, typography and
optional image. Page concepts retain their linked pageSlug; double-click is
reserved for opening that wiki page. Concepts may alternatively retain a
cmapSlug for another stored CMap or a parentCmapLink for navigation back
from a child map. Images are data URLs inside the persisted CMap JSON document.
Font families are selected from a practical list and font sizes are stored in
typographic points. The host can change the linked page or CMap independently
of the visible label and provides background and text-colour pickers.
Linking phrases are compact borderless nodes at the intentional bend between two connector segments. Their position is stored with the rest of the map. When an endpoint is deleted, a genuinely branching phrase is retained while it still has at least one incoming and one outgoing concept. Losing the final endpoint on either side removes the phrase and all its remaining segments.
Multiple selected items can be moved or deleted together. Grouping is a structural operation: the editor creates an expanded sub-CMap with a named main concept and adopts the selection as its contents. Ungrouping dissolves a selected inline sub-CMap or moves selected child items one level outward.
toDocument and loadDocument round-trip the complete editor model: items,
formatting, positions, connectors, recursive submap membership and promoted
map references. The wiki host persists this JSON document through its CMap API.
The editor keeps up to one hundred complete document states for Undo and Redo.
One drag or resize gesture forms one history step. The public undo, redo,
canUndo, canRedo and resetHistory methods are also used by the wiki host
for keyboard shortcuts and context-menu state.
cmap.css contains all CMap presentation and interaction styles.
The source files deliberately remain separate but form one component and are
loaded directly from /cmap/; there is no runtime download or vendor patch.