Import the wohle measure function instead of patching it (preparation for future changes)

src/foundry_imports.js

@@ -95,3 +95,72 @@ export function onMouseMove(event) {
 		this._state = Ruler.STATES.MEASURING;
 	}
 }
+
+// This is a modified version of Ruler.measure form foundry 0.7.9
+export function measure(destination, {gridSpaces=true} = {}) {
+	if (this.isDragRuler && !this.draggedToken.isVisible)
+		return []
+	destination = new PIXI.Point(...canvas.grid.getCenter(destination.x, destination.y));
+	const waypoints = this.waypoints.concat([destination]);
+	const r = this.ruler;
+	this.destination = destination;
+
+	// Iterate over waypoints and construct segment rays
+	const segments = [];
+	for (let [i, dest] of waypoints.slice(1).entries()) {
+		const origin = waypoints[i];
+		const label = this.labels.children[i];
+		const ray = new Ray(origin, dest);
+		if (ray.distance < 10) {
+			if (label) label.visible = false;
+			continue;
+		}
+		segments.push({ ray, label });
+	}
+
+	// Compute measured distance
+	const distances = canvas.grid.measureDistances(segments, { gridSpaces });
+	let totalDistance = 0;
+	for (let [i, d] of distances.entries()) {
+		let s = segments[i];
+		s.startDistance = totalDistance
+		totalDistance += d;
+		s.last = i === (segments.length - 1);
+		s.distance = d;
+		s.text = this._getSegmentLabel(d, totalDistance, s.last);
+	}
+
+	// Clear the grid highlight layer
+	const hlt = canvas.grid.highlightLayers[this.name] || canvas.grid.addHighlightLayer(this.name);
+	hlt.clear();
+
+	// Draw measured path
+	r.clear();
+	for (let s of segments) {
+		const { ray, label, text, last } = s;
+
+		// Draw line segment
+		r.lineStyle(6, 0x000000, 0.5).moveTo(ray.A.x, ray.A.y).lineTo(ray.B.x, ray.B.y)
+			.lineStyle(4, this.color, 0.25).moveTo(ray.A.x, ray.A.y).lineTo(ray.B.x, ray.B.y);
+
+		// Draw the distance label just after the endpoint of the segment
+		if (label) {
+			label.text = text;
+			label.alpha = last ? 1.0 : 0.5;
+			label.visible = true;
+			let labelPosition = ray.project((ray.distance + 50) / ray.distance);
+			label.position.set(labelPosition.x, labelPosition.y);
+		}
+
+		// Highlight grid positions
+		this._highlightMeasurement(ray, s.startDistance);
+	}
+
+	// Draw endpoints
+	for (let p of waypoints) {
+		r.lineStyle(2, 0x000000, 0.5).beginFill(this.color, 0.25).drawCircle(p.x, p.y, 8);
+	}
+
+	// Return the measured segments
+	return segments;
+}

src/main.js

@@ -1,14 +1,13 @@
 "use strict"
 
 import {availableSpeedProviders, currentSpeedProvider, registerModule, registerSystem, setCurrentSpeedProvider} from "./api.js"
-import {moveTokens, onMouseMove} from "./foundry_imports.js"
+import {measure, moveTokens, onMouseMove} from "./foundry_imports.js"
 import {registerSettings, settingsKey} from "./settings.js"
 
 Hooks.once("init", () => {
 	registerSettings()
 	hookTokenDragHandlers()
 	hookRulerFunctions()
-	patchRulerMeasure()
 	patchRulerHighlightMeasurement()
 
 	availableSpeedProviders["native"] = nativeSpeedProvider
@@ -89,6 +88,16 @@ function hookRulerFunctions() {
 		}
 		originalUpdate.call(this, data)
 	}
+
+	const originalMeasure = Ruler.prototype.measure
+	Ruler.prototype.measure = function (destination, options={}) {
+		if (this.isDragRuler) {
+			return measure.call(this, destination, options)
+		}
+		else {
+			return originalMeasure.call(this, destination, options)
+		}
+	}
 }
 
 function onTokenLeftDragStart(event) {
@@ -144,22 +153,6 @@ function strInsertAfter(haystack, needle, strToInsert) {
 	return haystack.slice(0, pos) + strToInsert + haystack.slice(pos)
 }
 
-// These patches were written with foundry-0.7.9.js as reference
-function patchRulerMeasure() {
-	let code = Ruler.prototype.measure.toString()
-	// Replace CRLF with LF in case foundry.js has CRLF for some reason
-	code = code.replace(/\r\n/g, "\n")
-	// Remove function signature and closing curly bracket (those are on the first and last line)
-	code = code.slice(code.indexOf("\n"), code.lastIndexOf("\n"))
-	code = strInsertAfter(code, "for ( let [i, d] of distances.entries() ) {\n", "segments[i].startDistance = totalDistance\n")
-	code = strInsertAfter(code, "this._highlightMeasurement(ray", ", s.startDistance")
-
-	// Don't show ruler if the measured token is invisible
-	code = "if (this.isDragRuler && !this.draggedToken.isVisible) return [];" + code
-
-	Ruler.prototype.measure = new Function("destination", "{gridSpaces=true}={}", code)
-}
-
 function nativeSpeedProvider(token, playercolor) {
 	const speedAttribute = game.settings.get(settingsKey, "speedAttribute")
 	if (!speedAttribute)