FIX: allows modals to disable swipe to close (#26460)

Prior to this fix the `swipe` modifier could not be disabled and we were not using the `this.dimissable` property to apply/not apply it.

This commit adds a new `enabled` param to the `swipe` modifier, which is used in modals with the value of `this.dismissable`.

Note this commit also adds tests for this modifier.

app/assets/javascripts/discourse/app/components/d-modal.gjs

@@ -302,9 +302,9 @@ export default class DModal extends Component {
             <div
               class={{concatClass "d-modal__header" @headerClass}}
               {{swipe
-                didStartSwipe=this.handleSwipeStarted
                 didSwipe=this.handleSwipe
                 didEndSwipe=this.handleSwipeEnded
+                enabled=this.dismissable
               }}
             >
               {{yield to="headerAboveTitle"}}
@@ -396,9 +396,9 @@ export default class DModal extends Component {
         <div
           class="d-modal__backdrop"
           {{swipe
-            didStartSwipe=this.handleSwipeStarted
             didSwipe=this.handleSwipe
             didEndSwipe=this.handleSwipeEnded
+            enabled=this.dismissable
           }}
           {{on "click" this.handleWrapperClick}}
         ></div>

app/assets/javascripts/discourse/app/modifiers/swipe.js

@@ -26,10 +26,11 @@ export default class SwipeModifier extends Modifier {
    * @type {Element}
    */
   element;
+  enabled = true;
 
   constructor(owner, args) {
     super(owner, args);
-    registerDestructor(this, (instance) => instance.cleanup(instance.element));
+    registerDestructor(this, (instance) => instance.cleanup());
   }
 
   /**
@@ -41,8 +42,14 @@ export default class SwipeModifier extends Modifier {
    * @param {Function} options.didStartSwipe Callback to be executed when a swipe starts.
    * @param {Function} options.didSwipe Callback to be executed when a swipe moves.
    * @param {Function} options.didEndSwipe Callback to be executed when a swipe ends.
+   * @param {Boolean} options.enabled Enable or disable the swipe modifier.
    */
-  modify(element, _, { didStartSwipe, didSwipe, didEndSwipe }) {
+  modify(element, _, { didStartSwipe, didSwipe, didEndSwipe, enabled }) {
+    if (enabled === false) {
+      this.enabled = enabled;
+      return;
+    }
+
     this.element = element;
     this.didSwipeCallback = didSwipe;
     this.didStartSwipeCallback = didStartSwipe;
@@ -121,12 +128,14 @@ export default class SwipeModifier extends Modifier {
 
   /**
    * Cleans up the modifier by removing event listeners from the element.
-   *
-   * @param {Element} element The DOM element from which to remove event listeners.
    */
-  cleanup(element) {
+  cleanup() {
-    element.removeEventListener("touchstart", this.handleTouchStart);
+    if (!this.enabled) {
-    element.removeEventListener("touchmove", this.handleTouchMove);
+      return;
-    element.removeEventListener("touchend", this.handleTouchEnd);
+    }
+
+    this.element?.removeEventListener("touchstart", this.handleTouchStart);
+    this.element?.removeEventListener("touchmove", this.handleTouchMove);
+    this.element?.removeEventListener("touchend", this.handleTouchEnd);
   }
 }

app/assets/javascripts/discourse/tests/modifiers/swipe-test.gjs

@@ -0,0 +1,85 @@
+import { render, triggerEvent } from "@ember/test-helpers";
+import { setupRenderingTest } from "ember-qunit";
+import hbs from "htmlbars-inline-precompile";
+import { module, test } from "qunit";
+
+module("Integration | Modifier | swipe", function (hooks) {
+  setupRenderingTest(hooks);
+
+  test("it calls didStartSwipe on touchstart", async function (assert) {
+    this.didStartSwipe = (state) => {
+      assert.ok(state, "didStartSwipe called with state");
+    };
+
+    await render(hbs`<div {{swipe didStartSwipe=this.didStartSwipe}}></div>`);
+
+    await triggerEvent("div", "touchstart", {
+      touches: [{ clientX: 0, clientY: 0 }],
+    });
+  });
+
+  test("it calls didSwipe on touchmove", async function (assert) {
+    this.didSwipe = (state) => {
+      assert.ok(state, "didSwipe called with state");
+    };
+
+    await render(hbs`<div {{swipe didSwipe=this.didSwipe}}></div>`);
+
+    await triggerEvent("div", "touchstart", {
+      touches: [{ clientX: 0, clientY: 0 }],
+      changedTouches: [{ clientX: 0, clientY: 0 }],
+    });
+
+    await triggerEvent("div", "touchmove", {
+      touches: [{ clientX: 5, clientY: 5 }],
+    });
+  });
+
+  test("it calls didEndSwipe on touchend", async function (assert) {
+    this.didEndSwipe = (state) => {
+      assert.ok(state, "didEndSwipe called with state");
+    };
+
+    await render(hbs`<div {{swipe didEndSwipe=this.didEndSwipe}}></div>`);
+
+    await triggerEvent("div", "touchstart", {
+      touches: [{ clientX: 0, clientY: 0 }],
+      changedTouches: [{ clientX: 0, clientY: 0 }],
+    });
+
+    await triggerEvent("div", "touchmove", {
+      touches: [{ clientX: 10, clientY: 0 }],
+      changedTouches: [{ clientX: 10, clientY: 0 }],
+    });
+
+    await triggerEvent("div", "touchend", {
+      changedTouches: [{ clientX: 10, clientY: 0 }],
+    });
+  });
+
+  test("it does not trigger when disabled", async function (assert) {
+    let calls = 0;
+
+    this.didStartSwipe = () => {
+      calls++;
+    };
+
+    this.set("isEnabled", false);
+
+    await render(
+      hbs`<div {{swipe didStartSwipe=this.didStartSwipe enabled=this.isEnabled}}></div>`
+    );
+
+    await triggerEvent("div", "touchstart", {
+      touches: [{ clientX: 0, clientY: 0 }],
+    });
+
+    this.set("isEnabled", true);
+
+    await triggerEvent("div", "touchstart", {
+      touches: [{ clientX: 0, clientY: 0 }],
+    });
+
+    assert.deepEqual(calls, 1, "didStartSwipe should be called once");
+  });
+});