🎸 feat |Token|Use Foundry undo system to track move history

Store token move history to flag on the token.
Now when the token move is undone, the flag is automatically changed back.

scripts/Token.js

@@ -1,11 +1,13 @@
 /* globals
 canvas,
 CanvasAnimation,
+foundry,
 game,
 Ruler
 */
 /* eslint no-unused-vars: ["error", { "argsIgnorePattern": "^_" }] */
 
+import { MODULE_ID, FLAGS } from "./const.js";
 import { Settings } from "./settings.js";
 import { log } from "./util.js";
 
@@ -18,33 +20,44 @@ PATCHES.PATHFINDING = {};
 // ----- NOTE: Hooks ----- //
 
 /**
- * Hook updateToken to track token movement.
- * @param {Document} document                       The existing Document which was updated
- * @param {object} change                           Differential data that was used to update the document
- * @param {DocumentModificationContext} options     Additional options which modified the update request
- * @param {string} userId                           The ID of the User who triggered the update workflow
+ * Hook preUpdateToken to track token movement
+ * @param {Document} document                       The Document instance being updated
+ * @param {object} changed                          Differential data that will be used to update the document
+ * @param {Partial<DatabaseUpdateOperation>} options Additional options which modify the update request
+ * @param {string} userId                           The ID of the requesting user, always game.user.id
+ * @returns {boolean|void}                          Explicitly return false to prevent update of this Document
  */
-function updateToken(document, changes, _options, _userId) {
+function preUpdateToken(document, changes, _options, _userId) {
   const token = document.object;
   if ( token.isPreview
-    || !(Object.hasOwn(changes, "x")|| Object.hasOwn(changes, "y") || Object.hasOwn(changes, "elevation")) ) return;
+    || !(Object.hasOwn(changes, "x") || Object.hasOwn(changes, "y") || Object.hasOwn(changes, "elevation")) ) return;
 
+  // Don't update move data if the move flag is being updated (likely due to control-z undo).
+  if ( foundry.utils.hasProperty(changes, `flags.${MODULE_ID}.${FLAGS.MOVEMENT_HISTORY}`) ) return;
+
+  // Store the move data in a token flag so it survives reloads and can be updated on control-z undo by another user.
+  // First determine the current move data.
+  let lastMoveDistance = 0;
+  let combatMoveData = {};
   const ruler = canvas.controls.ruler;
-  if ( ruler.active && ruler.token === token ) token._lastMoveDistance = ruler.totalMoveDistance;
-  else token._lastMoveDistance = Ruler.measureMoveDistance(token.position, token.document._source, { token }).moveDistance;
+  if ( ruler.active && ruler.token === token ) lastMoveDistance = ruler.totalMoveDistance;
+  else lastMoveDistance = Ruler.measureMoveDistance(token.position, token.document._source, { token }).moveDistance;
   if ( game.combat?.started ) {
     // Store the combat move distance and the last round for which the combat move occurred.
     // Map to each unique combat.
-    const combatId = game.combat.id;
-    token._combatMoveData ??= new Map();
-    if ( !token._combatMoveData.has(combatId) ) {
-      token._combatMoveData.set(combatId, { lastMoveDistance: 0, lastRound: -1 });
-    }
-    const combatData = token._combatMoveData.get(combatId);
-    if ( combatData.lastRound < game.combat.round ) combatData.lastMoveDistance = token._lastMoveDistance;
-    else combatData.lastMoveDistance += token._lastMoveDistance;
+    const combatData = {...token._combatMoveData};
+    if ( combatData.lastRound < game.combat.round ) combatData.lastMoveDistance = lastMoveDistance;
+    else combatData.lastMoveDistance += lastMoveDistance;
     combatData.lastRound = game.combat.round;
+    combatMoveData = { [game.combat.id]: combatData };
   }
+
+  // Combine with existing move data in the token flag.
+  const flagData = document.getFlag(MODULE_ID, FLAGS.MOVEMENT_HISTORY) ?? {};
+  foundry.utils.mergeObject(flagData, { lastMoveDistance, combatMoveData });
+
+  // Update the flag with the new data.
+  foundry.utils.setProperty(changes, `flags.${MODULE_ID}.${FLAGS.MOVEMENT_HISTORY}`, flagData);
 }
 
