ddd

client/input/interaction-state.js

@@ -0,0 +1,52 @@
+(function(root,factory){
+  const api=factory();
+  if(typeof module==='object'&&module.exports)module.exports=api;
+  root.BendInteractionState=api;
+})(typeof globalThis!=='undefined'?globalThis:this,function(){
+  'use strict';
+
+  const DEFAULT_SCOPES=Object.freeze({
+    any:Object.freeze(['camera','drawing','claim','wheel','reaction','minimap','dialog']),
+    pointer:Object.freeze(['camera','drawing','claim','reaction','minimap']),
+    camera:Object.freeze(['camera','wheel']),
+    persistence:Object.freeze(['camera','drawing','claim','wheel','reaction','minimap']),
+    world:Object.freeze(['camera','drawing','claim','wheel','reaction','minimap']),
+    overview:Object.freeze(['camera','drawing','claim','wheel','reaction','minimap']),
+    worker:Object.freeze(['drawing','claim'])
+  });
+
+  function createInteractionState(scopeDefinitions=DEFAULT_SCOPES){
+    const owners=new Map(),listeners=new Set(),scopes=new Map(
+      Object.entries(scopeDefinitions).map(([name,kinds])=>[name,new Set(kinds)])
+    );
+    let revision=0;
+    const snapshot=()=>Object.freeze({
+      revision,
+      activeKinds:Object.freeze([...owners.keys()]),
+      owners:Object.freeze(Object.fromEntries(owners))
+    });
+    const notify=()=>{const state=snapshot();for(const listener of listeners)listener(state)};
+    const set=(kind,owner)=>{
+      const key=String(kind||'');if(!key)throw new TypeError('Interaction kind is required');
+      const next=owner==null||owner===false?null:String(owner),previous=owners.get(key)||null;
+      if(previous===next)return false;
+      if(next==null)owners.delete(key);else owners.set(key,next);
+      revision++;notify();return true;
+    };
+    const active=(scope='any')=>{
+      const kinds=scopes.get(scope);if(!kinds)throw new TypeError(`Unknown interaction scope: ${scope}`);
+      for(const kind of kinds)if(owners.has(kind))return true;
+      return false;
+    };
+    return Object.freeze({
+      set,
+      clear:kind=>set(kind,null),
+      owner:kind=>owners.get(String(kind||''))||null,
+      active,
+      snapshot,
+      subscribe(listener){if(typeof listener!=='function')throw new TypeError('Listener must be a function');listeners.add(listener);return()=>listeners.delete(listener)}
+    });
+  }
+
+  return Object.freeze({DEFAULT_SCOPES,createInteractionState});
+});