If a terrain module is installed, suggest installing Terrain Ruler to the user

lang/de.json

@@ -2,6 +2,11 @@
 	"drag-ruler": {
 		"dependencies": {
 			"ok": "OK",
+			"terrain-ruler": {
+				"title": "Wie man schwieriges Gelände mit Drag Ruler misst",
+				"text": "Du hast das {moduleName} Modul installiert. Drag Ruler kann schwieriges Gelände, das mit diesem Modul platziert wurde in seinen Messungen berücksichtigen. Hierzu greift Drag Ruler auf die Funktionalität von Terrain Ruler zurück. Wenn Terrain Ruler installiert und aktiviert ist wird Drag Ruler automatisch anfangen schwiriges Gelände in den Messungen zu berücksichtigen.",
+				"neverShowAgain": "Zeige dies nie wieder an"
+			},
 			"socketlib": {
 				"title": "Socketlib Modul fehlt",
 				"text": "Drag Ruler benötigt das socketlib-Modul, um korrekt zu funktionieren. Bitte aktiviere das socketlib-Modul in dieser Welt."

lang/en.json

@@ -2,6 +2,11 @@
 	"drag-ruler": {
 		"dependencies": {
 			"ok": "OK",
+			"terrain-ruler": {
+				"title": "How to measure difficult terrain with Drag Ruler",
+				"text": "You have the {moduleName} module enabled. Drag Ruler is able to measure difficult terrain that was placed down using that module. To make this possible Drag Ruler utilizes the Terrain Ruler module. If Terrain Ruler is installed and activated Drag Ruler will automatically start to respect difficult terrain in it's measurements.",
+				"neverShowAgain": "Never show this again"
+			},
 			"socketlib": {
 				"title": "Socketlib Module Missing",
 				"text": "Drag Ruler requires the socketlib module to work properly. Please activate the socketlib module in this world."

src/compatibility.js

@@ -1,5 +1,6 @@
 import {getCostFromSpeedProvider} from "./api.js";
 import {getColorForDistance} from "./main.js"
+import {settingsKey} from "./settings.js";
 import {getAreaFromPositionAndShape, highlightTokenShape} from "./util.js";
 
 export function getHexSizeSupportTokenGridCenter(token) {
@@ -50,4 +51,34 @@ export function checkDependencies() {
 			}).render(true);
 		}
 	}
+	else if (!game.modules.get("terrain-ruler")?.active && game.user.isGM && !game.settings.get(settingsKey, "neverShowTerrainRulerHint")) {
+		const lastHint = game.settings.get(settingsKey, "lastTerrainRulerHintTime");
+		if (Date.now() - lastHint > 604800000) { // One week
+			let enabledTerrainModule;
+			if (game.modules.get("enhanced-terrain-layer")?.active) {
+				enabledTerrainModule = game.modules.get("enhanced-terrain-layer").data.title;
 			}
+			else if (game.modules.get("TerrainLayer")?.active) {
+				enabledTerrainModule = game.modules.get("TerrainLayer").data.title;
+			}
+			new Dialog({
+				title: game.i18n.localize("drag-ruler.dependencies.terrain-ruler.title"),
+				content: `<h2>${game.i18n.localize("drag-ruler.dependencies.terrain-ruler.title")}</h2><p>${game.i18n.format("drag-ruler.dependencies.terrain-ruler.text", {moduleName: enabledTerrainModule})}</p>`,
+				buttons: {
+					ok: {
+						icon: '<i class="fas fa-check"></i>',
+						label: game.i18n.localize("drag-ruler.dependencies.ok"),
+						callback: () => game.settings.set(settingsKey, "lastTerrainRulerHintTime", Date.now()),
+					},
+					neverShowAgain: {
+						icon: '<i class="fas fa-times"></i>',
+						label: game.i18n.localize("drag-ruler.dependencies.terrain-ruler.neverShowAgain"),
+						callback: () => game.settings.set(settingsKey, "neverShowTerrainRulerHint", true),
+					}
+				},
+				close: () => game.settings.set(settingsKey, "lastTerrainRulerHintTime", Date.now())
+			}).render(true);
+		}
+	}
+}
+

src/settings.js

@@ -47,6 +47,18 @@ export function registerSettings() {
 		default: true,
 	});
 
+	game.settings.register(settingsKey, "lastTerrainRulerHintTime", {
+		config: false,
+		type: Number,
+		default: 0,
+	});
+
+	game.settings.register(settingsKey, "neverShowTerrainRulerHint", {
+		config: false,
+		type: Boolean,
+		default: false,
+	});
+
 	// This setting will be modified by the api if modules register to it
 	game.settings.register(settingsKey, "speedProvider", {
 		scope: "world",