 // ----- NOTE: Wraps ----- //
@@ -139,16 +152,31 @@ async function _onDragLeftDrop(wrapped, event) {
  * Token.prototype.lastMoveDistance
  * Return the last move distance. If combat is active, return the last move since this token
  * started its turn.
- * @returns {number}
+ * @type {number}
  */
 function lastMoveDistance() {
   if ( game.combat?.started ) {
-    if ( !this._combatMoveData ) return 0;
-    const combatData = this._combatMoveData.get(game.combat.id);
-    if ( !combatData || combatData.lastRound < game.combat.round ) return 0;
+    const combatData = this._combatMoveData;
+    if ( combatData.lastRound < game.combat.round ) return 0;
     return combatData.lastMoveDistance;
   }
-  return this._lastMoveDistance || 0;
+  return this.document.getFlag(MODULE_ID, FLAGS.MOVEMENT_HISTORY)?.lastMoveDistance || 0;
+}
+
+/**
+ * Token.prototype._combatData
+ * Map that stores the combat move data.
+ * Constructed from the relevant flag.
+ * @type {object}
+ * - @prop {number} lastMoveDistance    Distance of last move during combat round
+ * - @prop {number} lastRound           The combat round in which the last move occurred
+ */
+function _combatMoveData() {
+  const combatId = game.combat?.id;
+  const defaultData = { lastMoveDistance: 0, lastRound: -1 };
+  if ( typeof combatId === "undefined" ) return defaultData;
+  const combatMoveData = this.document.getFlag(MODULE_ID, FLAGS.MOVEMENT_HISTORY)?.combatMoveData ?? { };
+  return combatMoveData[combatId] ?? defaultData;
 }
 
 // ----- NOTE: Patches ----- //
@@ -162,8 +190,8 @@ PATCHES.PATHFINDING.WRAPS = { _onUpdate };
 
 PATCHES.TOKEN_RULER.MIXES = { _onDragLeftDrop, _onDragLeftCancel };
 
-PATCHES.MOVEMENT_TRACKING.HOOKS = { updateToken };
-PATCHES.MOVEMENT_TRACKING.GETTERS = { lastMoveDistance };
+PATCHES.MOVEMENT_TRACKING.HOOKS = { preUpdateToken };
+PATCHES.MOVEMENT_TRACKING.GETTERS = { lastMoveDistance, _combatMoveData };
 
 // ----- NOTE: Helper functions ----- //
 

scripts/const.js

@@ -17,7 +17,8 @@ export const FLAGS = {
   MOVEMENT_PENALTY: "movementPenalty",
   SCENE: {
     BACKGROUND_ELEVATION: "backgroundElevation"
-  }
+  },
+  MOVEMENT_HISTORY: "movementHistory"
 };
 
 export const MODULES_ACTIVE = { API: {} };

scripts/patching.js

@@ -18,7 +18,6 @@ import { PATCHES as PATCHES_TokenPF } from "./pathfinding/Token.js";
 
 // Movement tracking
 import { PATCHES as PATCHES_TokenHUD } from "./token_hud.js";
-import { PATCHES as PATCHES_TokenLayer } from "./TokenLayer.js";
 
 // Settings
 import { PATCHES as PATCHES_ClientSettings } from "./ModuleSettingsAbstract.js";
@@ -32,7 +31,6 @@ const PATCHES = {
   DrawingConfig: PATCHES_DrawingConfig,
   Ruler: PATCHES_Ruler,
   Token: mergeObject(mergeObject(PATCHES_Token, PATCHES_TokenPF), PATCHES_TokenHUD),
-  TokenLayer: PATCHES_TokenLayer,
   Wall: PATCHES_Wall
 };