fix(touch): allow pointerDown veto to stop tracking and free scroll

projects/igniteui-angular/core/src/core/touch.ts

@@ -41,8 +41,14 @@ export interface IgxGestureEvent {
  * @internal
  */
 export interface IgxTouchManagerCallbacks {
-    /** Fired on pointer down once the pointer type passes the configured filter, before any movement. */
-    pointerDown?: (event: IgxGestureEvent) => void;
+    /**
+     * Fired on pointer down once the pointer type passes the configured filter, before any movement.
+     *
+     * Return `false` to veto the gesture (e.g. when the touch does not start in an active zone).
+     * The manager then stops tracking immediately and best-effort releases the pointer capture, so
+     * normal page/component scrolling is not blocked by the `touchmove` listener.
+     */
+    pointerDown?: (event: IgxGestureEvent) => boolean | void;
     /** Fired on the first pointer move of a tracked gesture, once movement begins (mirrors Hammer's `panstart`). */
     panStart?: (event: IgxGestureEvent) => void;
     /** Fired on each pointer move while a gesture is tracked. */
@@ -211,7 +217,12 @@ export class IgxTouchManager {
             }
         }
 
-        this.callbacks.pointerDown?.(this._createEvent(event));
+        // Let the consumer veto the gesture (e.g. the touch did not start in an active
+        // zone). Returning `false` stops tracking immediately so the `touchmove` listener
+        // does not block normal scrolling and other gestures are not interfered with.
+        if (this.callbacks.pointerDown?.(this._createEvent(event)) === false) {
+            this._stopTracking(event.pointerId);
+        }
     };
 
     private _onPointerMove = (event: PointerEvent) => {
@@ -265,4 +276,21 @@ export class IgxTouchManager {
             event.preventDefault();
         }
     }
+
+    /** Stops tracking the current gesture and best-effort releases the pointer capture. */
+    private _stopTracking(pointerId: number): void {
+        this._tracking = false;
+        this._panStarted = false;
+        this._pointerId = null;
+        this._startTarget = null;
+
+        if (this._setPointerCapture && typeof (this.target as Element).releasePointerCapture === 'function') {
+            try {
+                (this.target as Element).releasePointerCapture(pointerId);
+            } catch {
+                // `releasePointerCapture` can throw when the pointer is no longer captured.
+                // Releasing is a best-effort cleanup, so ignore it.
+            }
+        }
+    }
 }

projects/igniteui-angular/navigation-drawer/src/navigation-drawer/navigation-drawer.component.ts

@@ -755,9 +755,9 @@ export class IgxNavigationDrawerComponent implements
         }
     };
 
-    private panStart = (evt: IgxGestureEvent) => {
+    private panStart = (evt: IgxGestureEvent): boolean => {
         if (!this.enableGestures || this.pin || evt.pointerType !== 'touch') {
-            return;
+            return false;
         }
         const startPosition = this.position === 'right' ? this.getWindowWidth() - (evt.center.x + evt.distance)
             : evt.center.x - evt.distance;
@@ -778,7 +778,13 @@ export class IgxNavigationDrawerComponent implements
                 // slide reveals the full panel instead of just its padding/border.
                 this.renderer.setStyle(this.drawer, 'width', `${this.getExpectedWidth(false)}px`);
             }
+            return true;
         }
+
+        // The touch did not start in the edge zone (and the drawer is closed), so this
+        // gesture should be ignored. Returning `false` lets the touch manager stop
+        // tracking immediately and not interfere with normal page scrolling.
+        return false;
     };
 
     private pan = (evt: IgxGestureEvent) => {