Simplify custom Actions: universal Action predicates instead of

action-specific guards.

src/actions/guards.ts

@@ -1,25 +0,0 @@
-import { Action, ActionName, DisableFn, EnableFn } from "./types";
-
-const disablers = {} as Record<ActionName, DisableFn[]>;
-const enablers = {} as Record<Action["name"], EnableFn[]>;
-
-export const getActionDisablers = () => disablers;
-export const getActionEnablers = () => enablers;
-
-export const registerDisableFn = (name: ActionName, disabler: DisableFn) => {
-  if (!(name in disablers)) {
-    disablers[name] = [] as DisableFn[];
-  }
-  if (!disablers[name].includes(disabler)) {
-    disablers[name].push(disabler);
-  }
-};
-
-export const registerEnableFn = (name: Action["name"], enabler: EnableFn) => {
-  if (!(name in enablers)) {
-    enablers[name] = [] as EnableFn[];
-  }
-  if (!enablers[name].includes(enabler)) {
-    enablers[name].push(enabler);
-  }
-};

src/actions/manager.tsx

@@ -2,15 +2,12 @@ import React from "react";
 import {
   Action,
   UpdaterFn,
-  ActionName,
   ActionResult,
   PanelComponentProps,
   ActionSource,
-  DisableFn,
-  EnableFn,
+  ActionPredicateFn,
   isActionName,
 } from "./types";
-import { getActionDisablers, getActionEnablers } from "./guards";
 import { ExcalidrawElement } from "../element/types";
 import { AppClassProperties, AppState } from "../types";
 import { trackEvent } from "../analytics";
@@ -44,10 +41,8 @@ const trackAction = (
 };
 
 export class ActionManager {
-  actions = {} as Record<ActionName | Action["name"], Action>;
-
-  disablers = {} as Record<ActionName, DisableFn[]>;
-  enablers = {} as Record<Action["name"], EnableFn[]>;
+  actions = {} as Record<Action["name"], Action>;
+  actionPredicates = [] as ActionPredicateFn[];
 
   updater: (actionResult: ActionResult | Promise<ActionResult>) => void;
 
@@ -75,36 +70,9 @@ export class ActionManager {
     this.app = app;
   }
 
-  registerActionGuards() {
-    const disablers = getActionDisablers();
-    for (const d in disablers) {
-      const dName = d as ActionName;
-      disablers[dName].forEach((disabler) =>
-        this.registerDisableFn(dName, disabler),
-      );
-    }
-    const enablers = getActionEnablers();
-    for (const e in enablers) {
-      const eName = e as Action["name"];
-      enablers[e].forEach((enabler) => this.registerEnableFn(eName, enabler));
-    }
-  }
-
-  registerDisableFn(name: ActionName, disabler: DisableFn) {
-    if (!(name in this.disablers)) {
-      this.disablers[name] = [] as DisableFn[];
-    }
-    if (!this.disablers[name].includes(disabler)) {
-      this.disablers[name].push(disabler);
-    }
-  }
-
-  registerEnableFn(name: Action["name"], enabler: EnableFn) {
-    if (!(name in this.enablers)) {
-      this.enablers[name] = [] as EnableFn[];
-    }
-    if (!this.enablers[name].includes(enabler)) {
-      this.enablers[name].push(enabler);
+  registerActionPredicate(predicate: ActionPredicateFn) {
+    if (!this.actionPredicates.includes(predicate)) {
+      this.actionPredicates.push(predicate);
     }
   }
 
@@ -196,10 +164,7 @@ export class ActionManager {
   /**
    * @param data additional data sent to the PanelComponent
    */
-  renderAction = (
-    name: ActionName | Action["name"],
-    data?: PanelComponentProps["data"],
-  ) => {
+  renderAction = (name: Action["name"], data?: PanelComponentProps["data"]) => {
     const canvasActions = this.app.props.UIOptions.canvasActions;
 
     if (
@@ -243,7 +208,7 @@ export class ActionManager {
   };
 
   isActionEnabled = (
-    action: Action | ActionName,
+    action: Action,
     opts?: {
       elements?: readonly ExcalidrawElement[];
       data?: Record<string, any>;
@@ -254,29 +219,19 @@ export class ActionManager {
     const appState = this.getAppState();
     const data = opts?.data;
 
-    const _action = isActionName(action) ? this.actions[action] : action;
-
     if (
       !opts?.guardsOnly &&
-      _action.predicate &&
-      !_action.predicate(elements, appState, this.app.props, this.app, data)
+      action.predicate &&
+      !action.predicate(elements, appState, this.app.props, this.app, data)
     ) {
       return false;
     }
-
-    if (isActionName(_action.name)) {
-      return !(
-        _action.name in this.disablers &&
-        this.disablers[_action.name].some((fn) =>
-          fn(elements, appState, _action.name as ActionName),
-        )
-      );
-    }
-    return (
-      _action.name in this.enablers &&
-      this.enablers[_action.name].some((fn) =>
-        fn(elements, appState, _action.name),
-      )
-    );
+    let enabled = true;
+    this.actionPredicates.forEach((fn) => {
+      if (!fn(action, elements, appState, data)) {
+        enabled = false;
+      }
+    });
+    return enabled;
   };
 }

src/actions/register.ts

@@ -1,14 +1,8 @@
-import { Action, isActionName } from "./types";
+import { Action } from "./types";
 
-let actions: readonly Action[] = [];
-let customActions: readonly Action[] = [];
-export const getCustomActions = () => customActions;
-export const getActions = () => actions;
+export let actions: readonly Action[] = [];
 
 export const register = <T extends Action>(action: T) => {
-  if (!isActionName(action.name)) {
-    customActions = customActions.concat(action);
-  }
   actions = actions.concat(action);
   return action as T & {
     keyTest?: unknown extends T["keyTest"] ? never : T["keyTest"];

src/actions/types.ts

@@ -31,20 +31,13 @@ type ActionFn = (
   app: AppClassProperties,
 ) => ActionResult | Promise<ActionResult>;
 
-// Return `true` to indicate the standard Action with name `actionName`
-// should be disabled given `elements` and `appState`.
-export type DisableFn = (
+// Return `true` *unless* `Action` should be disabled
+// given `elements`, `appState`, and optionally `data`.
+export type ActionPredicateFn = (
+  action: Action,
   elements: readonly ExcalidrawElement[],
   appState: AppState,
-  actionName: ActionName,
-) => boolean;
-
-// Return `true` to indicate the custom Action with name `actionName`
-// should be enabled given `elements` and `appState`.
-export type EnableFn = (
-  elements: readonly ExcalidrawElement[],
-  appState: AppState,
-  actionName: Action["name"],
+  data?: Record<string, any>,
 ) => boolean;
 
 export type UpdaterFn = (res: ActionResult) => void;