Organizing input actions in device folders

js/input/mouse/MouseWheel.js

@@ -0,0 +1,42 @@
+import Pointing from "./Pointing"
+
+export default class MouseWheel extends Pointing {
+
+    /**
+     * 
+     * @param {HTMLElement} target 
+     * @param {import("../../Blueprint").default} blueprint 
+     * @param {Object} options 
+     */
+    constructor(target, blueprint, options) {
+        options.wantsFocusCallback = true
+        super(target, blueprint, options)
+        this.looseTarget = options?.looseTarget ?? true
+        let self = this
+
+        this.mouseWheelHandler = e => {
+            e.preventDefault()
+            const location = self.getLocation(e)
+            self.wheel(Math.sign(e.deltaY), location)
+        }
+        this.mouseParentWheelHandler = e => e.preventDefault()
+
+        if (this.blueprint.focused) {
+            this.movementSpace.addEventListener("wheel", this.mouseWheelHandler, false)
+        }
+    }
+
+    blueprintFocused() {
+        this.movementSpace.addEventListener("wheel", this.mouseWheelHandler, false)
+        this.movementSpace.parentElement?.addEventListener("wheel", this.mouseParentWheelHandler)
+    }
+
+    blueprintUnfocused() {
+        this.movementSpace.removeEventListener("wheel", this.mouseWheelHandler, false)
+        this.movementSpace.parentElement?.removeEventListener("wheel", this.mouseParentWheelHandler)
+    }
+
+    /* Subclasses will override the following method */
+    wheel(variation, location) {
+    }
+}