Add getDrawSelectionConfig

FEATURE: The new `getDrawSelectionConfig` function returns the `drawSelection`
configuration for a given state.

See https://discuss.codemirror.net/t/how-to-get-cursor-blinking-rate-in-another-extension/7077

src/README.md

@@ -37,6 +37,8 @@ component that displays the editor state and allows text input.
 
 @drawSelection
 
+@getDrawSelectionConfig
+
 @dropCursor
 
 @highlightActiveLine

src/draw-selection.ts

@@ -53,6 +53,13 @@ export function drawSelection(config: SelectionConfig = {}): Extension {
   ]
 }
 
+/// Retrieve the [`drawSelection`](#view.drawSelection) configuration
+/// for this state. (Note that this will return a set of defaults even
+/// if `drawSelection` isn't enabled.)
+export function getDrawSelectionConfig(state: EditorState): SelectionConfig {
+  return state.facet(selectionConfig)
+}
+
 function configChanged(update: ViewUpdate) {
   return update.startState.facet(selectionConfig) != update.state.facet(selectionConfig)
 }

src/index.ts

@@ -5,7 +5,7 @@ export {BlockInfo} from "./heightmap"
 export {MouseSelectionStyle} from "./input"
 export {BidiSpan, Direction} from "./bidi"
 export {KeyBinding, keymap, runScopeHandlers} from "./keymap"
-export {drawSelection} from "./draw-selection"
+export {drawSelection, getDrawSelectionConfig} from "./draw-selection"
 export {dropCursor} from "./dropcursor"
 export {highlightSpecialChars} from "./special-chars"
 export {scrollPastEnd} from "./scrollpastend"